AK2573A Datasheet, PDF (12/38 Pages) Asahi Kasei Microsystems – 125M / 156M Laser Diode Driver + APC

ASAHI KASEI
[AK2573A]
2. Driver
Fig 2-1 illustrates the block diagram of the driver function.
AK2573A has two current DACs, I-DAC1 and I-DAC2. I-DAC1 is for modulation current and I-DAC2 is for bias
current. Table 1-1 and 1-2 show I-DAC1, I-DAC2 characteristics.
Fig 2-1 Driver Block Diagram
LD
AK2573A
I-DAC2
I-DAC1
IBIAS
Ibias
IMOD
IMODN
Imod
Driver
(1) I-DAC1 (Table 2-1)
RE_DAC1_
GAIN
1
0
DAC1_GAIN
1
1/2
Output current @
Full code (typ)
85 mA
43 mA
Output Current
Range (typ)
0 to 85 mA
0 to 43 mA
Current step /
LSB (typ)
0.333 mA
0.169 mA
(2) I-DAC2 (Table 2-2)
RE_DAC2_
GAIN
1
0
DAC2_GAIN
1
1/2
Output current @
Full code (typ)
54 mA
27 mA
Output Current
Range (typ)
0 to 54 mA
0 to 27 mA
Current step /
LSB (typ)
0.212 mA
0.106 mA
(3) I-DAC1 / I-DAC2 Common Characteristics
Resolution: 8bit
DNL: +/- 1 LSB @ code = 20h to FFh
3. DATA / CLK I/F (LVPECL)
The AK2573A supports direct data or latched data input (see Table 3-1). Connect CLKP = VSS, and connect CLKN
= VDD or leave open when SEL =“L”.
Table 3-1 Data input
SEL (CMOS)
“L”
“H”
Direct data
Latched data with clock
<MS0189-E-01>
-12-
2004/5