VITESSE VSC7961YD, VSC7961W Datasheet

VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7961

3.125Gb/s PECL Limiting Amplifier with LOS Detect

Features Applications

• 3.3V or 5V Power Supply

• Typical Supply Current of 32mA

• Positive Emitter-Coupled Logic (PECL) Outputs

• Optional Output Squelch

• Loss of Signal Detect

• Output Offset Correction

• Rise/Fall Times Faster than 100ps

• Packages: TSSOP-16, Bare Die

• SONET/SDH at 622Mb/s, 1.244Gb/s, 2.488Gb/s,

and 3.125Gb/s

• Full-Speed Fibre Channel (1.062Gb/s)

• Small Form Factor (SFF) Receivers

• ATM Optical Receivers

General Description

The VSC7961 is a single-su pply li miti ng am plifi er with Loss of Signal (LOS ) dete ct fo r SON ET/SD H and
Fibre Channel applications up to 3.125Gb/s. The VSC7961 provides a constant output signal swing for a wide
range of input volta ges and has P ositive E mitter-Coupled Logic (PECL). The VSC7959 p rovides the same func­tionality as the VSC7961 with Current-Mode Logic (CML) outputs. Key features of the VSC7961 are its RMS
power detectors for programmable LOS detection, optional ou tput squelch, adjustable ou tput levels, excellent
jitter performance, and fast edge rates. The VSC7961 is available in die form or in a TSSOP-16 package.

Block Diagram

TH

IN+

IN-

VSC7961

100

Ω

Offset Correction

RMS Power

Detect and

Control

Lowpass Filter

CZ1 CZ2

10pF

V

CC

8k

Ω

V

CC

8k

Ω

Output Control

LOS

LOS

SQUELCH

LEVEL

OUT+
OUT-

G52360-0, Rev 2.0 Page 1
02/09/01

© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012

Tel: (800) VITESSE • FAX: [phone] • Email: [e-mail]

Internet: www.vitesse.com

VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

3.125Gb/s PECL Limiting Amplifier with LOS Detect

Electrical Characteristics

Table 1: DC Specifications

Symbol Parameter Min Typ Max Units Conditions

V

CC

I

CC

I

EE

I

CCSQ

I

EESQ

I

SQ

PSSR Power Supply Rejection Ratio 20 dB f < 2MHz

NOTE: (1) See Figure 4 for supply current measurement setup.

Table 2: DC Specifications

Symbol Parameter Min Typ Max Units Conditions

V

IN

J

D

J

R

t

R, tF

V

N

R

DIFF

f

L

V

SQ

V

OH

V

OL

Z

O

NOTES: (1) Deterministic jitter measured peak-to-peak with K28.5 pattern. (2) Random jitter measured with minimum input.

Power Supply Voltage 3.135 5.5 V

Power Supply Current

Power Supply Current

Power Supply Current when
Squelched

Power Supply Current when
Squelched

Squelch Input Current 0 400 µA

Data Rate 3.125 Gb/s
Input V oltage Range 10 1200 mV Peak-to-peak
Deterministic Jitter 25 ps See Note 1
Random Jitter 8 ps See Note 2, RMS
Rise and Fall Times 55 100 ps 20% to 80%
Input Referred Noise 230 µV RMS, IN+ to IN­Differential Input Resistance 100 Ω IN+ to IN-

Low Frequency Cutof f
Output Signal When Squelched 20 mV Output AC-coupled
PECL Output High Voltage

PECL Output Low Voltage
Output Resistance 100 Ω Single-ended

(1)

(1)

(1)

(1)

59 mA VCC = 3.3V
62 mA V
31 mA VCC = 3.3V
35 mΑ V
58 mA VCC = 3.3V
62 mA VCC = 5V
20 mA VCC = 3.3V
23 mA V

2MHzC
2kHzC

-1025 -850 mV

-850 mV Squelched

-1810 -1620 mV

-1620 mV Squelched

CC

CC

CC

= 5V

= 5V

= 5V

open

Z

= 0.1µF

Z

VSC7961

Page 2 G52360-0, Rev 2.0

© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012

Tel: (800) VITESSE • FAX: [phone] • Email: [e-mail]

Internet: www.vitesse.com

02/09/01

VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7961

3.125Gb/s PECL Limiting Amplifier with LOS Detect

Table 3: Loss of Signal Specifications

Symbol Parameter Min Typ Max Units Conditions

H
I

V

V

V
V

LOS

LOS

THA

THD

LOSH
LOSL

LOS Hystersis 3.1 3.3 5.5 dB H
LOS Assert/Deassert Time 0.22 0.25 0.28 µs

8.2 mV R

LOS Assert Threshold

LOS Deassert Threshold

LOS Output HIGH Volta ge 3.3 V I
LOS Output LOW Voltage 0.168 V I

12.8 19.8 21.8 mV R

57.2 mV R

11.4 mV R

26.2 29.0 31.6 mV R

75.2 mV R

= 20 log (V

LOS

= 2.5kΩ

TH

= 7kΩ

TH

= 20kΩ

TH

= 2.5kΩ

TH

= 7kΩ

TH

= 20kΩ

TH

= –30µA

LOS

= +1.2µA

LOS

Table 4: Loss of Signal Truth Table

SQUELCH LOS Output

High Low Off

Low High On

High Low On

Low Low On

THD/VTHA

)

Absolute Maximum Ratings

(1)

Power Supply Voltage (VCC).............................................................................................................-0.5V to +6V

Maximum Junction Temperature Range .........................................................................................................TBD

Storage Temperature Range (T

NOTE: (1) CAUTION: Stresses listed under “Absolute Maximum Ratings” may be applied to devices one at a time without caus-

ing permanent damage. Functionality at or above the values listed is not implied. Exposure to these values for extended
periods may affect device reliability.

).................................................................................................-55°C to +150°C

S

Recommended Operating Conditions

Positive Voltage Rail (VCC)..................................................................................................................3.3V or 5V

Junction Temperature Range (T
Ambient Temperature Range (T

G52360-0, Rev 2.0 Page 3
02/09/01

© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012

)................................................................................................-40°C to +100°C

J

).................................................................................................-40°C to +85°C

A

Tel: (800) VITESSE • FAX: [phone] • Email: [e-mail]

Internet: www.vitesse.com