TOP222YN

Switching Frequency : 100 KHz
Operating Temperature Range : - 40 C to + 150 C
Packaging : Tube
Output Voltage : 5.7 V
Input / Supply Voltage (Max) : 265 VAC
Input / Supply Voltage (Min) : 85 VAC
Duty Cycle (Max) : 70 %
Supply Current : 1.2 mA
Mounting Style : Through Hole
Package / Case : TO-220


Description

The TOP222YN is one member of the TOP222 series.The internal oscillator linearly charges and discharges the internal capacitance between two voltage levels to create a sawtooth waveform for the pulse width modulator.The TOP222YN oscillator sets the pulse width modulator/current limit latch at the beginning of each cycle.The nominal frequency of 100 kHz was chosen to minimize EMI and maximize efficiency in power supply applications.Trimming of the current reference improves oscillator frequency accuracy.

Features of the TOP222YN are:(1)lowest cost, lowest component count switcher solution; (2)cost competitive with linears above 5W; (3)very low AC/DC lossesup to 90% efficiency; (4)built-in auto-restart and current limiting; (5)latching thermal shutdown for system level protection; (6)implements flyback, forward, boost or buck topology; (7)works with primary or opto feedback; (8)stable in discontinuous or continuous conduction mode; (9)source connected tab for low EMI; (10)circuit simplicity and design tools reduce time to market.The 5V secondary is used to supply the stand-by function and the 12V non-isolated output is used to supply power for the PWM controller of the main power supply and other primary side functions.The leading edge blanking circuit inhibits the current limit comparator for a short time after the output MOSFET is turned on.The leading edge blanking time has been set so that current spikes caused by primary-side capacitances and secondary-side rectifier reverse recovery time will not cause premature termination of the switching pulse.

The absolute maximum ratings of the TOP222YN can be summarized as:(1)DRAIN voltage:-0.3 to 700V;(2)storage temperature:-65 to 125;(3)CONTROL voltage:-0.3 to 9V;(4)CONTROL current:100mA;(5)operating junction temperature:-40 to 150;(6)lead temperature:260.Under some conditions, externally provided bias or supply current driven into the CONTROL pin can hold the TOPSwitch in one of the 8 auto-restart cycles indefinitely and prevent starting.To avoid this problem when doing bench evaluations, it is recommended that the Vc power supply be turned on before the DRAIN voltage is applied.TOPSwitch can also be reset by shorting the CONTROL pin to the SOURCE pin momentarily.Short interruptions of AC power may cause TOPSwitch to enter the 8-count auto-restart cycle before starting again.This is because the input energy storage capacitors are not completely discharged and the CONTROL pin capacitance has not discharged below the internal power-up reset voltage.