1
TC820
3-3/4 DIGIT A/D CONVERTER WITH FREQUENCY
COUNTER AND LOGIC PROBE
FEATURES
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Multiple Analog Measurement System
— Digit A/D Converter
— Frequency Counter
— Logic Probe
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Low Noise A/D Converter:
— Differential Inputs, (1pA Bias Current)
— On-Chip 50PPM/
°
C Voltage Reference
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Frequency Counter:
— 4Mhz Maximum Input Frequency
— Auto-ranging Over Four Decade Range
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Logic Probe:
— Two LCD Annunciators
— Buzzer Driver
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3-3/4 Digit Display with Overrange Indicator
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LCD Display Driver with Built-in Contrast Control
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Data Hold Input for Comparison Measurements
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Low Battery Detect with LCD Annunciator
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Underrange and Overrange Outputs
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On-Chip Buzzer Driver with Control Input
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44-Pin Plastic Flat Pack or PLCC or 40-Pin Plastic
DIP Packages
2
3
4
Temperature
Range
GENERAL DESCRIPTION
The TC820 is a 3-3/4 digit, multi-measurement system
especially suited for use in portable instruments. It inte-
grates a dual slope A/D converter, auto-ranging frequency
counter and logic probe into a single 44-pin surface mount
or 40-pin through hole package. The TC820 operates from
a single 9V input voltage (battery) and features a built-in
battery low flag. Function and decimal point selection are
accomplished with simple logic inputs designed for direct
connection to an external microcontroller or rotary switch.
Ease of use, low power operation and high functional
integration make the TC820 desirable in a variety of analog
measurement applications.
ORDERING INFORMATION
Part No.
TC820CKW
TC820CLW
Resolution
3-3/4 Digits
3-3/4 Digits
Package
TC820CPL
3-3/4 Digits
44-Pin Plastic
0°C to +70°C
Quad Flat Package
44-Pin Plastic
0°C to +70°C
Leadless Chip
Carrier
40-Pin Plastic DIP 0°C to +70°C
5
6
FUNCTIONAL BLOCK DIAGRAM
TRIPLEX LCD
LOGIC HIGH
LOGIC LOW
OVERRANGE
PKHOLD
LOW BATT
ANNUNCIATOR DRIVE
LOW DRIFT VOLTAGE
DIFFERENTIAL
REFERENCE
CLOCK
OSCILLATOR
TRIPLE LCD
DRIVERS
EOC
UNDERRANGE
OVERRANGE
ANALOG
INPUT
FULL-SCALE
SELECT
FREQUENCY
INPUT
3-3/4 DIGIT
A/D CONVERTER
ANALOG GND
PEAK HOLD
COMPARATOR
DECIMAL
POINT
DRIVERS
DECIMAL
POINT
SELECT
AUTORANGING
FREQUENCY
COUNTER
LOGIC
PROBE
DIGITAL GROUND
LOW
BATTERY
DETECT
BUZZER
DRIVER
BUZZER
CONTROL
FUNCTION
SELECT
VOLTS
FREQUENCY
LOGIC
FUNCTION
SELECT
7
TC820
TO LCD
AND BUZZER
LOGIC
PROBE
INPUT
+
PEAK
HOLD
9V
8
TC820-10 10/17/96
TELCOM SEMICONDUCTOR, INC.
3-149