8143 Datasheet, PDF (15/24 Pages) Maxwell Technologies – 12-Bit Serial Daisy Chain D/A Converter

12-Bit Serial Daisy-Chain D/A Converter
8143
INPUT REGISTER/DIGITAL
OUTPUT
STB4
1
X
X
X
STB3
X
0
X
X
TABLE 1. TRUTH TABLE
CONTROL INPUTS
DAC
REGISTER
CONTROL INPUT
STB2
STB1
CLR
LD2
LD1
X
X
X
X
1
X
X
1
0
X
X
1
1
X
1
X
1
1
0
0
OPERATION
NOTES
No operation (input register ²
and SRO)
Reset DAC register to zero ²,³
code (Code: 0000 0000
0000) Asynchronous opera-
tions)
No operation (DAC register ²
and SRO)
Load DAC register with the ²
contents of input register
1. Serial data is loaded into Input Register MSB first, on edges shown. is positive edges, is negative edge.
2. 0 = Logic LOW, 1 = Logic HIGH, X = Don’t care.
3. CLR = 0 asynchronously resets DAC register to 0000 0000 0000, but has no effect on Input Register.
Applications Information
Unipolar Operation (2-Quadrant)
The circuit shown in Figures 16 and 17 may be used with an ac or dc reference voltage. The circuit’s output will range
between 0V and 10V (4095/4096) depending upon the digital input and the analog output is shown in Table 4. The
V_REF voltage range is the maximum input voltage range of the op amp or ±25V, whichever is lowest.
TABLE 4. UNIPOLAR CODE TABLE1,²
DIGITAL INPUT
MSBLSB
NOMINAL ANALOG OUTPUT (V_OUT AS SHOWN IN
FIGURES 16 AND 17)
111111111111
-V_REF (4095/4096)
100000000001
-V_REF (2049/4096)
100000000000
-V_REF (2048/4096) = -V_REF/2
011111111111
-V_REF (2047/4096)
000000000001
-V_REF (1/4096)
000000000000
-V_REF (0/4096) = 0
1. Nominal full scale for the circuits of Figures 16 and 17 is given by
FS = -V_REF (4095/4096)
2. Nominal LSB magnitude for the circuit of Figure 16 and 17 is given by
LSB = V_REF(1/4096) or V_REF(2^-N).
07.23.03 REV 3
All data sheets are subject to change without notice 15
©2003 Maxwell Technologies.
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