AK2571 Datasheet, PDF (47/52 Pages) Asahi Kasei Microsystems – Single-Chip Automatic Power/Temperature Control for WDM Laser Diodes

AKM Confidential
AK2571
(12) EA_MOD characteristics
Dithering current by EA_MOD function is added to current of I-DAC1and output through IOUT1pin. Output current
through I-DAC1 shifts if this function is enabled by the register R_EA_SW(E_EA_SW).
(1) Dithering Frequency
The dither frequency is selected through register (EEPROM) R_(E_) EA_FREQ, and is derived by dividing the OSC
2.048MHz(typ) clock.
R_EA_FREQ Division
(E_EA_FREQ)
[2:0]
000
1/128
001
1/64
010
1/32
011
1/16
100
1/8
Dithering Frequency
(Design target)
min
Typ
max
16kHz
32kHz
64kHz
128kHz
256kHz
Remarks
Default
(2) Dithering current gain
R_EA_GAIN
(E_EA_GAIN)
[1:0]
00
01
10
11
Dithering current gain
(Design target)
min
typ
max
16%
8%
4%
2%
Remarks
Default
(13) IDAC2, IDAC3 characteristics
Parameter
Condition
Min
typ
max Unite Remarks
Resolution
8
bit
INL
-2
+2
LSB
Maximum output current
19.28
21.42
23.56
mA ±10%
*1)*5)
Minimum output current
2.68
mA *2)*5)
Step (=1LSB)
0.084
mA/step *3)*5)
Output voltage
1.8
V *4)
DNL
-1
+1
LSB
Input digital code
D[7:0] (00)h - (FF)h (straight binary)
*1) at maximum (FF)h setting, gain is 1.
*2) at minimum (20)h setting, gain is 1. Linearity from (00)h to (20)h is not guaranteed.
*3) output current ”Iidac23” is indicated by the expression below, if gain is ”G”, DAC setting code is ”K”.
Iidac23 = (21.42 / 255) * G * K [mA]
*4) Construct external circuit to ensure the voltage of IOUT2 doesn’t exceed this value. If it is over, output current can’t be
guaranteed and APC operations may not work correctly.
*5) The register below sets the maximum output current, minimum output current and resolution. . Their performance is
regulated from a register value of (20)h. When the register value is below 20h, linearity is not guaranteed.
<Rev. 0.6E Preliminary>
-47-
2001/11