TC7106
TC7106A
TC7107
1
2
3
4
5
6
7
8
TC7107A
3-1/2 DIGIT A/D CONVERTERS
GENERAL DESCRIPTION
FEATURES
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 preci-
sion reference with a 20ppm/°C max temperature coeffi-
cient. This represents a 4 to 7 times improvement over
similar 3-1/2 digit converters. Existing 7106 and 7107 based
systems may be upgraded without changing external pas-
sive 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 1012Ω input impedance. The
differential reference input allows ratiometric measurements
for ohms or bridge transducer measurements. The
15µVP–P noise performance guarantees a “rock solid” read-
ing. The auto-zero cycle guarantees a zero display read-
ing with a zero-volts input.
■ Internal Reference with Low Temperature Drift
TC7106/7 ....................................... 80ppm/°C Typical
TC7106A/7A.................................. 20ppm/°C Typical
■ Drives LCD (TC7106) or LED (TC7107) Display
Directly
■ Guaranteed 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 9 V Battery Operation (TC7106A)
■ High Impedance CMOS Differential Inputs.... 1012Ω
■ Differential Reference Inputs Simplify Ratiometric
Measurements
■ Low Power Operation..................................... 10mW
ORDERING INFORMATION
PART CODE
TC710X X X XXX
6 = LCD
7 = LED
}
A or blank*
R (reversed pins) or blank (CPL pkg only)
* "A" parts have an improved reference TC
Package Code (see below):
0.1µF
LCD DISPLAY (TC7106/A) OR
COMMON ANODE LED
DISPLAY (TC7107/A)
33
34
+
–
C
REF
C
REF
1MΩ
Package
Code
Temperature
Range
31
SEGMENT
DRIVE
+
2–19
+
V
IN
22–25
ANALOG
INPUT
–
Package
Pin Layout
0.01µF
20
–
30
32
POL
BP
V
IN
MINUS SIGN
BACKPLANE
DRIVE
CKW
CLW
CPL
IPL
44-Pin PQFP
44-Pin PLCC
40-Pin PDIP
40-Pin PDIP
40-Pin CerDIP
Formed Leads
—
0°C to +70°C
0°C to +70°C
21
1
ANALOG
COMMON
+
V
Normal
Normal
Normal
0°C to +70°C
24kΩ
1kΩ
28
TC7106/A
TC7107/A
+
V
BUFF
– 25°C to +85°C
– 25°C to +85°C
9V
V
47kΩ
+
REF
36
V
0.47µF
29
REF
IJL
C
V
AZ
–
35 100mV
26
V
REF
0.22µF
27
–
AVAILABLE PACKAGES
V
INT
OSC OSC OSC
2
3
1
TO ANALOG
COMMON (PIN 32)
C
39
38
40
OSC
R
100pF
3 CONVERSIONS/SEC
200mV FULL SCALE
OSC
100kΩ
40-Pin CERDIP
40-Pin Plastic DIP
Figure 1. TC7106/A/7/A Typical Operating Circuit
44-Pin Plastic Quad Flat
Package Formed Leads
44-Pin Plastic Chip
Carrier PLCC
TC7106/6A/7/7A-7 11/4/96
TELCOM SEMICONDUCTOR, INC.
3-183