UG-549
ADuCM310 Hardware Reference Manual
Rev. C | Page 48 of 192
VDAC Channel 2, Channel 3, Channel 6, and Channel 7
These four VDAC channels are implemented on the low voltage analog die with the output buffer implemented on the high voltage die.
The high voltage die implements the amplification and output buffer structure.
The circuitry on the high voltage die for each VDAC assumes an input range of 0 V to 2.5 V. For VDAC 6 and VDAC7, this is then
amplified by a factor of 2 to give an output range of 0 V to 5 V. For VDAC 2 and VDAC3, it is amplified and level shifted to 0 V to −5 V.
There are no separate memory mapped registers for the high voltage die portion of these VDACs.
Figure 14 shows the headroom limits for VDAC7 when VDACV
DD
= 5 V for varying output loads. Headroom means the difference
between VDACV
DD
and the maximum allowed output voltage on VDAC7.
LOAD ON VDAC7 (Ω)
HE
ADRO
O
M
V
DACV
DD
– V
DAC7
MA
XI
MU
M O
U
T
PU
T
VO
LT
A
G
E (m
V)
700
600
500
400
300
200
100
0
100
200
300
500
1000
HEADROOM 25°C
HEADROOM 125°C
1
1461-
014
Figure 14. VDAC Headroom Requirements
VDAC Calibration Tables
Offset values are available for all eight VDACs.
For offset, the ATE production test program logs the measured voltage in nV (integer format) to a flash table. Code 0 is applied to all
VDACs for this test.
Only use the offset calibration value when setting the DAC output voltage to <150 mV.
Table 44. VDAC Offset Values
VDAC
Calibration Type
Address
Unit
Type
DAC Code Used
0
Offset
0x40C00
nV
Integer
0x00000000
1
Offset
0x40C04
nV
Integer
0x00000000
2
Offset
0x40C08
nV
Integer
0x00000000
3
Offset
0x40C0C
nV
Integer
0x00000000
4
Offset
0x40C10
nV
Integer
0x00000000
5
Offset
0x40C14
nV
Integer
0x00000000
6
Offset
0x40C18
nV
Integer
0x00000000
7
Offset
0x40C1C
nV
Integer
0x00000000