ncv33161 ON Semiconductor, ncv33161 Datasheet - Page 14

• Manufacturer Part Number: ncv33161
• Description: Universal Voltage Monitors
• Manufacturer: ON Semiconductor

The above figure shows the MC34161 configured as a step-down converter. Channel 1 monitors the output voltage while Channel
2 performs the oscillator function. Upon initial powerup, the converters output voltage will be below nominal, and the output of Channel
1 will allow the oscillator to run. The external switch transistor will eventually pump-up the output capacitor until its voltage exceeds
the input threshold of Channel 1. The output of Channel 1 will then switch low and disable the oscillator. The oscillator will commence
operation when the output voltage falls below the lower threshold of Channel 1.
V
12V
in
0.01
330
Line Regulation
Load Regulation
Output Ripple
Efficiency
+
4.7k
1.6k
Test
1
7
2
3
+
+
1.27V
1.27V
MC34161, MC33161, NCV33161
+
-
+
-
Figure 27. Step-Down Converter
V
V
V
V
in
in
in
in
2.54V
Reference
= 9.5 V to 24 V, I
= 12 V, I
= 12 V, I
= 12 V, I
+
+
4
2.8V
0.6V
http://onsemi.com
-
+
-
+
8
O
O
O
Conditions
= 0.25 mA to 250 mA
= 250 mA
= 250 mA
14
O
= 250 mA
0.01
6
5
470
0.005
47k
MPS750
1.8k
40 mV = ±0.1%
2.0 mV = ±0.2%
50 mVpp
87.8%
1N5819
470mH
Results
+
1000
V
5.0V/250mA
O