ASAHI KASEI
[AK2573A]
AK2573A
125M / 156M Laser Diode Driver + APC
Features
Description
- 1 chip 125M / 156M Laser Diode Driver (LDD) +
Digital APC (APC_FF and APC_FB)
- Programmable laser BIAS and modulation current
controlled by an on-chip temperature sensor
(APC_FF)
- Digital feedback circuit for APC (APC FB)
- Two current output 8 bit DACs,
I-DAC1: 85mA sink for modulation current
I-DAC2: 54mA sink for BIAS current
- TXFAULT detection and 1kbit ID Field (EEPROM)
for SFP (Small Form-factor Pluggable) support
- I2CTM compatible digital I/F
The AK2573A is a 1chip LDD (Laser Diode Driver) and
an APC (Auto Power Control) for laser direct
modulation application. It contains up to 156M LDD,
programmable duty adjustment, BIAS and modulation
currents, a digital feedback circuit, BIAS and
modulation current monitors, failure alarms, I2CTM
interface, an EEPROM for storing LD characteristics
and user information, and TXFAULT detection for SFP
application. The AK2573A has two APC functions;
APC FF (Feed-forward) and APC FB (Feedback). APC
FF supplies a programmed current in response to the
temperature. APC FB provides a stable auto power
control function with an internal digital feedback
algorithm.
- Duty adjustment
- Power failure alarm (OPTALM), Over current alarm
(CURRALM), Temperature alarm (TEMPALM),
Data alarm (DATAALM) and TXFAULT for failure
alarm
All program and operational functions can be set
through the I2CTM compatible interface and stored in the
on-chip EEPROM.
- BIAS and modulation current monitors (* 0.0095)
- Single 3.3V +/- 0.2V operation
Ordering Information
Product Number
AK2573AVB
PKG
Applications
STM-1 / OC-3 (156Mbps) Optical Interface Module
TS–1000 (125Mbps) Optical Interface Module
BCC++ 48 (7mm * 7mm)
I2CTM is a trademark o f Philips Corporation.
Block Diagram
SEL
DATAP
DATAN
DATA
(LVPECL)
IMODN
DUTY_
ADJ
LD
DRIVER
CLKP
CLKN
FF
CLK
(LVPECL)
IMOD
Imod
OSC
MODMON
I-DAC1
I-DAC2
* 0.0095
APC
Ibias
TEMPSENS
ADC
EEPROM
IBIAS
TEMPMON
* 0.0095
BIASMON
DATAALM
OPTALM
PDMON
Monitor
PD
ALM
CURRALM
TEMPALM
TXFAULT*
PDGAIN
PDIN
BIAS
RPD
CPD
Digital I/F
TXDIS1
TXDIS2
SHUTDOWN
CONTROL
BIAS_GEN
RB (12k)
*: Open Drain
**: Pull-up
SCL SDA* WP**
<MS0189-E-01>
-1-
2004/5