AK2574 Datasheet, PDF (21/30 Pages) Asahi Kasei Microsystems – 156M Laser Diode Driver + APC for Burst Mode

ASAHI KASEI
[AK2574]
Table 3-2 PDIN capacitance (CPDIN)
Item
min
typ
max
PDIN Capacitance (CPDIN)
14
26
Table 3-3 TXACT Reference Voltage
RE_DAC_TXACT
txact_ref
min
typ
max unit
011
0.86
0.9
0.94
V
010
0.76
0.8
0.84
V
001
0.66
0.7
0.74
V
000
0.56
0.6
0.64
V
100
0.46
0.5
0.54
V
101
0.36
0.4
0.44
V
110
0.26
0.3
0.34
V
111
0.16
0.2
0.24
V
Unit
Remark
pF
Remarks
3.2 CLKALM
CLKALM is detected when input CLK is 0’s or 1’s fixed more than 100ns (typ). The polarity of CLKALM can be set
by RE_CLKALM_POL (0: “H” at detection, 1: “L” at detection). AK2574 goes into “shutdown” (see 4. Shutdown)
when CLKALM is detected.
4. Shutdown
Table 4-1 shows the shutdown condition and Table 4-2 shows AK2574 operation at shutdown. AK2574 goes into
“Shutdown” when TXDIS request from TXDIS pin or CLKALM detection. The polarity of TXDIS can be set by
RE_TXDIS_POL (0:“H” shutdown, 1:“L” shutdown).
Table 4-1 Shutdown Condition
TXDIS (Note1) CLKALM (Note2)
Operation
1
X
Shutdown
0
0
Normal Operation
0
1
Shutdown
Note 1: 1 means shutdown request from TXDIS pin.
Note 2: 1 means CLKALM detection.
Remarks
Shutdown by pin
Shutdown by CLKALM detection
Table 4-2 AK2574 operation at shutdown
Function
Operation
I-DAC1 / 2 output High-Z (0mA output)
APC_FF
Normal Operation
MOD Driver
DATA=0
BIAS Driver
OFF (BRST=0)
CLKALM
Normal Operation
TXACT
Hold non-detected polarity
Remarks
<MS0266-E-00>
-21-
2003/12