Description

The HA17384S/H and HA17385H are PWM control switching regulator IC series suitable for highspeed, current-mode switching power supplies. With ICs from this series and a few external parts, a small, low cost flyback-transformer switching power supply can be constructed, which facilitates good line regulation by current mode control. Synchronous operation driven after an external signal can also be easily obtained which offers various applications such as a power supply for monitors small multi-output power supply.

Features

• High-safety UVL circuit is used (Both VIN and Vref are monitored)

• High speed operation:

⎯ Current detection response time: 100 ns Typ

⎯ Maximum oscillation frequency: 500 kHz

• Low standby current: 170 µA Typ

• Wide range dead band time (Discharge current of timing capacitance is constant 8.4 mA Typ)

• Able to drive power MOSFET directly (Absolute maximum rating of output current is ±1 A peak)

• OVP function (over voltage protection) is included *1 (Output stops when FB terminal voltage is 7.0 V Typ or higher)

• TSD function (thermal shut-down protection) is included *1

(Output stops when the temperature is 160°C Typ or higher)

• Zener protection is included (Clamp voltage between VIN and GND is 34 V Typ)

• Wide operating temperature range:

⎯ Operating temperature: –20°C to +105°C

⎯ Junction temperature: 150°C *2

Notes: 1. H series only.

2. S series only.

Functions

• Under-voltage lockout system

• Reference voltage regulator of 5.0 V ± 2

• Triangular wave (sawtooth) oscillator

• Error amplifier

• Totem pole output driver circuit (direct driving for power MOS FETs)

• Current-detection comparator circuit for current mode

• OVP function (over voltage protection) *1

• TSD function (thermal shut-down protection) *1

• Protect function by zener diode (between power input and GND)

Note: 1. H series only.