Datasheet SY88993AV Datasheet (MICREL)

5V/3.3V 3.2Gbps HIGH-SPEED
LIMITING POST AMPLIFIER

SY88993AV

FEATURES

■ > 3.2Gbps operation

■ Low noise CML Data Outputs

■ Chatter-Free LOS generation

■ Open Collector TTL LOS output

■ TTL /EN Input

■ Differential PECL inputs for data

■ Single 3.3V or 5V power supply

■ Designed for use with SY88922V and SY88905

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

PIN CONFIGURATION

LOS

1/EN

D

IN

2

/D

IN

V

REF

LVL

MSOP

3

K10-1

4
5

10 V

9
8
7
6

CC

D

OUT

/D

OUT

LOS
GND

DESCRIPTION

The SY88993AV limiting post amplifier with its high and
wide bandwidth is ideal for use as a post amplifier in fiber­optic receivers with data rates up to 3.2Gbps. Signals as
small as 4mVp-p can be amplified to drive devices with
CML inputs or AC coupled PECL inputs. The SY88993AV
generates a chatter-free Loss of Signal (LOS) open collector
TTL output.

The SY88993AV 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
adjusted. The LOS
resistor divider between VCC and V

pin the sensitivity of the level detect can be

LVL

voltage can be set by connecting a

LVL

, Figure 3.

REF

BLOCK DIAGRAM

D

V

D

REF

V

CC

IN

Limiting
Amplifer

IN

CML
Buffer

Enable

D

D

EN

OUT

OUT

APPLICATIONS

■ 1.25Gbps and 2.1Gbps Gigabit Ethernet

■ 531Mbps, 1062Mbps and 2.5Gbps SONET/SDH Fibre

Channel

■ 622Mbps

■ Gigabit interface converter (GBIC)

■ Small Form Factor Trancievers

■ Parallel 10G Ethernet

LOS

GND

LVL

SY88993AV

LOS

Level
Detect

V

CC

4.7k to 10k

LOS

1

Rev.: A Amendment: /1
Issue Date: October, 2000

Micrel

SY88993AV

PIN NAMES

Pin Type Function

D

IN

/D

IN

LOS
/EN TTL Input Output Enable (Active Low)
LOS TTL Output Loss of Signal Indicator

GND Ground Ground
D

OUT

/D

OUT

V

CC

V

REF

ABSOLUTE MAXIMUM RATINGS

LVL

Data Input Data Input
Data Input Inverting Data Input
Input Loss of Signal Level Set

(Open Collector) (Active High)

CML Output Data Output
CML Output Inverting Data Output
Power Supply Positive Power Supply
Output Reference Voltage Output

for LOS Level Set (see Fig. 3)

(1)

GENERAL DESCRIPTION

General

The SY88993AV 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
SY88993AV limiting amplifier quantizes the signal and
outputs a voltage-limited waveform.

The /EN pin allows the user to disable the output signal
without removing the input signal.

Symbol Rating Value Unit

V

CC

DIN, /D

IN

T

A

T

store

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.

Power Supply Voltage 0 to +7.0 V
Input Voltage 0 to V

CC

Operating Temperature Range –40 to +85 °C
Storage Temperature Range –55 to +125 °C

V

2

Micrel

SY88993AV

DC ELECTRICAL CHARACTERISTICS

VCC = +3.3V ±10% or +5V ±10%, R

Symbol Parameter Min. Max. Min. Max. Min. Typ. Max. Min. Max. Unit

I

CC

I

IL

I

IH

I

OH

V

OFFSET

V

CMR

LOS
V

OL

V

REF

V

IH

V

IL

NOTES:

1. No output load. VCC = 5V ±10% or 3.3V ±10%

2. VOH = 5.5V.

3. IOL = +2mA.

4. VIN = 0.5V

5. VIN = 2.7V

6. VIN = V

Power Supply 5.0V — 55 — 55 — 43 55 — 65 mA

(1)

Current

3.3V — 50 — 50 — 40 50 — 60 mA

/EN Input LOW –0.3
Current

/EN Input HIGH — 20
Current — 100

LOS Output Leakage

(2)

Differential Output — ±80 — ±80 — ±9 ±80 — ±80 mV
Offset

Common Mode Range GND±2VCC–0.2 GND±2VCC–0.2 GND±2V

LVL

LOS

Level V

LVL

LOS Output Low — 0.5 — 0.5 — — 0.5 — 0.5 V

(3)

Level
Reference Voltage

VCC –1.38 VCC –1.26 VCC –1.38 VCC –1.26 VCC –1.38 VCC –1.32 VCC –1.26 VCC –1.38 VCC –1.26
/EN Input HIGH Voltage 2.0 — 2.0 — 2.0 — — 2.0 — V
/EN Input LOW Voltage — — 0.8 — 0.8 — — 0.8 — V

CC

= 50Ω to V

LOAD

A = –40°CTA = 0°CTA = +25°CTA = +85°C

T

(4)

— –0.3

(5)

(6)

CC

(4)

—20
— 100

— –0.3

(5)

(6)

(4)

——20
— — 100

— — –0.3

(5)

(6)

(4)

—20
— 100

—mA

(5)

(6)

— 100 — 100 — — 100 — 100 uA

–0.2 GND±2VCC–0.2 V

CC

REF

V

CC

V

REF

V

CC

V

REF

—VCCV

REF

V

CC

µA

V

V

3

Micrel

SY88993AV

AC ELECTRICAL CHARACTERISTICS

VCC = +3.3V ±10% or +5V ±10%, R

Symbol Parameter Min. Max. Min. Max. Min. Typ. Max. Min. Max. Unit

HYS LOS Hysteresis 2 8 2 8 2 4.6 8 2 8 dB
PSRR Power Supply

Rejection Ratio

t

OFFL

t

OFFH

t

ONL

, t

t

r

V

ID

V

OD

V

SR

Output Spec (D

V

OH

V

OL

Z

O

LOS Release Time
Minimum Input

LOS Release Time
Maximum Input

LOS Assert Time
Differential Output

f

Rise/Fall Time
Input Voltage Range 4 1800 4 1800 4 — 1800 4 1800 mVp-p
Differential Output — 600 — 600 — 800

Voltage Swing
LOS Sensitivity Range 4 50 4 50 4 — 50 4 50 mVp-p

OUT

HIGH Level Output V
Voltage

LOW Level Output
ß

Single-Ended Output
Impedance

Input Spec (DIN and /DIN)

A

V(Diff)

B

–3dB

S

21

Differential Voltage — — — — — 39 — — — dB
Gain

3dB Bandwidth — — — — — 2.5 — — — GHz
Single-Ended Small 26 — 26 — 26 33 — 26 — dB

Signal-Gain

(1)

(20%-80%)

(4)

and /D

(2)

(2)

(2)

(3)

OUT

(6)

)

CC

(7)

= 50Ω to V

LOAD

CC

TA = –40°C TA = 0°C TA = +25°C TA = +85°C

—— — — — 35 — — —dB

— 0.5 — 0.5 — 0.1 0.5 — 0.5 µs

— 0.5 — 0.5 — 0.1 0.5 — 0.5 µs

— 0.5 — 0.5 — 0.2 0.5 — 0.5 µs
— 120 — 120 — 60 120 — 120 ps

(5)

1200 600 — mVp-p

–20 V

—

V

CC

CC

–300

V

CC

—

–20 V

V

CC

CC

–300

V

CC

–20 V

—

V

CC

–5 V

CC

–400 V

CC

CC

–300

V

CC

–20 V

—

CC

V

–300

CC

40 60 40 60 40 50 60 40 60 Ω

mV

mV

NOTES:

1. Input referred noise = RMS output noise/low frequency gain. Input referred, 55MHz.

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

3. With input signal VID > 50mVp-p with 50Ω load.

4. Input is a 200MHz square wave, tr < 300ps, 50Ω load.

5. VID > 5mVp-p.

6. Output levels are based on 50Ω impedance. If the load impedance is different, the output level will be changed.

7. See output structure.

4

Micrel

PERFORMANCE CURVE

SY88993AV

LOS Assert and Deassert

100

INPUT LEVEL (mVp-p)

Levels vs LOS

90
80
70
60
50
40
30
20
10

0

0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2

LOS

3.3V
T

2.5Gbps
Pattern 2

= VCC – V (V)

LVL

= 25°C

A

Figure 4.

LOS Assert and Deassert

100

INPUT LEVEL (mVp-p)

Levels vs LOS

90
80
70
60
50
40
30
20
10

0

0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2

LOS

3.3V
T

2.5Gbps
Pattern 2

= VCC – V (V)

LVL

= 25°C

A

LVL

LVL

LOS Assert and Deassert

100

23

-1

INPUT LEVEL (mVp-p)

Levels vs LOS

90
80
70
60
50
40
30
20
10

0

0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2

LOS

LVL

LVL

5.0V
T

= 25°C

A

2.5Gbps
Pattern 2

= VCC– V (V)

23

-1

Figure 5.

LOS Assert and Deassert

100

7

-1

INPUT LEVEL (mVp-p)

Levels vs LOS

90
80
70
60
50
40
30
20
10

0

0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2

LOS

LVL

LVL

5.0V
T

= 25°C

A

2.5Gbps
Pattern 2

= VCC – V (V)

7

-1

Figure 6.

Figure 7.

5

Micrel

R1

R2

V

CC

V

REF

LOS

LVL

APPLICATION NOTE

Output Termination

The SY88993AV outputs must be terminated with a 50Ω

load to VCC.

Layout and PCB Design

Since the SY88993AV 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 power
supply.

The SY88993AV 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.

50Ω

SY88993AV

V

V

CC

50Ω

16mA

Z

= 50Ω

0

D

OUT

/D

OUT

= 50Ω

Z

0

CC

50Ω 50Ω

22nF

22nF

0.1µF

ESD STRUCTURE

D

IN

/D

IN

50Ω

50Ω

V

REF

Figure 1. Differential Input Configuration

V

CC

GND

GND

ESD STRUCTURE

Figure 2. Differential Output Configuration

NOTES:

1. Resistor Divider = R2/ (R1 + R2)

2. R1 + R2 ≥ 5kΩ

Figure 3. LOS

Circuit

LVL

PRODUCT ORDERING CODE

6

Ordering Package Operating

Code Type Range

SY88993AVKC K10-1 Commercial

Micrel

GBIC Terminal

RX_DATA–

RX_DATA+

TX_DATA–

TX_DATA+

RX_LOS

200

Ω

GND

200Ω

68

0.01µF

0.01µF

Ω

68Ω

/EN

GND

GND

OUT

/OUT

Laserdiode

Photodiode

SY88904

1000pF

LOS

SY88922

/EN

TX_DISABLE

TX_FAULT

22nF

22nF

SY88993V

20KΩ

0.1µF

0.1µF

0.1µF

MD

0.1µF

0.1µF

2MΩ

From

Transimpedance

Amp.

20kΩ

0.1µF

Laser

Module

TX_OUT

TX_FAULT

TX_DISABLE

V

CC

V

CC

D

IN

/D

IN

V

REF

R

SET

V

CC

V

CC

V

CC

R

SER

V

CC

I

BIAS

R

WIN

V

CCDET

I

BIAS

FB

I

BIAS

SET

I

LIMIT

SET

I

PIN

SET

V

REF

V

CC

LOS

IN

LOS

OUT

D

IN

/D

IN

V

REF

V

CC

LOS

LVL

20kΩ 20kΩ 20kΩ

D

OUT

/D

OUT

50Ω

50Ω

0.01µF

0.01µF

APPLICATION EXAMPLE FOR 3-CHIP SET SOLUTION

SY88993AV

7

Micrel

10 LEAD MSOP (K10-1)

SY88993AV

Rev. 00

8

Micrel

SY88993AV

MICREL-SYNERGY 3250 SCOTT BOULEVARD SANTA CLARA CA 95054 USA

TEL + 1 [phone] FAX + 1 [phone] WEB http://www.micrel.com

This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or

other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.

© 2000 Micrel Incorporated

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