HY3842

HY3842/43/44/45 DESCRIPTION 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 HY 3842D-N, HY3843D-N, can operate within 100% duty cycle. The HY3844D-N, HY3845D-N, can operate w i thin 50% duty cycle. The HY384XD-N have Start-Up Current 0.17mA (typ). PIN CONNECTION (TOP VIEW) FEATURES Low Start-Up and Operating Current High Current Totem Pole Output Under voltage Lockout With Hysteresis Operating Frequency Up To 500KHz BLOCK DIAGRAM (toggle flip flop used only in HY3844, HY3845) Absolute Maximum Ratings Characteristic Supply Voltage (low impedance source) Output Current Input Voltage (Analog Inputs pins 2,3) Error Amp Output Sink Current Power Dissipation (TA=25 C) Storage Temperature Range Lead Temperature (soldering 5 sec.) 0 Symbol VCC IO VI ISINK (E.A) PO Tstg TL Value 30 ±1 −0.3 to 5.5 10 1 -65 to150 260 Uni...