The HY3842D-N/3843D-N/3844D-N/3845D-N, are fixed frequency
current mode PWM controller. They are specially designed for OFF−Line and DC to DC
converter applications with a minimal external components. Internally implemented circuits
include a trimmed oscillator for precise duty cycle control, a temperature compensated
reference, high gain error amplifier, current sensing comparator, and a high current totem pole
output ideally suited for driving a power MOSFET. Protection circuitry
includes built under voltage lockout and current limiting.
The HY3842D-N, HY3844D-N, have UVLO thresholds of 16 V (on) and 10 V (off).
The corresponding thresholds for the HY3843D-N/3845D- N are 8.4V (on) and 7.6V (off).
The HY3842D-N, HY3843D-N, can operate within 100% duty cycle. The HY3844D-N,
HY3845D-N, can operate within 50% duty cycle.
The HY384XD-N have Start-Up Current 0.17mA (typ).
• Low Start-Up and Operating Current
• High Current Totem Pole Output
• Under voltage Lockout With Hysteresis
• Operating Frequency Up To 500KHz
(toggle flip flop used only in HY3844, HY3845)
Absolute Maximum Ratings
Supply Voltage (low impedance source)
Input Voltage (Analog Inputs pins 2,3)
Error Amp Output Sink Current
Power Dissipation (TA=250C)
Storage Temperature Range
Lead Temperature (soldering 5 sec.)
−0.3 to 5.5
Free Datasheet http://www.nDatasheet.com