TC7116
TC7116A
TC7117
TC7117A
3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTERS WITH HOLD
FEATURES
s
Low Temperature Drift Internal Reference
TC7116/TC7117 ............................. 80 ppm/
°
C Typ
TC7116A/TC7117A ........................ 20 ppm/
°
C Typ
s
Display Hold Function
s
Directly Drives LCD or LED Display
s
Guaranteed Zero Reading With Zero Input
s
Low Noise for Stable
Display ......... 2V or 200 mV Full-Scale Range (FSR)
s
Auto-Zero Cycle Eliminates Need for Zero
Adjustment Potentiometer
s
True Polarity Indication for Precision Null
Applications
s
Convenient 9V Battery Operation
(TC7116/TC7116A)
s
High Impedance CMOS Differential Inputs .... 10
12
Ω
s
Low Power Operation .................................... 10 mW
1
GENERAL DESCRIPTION
The TC7116A/TC7117A are 3-1/2 digit CMOS analog-
to-digital converters (ADCs) containing all the active
components necessary to construct a 0.05% resolution
measurement system. Seven-segment decoders, polarity
and digit drivers, voltage reference, and clock circuit are
integrated on-chip. The TC7116A drives liquid crystal
displays (LCDs) and includes a backplane driver. The
TC7117A drives common anode light emitting diode (LED)
displays directly with an 8-mA drive current per segment.
These devices incorporate a display hold (HLDR)
function. The displayed reading remains indefinitely, as
long as HLDR is held high. Conversions continue, but
output data display latches are not updated. The reference
–
low input (V
REF
) is not available as it is with the TC7106/
–
7107. V
REF
is tied internally to analog common in the
TC7116A/7117A devices.
The TC7116A/7117A reduces linearity error to less
than 1 count. Roll-over error (the difference in readings for
equal magnitude but opposite polarity input signals) is
below
±1
count. High-impedance differential inputs offer 1
pA leakage current and a 10
12
Ω
input impedance. The 15
µV
P-P
noise performance guarantees a “rock solid” reading.
The auto-zero cycle guarantees a zero display reading with
a 0V input.
The TC7116A and TC7117A feature a precision, low-
drift internal reference, and are functionally identical to the
TC7116/TC7117. A low-drift external reference is not
normally required with the TC7116A/TC7117A.
0.1 µF
34
1 MΩ
+
ANALOG 0.01 µF
INPUT
–
+
C REF
31 +
V IN
–
30 V IN
32 ANALOG
COMMON
LCD DISPLAY (TC7116/7116A)
33
1
OR COMMON ANODE LED
DISPLAY (TC7117/7117A)
–
HLDR
C REF
2–19 SEGMENT
22–25 DRIVE
POL 20
BP/GND 21
V+
35
24 kΩ
+
36
VREF
100 mV
1 kΩ
9V
MINUS SIGN
BACKPLANE
DRIVE
DISPLAY
HOLD
2
3
4
5
6
7
ORDERING INFORMATION
PART CODE
TC711X 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):
Package
Code
CKW
CLW
CPL
IJL
Package
44-Pin PQFP
44-Pin PLCC
40-Pin Plastic DIP
40-Pin CerDIP
Temperature
Range
0°C to +70°C
0°C to +70°C
0°C to +70°C
– 25°C to +85°C
AVAILABLE PACKAGES
40-Pin Plastic
DIP
40-Pin CerDIP
47 kΩ
TC7116/A
28 V
BUFF TC7117/A
0.47 µF
29
0.22 µF
27
CAZ
+
VREF
44-Pin Plastic Quad Flat
Package Formed Leads
V – 26
VINT
OSC2 OSC3 OSC1
39
38 COSC 40
R OSC 100 pF
100 kΩ
TO ANALOG
COMMON (PIN 32)
3 CONVERSIONS/SEC
44-Pin Plastic Chip
Carrier PLCC
Figure 1. Typical TC7116/A/7/A Operating Circuit
TC7116/A/7117/A-7 10/18/96
8
3-203
TELCOM SEMICONDUCTOR, INC.