ASAHI KASEI
[AK2573A]
Reference
Table 4-4 Example of APC FFand APC FB combination
RE_APC_ RE_APC_ BIAS
MOD
Remarks
FF_SET
FB_SET (I-DAC2) (I-DAC1)
01
10
01
00
01
10
11
FB
FF
FF
FB
FF
The initial value of APC FB according to the Fig 4-4
temperature can be set to accelerate power up time.
The initial value of APC FB according to the Fig 4-5
temperature can be set to accelerate power up time.
Both BIAS and MOD current are detrmined by Fig 4-6
APC_FF. APC_FB is not work.
10
11
11
11
01
FF
FF
FF+FB Both BIAS and MOD current are detrmined by Fig 4-7
APC_FF. APC_FB is set to MODfor LD aging.
FF
FF+FB
FB
Both BIAS and MOD current are detrmined by Fig 4-8
APC_FF. APC_FB is set to BIAS for LD aging.
FF+FB Dual Feedback function.
BIAS current is determined by APC_FB. MOD
Fig 4-9
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.
10
11
FF+FB
FB
Fig4-10
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
00
11
11
11
-
-
-
-
Prohibit
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 4-5 APC example-2 (MOD=FB, BIAS=FF)
R_DAC1_FF =
R_DAC1_FF
RE_DAC1_GAIN
RE_DAC1_GAIN
0
I-DAC1
85/255
I-DAC1
85/255
R_DAC1_FB
R_DAC1_FB
= R_APC_FB
R_APC_FB
R_DAC1
Imod
Ibias
R_APC_FB
R_DAC1
Imod
Ibias
= 0
0
1
+
+
G_DAC1
1
0
+
G_DAC1
I-DAC2
54/255
I-DAC2
54/255
R_DAC2_FB
= R_APC_FB
R_DAC2_FB
= 0
R_DAC2
R_DAC2
G_DAC2
+
G_DAC2
R_DAC1 = R_DAC1_FF
R_DAC2_FF = 0
RE_DAC2_GAIN
R_DAC1 = R_DAC1_FB = R_APC_FB
R_DAC2 = R_DAC2_FF
R_DAC2_FF
RE_DAC2_GAIN
R_DAC2 = R_DAC2_FB = R_APC_FB
G_DAC1/G_DAC2 = 1 or 0.5
G_DAC1/G_DAC2 = 1 or 0.5
Fig 4-6 APC example-3 (MOD=FF, BIAS=FF)
R_DAC1_FF
RE_DAC1_GAIN
I-DAC1
85/255
R_DAC1_FB
= 0
R_APC_FB
R_DAC1
Imod
Ibias
0
0
+
+
G_DAC1
I-DAC2
54/255
R_DAC2_FB
=0
R_DAC2
G_DAC2
R_DAC2_FF
RE_DAC2_GAIN
R_DAC1 = R_DAC1_FF
R_DAC2 = R_DAC2_FF
G_DAC1/G_DAC2 = 1 or 0.5
<MS0189-E-01>
-17-
2004/5
AKM [ ASAHI KASEI MICROSYSTEMS ]
