TC820 TelCom Semiconductor, TC820 Datasheet - Page 4

• Manufacturer Part Number: TC820
• Description: 3-3/4 DIGIT A/D CONVERTER WITH FREQUENCY COUNTER AND LOGIC PROBE
• Manufacturer: TelCom Semiconductor

ELECTRICAL CHARACTERISTICS (Cont.)
Symbol
PIN DESCRIPTION
3-152
TC820
Package)
V
V
V
V
Pin No.
(40-Pin
IL
IH
OL
OL
10
11
12
13
14
15
16
17
18
19
—
1
2
3
4
5
6
7
8
9
Parameter
Buzzer Frequency
Counter Timebase Period
Low Battery Flag Voltage
Input Low Voltage
Input High Voltage
Output Low Voltage,
UR, OR Outputs
Output High Voltage,
UR, OR Outputs
Control Pin
Pull-Down Current
(44-Pin Flat
Package)
Pin No.
40
41
42
43
44
10
11
12
13
14
15
1
2
3
4
5
6
7
8
9
ANNUNC
Symbol
RANGE/
BC4P3
BC3P2
BC2P1
PKFE1
BC1BT
LOGIC
DGND
AGD4
AGD3
AGD2
FREQ
OFE2
AGD1
HFE3
V
L-E4
BP3
BP2
BP1
DISP
Test Conditions
f
f
V
I
I
V
OSC
OSC
L
L
DD
IN
= 50 A
= 50 A
= V
Description
LCD segment driver for L ("logic LOW"), polarity, and "e" segment of most
significant digit (MSD).
LCD segment drive for "a," "g," and "d" segments of MSD.
LCD segment drive for "b" and "c" segments of MSD and decimal point 3.
LCD segment drive for H ("logic HIGH"), and "f" and "e" segments of third LSD.
LCD segment drive for "a," "g," and "d" segments of third LSD.
LCD segment drive for "b" and "c" segments of third LSD and decimal point 2.
LCD segment drive for "overrange," and "f" and "e" segments of second LSD.
LCD segment drive for "a," "g," and "d" segments of second LSD.
LCD segment drive for "b " and "c" segments of second LSD and decimal point 1.
LCD segment drive for "hold peak reading," and "f" and "e" segments of LSD.
LCD segment drive for "a," "g," and "d" segments of LSD.
LCD segment drive for "b" and "c" segments of LSD and "low battery."
LCD backplane #3.
LCD backplane #2.
LCD backplane #1.
Sets peak LCD drive signal: V
compensate for temperature variation of LCD crystal threshold voltage.
Internal logic digital ground, the logic "0" level. Nominally 4.7V below V
Square-wave output at the backplane frequency, synchronized to BP1. ANNUNC
can be used to control display annunciators. Connecting an LCD segment to
ANNUNC turns it on; connecting it to its backplane turns it off.
Logic mode control input. When connected to V
The LCD displays "OL" and the decimal point inputs control the HIGH and LOW
annunciators. When the "low" annunciator is on, the buzzer will also be on. When
unconnected or connected to DGND, the TC820 is in the voltage/frequency
measurement mode. This pin has a 5 A internal pull-down to DGND.
Dual-purpose input. In range mode, when connected to V
will be 200 counts instead of 2000 counts and the LCD will display the analog input
divided by 10. (See text for limitation with TC820.) In frequency mode, this pin is the
frequency input. A digital signal applied to this pin will be measured with a 1-second
time base. There is an internal 5 A pull-down to DGND.
to V
= 40kHz
= 40kHz
DD
SS
PEAK
V
V
= (V
DD
DD
3-3/4 A/D CONVERTER WITH
Min
6.7
—
—
—
—
—
DD
– 1.5
– 1.5
) –V
TELCOM SEMICONDUCTOR, INC.
FREQUENCY COUNTER
DISP
DD
Typ
, the converter is in logic mode.
. V
—
—
—
—
5
1
7
5
AND LOGIC PROBE
DISP
DD
may also be used to
DGND + 1.5
DGND + 0.4
, the integration time
Max
7.3
—
—
—
—
—
DD
.
Second
Units
kHz
V
V
V
V
V
A