CAT522_04 Datasheet, PDF (8/11 Pages) Catalyst Semiconductor – Configured Digitally Programmable Potentiometer

CAT522
APPLICATION CIRCUITS (Cont.)
+5V
VREF
VDD
VREFH
FINE ADJUST
DPP
RC
=
——^VR—^E—^F —
256 _* 1 µA
Fine adjust gives ± 1 LSB change in V _OFFSET
when VOFFSET =
—^VR—^E—^F
2
127RC
CAT522
COARSE ADJUST
DPP
+V
RC
V _{OFFSET +}
–
GND
VREFL
+5V
+VREF
VDD
VREFH
FINE ADJUST
DPP
CAT522
COARSE ADJUST
DPP
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 DPP Outputs
for Single Power Supply Systems
Coarse-Fine Offset Control by Averaging DPP Outputs
for Dual Power Supply Systems
CONTROL
& DATA
V+
I > 2 mA
VDD
VREFH
CAT522
GND
VREFL
VREF= 5.000V
LT 1029
CONTROL
& DATA
28 - 32V
15K
10 µF
1N5231B
VDD
VREFH ^5.1V
CAT522
+
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. 2004, Rev. E
8