2スイッチトポロジPWMコントローラ、高効率、並列接続可能な電源設計が可能
SUNNYVALE, CA-August 21, 2003-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX5051, a two-switch topology PWM controller IC that facilitates the design of clamped, two-switch forward converters. The two-switch topology reduces voltage stress on the external MOSFETs, allows the use of lower RDS(ON) MOSFETs, and recovers energy stored in transformer leakage and magnetizing inductance. Moreover, commonly used transformer reset winding and snubber circuits are no longer needed. Power supplies designed with the MAX5051 offer the benefit of high reliability, low component stress, and high efficiency.
The MAX5051 operates with an input voltage range of 11V to 76V and is well suited for stepping down a 48V bus to lower voltages in telecom, networking, and server applications. The device includes integrated high- and low-side gate drivers capable of providing 2A peak current drive for external
N-channel MOSFETs. Several MAX5051s can be paralleled, allowing the design of scalable power supplies with high output currents. A master/slave configuration drives the second converter 180° out-of-phase, reducing input ripple current and the required input capacitance. The switching frequency can
be externally set to over 500kHz. The device also provides a look-ahead PWM signal for secondary-side synchronous rectification. In addition, fault protection allows the power supply to integrate cycle-by-cycle current-limit events for a programmable amount of time before shutting down. Under sustained over-current conditions, the power supply shuts off and restarts with a new soft-start cycle.
Rated for operation over a wide -40°C to +125°C temperature range, the MAX5051 is available in a thermally enhanced 28-pin TSSOP package. Prices start at $2.14 (1000-up, FOB USA).
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