AK2574 Datasheet, PDF (5/30 Pages) Asahi Kasei Microsystems – 156M Laser Diode Driver + APC for Burst Mode

ASAHI KASEI
[AK2574]
Pin Description (Continued)
PIN# Symbol
Function
I/O
27, 28 IMODN Negative MOD current output.
Ao
Sinks MOD current when input data is “L”.
29, 30 IMOD
Positive MOD current output.
Ao
Sinks up to 85mA (typ) MOD current when input data is “H”.
MOD current is adjusted with I-DAC1.
IMOD voltage should be (VDD – 1.8V) or more.
31 VSSMD VSS for MOD current drive circuit.
PWR
32 VSSBI
VSS for BIAS current drive circuit.
PWR
33, 34 IBIAS
BIAS current output. Sinks up to 54mA (typ) current.
Ao
BIAS current is adjusted with I-DAC2.
IBIAS voltage should be (VDD – 1.8V) or more.
35 VSSBI
VSS for BIAS current drive circuit.
PWR
36 IBIASC1 Connect to VSS with 0.1uF ± 50% (in the operating temerature Ao
range) capacitor.
37 NC
No Connection. Connect to the VSS (recommended) or leave open.
38 IBIASC2 Connect to VSS with 0.1uF ± 50% (in the operating temerature Ao
range) capacitor.
39 IBIASR1 Connect to IBIASSC1 with 330Ω± 1% resistor.
Ao
40 PDIN
Monitor PD voltage input. Monitor PD current is converted to the Ai
voltage with resistor.
41 TEMPMON Temperature sensor monitor output.
Ao
42 BIAS
43 AVDD
44 AVSS
45 TXACT
46 TEST1
47 DVSS
48 DVDD
BIAS reference for internal circuit. Connect to VSS with 12kΩ± Ao
1% resistor.
Power supply for analog circuit.
PWR
VSS for analog circuit.
PWR
TXACT is set when PDIN voltage beyond the reference voltage Do
(DACAPC output) and is kept during BRST=”H”. TXACT is reset
when BRST is transient “H” → “L”. The polarity can be set with
EEPROM. TXACT is valid within 2ms after power-up.
Test input. Connect to VSS for normal operation
Di
VSS for digital circuit.
Power supply for digital circuit.
PWR
PWR
Remark
AC load
≤ 30pF
DC load
≥ 50kΩ
Connect to
VSS.
Center PAD of PKG should be connected to the VSS for good electrical performance and radiation of heat.
<MS0266-E-00>
-5-
2003/12