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625kHz, Isolated/Nonisolated, Current-Mode PWM Controllers Are Ideal for Universal Offline, Telecom, or 12V Input Voltages

SUNNYVALE, CA-March 13, 2006-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX15000/MAX15001 high-frequency, current-mode PWM controllers with a programmable switching frequency (12.5kHz to 625kHz) that is trimmed to provide ±10% accuracy. These devices include an error amplifier for the design of isolated and nonisolated power supplies. Because this error amplifier regulates tertiary winding output voltage, the MAX15000/MAX15001 can be used for low-cost, primary-side-regulated isolated power-supply designs. Thus, neither an optocoupler nor a secondary-side shunt regulator are required. To further reduce cost and simplify design, the undervoltage lockout (UVLO) flag output allows the sequencing of a secondary-side controller.

The MAX15000 is well suited for either rectified offline (85VAC to 265VAC) or telecom (36V to 72V) input voltages, while the MAX15001 operates over the 9.5V to 24V input voltage range. This makes the MAX15001 ideal for 12V applications such as boost regulators, SEPIC regulators, or isolated power supplies.

Both devices have low 50µA standby current, which allows the use of high-value, 1/4W startup resistors and low-value, ceramic startup capacitors. The low standby current enables fast power-supply startup, while the dissipation across the startup resistor is substantially reduced even when operating from a rectified 120VAC line. Both devices include digital soft-start for superior control of the output voltage rise during initial startup under any load conditions. Startup output-voltage overshoots are, therefore, virtually eliminated.

The MAX15000/MAX15001 are available with a choice of 50% or 75% duty cycle. They include a ±1% accurate UVLO threshold that allows the designer to set the input start voltage using an external resistor-divider. The controllers can be shut down by pulling the UVLO pin low. These devices operate over the extended temperature range (-40°C to +85°C), and are available in a surface-mount, 10-pin µMAX® package. Pricing starts at $0.93 (1000-up, FOB USA).

µMAX is a registered trademark of Maxim Integrated Products, Inc.