Quasi-Resonant PWM Controller
ICE2QS01
Pin Configuration and Functionality
1
Pin Configuration and Functionality
REG (Regulation)
1.1
Pin Configuration
Normally, an external capacitor is connected to this pin
for a smooth voltage Vreg. Internally, this pin is
connected to the PWM signal generator for switch-off
determination (together with the current sensing
signal), the digital signal processing for the frequency
reduction with decreasing load during normal
operation, and the burst mode controller for entering
burst mode operation determination and burst ratio
control during burst mode operation. Additionally, the
open-loop / over-load protection is implemented by
monitoring the voltage at this pin.
Pin
Symbol Function
1
ZC
Zero Crossing
2
REG
CS
Regulation
3
Primary Current Sensing
High Voltage input
gate driver output
IC supply voltage
Common ground
4, 5
6
HV
OUT
VCC
GND
7
CS (Current Sensing)
This pin is connected to the shunt resistor for the
primary current sensing, externally, and the PWM
signal generator for switch-off determination (together
with the regulation voltage), internally. Moreover, short-
winding protection is realised by monitoring the voltage
8
1.2
Package PG-DIP-8
Vcs during on-time of the main power switch.
ZC
1
8
7
6
5
GND
VCC
OUT
HV
HV (High Voltage)
The pin HV is connected to the bus voltage, externally,
and to the power cell, internally. The current through
this pin pre-charges the VCC capacitor once the supply
bus voltage is applied. Additionally, the current through
this pin supplies the IC in case that the output voltage
is lowered during active burst mode operation, or
during latch-off mode.
REG
CS
2
3
4
OUT (Gate drive output)
This output signal drives the external main power
HV
switch, which is a power MOSFET in most case.
VCC (Power supply)
This is the IC power supply pin. Externally, this pin is
connected to the VCC capacitor, which is supplied by
the inside power cell during VCC charge-up, burst
mode operation at lowered output voltage or during
latched-off of the IC, and the auxiliary winding during
normal operation or burst mode operation with high
enough voltage across the auxiliary winding. Based on
this voltage, the VCC under- or over-voltage protection
are implemented.
Figure 1
Pin Configuration PG-DIP-8(top view)
1.3
Pin Functionality
ZC (Zero Crossing)
At this pin, the voltage from the auxiliary winding after
a time delay circuit is applied. Internally, this pin is
connected to the zero-crossing detector for switch-on
determination. Additionally, the output overvoltage
detection is realized by comparing the voltage Vzc with
an internal preset threshold.
GND (Ground)
This is the common ground of the controller.
Version 2.1
5
December 2006
INFINEON [ Infineon ]
