File Number

4749.2

HIP6501A

Triple Linear Power Controller with ACPI
Control Interface

The HIP6501A, paired with either the HIP6020 or HIP6021,
simplifies the implementation of ACPI-compliant designs in
microprocessor and computer applications. The IC
integrates two linear controllers and a low-current pass
transistor, as well as the monitoring and control functions
into a 16-pin SOIC package. One linear controller generates
the 3.3V

DUAL

voltage plane from an ATX power supply's

5VSB output during sleep states (S3, S4/S5), powering the
PCI slots through an external pass transistor, as instructed
by the status of the 3.3V

DUAL

enable pin. An additional pass

transistor is used to switch in the ATX 3.3V output for PCI
operation during S0 and S1 (active) operatingstates. The
second linear controller supplies the computer system's
2.5V/3.3V memory power through an external pass
transistor in active states. During S3 state, an integrated
pass transistor supplies the 2.5V/3.3V sleep-state power. A
third controller powers up a 5V

DUAL

plane by switching in

the ATX 5V output in active states, or the ATX 5VSB in sleep
states.

The HIP6501A's operating mode (active-state outputs or
sleep-state outputs) is selectable through two control pins:
S3 and S5. Further control of the logic governing activation
of different power modes is offered through two enabling
pins: EN3VDL and EN5VDL. In active states, the 3.3V

DUAL

linear regulator uses an external N-Channel pass MOSFET
to connect the output (V

OUT1

) directly to the 3.3V input

supplied by an ATX (or equivalent) power supply, while
incurring minimal losses. In sleep state, the 3.3V

DUAL

output

is supplied from the ATX 5VSB through an NPN transistor,
also external to the controller. Active state power delivery for
the 2.5/3.3V

MEM

output is done through an external NPN

transistor, or an NMOS switch for the 3.3V setting. In sleep
states, conduction on this output is transferred to an internal
pass transistor. The 5V

DUAL

output is powered through two

external MOS transistors. In sleep states, a PMOS (or PNP)
transistor conducts the current from the ATX 5VSB output,
while in active states, current flow is transferred to an NMOS
transistor connected to the ATX 5V output. Similar to the
3.3V

DUAL

output, the operation of the 5V

DUAL

output is

dictated not only by the status of the S3 and S5 pins, but that
of the EN5VDL pin as well.

Features

· Provides 3 ACPI-Controlled Voltages

- 5V Active/Sleep (5V

DUAL

)

- 3.3V Active/Sleep (3.3V

DUAL

)

- 2.5V/3.3V Active/Sleep (2.5V

MEM

)

· Simple Control Design - No Compensation Required

· Excellent Output Voltage Regulation

- 3.3V

DUAL

Output:

2.0% Over Temperature; Sleep

States Only

- 2.5V/3.3V Output:

2.0% Over Temperature; Both

Operational States (3.3V setting in sleep only)

· Fixed Output Voltages Require No Precision External

Resistors

· Small Size

- Small External Component Count

· Selectable 2.5V

MEM

Output Voltage Via FAULT/MSEL Pin

- 2.5V for RDRAM Memory

- 3.3V for SDRAM Memory

· Under-Voltage Monitoring of All Outputs with Centralized

FAULT Reporting

· Adjustable Soft-Start Function Eliminates 5VSB

Perturbations

Pinout

HIP6501A (SOIC)

TOP VIEW

Ordering Information

PART NUMBER

TEMP.

RANGE (

PACKAGE

PKG.

NO.

HIP6501ACB

0 to 70

16 Ld SOIC

M16.15

HIP6501EVAL1

Evaluation Board

EN3VDL

3V3DLSB

3V3DL

EN5VDL

5VSB

VSEN2

12V

DLA

FAULT/MSEL

5VDL

DRV2

GND

5VDLSB

Data Sheet

February 2000

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

Absolute Maximum Ratings

Thermal Information

Supply Voltage, V

5VSB

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7.0V

12V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND - 0.3V to +14.5V
DLA, DRV2. . . . . . . . . . . . . . . . . . . . . . . .GND - 0.3V to V

12V

+0.3V

All Other Pins . . . . . . . . . . . . . . . . . . . . .GND - 0.3V to 5VSB + 0.3V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . Class 3 [5kV]

Recommended Operating Conditions

Supply Voltage, V

5VSB

. . . . . . . . . . . . . . . . . . . . . . . . . . . +5V

Secondary Bias Voltage, V

12V

. . . . . . . . . . . . . . . . . . . . +12V

10%

Digital Inputs, V

S3,

S5,

EN3VDL,

EN5VDL

. . . . . . . . . 0 to +5.5V

Ambient Temperature Range . . . . . . . . . . . . . . . . . . . . . 0

C to 70

Junction Temperature Range . . . . . . . . . . . . . . . . . . . . 0

C to 125

Thermal Resistance (Typical, Note 1)

(

C/W)

SOIC Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

100

Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .150

Maximum Storage Temperature Range . . . . . . . . . . -65

C to 150

Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300

(SOIC - Lead Tips Only)

CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

NOTE:

is measured with the component mounted on an evaluation PC board in free air.

Electrical Specifications

Recommended Operating Conditions, Unless Otherwise Noted. Refer to Figures 1, 2 and 3

PARAMETER

SYMBOL

TEST CONDITIONS

MIN

TYP

MAX

UNITS

VCC SUPPLY CURRENT

Operating Supply Current

5VSB

Shutdown Supply Current

5VSB(OFF)

= 0.8V, S3 = 0, S5 = 0

POWER-ON RESET, SOFT-START, AND 12V MONITOR

Rising 5VSB POR Threshold

4.5

5VSB POR Hysteresis

0.2

Rising 12V Threshold

10.8

Soft-Start Current

Shutdown Soft-Start Voltage

0.8

2.5V/3.3V LINEAR REGULATOR (V

OUT2

)

Regulation

2.0

VSEN2 Nominal Voltage Level

VSEN2

SEL

= 1k

2.5

VSEN2 Nominal Voltage Level

VSEN2

SEL

= 10k

3.3

VSEN2 Under-voltage Rising Threshold

VSEN2 Under-voltage Hysteresis

VSEN2 Output Current

VSEN2

5VSB = 5V

250

300

DRV2 Output Drive Current

DRV2

5VSB = 5V, R

SEL

= 1k

DRV2 Output Impedance

SEL

= 10k

200

3.3VDUAL LINEAR REGULATOR (V

OUT1

)

Sleep-Mode Regulation

2.0

3V3DL Nominal Voltage Level

3V3DL

3.3

3V3DL Under-voltage Rising Threshold

2.450

3V3DL Under-voltage Hysteresis

200

3V3DLSB Output Drive Current

3V3DLSB

5VSB = 5V

5.0

8.5

DLA Output Impedance

HIP6501A

Functional Pin Description

5VSB (Pin 1)

Provide a 5V bias supply for the IC to this pin by connecting
it to the ATX 5VSB output. This pin also provides the base
bias current for all the external NPN transistors controlled by
the IC. The voltage at this pin is monitored for power-on
reset (POR) purposes.

GND (Pin 8)

Signal ground for the IC. All voltage levels are measured with
respect to this pin.

S3 and S5 (Pins 6 and 7)

These pins switch the IC's operating state from active (S0,
S1) to S3 and S4/S5 sleep states. Connect S3 to SLP_S3
and S5 to SLP_S5. These are digital inputs featuring internal
70k

(typical) resistor pull-ups to 5VSB. Internal circuitry de-

glitches the S3 pin for disturbances. Additional circuitry
blocks any illegal state transitions (such as S3 to S4/S5 or
vice versa). When entering an S4/S5 sleep state, the S3
signal is allowed to go low as far as 200

s (typically) ahead

of the S5 signal.

EN3VDL and EN5VDL (Pins 2 and 5)

These pins control the logic governing the output behavior in
response to S3 and S4/S5 requests. These are digital inputs
whose status can only be changed during active states
operation or during chip shutdown (SS pin grounded by
external open-drain device). The input information is latched-
in when entering a sleep state, as well as following 5VSB
POR release or exit from shutdown.

FAULT/MSEL (Pin 9)

This is a multiplexed function pin allowing the setting of the
memory output voltage to either 2.5V or 3.3V (for RDRAM or
SDRAM memory systems). The memory voltage setting is
latched-in 3ms (typically) after 5VSB POR release. In case
of an under-voltage on any of the outputs or an over-
temperature event, this pin is used to report the fault
condition by being pulled to 5VSB.

SS (Pin 13)

Connect a small ceramic capacitor (allowable range: 5nF-
0.22

F; 0.1

F recommended) from this pin to GND. The

internal Soft-Start (SS) current source along with the
external capacitor creates a voltage ramp used to control the
ramp-up of the output voltages. Pulling this pin low with an
open-drain device shuts down all the outputs as well as

5VDUAL SWITCH CONTROLLER (V

OUT3

)

5VDL Under-Voltage Rising Threshold

3.750

5VDL Under-Voltage Hysteresis

260

5VDLSB Output Drive Current

5VDLSB

5VDLSB = 4V

-20

-40

5VDLSB Pull-up Impedance to 5VSB

350

TIMING INTERVALS

Active State Assessment Past 12V
Threshold

Note 2

Maximum Allowable S3 to S5 Skew

200

5VSB POR Extension Past Threshold
Voltage

3.3

CONTROL I/O (S3, S5, EN3VDL, EN5VDL, FAULT)

High Level Threshold

2.2

Low Level Threshold

0.8

S3,S5 Internal Pull-up Impedance to 5VSB

FAULT Output Impedance

FAULT = high

100

FAULT Under-Voltage Reporting Delay

TEMPERATURE MONITOR

Fault-Level Threshold

Note 3

125

Shutdown-Level Threshold

Note 3

150

NOTES:

2. Guaranteed by Correlation.

3. Guaranteed by Design.

Electrical Specifications

Recommended Operating Conditions, Unless Otherwise Noted. Refer to Figures 1, 2 and 3 (Continued)

PARAMETER

SYMBOL

TEST CONDITIONS

MIN

TYP

MAX

UNITS

HIP6501A

forces the FAULT pin low. The C

capacitor is also used to

provide a controlled voltage slew rate during active-to-sleep
transitions on the 3.3V

DUAL

and 2.5/3.3V

MEM

outputs.

12V (Pin 14)

Connect this pin to the ATX (or equivalent) 12V output. This
pin is used to monitor the status of the power supply as well
as provide bias for the NMOS-compatible output drivers. 12V
presence at the chip in the absence of bias voltage, or
severe 12V brownout during active states (S0, S1) operation
can lead to chip misbehavior.

VSEN2 (Pin 16)

Connect this pin to the memory output (V

OUT2

). In sleep

states, this pin is regulated to 2.5V or 3.3V (based on R

SEL

)

through an internal pass transistor capable of delivering
300mA (typically). When V

OUT2

is programmed to 2.5V, the

active-state voltage at this pin is regulated through an
external NPN transistor connected at the DRV2 pin. For the
3.3V setting, the ATX 3.3V is passed to this pin through a
fully on N-MOS transistor. During all operating states, the
voltage at this pin is monitored for under-voltage events.

DRV2 (Pin 15)

For the 2.5V RDRAM systems, connect this pin to the base
of a suitable NPN transistor. This pass transistor regulates
the 2.5V output from the ATX 3.3V during active states
operation. For 3.3V SDRAM systems connect this pin to the
gate of a suitable N-MOS transistor; this transistor is used to
switch in the ATX 3.3V output.

3V3DL (Pin 4)

Connect this pin to the 3.3V dual output (V

OUT1

). In sleep

states, the voltage at this pin is regulated to 3.3V; in active
states, ATX 3.3V output is delivered to this node through a
fully on N-MOS transistor. During all operating states, this
pin is monitored for under-voltage events.

3V3DLSB (Pin 3)

Connect this pin to the base of a suitable NPN transistor. In
sleep states, this transistor is used to regulate the voltage at
the 3V3DL pin to 3.3V.

DLA (Pin 10)

Connect this pin to the gates of suitable N-MOSFETs, which
in active states, are used to switch in the ATX 3.3V and 5V
outputs into the 3.3V

DUAL

and 5V

DUAL

outputs,

respectively.

5VDL (Pin 12)

Connect this pin to the 5V

DUAL

output (V

OUT3

). In either

operating state, the voltage at this pin is provided through a
fully on MOS transistor. This pin is also monitored for under-
voltage events.

5VDLSB (Pin 11)

Connect this pin to the gate of a suitable P-MOSFET or
bipolar PNP. In sleep states, this transistor is switched on,
connecting the ATX 5VSB output to the 5V

DUAL

regulator

output.

Description

Operation

The HIP6501A controls 3 output voltages (Refer to Figures
1, 2, and 3). It is designed for microprocessor computer
applications with 3.3V, 5V, 5VSB, and 12V outputs from an
ATX power supply. The IC is composed of two linear
controllers supplying the PCI slots' 3.3V

AUX

power

(3.3V

DUAL

, V

OUT1

) and the 2.5V RDRAM or 3.3V SDRAM

memory power (2.5/3.3V

MEM

, V

OUT2

), and a dual switch

controller supplying the 5V

DUAL

voltage (V

OUT3

). In

addition, all the control and monitoring functions necessary
for complete ACPI implementation are integrated into the
HIP6501A.

Initialization

The HIP6501A automatically initializes upon receipt of input
power. The Power-On Reset (POR) function continually
monitors the 5VSB input supply voltage, initiating soft-start
operation after it exceeds its POR threshold (in either S3 or
S4/S5 states). To ensure stabilization of the 5VSB supply
before operation is allowed, POR is released 3.3ms
(typically) after 5VSB exceeds the POR threshold. The
5VSB POR trip event is also used to lock in the memory
voltage setting based on R

SEL

Operational Truth Tables

The EN3VDL and EN5VDL pins offer a host of choices in
terms of the overall system architecture and supported
features. Tables 1-3 describe the truth combinations
pertaining to each of the three outputs.

As seen in Table 1, EN3VDL simply controls whether the
3.3VDUAL plane remains powered up during S4/S5 sleep
state.

TABLE 1. 3.3V

DUAL

OUTPUT (V

OUT1

) TRUTH TABLE

EN3VDL

3V3DL

COMMENTS

3.3V

S0, S1 STATES (Active)

3.3V

Note 4

Maintains Previous State

3.3V

S4/S5

3.3V

S0, S1 STATES (Active)

3.3V

Note 4

Maintains Previous State

S4/S5

NOTE:

4. Combination not allowed.

HIP6501A

Very similarly, Table 2 details the fact that EN5VDL status
controls whether the 5V

DUAL

plane supports sleep states.

As seen in Table 3, 2.5/3.3V

MEM

output is maintained in S3

(Suspend-To-RAM), but not in S4/S5 state. The dual-voltage
support accommodates both SDRAM as well as RDRAM
type memories.

Additionally, the internal circuitry does not allow the
transition from an S3 (suspend to RAM) state to an S4/S5
(suspend to disk/soft off) state or vice versa. The only `legal'
transitions are from an active state (S0, S1) to a sleep state
(S3, S4/S5) and vice versa.

Functional Timing Diagrams

Figures 4-8 are timing diagrams, detailing the power
up/down sequences of all three outputs in response to the
status of the enable (EN3VDL, EN5VDL) and sleep-state
pins (S3, S5), as well as the status of the ATX supply.

The status of the EN3VDL and EN5VDL pins can only be
changed while in active (S0, S1) states, when the bias
supply (5VSB pin) is below POR level, or during chip
shutdown (SS pin shorted to GND); a status change of these
two pins while in a sleep state is ignored.

Not shown in these diagrams is the de-glitching feature used
to protect against false sleep state tripping. Once the status
of the S3 pin changes, an internal timer is activated. If at the
end of the timeout period (typically 200

s) the input pins

present a valid state change request, then the controller
transitions to the new configuration. Otherwise, the
previously attained valid state is maintained until valid
control signals are received from the system. This particular
feature is useful in noisy computer environments if the
control signals have to travel over significant distances.

TABLE 2. 5V

DUAL

OUTPUT (V

OUT3

) TRUTH TABLE

EN5VDL

5VDL

COMMENTS

S0, S1 STATES (Active)

Note 5

Maintains Previous State

S4/S5

S0, S1 STATES (Active)

Note 5

Maintains Previous State

S4/S5

NOTE:

5. Combination not allowed.

TABLE 3. 2.5/3.3V

MEM

OUTPUT (V

OUT2

) TRUTH TABLE

SEL

2.5/3.3V

MEM

COMMENTS

2.5V

S0, S1 STATES (Active)

2.5V

Note 6

Maintains Previous State

S4/S5

10k

3.3V

S0, S1 STATES (Active)

10k

3.3V

10k

Note 6

Maintains Previous State

10k

S4/S5

NOTE:

6. Combination not allowed.

FIGURE 4. 3V

DUAL

AND 5V

DUAL

TIMING DIAGRAM FOR

EN3VDL = 1, EN5VDL = 1

FIGURE 5. 3V

DUAL

AND 5V

DUAL

TIMING DIAGRAM FOR

EN3VDL = 1, EN5VDL = 0

5VSB

12V

5VDLSB

DLA

3V3DLSB

3V3DL

5VDL

5VSB

12V

5VDLSB

DLA

3V3DLSB

3V3DL

5VDL

HIP6501A

Soft-Start Circuit

Soft-Start into Sleep States (S3, S4/S5)

The 5VSB POR function initiates the soft-start sequence. An
internal 10

A current source charges an external capacitor

to 5V. The error amplifiers reference inputs are clamped to a
level proportional to the SS (Soft-Start) pin voltage. As the
SS pin voltage slews from about 1.25V to 2.5V, the input
clamp allows a rapid and controlled output voltage rise.

Figure 9 shows the soft-start sequence for the typical
application start-up in a sleep state with all output voltages
enabled. At time T0 5V

(bias) is applied to the circuit. At

time T1, 5V

surpasses POR level, and an internal fast

charge circuit quickly raises the SS capacitor voltage to
approximately 1V. At this point, the 10

A current source

continues the charging up to T2, where a voltage of 1.25V
(typically) is reached and an internal clamp limits further
charging. Clamping of the soft-start voltage (T2 to T3
interval) should only be noticed with capacitors smaller than
0.1

F; soft-start capacitors of 0.1

F and above should

present a soft-start ramp void of this plateau. At time T3,
3ms (typically) past the 5V

POR (T1), the memory output

voltage selection is latched in and the charging of the soft-
start capacitor resumes, using the 10

A current source. At

this point, the error amplifiers' reference inputs are starting
their transitions, causing the output voltages to ramp up
proportionally. The ramping continues until time T4 when all
the voltages reach the set value. At time T5, when the soft-
start capacitor value reaches approximately 2.8V, the under-
voltage monitoring circuits are activated and the soft-start
capacitor is quickly discharged down to the value attained at
time T2 (approximately 1.25V).

FIGURE 6. 3V

DUAL

AND 5V

DUAL

TIMING DIAGRAM FOR

EN3VDL = 0, EN5VDL = 1

FIGURE 7. 3V

DUAL

AND 5V

DUAL

TIMING DIAGRAM FOR

EN3VDL = 0, EN5VDL = 0

FIGURE 8. 2.5/3.3V

MEM

TIMING DIAGRAM

5VSB

12V

5VDLSB

DLA

3V3DLSB

3V3DL

5VDL

5VSB

12V

5VDLSB

DLA

3V3DLSB

3V3DL

5VDL

5VSB

12V

DRV2

VSEN2

INTERNAL

DEVICE

FIGURE 9. SOFT-START INTERVAL IN A SLEEP STATE (ALL

OUTPUTS ENABLED)

TIME

SOFT-START

(1V/DIV)

OUTPUT

(1V/DIV)

VOLTAGES

OUT1

(3.3V

DUAL

)

OUT2

(2.5V

MEM

)

OUT3

(5V

DUAL

)

T1 T2 T3

5VSB

(1V/DIV)

UV DETECT ENABLE

(LOGIC LEVEL)

HIP6501A

Soft-Start into Active States (S0, S1)

If both S3 and S5 are logic high at the time the 5VSB is
applied, the HIP6501A will assume an active state and keep
off the controlled external transistors until about 50ms after
the ATX's 12V output (sensed at the 12V pin) exceeds the
set threshold (typically 10.8V). This timeout feature is
necessary in order to ensure the main ATX outputs are
stabilized. The timeout also assures smooth transitions from
sleep into active when sleep states are being supported.

During sleep to active state transitions from conditions
where the outputs are initially 0V (such as S4/S5 to S0
transition with EN3VDL = 1 and EN5VDL = 0, or simple
power-up sequence directly into active state), the 3V

DUAL

and 5V

DUAL

outputs go through a quasi soft-start by being

pulled high through the body diodes of the N-channel
MOSFETs connected between these outputs and the 3.3V
and 5V ATX outputs, respectively. Figure 10 shows this start-
up scenario.

is already present when the main ATX outputs are

turned on at time T0. Similarly, the soft-start capacitor has
already been charged up to 1.25V and the clamp is active,
awaiting for the 12V POR timer to expire. As a result of
3.3V

and 5V

ramping up, the 3.3V

DUAL

and 5V

DUAL

output capacitors charge up through the body diodes of Q3
and Q5, respectively (see Figure 3). At time T1, the 12V ATX
output exceeds the HIP6501A's 12V under-voltage
threshold, and the internal 50ms (typical) timer is initiated. At
T2 the time-out initiates a soft-start, and the memory output
is ramped-up, reaching regulation limits at time T3.

Simultaneous with the memory voltage ramp-up, the DLA
pin is pulled high (to 12V), turning on Q3 and Q5, and
bringing the 3.3V

DUAL

and 5V

DUAL

outputs in regulation at

time T2. At time T4, when the soft-start voltage reaches
approximately 2.8V, the under-voltage monitoring circuits are
enabled and the soft-start capacitor is quickly discharged to
approximately 2.45V.

Requests to go into a sleep state during an active state soft-
start ramp-up result in a chip reset, followed by a new soft-
start sequence into the desired state.

Fault Protection

All the outputs are monitored against under-voltage events.
A severe over-current caused by a failed load on any of the
outputs, would, in turn, cause that specific output to
suddenly drop. If any of the output voltages drop below 69%
of their set value, such event is reported by having the
FAULT/MSEL pin pulled to 5V. Additionally, the 2.5/3.3V
memory regulator is internally current limited while in a sleep
state. Exceeding the maximum current rating of this output in
a sleep state can lead to output voltage drooping. If
excessive, this droop can ultimately trip the under-voltage
detector and send a FAULT signal to the computer system.
However, a FAULT condition will only set off the FAULT flag,
and it will not shut off or latch off any part of the circuit. If
shutdown or latch off of the circuit is desired, this can be
achieved by externally pulling or latching the SS pin low.
Pulling the SS pin low will also force the FAULT pin to go low.

Under-voltage sensing is disabled on all disabled outputs
and during soft-start ramp-up intervals. SS voltage reaching
the 2.8V threshold signals activation of the under-voltage
monitor.

Another condition that could set off the FAULT flag is chip
over-temperature. If the HIP6501A reaches an internal
temperature of 125

C (minimum), the FAULT flag is set

(FAULT/MSEL pulled high), but the chip continues to operate
until the temperature reaches 150

C (typical), when

unconditional latched shutdown of all outputs takes place.
The thermal latch can be reset only by cycling the 5V

off,

and then on.

Output Voltages

The output voltages are internally set and do not require any
external components. Selection of the memory voltage is
done by means of an external resistor connected between
the FAULT/MSEL pin and ground. An internal 40

A (typical)

current source creates a voltage drop across this resistor.
During every 5VSB trip above POR level, this voltage is
compared with an internal reference (200mV typically).
Based on this comparison, the output voltage is set at either
2.5V (R

SEL

= 1k

), or 3.3V (R

SEL

= 10k

). It is very

important that no capacitor is connected to the FAULT/MSEL
pin; the presence of a capacitive element at this pin can lead
to false memory voltage selection. See Figure 11 for details.

FIGURE 10. SOFT-START INTERVAL IN AN ACTIVE STATE

TIME

SOFT-START

(1V/DIV)

OUTPUT

(1V/DIV)

VOLTAGES

INPUT VOLTAGES

(2V/DIV)

+5V

+12V

DLA PIN

+5VSB

OUT2

(2.5V

MEM

)

OUT1

(3.3V

DUAL

)

OUT3

(5V

DUAL

)

(2V/DIV)

+3.3V

HIP6501A

Application Guidelines

Soft-Start Interval

The 5VSB output of a typical ATX supply is capable of
725mA. During power-up in a sleep state, it needs to provide
sufficient current to charge up all the output capacitors and
simultaneously provide some amount of current to the output
loads. Drawing excessive amounts of current from the 5VSB
output of the ATX can lead to voltage collapse and induce a
pattern of consecutive restarts with unknown effects on the
system's behavior or health.

The built-in soft-start circuitry allows tight control of the slew-
up speed of the output voltages controlled by the HIP6501A,
thus enabling power-ups free of supply drop-off events.
Since the outputs are ramped up in a linear fashion, the
current dedicated to charging the output capacitors can be
calculated with the following formula:

, where

- soft-start current (typically 10

- soft-start capacitor

- bandgap voltage (typically 1.26V)

(

OUT

) - sum of the products between the

capacitance and the voltage of an output.

Due to the various system timing events, it is recommended
that the soft-start interval not be set to exceed 30ms.
Additionally, the recommended soft-start capacitor range
spans from 5nF up to 0.22

F (0.1

F recommended).

Shutdown

In case of a FAULT condition that might endanger the
computer system, or at any other time, the HIP6501A can be
shut down by pulling the SS pin below the specified
shutdown level (typically 0.8V) with an open drain or open
collector device capable of sinking a minimum of 2mA.
Pulling the SS pin low effectively shuts down all the pass
elements. Upon release of the SS pin, the HIP6501A

undergoes a new soft-start cycle and resumes normal
operation in accordance to the ATX supply and control pins
status.

Layout Considerations

The typical application employing a HIP6501A is a fairly
straight-forward implementation. Similar to any other linear
regulators, attention has to be paid to a few potentially
sensitive small signal components, such as those connected
to high-impedance nodes or those supplying critical by-pass
currents.

The power components (pass transistors) and the controller
IC should be placed first. The controller should be placed in
a central position on the motherboard, closer to the memory
load if possible. Ensure the VSEN2 connection is properly
sized to carry 200mA without significant resistive losses. The
pass transistors should be placed on pads capable of
heatsinking, matching the device's power dissipation. Where
applicable, multiple via connections to a large internal plane
can significantly lower localized device temperature rise.

Placement of the decoupling and bulk capacitors should
follow a placement reflecting their purpose. As such, the
high-frequency decoupling capacitors (C

) should be

placed as close as possible to the load they are decoupling;
the ones decoupling the controller (C

12V

, C

5VSB

) close to

the controller pins, the ones decoupling the load close to the
load connector or the load itself (if embedded). The bulk

FIGURE 11. 2.5/3.3V

MEM

OUTPUT VOLTAGE SELECTION

CIRCUITRY DETAILS

FAULT/MSEL

MEM VOLTAGE
SELECT COMP

SEL

MEM

10k

2.5V

3.3V

0.2V

COUT

--------------------------------

OUT

(

)

FIGURE 12. PRINTED CIRCUIT BOARD ISLANDS

OUT1

+12V

VIA CONNECTION TO GROUND PLANE

ISLAND ON POWER PLANE LAYER

ISLAND ON CIRCUIT/POWER PLANE LAYER

BULK2

HIP6501A

12V

OUT2

OUT3

GND

VSEN2

5VDLSB

DRV2

3V3DLSB

KEY

12V

5VSB

+5V

DLA

BULK1

BULK3

5VSB

HF1

HF3

5VDL

+5V

HF2

+3.3V

3V3DL

HIP6501A

capacitance (aluminum electrolytics or tantalum capacitors)
placement is not as critical as the high-frequency capacitor
placement, but having these capacitors close to the load
they serve is preferable.

The only critical small signal component is the soft-start
capacitor, C

. Locate this component close to SS pin of the

control IC and connect to ground through a via placed close
to the capacitor's ground pad. Minimize any leakage current
paths from SS node, since the internal current source is only
10

A multi-layer printed circuit board is recommended. Figure
12 shows the connections of most of the components in the
converter. Note that the individual capacitors each could
represent numerous physical capacitors. Dedicate one solid
layer for a ground plane and make all critical component
ground connections through vias placed as close to the
component as possible. Dedicate another solid layer as a
power plane and break this plane into smaller islands of
common voltage levels. Ideally, the power plane should
support both the input power and output power nodes. Use
copper filled polygons on the top and bottom circuit layers to
create power islands connecting the filtering components
(output capacitors) and the loads. Use the remaining printed
circuit layers for small signal wiring.

Component Selection Guidelines

Output Capacitors Selection

The output capacitors for all outputs should be selected to
allow the output voltage to meet the dynamic regulation
requirements of active state operation (S0, S1). The load
transient for the various microprocessor system's
components may require high quality capacitors to supply
the high slew rate (di/dt) current demands. Thus, it is
recommended that capacitors C

OUT1

and C

OUT2

should be

selected for transient load regulation.

Also, during the transition between active and sleep states,
there is a short interval of time during which none of the
power pass elements are conducting - during this time the
output capacitors have to supply all the output current. The
output voltage drop during this brief period of time can be
approximated with the following formula:

, where

OUT

- output voltage drop

ESR

OUT

- output capacitor bank ESR

OUT

- output current during transition

OUT

- output capacitor bank capacitance

- active-to-sleep or sleep-to-active transition time (10

typical)

Since the output voltage drop is heavily dependent on the
ESR (equivalent series resistance) of the output capacitor
bank, the capacitors should be chosen to maintain the
output voltage above the lowest allowable regulation level.

Input Capacitors Selection

The input capacitors for an HIP6501A application must have
sufficiently low ESR so that the input voltage does not dip
excessively when energy is transferred to the output
capacitors. If the ATX supply does not meet the
specifications, certain imbalances between the ATX's
outputs and the HIP6501A's regulation levels could result in
a brisk transfer of energy from the input capacitors to the
supplied outputs. When transiting from active to sleep
states, this phenomena could result in the 5VSB voltage
dropping below the POR level (typically 4.3V) and
temporarily disabling the HIP6501A. The solution to this
potential problem is to use larger input capacitors (on 5VSB)
with a lower total combined ESR.

Transistor Selection/Considerations

The HIP6501A typically requires one P-Channel and two
N-Channel power MOSFETs and two bipolar NPN transistors.

One general requirement for selection of transistors for all
the linear regulators/switching elements is package selection
for efficient removal of heat. The power dissipated in a linear
regulator/switching element is:

Select a package and heatsink that maintains the junction
temperature below the rating with the maximum expected
ambient temperature.

The active element on the 2.5V/3.3V

MEM

output has

different requirements for each of the two voltage settings. In
2.5V systems utilizing RDRAM (or voltage-compatible)
memory, Q1 must be a bipolar NPN capable of conducting
the maximum required output current and it must have a
minimum current gain (h

) of 100-150 at this current and

0.7V V

. In such systems, the 2.5V output is regulated

from the ATX 3.3V output while in an active state. In 3.3V
systems (SDRAM or compatible) Q1 must be an N-Channel
MOSFET, since the MOSFET serves as a switch during
active states (S0, S1). The main criteria for the selection of
this transistor is output voltage budgeting. The maximum
r

DS(ON)

allowed at highest junction temperature can be

expressed with the following equation:

, where

IN MIN

- minimum input voltage

OUT MIN

- minimum output voltage allowed

OUT MAX

- maximum output current

The gate bias available for this MOSFET is approximately 8V.

OUT

ESR

OUT

------------------

LINEAR

OUT

(

)

DS ON

(

)

MAX

IN MIN

OUTMIN

OUT MAX

------------------------------------------------------------

HIP6501A

If a P-Channel MOSFET is used to switch the 5VSB output
of the ATX supply into the 5V

DUAL

output during S3 and

S4/S5 states (as dictated by EN5VDL status), then, similar
to the situation where Q1 is a MOSFET, the selection criteria
of this device is also proper voltage budgeting. The
maximum r

DS(ON)

, however, has to be achieved with only

4.5V of V

, so a logic level MOSFET needs to be selected.

If a PNP device is chosen to perform this function, it has to
have a low saturation voltage while providing the maximum
sleep-state current and have a current gain sufficiently high
to be saturated using the minimum drive current (typically
20mA; 4mA during soft-start).

Q3, Q5

The two N-Channel MOSFETs are used to switch the 3.3V
and 5V inputs provided by the ATX supply into the
3.3VDUAL and 5VDUAL outputs, respectively, while in active
(S0, S1) states. Similar r

DS(ON)

criteria apply in these cases

as well, unlike the PMOS, however, these NMOS transistors
get the benefit of an increased V

drive (approximately 8V

and 7V, respectively).

The NPN transistor used as sleep-state pass element on the
3.3V

DUAL

output must have a minimum current gain of 100

at V

= 1.5V, and I

= 500mA throughout the in-circuit

operating temperature range.

HIP6501A

HIP6501A Application Circuit

Figure 13 shows an application circuit of an ACPI-compliant
power management system for a microprocessor computer
system. The power supply provides the PCI 3.3V

DUAL

voltage (V

OUT1

), the RDRAM 2.5V

MEM

memory voltage

OUT2

), and the 5V

DUAL

voltage (V

OUT3

) from +3.3V, +5V,

+5VSB, and +12VDC ATX supply outputs. For systems

employing SDRAM memory, replace R1 with 10k

and Q1

with an HUF76113SK8. Q4 can also be a PNP, such as an
MMBT2907AL. For detailed information on the circuit,
including a Bill-of-Materials and circuit board description,
see Application Note AN9846.

Also see Intersil's web page (http://www.intersil.com) or
Intersil AnswerFAX (321-724-7800) for the latest information.

2x150

150

220

GND

5VSB

+3.3V

+5V

VSEN2

DRV2

C8,9

HIP6501A

12V

+12V

OUT2

2.5V

MEM

OUT1

3.3V

DUAL

+5V

C11

OUT3

DUAL

3V3DL

3V3DLSB

DLA

5VDLSB

FAULT/MSEL

5VDL

EN5VDL

EN3VDL

C2
1

C3
220

C10
1

C12
1

2SD1802

FDV304P

SHUTDOWN

1/2 HUF76113DK8

C13

0.1

(FROM OPEN-DRAIN N-MOS)

C1
10

FIGURE 13. TYPICAL HIP6501A APPLICATION CIRCUIT

Q5
1/2 HUF76113DK8

HIP6501A

All Intersil semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification.

Intersil semiconductor products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time with-
out notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.

For information regarding Intersil Corporation and its products, see web site http://www.intersil.com

Sales Office Headquarters

NORTH AMERICA
Intersil Corporation
P. O. Box 883, Mail Stop 53-204
Melbourne, FL 32902
TEL: (321) 724-7000
FAX: (321) 724-7240

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100, Rue de la Fusee
1130 Brussels, Belgium
TEL: (32) 2.724.2111
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7F-6, No. 101 Fu Hsing North Road
Taipei, Taiwan
Republic of China
TEL: (886) 2 2716 9310
FAX: (886) 2 2715 3029

HIP6501A

Small Outline Plastic Packages (SOIC)

NOTES:

1. Symbols are defined in the "MO Series Symbol List" in Section 2.2 of

Publication Number 95.

2. Dimensioning and tolerancing per ANSI Y14.5M-1982.

3. Dimension "D" does not include mold flash, protrusions or gate burrs.

Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006
inch) per side.

4. Dimension "E" does not include interlead flash or protrusions. Interlead

flash and protrusions shall not exceed 0.25mm (0.010 inch) per side.

5. The chamfer on the body is optional. If it is not present, a visual index

feature must be located within the crosshatched area.

6. "L" is the length of terminal for soldering to a substrate.

7. "N" is the number of terminal positions.

8. Terminal numbers are shown for reference only.

9. The lead width "B", as measured 0.36mm (0.014 inch) or greater above

the seating plane, shall not exceed a maximum value of 0.61mm
(0.024 inch).

10. Controlling dimension: MILLIMETER. Converted inch dimensions are

not necessarily exact.

INDEX
AREA

-B-

0.25(0.010)

C A

B S

-A-

-C-

SEATING PLANE

0.10(0.004)

h x 45

0.25(0.010)

M16.15

(JEDEC MS-012-AC ISSUE C)

16 LEAD NARROW BODY SMALL OUTLINE PLASTIC
PACKAGE

SYMBOL

INCHES

MILLIMETERS

NOTES

MIN

MAX

MIN

MAX

0.0532

0.0688

1.35

1.75

0.0040

0.0098

0.10

0.25

0.013

0.020

0.33

0.51

0.0075

0.0098

0.19

0.25

0.3859

0.3937

9.80

10.00

0.1497

0.1574

3.80

4.00

0.050 BSC

1.27 BSC

0.2284

0.2440

5.80

6.20

0.0099

0.0196

0.25

0.50

0.016

0.050

0.40

1.27

Rev. 0 12/93

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