ASAHI KASEI
[AK2572]
AK2572
APC for Burst Mode Applicable Direct Modulation Laser Diode
FEATURES
■
Temperature compensation programming function
(APC_FF) of Bias current (0~85mA) and Modulation
current (0~10mA/0~2.2V) responding to the detected
temperature by the On-chip temperature sensor.
■
Stable feedback function in the digital scheme
(APC_FB).
■
SFP support TXFAULT function and 1k bit ID field
(EEPROM User Area).
■
LD Power leveling function by either Hardware pin
control or Register setting.
■
Various alarm functions of Optical output decline
(OPTALM), Excessive LD current (CURRALM),
Exceptional temperature (TEMPALM) and Irregular
external signals (EXTALM1 and EXTALM2).
■
Operation adjustment function via 2-wire Digital
interface after assembled into sub-system.
■
On-chip Oscillator allows a Self-running operation.
■
Single 3.3 V [Typ.] power supply.
OUTLINES
The AK2572 enables to keep the optical power of the direct
modulation LD (Laser Diode) constant by the APC
(Automatic Power Control) circuit. It consists of a current
programming function (APC_FF) responding to the
temperature characteristics of each LD, and a Digital
feedback function (APC_FB) to adjust the LD current
based on the monitoring PD (Photo Diode) current.
The AK2572 is also applicable to the Burst mode
transmission. The device equips a Power leveling function
to switch a temperature compensation programming data
by either Hardware pin control or Register setting.
The On-chip EEPROM (Non-volatile memory) allows to
adjust and to keep the individual setting data for each LD
characteristics via 2-wire Digital interface after being
assembled into sub-system. As 1k bits User Area is
allocated in the EEPROM, which supports the ID field of
the SFP specification, a proper operation required for the
SFP module is realized by using the TXFAULT function.
APPLICATIONS
For LD modules applied to Continuous and Burst mode
ORDERING GUIDE
Product Number
AK2572
Package Type
QFN28
（5.2mm×5.2mm）
BLOCK DIAGRAM
AVDD
TEMPMON
TEMP
-SENS
PDMON
Monitor PD
PDIN
Cpd
Rpd
BURST
EXTALM2/MOD_CTRL
EXTALM1
BIAS
RB (12k)
*:Open Drain
**:Internally Pulled-up
PDGAIN
ALM Detection
TEMPALM
CURRALM
OPTALM
EXTALM2
EXTALM1
OSC
2-wire Digital I/F
BIAS
MON
(x0.012)
BIASMON
I-DAC2
IOUT2
Ibias
ADC
R_TEMP
AVSS
DVDD DVSS
VDDMD
VDDBI VSSBI
Imod
LDD LD
I-DAC1
EEPROM
APC
V-DAC3
IOUT1
VOUT3 Vmod
TXFAULT*
BIAS_GEN
SHUTDOW N
CONTROL
TXDIS
TEST1 TEST2 TEST3 TEST4
SCL
SDA* W P**
<MS0290-E-01>
-1-
2004/8
AKM [ ASAHI KASEI MICROSYSTEMS ]
