MC1403B ON Semiconductor, MC1403B Datasheet - Page 5

• Manufacturer Part Number: MC1403B
• Description: PRECISION LOW VOLTAGE REFERENCE
• Manufacturer: ON Semiconductor

0.1 mF
3−1/2−Digit Voltmeter − Common Anode
Displays, Flashing Overrange
MC14433 is shown in the circuit diagram of Figure 8. The
reference voltage for the system uses an MC1403 2.5 V
reference IC. The full scale potentiometer can calibrate for
a full scale of 199.9 mV or 1.999 V. When switching from
2.0 V to 200 mV operation, R
the diagram.
the system is about 66 kHz. The resulting conversion time
is approximately 250 ms.
off. The flashing rate is one−half the conversion rate. This
V
* R
** Mylar Capacitor
+5.0 V
X
An example of a 3−1/2−digit voltmeter using the
When using R
When the input is overrange, the display flashes on and
R
I
I
= 470 kW for 2.0 V Range
= 27 kW for 200 mV Range
MC1403
1
0.1 mF **
0.1 mF
3
R
0.1 mF
I
2
*
C
equal to 300 kW, the clock frequency for
300 k
R
3
1
4
5
6
7
8
C
15
11
DS1
10
19
MC14433
I
20 k
is also changed, as shown on
DS2
18
2
DS3
12
17
DS4
24
16
23
22
21
20
13
14
9
0.1 mF
Figure 8. 3−1/2−Digit Voltmeter
+5.0 V
−5.0 V
−5.0 V
http://onsemi.com
5
3
4
11
9
−5.0 V
−5.0 V
0.1 mF
MC1403, B
7 10
C
D S
C
D
6
R
S
R
4
2
3
5
Q
Q
Q
Q
5
14
5.0 V
8
1
13
12
is done by dividing the EOC pulse rate by 2 with 1/2
MC14013B flip−flop and blanking the display using the
blanking input of the MC14543B.
digit lines driven with an MC14543B decoder and an
MC1413 LED driver. The MC1413 contains 7 Darlington
transistor drivers and resistors to drive the segments of the
display. The digit drive is provided by four MPS−A12
Darlington transistors operating in an emitter−follower
configuration. The MC14543B, MC14013B and LED
displays are referenced to V
This places the full power supply voltage across the display.
The current for the display may be adjusted by the value of
the segment resistors shown as 150 W in Figure 8.
2
8
1
6
+5.0 V
+5.0 V
The display uses an LED display with common anode
MC14013B
16
7
10
11
12
13
14
15
9
−5.0 V
−5.0 V
−5.0 V
50 mF
7
6
5
4
3
2
1
−5.0 V
51 k
+5.0 V
+5.0 V
MPS−A12
0.1 mF
10
11
12
13
14
15
16
Common
Anode
LED
Display
Minus Sign
200 W
110 W
Plus Sign
Segment Resistors
150 W (7)
EE
via Pin 13 of the MC14433.
f
g
e
MPS−A12
d
(4)
c
b a