|
Details, datasheet, quote on part number:VSC7939
| |
| Part: | VSC7939 |
| Category: | Optoelectronics => Drivers/Controllers => Laser => Laser Diodes->Modulator Drivers |
| Description: | 3.125Gb/s Laser Driver |
| Company: | Vitesse Semiconductor Corp. |
| Datasheet: | Download VSC7939 datasheet File size : 182 kB |
| Request For quote: | Find where to buy VSC7939
|
| |
Datasheet text preview:
VSC7939 Data Sheet
SONET/SDH 3.125Gb/s Laser Diode Driver with Automatic Power Control
FEATURES
q q q q q q q q
APPLICATIONS
q
Power Supply: +3.3V, +5V or 5.2V AC- or DC-Coupled to Laser Diode Programmable Modulation Current: 5mA to 60mA Programmable Bias Current: 2mA to 100mA Enable /Disable Control Typical Rise/Fall Times of 60ps Automatic Optical Average Power Control Modulation and Bias Current Monitors
SONET/SDH at 155Mb/s, 622Mb/s, 1.244Gb/s, 2.488Gb/s, 3.125Gb/s Full-Speed Fibre Channel (1.062Gb/s, 2.124Gb/s) OC-48, OC-12, OC-3 Modules SFF/SFP Modules CWDM Modules DWDM Modules
q q q q q
GENERAL DESCRIPTION
The VSC7939 is a single +3.3V, +5V or 5.2V supply laser diode driver for SONET/SDH applications up to 3.125Gb/s. External resistors set a wide range of bias and modulation currents for driving the laser. Data and clock inputs accept differential PECL signals. The Automatic Power Control (APC) loop maintains a constant average optical power over temperature and lifetime. The dominant pole of the APC loop can be controlled with an external capacitor. Other features include enable/disable control, short-circuit protection for the modulation and bias inputs, short rise and fall times, and failure-monitor output to indicate when the APC loop is unable to maintain the desired average optical power. The VSC7939 is available in die form, a 32-pin MLF, or 32-pin TQFP package.
VSC7939 Block Diagram
V CC
VSC7939
IOUT+ IOUTMUX
LP
CD CF RF V CC BIAS V CC V CC MODMON BIASMON APC MD FAIL BIASMAX CAPC APCSET
LATCH
DATA+
D
DATACLK+ CLK-
SET
Q
CLR Q
ENABLE DISABLE
MODSET
LP
G52350, Rev 4.1 10/9/02
© VITESSE SEMICONDUCTOR CORPORATION · 741 Calle Plano · Camarillo, CA 93012 Tel: (800) VITESSE · FAX: (805) 987-5896 · Email: prodinfo@vitesse.com Internet: www.vitesse.com
1 of 18
VSC7939 Data Sheet
SPECIFICATIONS
Typical values are for TA = +25°C and VCC = +3.3V operation, unless otherwise noted.
Table 1. DC Specifications
Symbol Parameter Mi n Typ 45 ICC Power Supply Current 60 65 mA Max 55 Units mA Condition RMODSET = 7.3k, RBIASMAX = 4.8k, IBIAS and IMOD excluded, VCC = +3.3V, unlatched RMODSET = 7.3k, RBIASMAX = 4.8k, IBIAS and IMOD excluded, VCC = +5V, unlatched IMOD = 60mA, IBIAS = 100mA included, VCC = +5.25V, +85°C, latched. Voltage at BIAS pin = (VCC - 1.6) ENABLE = LOW or DISABLE = HIGH(1) APC open loop. IBIAS = 100mA APC open loop. IBIAS = 2mA Refers to part-to-part variation VRMD = VCC - VMD APC closed loop IMD = 1mA(2) IMD = 18µA(2) Refers to part-to-part variation ENABLE = LOW or DISABLE = HIGH(1) See Note 2 IMOD = 60mA IMOD = 5mA IBIAS/IBIASMON IMOD/IMODMON
ICC_MAX IBIAS IBIAS_OFF SBIAS BIASAA VRMD IMD SMD_BIAS MDAA IMOD IMOD_OFF MODAA SMOD ABIAS AMOD
Maximum Power Supply Current Bias Current Range Bias Off Current Bias Current Stability Bias Current Absolute Accuracy Monitor Diode Reverse Bias Voltage Monitor Diode Reverse Current Range Monitor Diode Bias Setpoint Stability Monitor Diode Bias Absolute Accuracy Modulation Current Range Modulation Off Current Modulation Current Absolute Accuracy Modulation Current Stability BIASMON to IBIAS Gain MODMON to IMOD Gain -15 -8 0 0 -15 1.5 18 -4 8 0 -15 5 2
265 100 200 230 900 +1 5 1000 -5 0 90 +1 5 60 200 +1 5 -5 0 250 37 27 +480 +480
mA mA µA ppm/°C % V µA ppm/°C % mA µA % ppm/°C A/A A/A
1. Both IBIAS and IMOD will turn off if MODSET or BIASMAX are grounded. 2. Assumes laser diode to monitor diode transfer function does not change with temperature.
. Table 2. AC Specifications
Symbol tSU tH tDEN tR, tF PWD DCRANGE CIDMAX tJ JTOT Parameter Input Latch Setup Time Input Latch Hold Time Enable/Star t-up Delay Output Rise and Fall Time Pulse Width Distortion(1, 2) Duty Cycle Crossing Point Range Maximum Consecutive Identical Digits Jitter Generation Total Jitter 45 80 7 20 20 40 Min 100 100 250 60 10 80 50 55 Typ Max Units ps ps ns ps ps % bits p s p-p p s p-p 0-1 pattern PRBS23-1 pattern, IMOD = 60mA Condition LATCH = HIGH LATCH = HIGH APC open loop 20% to 80%, IMOD = 60mA, VCC = +3.3V, +5V
1. Measured with 622Mb/s 0-1 pattern, LATCH = HIGH. 2. PWD = (wider pulse - narrower pulse) / 2.
2 of 18
G52350, Rev 4.1 10/9/02
VSC7939 Data Sheet
Table 3. PECL and TTL/CMOS Inputs/Outputs
Symbol VID VICM IIN VIH VIL VOH VOL Parameter Differential Input Voltage Common-Mode Input Voltage Clock and Data Input Current TTL Input High Voltage (ENABLE, DISABLE, LATCH) TTL Input LOW Voltage (ENABLE, DISABLE, LATCH) TTL Output HIGH Voltage (FAIL) TTL Output LOW Voltage (FAIL) 2.4 VCC - 0.3 0.8 VCC 0.44 V V V Sourcing 50µA Sinking 100µA Min 100 VCC -1.49 -1 2.0 VCC -1.32 Typ Max 1600 VCC -VID/4 15 Units mVp-p V Condition (DATA+)-(DATA-) PECL-compatible
µA
V
Table 4. ENABLE/DISABLE Truth Table
ENAB LE Floating Floating Floating HI G H HI GH HI GH LOW LOW LOW DI SABL E Floating HIGH LOW Floating HIGH LOW Floating HIGH LOW Output Currents Of f Of f On Of f Of f On Of f Of f Of f
Table 5. LATCH Truth Table
LATCH Floating HIGH LOW Mode Clocked Clocked Bypass
3 of 18
G52350, Rev 4.1 10/9/02
|
|
