DESCRIPTION

3.3V and 5V power supply options

Up to 1.5Gbps operation

Low power

Low noise

Chatter-Free /LOS Generation

PECL /LOS Output

TTL /EN Input

Differential PECL inputs for data

/EN input is TTL with internal 27K pull up

Single power supply

Designed for use with Micrel-Synergy laser diode
driver and controller

Available in a tiny 10-pin (3mm) MSOP

The SY88913V limiting post amplifier with its high gain

and wide bandwidth is ideal for use as a post amplifier in
fiber-optic receivers with data rates up to 1.5Gbps.
Signals as small as 5mVp-p can be amplified to drive
devices with PECL inputs. The SY88913V generates a
chatter-free PECL Loss of Signal (/LOS) output.

The SY88913V incorporates a programmble level

detect function to identify when the input signal has been
lost. This information can be fed back to the /EN input of
the device to maintain stability under loss of signal
conditions. Using LOS

LVL

pin the sensitivity of the level

detect can be adjusted. The LOS

LVL

voltage can be set

by connecting a resistor divider between V

and V

REF

Figure 2. Figure 3 and 4 show the relationship between
input level sensitivity and the voltage set on LOS

LVL

FEATURES

5V/3.3V 1.25Gbps HIGH-SPEED
LIMITING POST AMPLIFIER

SY88913V

FINAL

APPLICATIONS

1.25Gbps Gigabit Ethernet

531Mbps and 1062Mbps Fibre Channel

622Mbps SONET

Gigabit Interface Converter

PIN CONFIGURATION

BLOCK DIAGRAM

/EN

DIN

/DIN

VREF

LOSLVL

10 VCC

DOUT

/DOUT

/LOS

GND

MSOP

K10-1

Limiting
Amplifer

ECL
Buffer

GND

Enable

Level
Detect

/EN

LOS

REF

LOS

LVL

OUT

Rev.: B

Amendment: /0

Issue Date:

August 2000

SY88913V

Micrel

General

The SY88913V is an integrated limiting amplifier intended

for high-frequency fiber-optic applications. The circuit
connects to typical transimpedance amplifiers found within
a fiber-optics link. The linear signal output from a
transimpedance amplifier can contain significant amounts
of noise, and may vary in amplitude over time. The
SY88913V limiting amplifier quantizes the signal and outputs
a voltage-limited waveform.

The TTL /EN pin allows the user to disable the signal

without removing the input signal.

GENERAL DESCRIPTION

Pin

Type

Function

Data Input

Inverting Data Input

LOS

LVL

Input

Loss of Signal Level Set

/EN

TTL Input

Output Enable (active Low)

/LOS

PECL Output

Loss of Signal Indicator
(active Low)

GND

Ground

OUT

PECL Output

Data Output

OUT

PECL Output

Inverting Data Output

Power Supply

Positive Power Supply

REF

Output

Reference Voltage Output
for LOS Level Set (see Fig. 2)

PIN NAMES

Symbol

Rating

Value

Unit

Power Supply Voltage

0 to +7.0

, /D

Input Voltage

0 to V

OUT

, /D

OUT

, /LOS

Output Voltage (with 50

load)

�2.5 to V

+0.3

LOS

LVL

Input Voltage

0 to V

REF

Output Voltage

�2.0 to V

Operating Temperature Range

�40 to +85

�

store

Storage Temperature Range

�55 to +125

�

ABSOLUTE MAXIMUM RATINGS

(1)

NOTE:

1. Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation is not implied

at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM RATlNG conditions for extended
periods may affect device reliability.

SY88913V

Micrel

= �40

�

= 0

�

= +25

�

= +85

�

Symbol

Parameter

Min.

Max.

Min.

Max.

Min.

Typ.

Max.

Min.

Max.

Unit

Power Supply

Current

(1)

3.3V

/EN Input LOW Current

�0.3

(5)

�0.3

(5)

�0.3

(5)

�0.3

(5)

/EN Input HIGH Current

(2)

�

100

(3)

100

(3)

100

(3)

100

(3)

CMR

Common Mode Range

GND +2.0 V

�1.0 GND +2.0 V

�1.0 GND +2.0

�1.0 GND +2.0 V

�1.0

offset

Differential Output Offset

�

100

�

100

�

100

�

100

LOS

LVL

LOS

LVL

Level

REF

OUT

and /D

OUT

�1085

�880 V

�1025 V

�880 V

�1025 V

�955 V

�880

�1025

�880

HIGH Output

OUT

and /D

OUT

�1830 V

�1555 V

�1810 V

�1620 V

�1810 V

�1705 V

�1620 V

�1810 V

�1620

LOW Output

REF

Reference Supply

(4)

�1.38

�1.26 V

�1.38 V

�1.26 V

�1.38

�1.32 V

�1.26

�1.38

�1.26

/EN Input HIGH Voltage

2.0

/EN Input LOW Voltage

0.8

NOTES:

1. No Output Load.

2. V

= 2.7V.

3. V

= V

DC ELECTRICAL CHARACTERISTICS

= +3.3V

�

10% or +5V

�

10%, R

LOAD

= 50

to V

�2V

4. I

REF

must be limited to be within �0.8mA (source) and 0.5mA (sink).

5. V

= 0.5V.

= �40

�

= 0

�

= +25

�

= +85

�

Symbol

Parameter

Min.

Max.

Min.

Max.

Min.

Typ.

Max.

Min.

Max.

Unit

Conditions

PSRR

Power Supply

(1)

Input referred,

Rejection Ratio

55MHz

Input Voltage Range

1800

1800 mVp-p

Differential Output

700

= 15mVp-p

Voltage Swing

(2)

200

250

200

= 5mVp-p

OFFL

/LOS Release Time

(3)

0.5

0.1

0.5

�

Minimum Input

ONL

/LOS Assert Time

(3)

0.5

0.2

0.5

�

OFFH

/LOS Release Time

(4)

0.5

0.1

0.5

�

Maximum Input

/LOS Sensitivity Range

mVp-p

HYS

/LOS Hysteresis

4.6

, t

Output Rise/Fall Time

260

170

260

> 100mVp-p

rin

fin

< 100mVp-p

AC ELECTRICAL CHARACTERISTICS

= +3.3V

�

10% or +5V

�

10%, R

LOAD

= 50

to V

�2V

NOTES:

1. Input referred noise = RMS output noise/low frequency gain.

2. Input is 622MHz square wave.

3. Input is a 200MHz square wave, tr < 300ps, 8mVp-p.

4. Input is a 200MHz square wave, tr < 300ps, 1.8Vp-p.

SY88913V

Micrel

PRODUCT ORDERING CODE

Ordering

Package

Operating

Code

Type

Range

SY88913VKC

K10-1

Commercial

Output Termination

The SY88913V outputs must be terminated with a 50

load to V

�2V (or Thevenin equivalent).

Layout and PCB Design

Since the SY88913V is a high-frequency component,

performance can largely be determined by board layout
and design. A common problem with high-gain amplifiers is
feedback from the large swing outputs to the input via the
power supply.

APPLICATION NOTE

LOS

LVL

REF

Figure 2. LOS

LVL

Circuit

NOTES:
LOS

LVL

= V

�1.32 +

R1 + R2

0.1

�

0.1

�

0.1

�

IN+

IN�

REF

Figure 1. Differential Input Configuration

The SY88913V ground pin should be connected to the

circuit board ground. Use multiple PCB vias close to the
part to connect to ground. Avoid long, inductive runs which
can degrade performance.

�

1.32

R1 + R2

Электронный компонент: SY88913V