IC-HT Datasheet, PDF (24/42 Pages) IC-Haus GmbH – DUAL CW LASER DIODE DRIVER

iC-HT
DUAL CW LASER DIODE DRIVER
ACC
DCO
8 Bit
D
A
10 Bit
D
A
OVC1
RACC1
+
-
ECIE1
LDK1
N
..750mA
CI1
CIL1
CI1
..10 nF..
10 Bit
A
D
LDK1
VDD
VB
AGND1
MDA1
ADSNF1
EM C
R
8 Bit
0
LASER CHANNEL 1
APC
DISP1
255
PLR1
MRL1
Figure 13: ACC with monitor photodiode
preliminary
Rev A1, Page 24/42
10 BIT LOGARITHMIC D/A CONVERTER
The 10 bit logarithmic D/A converter is used for set-
ting the regulator´s voltage reference. The D/A con-
verter is active in all operating modes. In iC-WK mode
only two values are available: 0.25 V (setting INS/WKR
pin lo) and 0.5 V (setting INS/WKR pin hi). In MCU
mode both APC and ACC use the D/A converter. With
a range from 0.1 V to 1.1 V and the typical step width
is 0.235%.
The D/A converter is configured through register
REFx(9:0). With REFx(9:0) = 0x000, D/A output value
is set to 0.1 V, and for REFx(9:0) = 0x3FF, D/A output
is configured to 1.1 V.
REF1
0x000
...
0x3FF
Addr. 0x13/14; bit 9:0
R/W 0x000
Channel 1 regulator reference voltage set to
minimum voltage
Channel 1 regulator reference voltage set to
Vref
=
Vref₀(1
+
∆
Vref (%)
100
)ⁿ
+
1_,
n
from
0
to
1023
Channel 1 regulator reference voltage set to
maximum voltage
REF2
0x000
...
0x3FF
Addr. 0x18/19; bit 9:0
R/W 0x000
Channel 2 regulator reference voltage set to
minimum voltage
Channel 2 regulator reference voltage set to
Vref
=
Vref₀(1
+
∆
Vref (%)
100
)ⁿ
+
1
,
n
from
0
to
1023
Channel 2 regulator reference voltage set to
maximum voltage
Table 50: Channel 2 regulator voltage reference
To calculate the D/A converter value for each REFx
value, use the following formular:
Vref
=
Vref₀(1
+
∆
Vref (%)
100
)^{n + 1} ,
n
from
0
to
1023
Where Vref₀ is the minimum value (typically 0.1 V),
∆ Vref (%) is the step value (typically 0.235 %) and n
is the value of REFx register in decimal.
Table 49: Channel 1 regulator voltage reference