TC7107CPL Microchip Technology, TC7107CPL Datasheet - Page 10

• Manufacturer Part Number: TC7107CPL
• Description: IC ADC 3 1/2DGT LED DVR 40-DIP
• Manufacturer: Microchip Technology

Specifications of TC7107CPL

• Package / Case: 40-DIP (0.600", 15.24mm)
• Display Type: LED
• Configuration: 7 Segment
• Digits Or Characters: A/D 3.5 Digits
• Current - Supply: 800µA
• Voltage - Supply: 5V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Architecture: Dual Slope
• Input Type: Voltage
• Maximum Power Dissipation: 1230 mW
• Maximum Operating Temperature: + 70 C
• Mounting Style: Through Hole
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 158-1129; 158-1129

TC7106/A/TC7107/A
5.0
DIGITAL SECTION (TC7106A)
The TC7106A
(Figure
5-2) contains all the segment
drivers necessary to directly drive a 3-1/2 digit liquid
crystal display (LCD). An LCD backplane driver is
included. The backplane frequency is the external
clock
frequency
divided
by
800.
For
three
conversions per second, the backplane frequency is
60Hz with a 5V nominal amplitude. When a segment
driver is in phase with the backplane signal, the
segment is “OFF.” An out of phase segment drive
signal causes the segment to be “ON” or visible. This
AC drive configuration results in negligible DC voltage
across each LCD segment. This insures long LCD
display life. The polarity segment driver is “ON” for
negative analog inputs. If V
+ and V
- are reversed,
IN
IN
this indicator will reverse.
When the TEST pin on the TC7106A is pulled to V+, all
segments are turned “ON.” The display reads -1888.
During this mode, the LCD segments have a constant
DC voltage impressed. DO NOT LEAVE THE
DISPLAY IN THIS MODE FOR MORE THAN
SEVERAL MINUTES! LCD displays may be destroyed
if operated with DC levels for extended periods.
The display font and the segment drive assignment are
shown in
Figure
5-1.
Display Font
1000s
100s'
10s'
1s '
'
FIGURE 5-1:
Display Font and Segment
Assignment
In the TC7106A, an internal digital ground is generated
from a 6-volt zener diode and a large P channel source
follower. This supply is designed to absorb the large
capacitive currents when the backplane voltage is
switched.
© 2008 Microchip Technology Inc.
DS21455D-page 10