MICROCHIP MIC38C43YM

The MIC38C4x are fixed-frequency, high performance, current-mode PWM controllers. BiCMOS devices are pin compatible with 384x bipolar devices, but feature several improvements. Undervoltage lockout circuitry allows the ‘42 and ‘44 versions to start up at 14.5V and operate down to 9V, and the ‘43 and ‘45 versions start at 8.4V with operation down to 7.6V. All versions operate up to 20V. When compared to bipolar 384x devices operating from a 15V supply, start-up current has been reduced to 50 μA typical and operating current has been reduced to 4.0 mA typical. Decreased output rise and fall times drive larger MOSFETs, and rail-to-rail output capability increases efficiency, especially at lower supply voltages. The MIC38C4x also features a trimmed oscillator discharge current and bandgap reference. The MIC38C4x denotes 8-pin plastic DIP, SOIC, and MSOP packages. MIC38C4x-1 denotes 14-pin plastic DIP and SOIC packages. 8-pin devices feature small size, while 14-pin devices separate the analog and power connections for improved performance and power dissipation.

• Fast 40 ns Output Rise and 30 ns Output Fall Times
• -40℃ to +85℃ Ambient Temperature Range Meets UC284x Specifications
• High-Performance, Low-Power BiCMOS Process
• Ultra-Low Start-Up Current (<50 μA Typical)
• Low Quiescent Operating Current (4 mA Typical)
• CMOS Outputs with Rail-to-Rail Swing
• Up to 500 kHz Current-Mode Operation
• Trimmed 5V Bandgap Reference
• Pin-for-Pin Compatible with UC3842/3843/3844/3845(A)
• Trimmed Oscillator Discharge Current
• UVLO with Hysteresis
• Low Cross-Conduction Currents

• Current-Mode, Offline, Switched-Mode Power Supplies
• Current-Mode, DC-to-DC Converters
• Step-Down Buck Regulators
• Step-Up Boost Regulators
• Flyback, Isolated Regulators
• Forward Converters
• Synchronous FET Converters