DA9187.002
29 January, 2004
OPERATING MODES
DAC maximum output voltage is set using VREFH and VREFL pins (= 255/256 * (VREFH-VREFL)+VREFL)
(note: VREFL=GND in case of MAS9187A1). XRESET pin is used for middle code preset: DAC registers are
reset and middle code will appear at the DAC output.
Serial input data is written to SDI while XCS is low. Data is read at CLK rising edge to on-chip shift register.
Rising XCS-pin stops data reading and 12 CLK-cycles are used as the input data (4 address bits and 8 data
bits). The last 12 bits before rising XCS are used as input data.
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Timing diagram
SDI
A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
CLK
XCS
V
OUT
APPLICATION AND TEST CIRCUIT INFORMATION
+3.0v
DAC Register Load
20
VDD
1
VREFH
MAS9187A2
8
XSHDN
O12
O11
CLK
SDI
XCS
O10
O9
O8
9
O7
O6
O5
O4
O3
19
18
17
16
15
14
7
6
5
4
3
2
Controller
Clock
Data In
Latch
12
13
100 nF
GND
10
O2
O1
VREFL
11
5 (7)