Analog Microelectronics, Inc.
1
AME811/AME811A/AME811R
3-1/2 Digit A/D Converter - Low Power
With HOLD And Differential Reference Inputs
n Key Features
l 100µV Resolution
l High Impedance Differential Inputs
l Differential Reference
l Drive LCD Directly
l Three New Convenient Features
(AME811A Only)
l Low-Battery Indication
l Integration Status Indication
l De-Integration Status Indication
n Applications
l Digital multimeter
l pH meter
l Capacitance meter
l Thermometer
l Digital Panel meter
l Photometer
n General Description
The AME811 family are high performance, low power.
3-1/2 digit, dual-slope integrating A/D converters, with
on-chip display drivers. The AME811 is designed for a
single battery operated system, will drive non-multi-
plexed LCD display directly.
These A/D converters are inherently versatile and ac-
curate. They are immune to the high noise environ-
ments. The true differential high impedance inputs and
differential reference are very useful for making
ratiometric measurement, such as resistance, strain
gauge and bridge transducers. The built-in auto-zero
feature automatically corrects the system offset with-
out any external adjustments.
Low-battery flag, integration and de-integration status
flags are three additional features which are available
in the 44-pin package, AME811ACKW.
n Typical Operating Circuit
* For the operating circuit of the reverse-pins version, please refer to
pin configuration on page 4 and pin description on page 5 & 6.
ANALOG
C
REF+
V
REF+
V
REF-
V
REF
C
REF-
IN PUT
IN HI
LCD DISPLAY
SEGMENT
DRIVE
IN LO
POL
BP
V+
COM
MINUS SIGN BACKPLANE
DRIVE
BUF
A/Z
INT
V
REF
FULL SCALE INPUT 200.0mV
100.0mV
TO ANALOG
COMMON (P32)
V-
OSC OSC
21
35
31
2-19
22-25
30
20
21
38
36
9V
33
26
4039
20pF 10pF
V+ V+
32
28
29
27
34
1M
47K
24K
1K
0.01
0.1
0.47
0.22
20M
40KHz
470K