ATS278
Two Phase Hall Effect Latch With FG Output
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev. 1.0 Oct 4, 2005
1/6
Features
- On-chip Hall plate
- Operating voltage: 3.5V~20V
- Internal bandgap regulator allows temperature
compensated operations and a wide operating
voltage range
- High output sinking capability up to 400mA for
driving large load
- Built-in protection diode only for chip reverse
power connecting
- Frequency Generation (FG) output
- Package: SIP-5L
Applications
- Dual-coil Brush-less DC Motor
- Dual-coil Brush-less DC Fan
- Revolution Counting
- Speed Measurement
General Description
ATS278 is an integrated Hall sensor with two output
drivers and rotor speed output, typically designed
for electronic commutation of two-phase brush-less
DC fan applications.
On-chip Hall sensor will generate Hall voltage due
to magnetics sensing. The amplifier will amplify the
Hall voltage. The Schmitt trigger determines
switching hysteresis and then control internal
driver's on/off to sink load current. Meanwhile, An
internal bandgap regulator is used to provide stable
bais due to temperature-compensation. FG pin will
provide switching frequency of driver. Major feature
is to minimize the external components by
building-in FG output transistor.
If a magnetic flux density larger than threshold Bop,
DO is turned on (low) and DOB is turned off (high).
The output state is held until a magnetic flux density
reversal falls below Brp causing DO to be turned off
and DOB turned on.
Ordering Information
ATS278 X - X X - X
P: SIP-5L
Package
Lead
L : Lead Free
Wafer Body
Magnetic
Characteristics
Blank or
A~Z : if necessary
to specify
A or B
*Packing: Bulk
Typical Application Circuit
278
1
5
4
3
2
5V/12V
Coil1
Coil2
R
pu
C1
+
Speed
R1
R2
C1
C2
R1 = R2 = 47
C1 = C2 = 2.2 F
The R, C value need to be fine tuned
base on coils design.
5V/12V DC Brush-less Fan with FG output function
ATS278
Two Phase Hall Effect Latch With FG Output
Anachip Corp.
www.anachip.com.tw Rev. 1.0 Oct 4, 2005
2/6
Block Diagram
REG.
Hall Plane
Amp
DO
GND
DOB
VCC
Comparators
3
4
5
2
1
1
FG
Pin Configuration
1 : FG
2 : VCC
3 : DO
4 : DOB
( Front View )
1
5
4
3
2
278
5 : GND
Name
P/I/O
Pin #
Description
FG
O 1
Frequency detection output
VCC
P 2
Positive power input
DO
O 3
Driver Output
DOB O 4
Driver Output ( Inverting )
GND P 5
Ground
ATS278
Two Phase Hall Effect Latch With FG Output
Anachip Corp.
www.anachip.com.tw Rev. 1.0 Oct 4, 2005
3/6
Absolute Maximum Ratings
Characteristics
Symbol
Values
Unit
Supply voltage
V
CC
20 V
Reverse V
CC
Polarity Voltage
V
RCC
-20 V
Magnetic flux density
B
Unlimited
Continuous 0.4
Hold 0.5
Output "on" current
Peak (Start Up)
Ic
0.7
A
Sink current of FG
I
FG
40
mA
Operating temperature range
Ta
-20~+85
C
Storage temperature range
Ts
-65~+150
C
Package Power Dissipation
PD
550
mW
Electrical Characteristics
( Ta=+25
C )
Characteristic
Symbol
Conditions
Min
Typ
Max
Unit
Supply Voltage
VCC
3.5
----
20
V
Output Saturation Voltage
Vce(sat)
Vcc=14V, IL=300mA
----
300
800
mV
Output Zener Breakdown
Vz*
46
V
Output Leakage Current
Icex
Vce=14V, Vcc=14V
----
<0.1
10
A
Supply Current
Icc
Vcc=20V, Output Open
----
16
25
mA
Output Rise Time
tr
Vcc=14V, RL=820
,
CL=20pF (Test Circuit)
---- 3.0
10 s
Output Falling Time
tf
Vcc=14V, RL=820
,
CL=20pF (Test Circuit)
---- 0.3 1.5 s
Switch Time Differential
t
Vcc=14V, RL=820
,
CL=20pF (Test Circuit)
---- 3.0
10 s
FG saturation voltage
V
FG
Vcc=14V, IL=20 mA
----
200
700
mV
*Note: The Vz may vary with the inductance/resistance of DC Fan. In order to reduce the risk of dynamic operation, the capacitor/
resistor is recommended to add below the DO/DOB as Application Circuit (on page 1).
14V
DO
DOB
pf
20
C
C
820
R
R
L2
L1
L2
L1
=
=
=
=
278
1
5
4
3
2
L1
R
L2
R
L1
C
L2
C
( Test circuit )
ATS278
Two Phase Hall Effect Latch With FG Output
Anachip Corp.
www.anachip.com.tw Rev. 1.0 Oct 4, 2005
4/6
Magnetic Characteristics(
Ta=+25
o
C)
(1mT=10 Gauss)
A grade
Characteristic
Symbol
Min.
Typ.
Max.
Unit
Operate Point
B
OP
10 - 60 Gauss
Release Point
B
RP
-60 - -10 Gauss
Hysteresis B
HYS
-
75
- Gauss
B grade
Characteristic
Symbol
Min.
Typ.
Max.
Unit
Operate Point
B
OP
5 -
80
Gauss
Release Point
B
RP
-80 - -5 Gauss
Hysteresis B
HYS
-
75
- Gauss
DOB
DO
12
10
8
6
4
2
OFF
OP
RP
ON
Output Voltage in Volts
12
10
8
6
4
2
OFF
RP
OP
ON
Output Voltage in Volts
-200
200
100
-100
0
-200
200
100
-100
0
Magnetic Flux Density in Gauss
Magnetic Flux Density in Gauss
Vsat
Vsat
ATS278
Two Phase Hall Effect Latch With FG Output
Anachip Corp.
www.anachip.com.tw Rev. 1.0 Oct 4, 2005
5/6
Performance Characteristics (SIP5)
Ta (
C)
25
50
60
70
80
85
90
95
100
Pd
(mW)
550 440 396 352 308 286 264 242 220
Ta (
C)
105
110
115
120
125
130
135
140
150
Pd
(mW)
198 176 154 132 110 88 66 44 0
Power Dissipation Curve
0
200
400
600
800
1000
0
25
50
75
100
125
150
Ta (C)
Pd (mW)
85
Timing Diagram
DO
DOB
FG
Rotatory
Rotor state
Locked
Rotatory
Locked
Marking Information
278
Part Number
Year:
( Front View )
"2" = 2002
"1" = 2001
X XX X x
Nth week: 01~52
ID Code: A~Z
Wafer Lot ID: L & a~z
is lead-free products
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