V 600, Pin functions, Circuit diagram – Martel Electronics V600 User Manual
Page 3: 3½ digit lcd voltmeter module, Solder links
PIN FUNCTIONS
1.
BP
Backplane connection from voltmeter IC.
2.
LO BAT LCD connection to "Low Battery" annunciator.
3.
DP1
Connect to V+ to display Decimal Point 1 (1.999).
4.
DP2
Connect to VDD to display Decimal Point 2 (19.99).
5.
DP3
Connect to VDD to display Decimal Point 3 (199.9).
6.
ROH
Positive output from internal reference.
7.
ROL
Negative output from internal reference.
8.
COM
The ground for the analogue section of the A/D converter, held actively at 2.8V (nom) below VDD.
COM must not be allowed to sink excessive current (> 100 A) by connecting it directly to a higher voltage.
9.
RFH
Positive input for reference voltage.
10. RFL
Negative input for reference voltage.
11. VSS
Negative power supply connection.
12. INLO
Negative measuring input with reference to IN HI.
13. INHI
Positive measuring input with reference to IN LO.
14. TEST
Connecting this pin to VDD to turn on display segments "-1888".
It should not be operated for more than a few seconds as the DC voltage applied to the LCD may "burn" the display.
This pin is nominally at 5V below VDD and is the ground for the digital section of the meter, it can be used as a negative
supply to power external logic up to a maximum of 1mA.
15. VDD
Positive power supply connection.
BP
Normally Open.
BAT
Normally Open.
µ
Solder Links:
Analogue inputs must be no closer than 1V
to either the positive or negative supply.
See application diagram on next page.
CIRCUIT DIAGRAM
V 600
3½ Digit LCD Voltmeter Module
VDD
15
2
1
3
4
5
14
13
12
8
9
10
6
7
11
VDD
VDD
IC2B
IC2A
IC2D
IC2C
INHI
INLO
COM
RFH
RFL
ROH
ROL
VSS
LO BAT
BAT
BP
BP
DP1
DP2
DP3
TEST
INT
V+
V- TEST
a1
a1
27
1
26
28
29
31
30
32
34
36
35
39
40
38
33
d1
d1
e1
e1
f1
f1
DP1
LOBAT
1.999
DP2
19.99
DP3
199.9
g1
g1
f2
f2
a2
a2
g2
g2
e3
e3
b2
b2
a3
a3
f3
f3
c2
c2
b3
b3
g3
g3
d2
d2
c3
c3
bc4
b4
c4
e2
e2
d3
d3
b1
b1
c1
c1
5
17
29
4
8
12
2
14
8
13
6
18
7
19
13
22
12
21
25
23
18
5
11
20
23
25
17
26
10
11
16
24
22
27
9
10
24
7
19
3
28
14
9
15
6
4
16
3
15
BUF
A/Z
IN HI
IN LO
COM
CREF+
CREF-
REF HI
REF LO
OSC1
OSC2
OSC3
IC1
IC2
4070
LCD1
4
6
5
14
7
3
1
2
11
13
12
10
8
9
R9
1M
R6
100k
R3 100k
C5
100pF
C4
100nF
C1
68nF
R1
300k
R2
1M
C2
220nF
C3
100nF
R5
3k
R4
1.5k
R8
1M
R7
1M
37
POL
POL
BP
COM
COM
20
2
21
1
30
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