NCP1207A_10 Datasheet, PDF (2/17 Pages) ON Semiconductor – PWM Current--Mode Controller for Free Running Quasi--Resonant Operation

NCP1207A, NCP1207B
Universal Network
*
+ _{OVP and NCP1207A/B}
Demag
1
8
2
7
3
6
4
5
+
*Please refer to the application information section
Figure 1. Typical Application
V_out
+
GND
PIN FUNCTION DESCRIPTION
Pin Pin Name
Function
1
Demag Core reset detection and OVP
2
FB
Sets the peak current setpoint
3
CS
Current sense input and skip
cycle level selection
4
GND
The IC ground
5
Drv
Driving pulses
6
V_CC
Supplies the IC
7
NC
--
8
HV
High--voltage pin
Description
The auxiliary FLYBACK signal ensures discontinuous operation and offers a fixed
overvoltage detection level of 7.2 V.
By connecting an Optocoupler to this pin, the peak current setpoint is adjusted
accordingly to the output power demand. By bringing this pin below the internal
skip level, device shuts off.
This pin senses the primary current and routes it to the internal comparator via an
L.E.B. By inserting a resistor in series with the pin, you control the level at which
the skip operation takes place.
--
The driver’s output to an external MOSFET.
This pin is connected to an external bulk capacitor of typically 10 mF.
This unconnected pin ensures adequate creepage distance. (No pin on
NCP1207B)
Connected to the high--voltage rail, this pin injects a constant current into the V_CC
bulk capacitor.
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