ICE2QS01 Datasheet, PDF (5/17 Pages) Infineon Technologies AG – Quasi-resonant PWM Controller

Quasi-Resonant PWM Controller
ICE2QS01
Pin Configuration and Functionality
1
1.1
Pin
1
2
3
4, 5
6
7
8
1.2
Pin Configuration and Functionality
Pin Configuration
Symbol Function
ZC
REG
CS
HV
OUT
Zero Crossing
Regulation
Primary Current Sensing
High Voltage input
gate driver output
REG (Regulation)
Normally, an external capacitor is connected to this pin
for a smooth voltage V_reg. 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.
VCC
GND
IC supply voltage
Common ground
Package PG-DIP-8
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
V_cs during on-time of the main power switch.
ZC
1
REG
2
CS
3
8
GND
HV (High Voltage)
The pin HV is connected to the bus voltage, externally,
and to the power cell, internally. The current through
7
VCC
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
6
OUT
during latch-off mode.
HV
4
5
HV
OUT (Gate drive output)
This output signal drives the external main power
switch, which is a power MOSFET in most case.
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 V_zc with
an internal preset threshold.
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.
GND (Ground)
This is the common ground of the controller.
Version 2.1
5
December 2006