SMALL, USB CURRENT-LIMITED SWITCH OFFERS LOW COST AND TIGHT ACCURACY
SUNNYVALE, CA-September 28, 1999-Maxim Integrated Products introduces the MAX1607 high-side MOSFET power switch. The MAX1607 is pin-compatible with the TPS2014 from Texas Instruments, but has a tight, ±17% accurate current limit (0.7A min, 0.85A nom, 1.0A max) versus only ±50% (0.66A min, 1.2A nom, 1.8A max) for the TPS2014. Improved accuracy better protects power distribution systems in universal serial bus (USB), PCMCIA cards, and other Hot Swap™ plug-in applications used by desktop computers, notebooks, and PDAs.
The MAX1607 prevents a system's power supply from crashing due to an overcurrent or short-circuit condition at the output of the switch. Using the MAX1607, the maximum current the system power supply needs to deliver is the guaranteed 1A max. The TPS2014 has continuous worst-case current of up to 1.8A, requiring a much larger and more expensive system power supply. Even if the output is shorted, the MAX1607 has a foldback scheme that reduces the current through the switch to only 500mA, further protecting the system. The TPS2014's input voltage range is limited to +4V to +5.5V. The MAX1607's input voltage ranges from +2.7V to +5.5V, making it ideal for both 3V and 5V systems.
An OC (overcurrent) output signals when the device is in current limit, thermal shutdown, or undervoltage lockout mode. The MAX1607 has an internal 10ms blanking period that prevents short, high-current transients from causing the OC pin to go low. If the overcurrent condition continues beyond 10ms, the MAX1607 will set OC low until the overcurrent is removed.
Quiescent current is a low 14µA (versus 73µA for the TPS2014) in the on state and drops to only 0.1µA when the switch is off. Thermal overload protection automatically limits power dissipation and junction temperature to safe levels. The MAX1607 comes in a small 8-pin SO package that is pin-compatible with the TPS2014, TPS2015, and TPS2041. The part is screened for the extended-industrial temperature range (-40°C to +85°C). Prices start from $0.80 (1000-up, FOB USA).
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