ak2573a AKM Semiconductor, Inc., ak2573a Datasheet - Page 17

• Manufacturer Part Number: ak2573a
• Description: 125m / 156m Laser Diode Driver Apc - Asahi Kasei Microsystems
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
Table 4-4 Example of APC FF and APC FB combination
RE_APC_FF_SET (Register or EEPROM) is composed of 2-bits. MSB shows BIAS (I-DAC2) and LSB shows MOD
(I-DAC1), and “ 1” indicates APC Feed-forward function is selected.
RE_APC_FB_SET (Register or EEPROM) is composed of 2-bits. MSB shows BIAS (I-DAC2) and LSB shows MOD
(I-DAC2), and “ 1” indicates APC Feedback function is selected.
Fig 4-4 APC example-1 (MOD=FF, BIAS=FB)
Fig 4-6 APC example-3 (MOD=FF, BIAS=FF)
<MS0189-E-01>
RE_APC_
FF_SET
R_DAC1 = R_DAC1_FF
R_DAC2 = R_DAC2_FB = R_APC_FB
R_DAC1 = R_DAC1_FF
R_DAC2 = R_DAC2_FF
R_APC_FB
R_APC_FB
01
10
11
11
11
01
10
00
11
0
0
0
1
RE_APC_
FB_SET
R_DAC2_FB
R_DAC1_FB
= R_APC_FB
R_DAC2_FB
R_DAC1_FB
10
01
00
01
10
11
11
11
11
= 0
=0
= 0
R_DAC1_FF
R_DAC1_FF
R_DAC2_FF
R_DAC2_FF = 0
+
+
+
+
BIAS
(I-DAC2)
FF+FB
FF+FB
R_DAC1
R_DAC2
R_DAC1
R_DAC2
FB
FF
FF
FF
FB
-
-
I-DAC1
I-DAC2
I-DAC1
I-DAC2
85/255
54/255
85/255
54/255
MOD
(I-DAC1)
G_DAC1/G_DAC2 = 1 or 0.5
G_DAC1/G_DAC2 = 1 or 0.5
FF+FB
FF+FB
RE_DAC2_GAIN
FF
FB
FF
FF
FB
RE_DAC2_GAIN
RE_DAC1_GAIN
RE_DAC1_GAIN
-
-
G_DAC1
G_DAC2
G_DAC1
G_DAC2
Remarks
The initial value of APC FB according to the
temperature can be set to accelerate power up time.
The initial value of APC FB according to the
temperature can be set to accelerate power up time.
Both BIAS and MOD current are detrmined by
APC_FF. APC_FB is not work.
Both BIAS and MOD current are detrmined by
APC_FF. APC_FB is set to MOD for LD aging.
Both BIAS and MOD current are detrmined by
APC_FF. APC_FB is set to BIAS for LD aging.
Dual Feedback function.
BIAS current is determined by APC_FB. MOD
current is determined by APC_FF and APC_FB.
The initial value of APC_FB according to the
temperature can be set to accelerate power up time.
Dual Feedback function.
MOD current is determined by APC_FB. BIAS
current is determined by APC_FF and APC_FB.
The initial value of APC_FB according to the
temperature can be set to accelerate power up time.
Prohibit
Prohibit
Imod
Ibias
Imod
Ibias
-17-
R_DAC1 = R_DAC1_FB = R_APC_FB
R_DAC2 = R_DAC2_FF
R_APC_FB
Fig 4-5 APC example-2 (MOD=FB, BIAS=FF)
1
0
R_DAC2_FB
= R_APC_FB
R_DAC1_FB
= 0
R_DAC1_FF =
R_DAC2_FF
+
+
0
R_DAC1
R_DAC2
I-DAC1
I-DAC2
85/255
54/255
G_DAC1/G_DAC2 = 1 or 0.5
[AK2573A]
RE_DAC1_GAIN
RE_DAC2_GAIN
Reference
Fig 4-4
Fig 4-5
Fig 4-6
Fig 4-7
Fig 4-8
Fig 4-9
Fig 4-10
G_DAC1
G_DAC2
2004/5
Imod
Ibias