tc7136a Microchip Technology Inc., tc7136a Datasheet - Page 8

• Manufacturer Part Number: tc7136a
• Description: Low Power 3-1/2 Digit Analog-to-digital Converter
• Manufacturer: Microchip Technology Inc.

TC7136/TC7136A
DS21461B-page 8
TABLE 2-1:
(40-Pin PDIP)
Pin Number
Normal
34
35
36
37
38
39
(Reverse)
PIN DESCRIPTION (CONTINUED)
(7)
(6)
(5)
(4)
(3)
(2)
(1)
Symbol
C
V
OSC3
OSC2
OSC1
V
TEST
REF
REF
REF
+
+
-
Description
A 0.1µF capacitor is used in most applications. If a large Common mode voltage
exists (for example, the V
used, a 1µF capacitor is recommended, which will hold the rollover error to
0.5 count.
See Pin 36.
The analog input required to generate a full scale output (1999 counts). Place
100mV between Pins 35 and 36 for 199.9mV full scale. Place 1V between Pins 35
and 36 for 2V full scale. See Section 6.6, Reference Voltage.
Lamp test. When pulled HIGH (to V+), all segments will be turned ON and the
display should read -1888. It may also be used as a negative supply for externally
generated decimal points. See Section 7.4, Test for additional information.
See Pin 40.
See Pin 40.
Pins 40, 39 and 38 make up the oscillator section. For a 48kHz clock
(3 readings per second), connect Pin 40 to the junction of a 180kΩ resistor and a
50pF capacitor. The 180kΩ resistor is tied to Pin 39 and the 50pF capacitor is tied
to Pin 38.
IN
- pin is not at analog common) and a 200mV scale is

2002 Microchip Technology Inc.