The MC34166, MC33166 series are high performance fixed frequency power switching regulators that contain the primary functions required for dc−to−dc converters. This series was specifically designed to be incorporated in step−down and voltage−inverting configurations with a minimum number of external components and can also be used cost effectively in step−up applications.

These devices consist of an internal temperature compensated reference, fixed frequency oscillator with on−chip timing components, latching pulse width modulator for single pulse metering, high gain error amplifier, and a high current output switch.

Protective features consist of cycle−by−cycle current limiting, undervoltage lockout, and thermal shutdown. Also included is a low power standby mode that reduces power supply current to 36 μA.

Features

• Output Switch Current in Excess of 3.0 A

• Fixed Frequency Oscillator (72 kHz) with On−Chip Timing

• Provides 5.05 V Output without External Resistor Divider

• Precision 2 Reference

• 0 to 95 Output Duty Cycle

• Cycle−by−Cycle Current Limiting

• Undervoltage Lockout with Hysteresis

• Internal Thermal Shutdown

• Operation from 7.5 V to 40 V

• Standby Mode Reduces Power Supply Current to 36 μA

• Economical 5−Lead TO−220 Package with Two Optional Leadforms

• Also Available in Surface Mount D2PAK Package

• Moisture Sensitivity Level (MSL) Equals 1

• Pb−Free Packages are Available