ncp1001 ON Semiconductor, ncp1001 Datasheet - Page 11

• Manufacturer Part Number: ncp1001
• Description: Integrated Off-line Switching Regulator
• Manufacturer: ON Semiconductor

Applications
wire−wrap or plug−in prototype board. In order to ensure
proper device operation and stability, it is important to
minimize the lead length and the associated inductance of
the ground pin. This pin must connect as directly as possible
to the printed circuit ground plane and should not be bent or
Bypass
Do not attempt to construct a converter circuit on a
Loop Compensation
AC Line
+
Input
+
Auto Restart Timing
Feedback
Input
V
CC
1
2
10 V
10 V
2.7 k
V
CC
+
10 mA
Limiter 8.6 V
7.0 kHz
Opto Fail−safe
Duty Cycle
Filter
Oscillator
Ramp
Clock
Figure 17. Representative Block Diagram
Auxiliary Output
NCP1000, NCP1001, NCP1002
+
8.5 V/
7.5 V
Ground
PWM
Comparator
Undervoltage
Current Limit
Comparator
Internal
Bias
Lockout
http://onsemi.com
+
Shutdown
Thermal
3
Start−Up
Power up−reset
State Control
11
PWM Latch
Ck R
Divide
S
R
offset by the board layout. The Power Switch Circuit pin can
be offset if additional layout creepage distance is required.
Due to the potentially high rate of change in switch current,
a capacitor (if used), at pin 2, should have traces as short as
possible, from pin 2 and ground. This will significantly
reduce the level of switching noise that can be imposed upon
the feedback control signal.
+
by 8
Q
Q
Start−Up
Leading Edge
Blanking
4
Driver
R
Snubber
pk
Power Switch
Circuit
5
+
Converter
DC Output
+
−