鈥?/div>
Low Rollover Error: 鹵1 Count Max
Nonlinearity Error: 鹵1 Count Max
Reading for 0V Input
True Polarity Indication at Zero for Null Detection
Multiplexed BCD Data Output
TTL-Compatible Outputs
Differential Input
Control Signals Permit Interface to UARTs and
Microprocessors
Blinking Display Visually Indicates Overrange
Condition
Low Input Current: 1pA
Low Zero Reading Drift: 2碌V/擄C
Auto-Ranging Supported with Overrange and
Underrange Signals
Available in PDIP and Surface-Mount Packages
General Description
The TC7135 4-1/2 digit A/D converter (ADC) offers
50ppm (1 part in 20,000) resolution with a maximum
nonlinearity error of 1 count. An auto zero cycle
reduces zero error to below 10碌V and zero drift to
0.5碌V/擄C. Source impedance errors are minimized by
a 10pA maximum input current. Rollover error is limited
to 鹵1 count.
Microprocessor based measurement systems are sup-
ported by BUSY, STROBE and RUN/HOLD control sig-
nals. Remote data acquisition systems with data
transfer via UARTs are also possible. The additional
control pins and multiplexed BCD outputs make the
TC7135 the ideal converter for display or
microprocessor based measurement systems.
Functional Block Diagram
SET V
REF
= 1V
V
REF
IN
100k鈩?/div>
鈥?V
1
2
V-
TC7135
UNDERRANGE
28
Applications
鈥?Precision Analog Signal Processor
鈥?Precision Sensor Interface
鈥?High Accuracy DC Measurements
Device Selection Table
Part Number
TC7135CLI
TC7135CPI
TC7135CBU
Package
28-Pin PLCC
28-Pin PDIP
64-Pin PQFP
Temperature Range
0擄C to +70擄C
0擄C to +70擄C
0擄C to +70擄C
REF IN
27
OVERRANGE
3 ANALOG
26
STROBE
COMMON
Analog GND
4
25
RUN/HOLD
INT OUT
1碌F
24
0.47碌F
5
DIGTAL GND
AZ IN
23
6
BUFF OUT POLARITY
22
100k鈩?/div>
7
CLOCK IN
C
REF
-
100
Signal
21
1碌F 8
k鈩?/div>
BUSY
Input
C
REF
+
9
20
-INPUT
(LSD) D1
19
0.1碌F
10
D2
+INPUT
18
11
D3
+5V
V+
12
17
D5 (MSD)
D4
13
16
B1 (LSB)
(MSB) B8
14
15
B2
B4
Clock
Input
120kHz
2002 Microchip Technology Inc.
DS21460B-page 1
漏
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