SOT23 POWER-SUPPLY SEQUENCERS
SUNNYVALE, CA-February 26, 2001-Maxim Integrated Products introduces the MAX6819/MAX6820 power-supply sequencers designed for dual-voltage processors and multivoltage systems. These devices monitor a primary supply voltage to enable or disable an external N-channel MOSFET switch for the secondary supply voltage. These devices help control supply voltage sequencing for systems components when system supplies turn-on/turn-off characteristics cannot be guaranteed such as from a system bus or silver box supply.
When the primary supply is below a user-adjustable voltage threshold, the N-channel MOSFET switch is off, keeping the secondary supply away from the system component. When the primary supply exceeds the voltage threshold, the internal charge pump turns on after a sequence delay of 200ms and drives the external N-channel MOSFET. The charge pump allows the N-channel MOSFET to be fully enhanced to reduce on-resistance losses.
The MAX6819 features a logic-driven enable input to enable and disable the MOSFET. The MAX6820 provides for the sequence delay to be externally adjusted with a capacitor. For multivoltage systems, these devices can be daisy-chained together to sequence more than two supplies within a system.
These devices operate from -40°C to +125°C and are available in a 6-pin SOT23 package. Prices start at $1.50 (2500-up, FOB USA).
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