AME811 Datasheet, PDF (1/15 Pages) Analog Microelectronics – 3-1/2 Digit A/D Converter - Low Power With HOLD And Differential Reference Inputs

Analog Microelectronics, Inc.
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.
1M
AN ALOG
IN PU T
0.01
47K
0.22
0.1
35
34
C_REF+ C_REF-
31 _{IN HI}
2-19 SEGMENT
22-25 DRIVE
LCD DISPLAY
30 _{IN LO}
32 _COM
POL ²⁰
BP ^{21MINUS SIGN}
V+ ³⁸
BACKPLANE
D RIVE
28 _BUF
0.47
29 ^A/Z
27 _INT
24K
V_REF+ ^{36 VREF} _1K
9V
V_REF- ³³
V- ²⁶
O SC₂
OSC₁
39 20M
40
470K
TO ANALO G
COM MON (P32)
V+
20pF
40KHz
V+
10pF
FULL SCALE IN PUT 200.0mV
V _REF
100.0mV
1