IL44608 Datasheet, PDF (2/13 Pages) IK Semicon Co., Ltd – External Components Reliable and Flexible SMPS Controller

IL44608N
PIN FUNCTION DESCRIPTION
Pin Symbol
Function
The Demag pin offers 3 different functions: Zero voltage crossing detection (50 mV), 24 μA cur-
1 Demag rent detection and 120 μA current detection. The 24 μA level is used to detect the secondary re-
configuration status and the 120 μA level to detect an Over Voltage status called Quick OVP.
The Current Sense pin senses the voltage developed on the series resistor inserted in the source of
the power MOSFET. When Isense reaches 1.0 V, the Driver output (pin 5) is disabled. This is
2
Isense
known as the Over Current Protection function. A 200 μA current source is flowing out of the pin
3 during the start–up phase and during the switching phase in case of the Pulsed Mode of opera-
tion. A resistor can be inserted between the sense resistor and the pin 2, thus a programmable peak
current detection can be performed during the SMPS stand–by mode.
3
Control
Input
A feedback current from the secondary side of the SMPS via the opto–coupler is injected into this
pin. A resistor can be connected between this pin and GND to allow the programming of the Burst
duty cycle during the Stand–by mode.
4 Ground This pin is the ground of the primary side of the SMPS.
5 Driver The current and slew rate capability of this pin are suited to drive Power MOSFETs.
This pin is the positive supply of the IC. The driver output gets disabled when the voltage be-
6
V_СС comes higher than 15 V and the operating range is between 6.6 V and 13 V. An intermediate vol-
tage level of 10 V creates a disabling condition called Latched Off phase.
7
This pin is to provide isolation between the V_i pin 8 and the V_CC pin 6.
This pin can be directly connected to a 500 V voltage source for start–up function of the IC. Dur-
8
V_i
ing the Start–up phase a 9.0 mA current source is internally delivered to the V_CC pin 6 allowing a
rapid charge of the V_CC capacitor. As soon as the IC starts–up, this current source is disabled.
Figure 1. Representative Block Diagram
2011, February, Rev. 01