12V, 120mA Flash Memory Programming Supply

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

* 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