tc7126a Microchip Technology Inc., tc7126a Datasheet - Page 8

• Manufacturer Part Number: tc7126a
• Description: 3-1/2 Digit Analog-to-digital Converters
• Manufacturer: Microchip Technology Inc.

TC7126/A
TABLE 2-1:
DS21458C-page 8
(40-Pin PDIP)
Pin Number
Normal
34
35
36
37
38
39
40
PIN FUNCTION TABLE (CONTINUED)
(Reversed)
(7)
(6)
(5)
(4)
(3)
(2)
(1)
Symbol
C
V
OSC3
OSC2
OSC1
V
TEST
REF
REF
REF
+
+
-
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 and 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 Selection”, Reference Voltage
for additional information.
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 (Pin 37)”, 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,
39 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
Description
© 2006 Microchip Technology Inc.