Analog Devices MAX734 Product Info

• Regulated +12V ±5% Output
• Guaranteed 120mA Output Current
• Tiny Flash Memory Programming Circuit:
  • Fits into 0.3in
  • 8-Pin SO and Plastic DIP Packages
  • Uses Tiny 18μH Inductor and 33μF Capacitors
• Logic-Controlled 70μA Shutdown
• 85% Typical Efficiency

The MAX734 is a + 12V-output, step-up, DC-DC switch-mode regulator. It delivers a guaranteed 120mA from a 4. 75V input, and is ideal for programming flash memories. Available in 8-pin SO and DIP packages, it uses only a diode, an 18μH inductor, and two 33μF capacitors. The entire circuit is completely surface-mountable and fits into less than 0.3in². The MAX734 also features a logic-controlled shutdown pin that allows direct microprocessor (μP) control. In-circuit testing ensures guaranteed output specifications over load, line, and temperature limits.

Battery-saving features include 85% efficiency, 1.2mA operating quiescent supply current, and 70μA _shutdown supply current. The operating supply current can be reduced to less than 500μA by toggling the shutdown pin with the μP.

The MAX734 uses current-mode pulse-width modulation (PWM) control to provide precise output regulation and low subharmonic noise. A fixed 170kHz oscillator frequency facilitates ripple filtering and allows the use of tiny external capacitors.

For higher-current solutions up to 250mA, refer to the MAX732 data sheet and evaluation kit (MAX732EVKIT-SO).

APPLICATIONS

• + 12V Flash Memory Programming Supplies
• PCMCIA +12V Supplies
• Solid-State Disk Drives
• Palmtop Computers
• Compact + 12V Op-Amp Supplies