TC7106 Microchip, TC7106 Datasheet - Page 17

• Manufacturer Part Number: TC7106
• Description: 3-1/2 Digit Analog-to-Digital Converters
• Manufacturer: Microchip

ments (a “111” display) to worst case (a “1888” display),
the resistor will change about 230mW, while a circuit
without the resistor will change about 470mW. There-
fore, the resistor will reduce the effect of display dissi-
pation on reference voltage drift by about 50%.
The change in LED brightness caused by the resistor is
almost unnoticeable as more segments turn off. If dis-
play brightness remaining steady is very important to
the designer, a diode may be used instead of the
resistor.
FIGURE 9-4:
10.0 TYPICAL APPLICATIONS
10.1
Several manufacturers supply standard LCDs to inter-
face with the TC7106A 3-1/2 digit analog-to-digital
converter.
Note: Contact LCD manufacturer for full product listing and
©
Manufacturer
Crystaloid
Electronics
AND
Epson
Hamlin, Inc.
2002 Microchip Technology Inc.
TP5
40
100
kΩ
1
specifications.
Liquid Crystal Display Sources
100
5.1Ω 1/4W
pF
1N4001
24kΩ
TP1
TP2
1kΩ
+5V
5282 Hudson Dr.
Hudson, OH 44236
216-655-2429
720 Palomar Ave.
Sunnyvale, CA 94086
408-523-8200
3415 Kashikawa st.
Torrance, CA 90505
213-534-0360
612 E. Lake St.
Lake Mills, WI 53551
414-648-236100
Address/Phone
0.1
µF
1MΩ
TP3
TC7107A
DIODE OR RESISTOR
LIMITS PACKAGE POWER
DISSIPATION
+
10
Display
0.01
µF
IN
30
–
kΩ
0.47
47
µF
TP
0.22
4
µ F
-5V
C5335, H5535,
T5135, SX440
FE 0201, 0701
FE 0203, 0701
FE 0501
LD-B709BZ
LD-H7992AZ
3902, 3933, 3903
Representative
Part Numbers*
Display
20
21
150Ω
10.2
Several LED manufacturers supply seven segment
digits with and without decimal point annunciators for
the TC7107A.
10.3
The TEST pin is connected to the internally generated
digital logic supply ground through a 500Ω resistor. The
TEST pin may be used as the negative supply for exter-
nal CMOS gate segment drivers. LCD display annunci-
ators for decimal points, low battery indication, or
function indication may be added without adding an
additional supply. No more than 1mA should be sup-
plied by the TEST pin; its potential is approximately 5V
below V+ (see Figure 10-1
FIGURE 10-1:
Hewlett-Packard
Components
AND
TC7106/A/TC7107/A
TC7106A
TC7106A
Manufacturer
TEST
V+
V+
Light Emitting Diode Display
Sources
Decimal Point and Annunciator
Drive
TEST
BP
BP
21
37
Decimal
Select
Point
DECIMAL POINT DRIVE
USING TEST AS LOGIC
GROUND
640 Page Mill Rd.
Palo Alto, CA 94304
720 Palomar Ave.
Sunnyvale, CA 94086
408-523-8200
).
Address/Phone
4030
4049
GND
V+
GND
V+
DS21455B-page 17
To LCD
Decimal
Point
To LCD
Backplane
To LCD
Decimal
Point
LED
LED
Display