
10
LTC1854/LTC1855/LTC1856
185456fa
UU
W
FU CTIO AL BLOCK DIAGRA
2.5V
REFERENCE
INTERNAL
CLOCK
1.6384X
4.096V
8k
AGND1
CONTROL
LOGIC
SERIAL I/O
INPUT MUX
AGND3
AGND2
REFCOMP
VREF
ADC–
MUXOUT+
MUXOUT–
ADC+
DGND
AVDD
DVDD
MUX ADDRESS
DATA OUT
CONVST
19
20
28
25
2
3
9
1
22
26
27
21
23
24
18
17
16
15
13
12
10
11
14
SDI
BUSY
SCK
RD
OVDD
SDO
18545 BD
12-/14-/16-BIT
SAMPLING ADC
+
–
COM
CH7
CH1
CH0
DGND (Pin 24): Digital Ground.
SDI (Pin 25): Serial Data Input.
SCK (Pin 26): Serial Data Clock.
UU
U
PI FU CTIO S
RD (Pin 27): Read Input. This active low signal enables the
digital output pin SDO and enables the serial interface, SDI
and SCK are ignored when RD is high.
CONVST (Pin 28): Conversion Start. The ADC starts a
conversion on CONVST’s rising edge.