CAT504 Datasheet, PDF (8/12 Pages) Catalyst Semiconductor – 8-Bit Quad DACpot

CAT504
APPLICATION CIRCUITS (Cont.)
+5V
VREF
VDD
VREFH
RC
=
——VR—E—F —
256 _* 1 µA
Fine adjust gives ± 1 LSB change in V _OFFSET
when VOFFSET = —VR—2E—F
FINE ADJUST
DAC
127RC
COARSE ADJUST
DAC
+V
RC
V _{OFFSET +}
–
GND
VREFL
+5V
+VREF
VDD
VREFH
FINE ADJUST
DAC
COARSE ADJUST
DAC
GND
VREFL
-V _REF
127RC
RC
RC
=
(—+V—R—EF—) _—- (—VO—FF—S—ET—+—)
1 µA
Ro
=
(—-V—RE—F—) +—(—VO—FF—S—ET—+—)
1 µA
+V
Ro
VOFFSET ₊
–
-V
Coarse-Fine Offset Control by Averaging DAC Outputs
for Single Power Supply Systems
CONTROL
& DATA
V+
I > 2 mA
VDD
VREFH
OCPAT 550044
GND
VREFL
VREF= 5.000V
LT 1029
Coarse-Fine Offset Control by Averaging DAC Outputs
for Dual Power Supply Systems
28 - 32V
CONTROL
& DATA
15K
10 µF
1N5231B
VDD
VREFH ^5.1V
COAPTT50044
+
GND
VREFL
–
1.00K
10K
LM 324
4.02 K
MPT3055EL
10 µF
35V
OUTPUT
0 - 25V
@ 1A
Digitally Trimmed Voltage Reference
Digitally Controlled Voltage Reference
Doc. No. 25048-0A 2/98 M-1
8