TC7106_06 Datasheet, PDF (1/32 Pages) Microchip Technology – 3-1/2 Digit Analog-to-Digital Converters

TC7106/A/TC7107/A
3-1/2 Digit Analog-to-Digital Converters
Features:
• Internal Reference with Low Temperature Drift:
- TC7106/7: 80ppm/°C Typical
- TC7106A/7A: 20ppm/°C Typical
• Drives LCD (TC7106) or LED (TC7107)
Display Directly
• Zero Reading with Zero Input
• Low Noise for Stable Display
• Auto-Zero Cycle Eliminates Need for Zero
Adjustment
• True Polarity Indication for Precision Null
Applications
• Convenient 9V Battery Operation (TC7106A)
• High-Impedance CMOS Differential Inputs: 10¹²Î©
• Differential Reference Inputs Simplify Ratiometric
Measurements
• Low-Power Operation: 10mW
Applications:
• Thermometry
• Bridge Readouts: Strain Gauges, Load Cells, Null
Detectors
• Digital Meters: Voltage/Current/Ohms/Power, pH
• Digital Scales, Process Monitors
• Portable Instrumentation
Device Selection Table
Package
Code
Package
Pin Layout
Temperature
Range
CPI
IPL
IJL
CKW
40-Pin PDIP
40-Pin PDIP
40-Pin CERDIP
44-Pin PQFP
CLW 44-Pin PLCC
Normal
Normal
Normal
Formed
Leads
—
0°C to +70°C
-25°C to +85°C
-25°C to +85°C
0°C to +70°C
0°C to +70°C
General Description:
The TC7106A and TC7107A 3-1/2 digit direct display
drive Analog-to-Digital Converters allow existing 7106/
7107 based systems to be upgraded. Each device has
a precision reference with a 20ppm/°C max tempera-
ture coefficient. This represents a 4 to 7 times improve-
ment over similar 3-1/2 digit converters. Existing 7106
and 7107 based systems may be upgraded without
changing external passive component values. The
TC7107A drives common anode light emitting diode
(LED) displays directly with 8mA per segment. A low
cost, high resolution indicating meter requires only a
display, four resistors, and four capacitors.The
TC7106A low-power drain and 9V battery operation
make it suitable for portable applications.
The TC7106A/TC7107A reduces linearity error to less
than 1 count. Rollover error – the difference in readings
for equal magnitude, but opposite polarity input signals,
is below ±1 count. High-impedance differential inputs
offer 1pA leakage current and a 10¹²Î© input imped-
ance. The differential reference input allows ratiometric
measurements for ohms or bridge transducer
measurements. The 15μV_P–P noise performance
ensures a “rock solid” reading. The auto-zero cycle
ensures a zero display reading with a zero volts input.
© 2006 Microchip Technology Inc.
DS21455C-page 1