1MHz, SINGLE-ENDED, CURRENT-MODE PWM CONTROLLERS ARE PIN COMPATIBLE WITH UC2842/UC2844 SERIES
SUNNYVALE, CA-May 3, 2004-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX5070A/MAX5070B highperformance,
single-ended, current-mode PWM controllers for isolated telecom
DC-DC or universal offline-input AC-DC power supplies. These devices are pin compatible with the industry-standard and multisourced UC2842/UCC2842 and UC2844/UCC2844 family of products. Moreover, the
MAX5070A/MAX5070B offer improved performance that allows designers to
upgrade existing power-supply designs for higher performance with minimal component changes.
The switching frequency of the MAX5070A/MAX5070B is externally
programmable from 20kHz to 1MHz, while the timing-capacitor discharge
current is trimmed to ±5%. This allows the maximum duty cycle to be accurately set, thereby avoiding transformer saturation. The maximum duty cycle for MAX5070A and MAX5070B is 100% and 50%, respectively. In addition, the switching frequency is trimmed for ±7% accuracy while the
current-limit threshold and start/stop voltages are trimmed for ±5% accuracy.The devices' fast 60ns cycle-by-cycle current-limit propagation delay allows a
fast response to output short circuit. Startup current is typically 35µA, which
allows the use of high-value startup resistors, thus reducing power dissipation
in the startup resistor in standby mode. The size of the startup capacitor is also
reduced. The MAX5070A/MAX5070B gate-driver outputs are capable of
sourcing 2A and sinking 1A. Both devices include overtemperature shutdown.
Rated for operation over a wide -40°C to +125°C temperature range, the
MAX5070A and MAX5070B are available in 8-pin SO and 8-pin µMAX®
packages. Prices start at $0.61 (1000-up, FOB USA).
µMAX is a registered trademark of Maxim Integrated Products, Inc.
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