Chip checks for overvoltage

Edited by the Electronicstalk editorial team Nov 20, 2001

The Semtech SC1437 precision voltage detector is an overvoltage detection circuit with a built-in timer and driver for an external MOSFET switch.

The Semtech SC1437 precision voltage detector is an overvoltage detection circuit with a built-in timer and driver for an external mosfet switch.

The programmable trigger voltage and timer delay make the device ideal for use in battery-powered portable electronics where precise notification of voltage levels is critical.

The SC1437 offers selectable delay modes - 0, 40 and 80ms without the use of an external resistor - to provide designers with maximum flexibility.

The internally set trigger voltage prevents accidental overvoltage conditions caused by battery supply voltage glitches.

An external resistor also allows trip point adjustment.

The device compares voltage on the input supply pin (V+) to either a preset standard or user-selectable voltage (3.1 to 6.2V) and offers true 2% accuracy over the entire industrial temperature range of -40 to +85C.

The device offers three preset voltage trip options (4.2, 4.5 or 4.7V); an external resistive divider allows still more flexibility.

The SC1437 also provides three separate functional output options that enable it to drive an N-channel mosfet, drive a P-channel mosfet, or serve as a voltage detector flag.

As a battery overvoltage detection device, the SC1437 provides a cost-effective secondary line of defence against charger failure.

Designed as a universal voltage detection device for use in battery packs, portable electronics, lithium ion protection circuits, programmable fuses, and CPU reset circuits, the SC1437 has an input voltage range from 1.8 to 6.8V, is compatible with lithium ion battery technologies and has a typical quiescent current under 10uA to maximise battery life.

The device features reverse battery protection for increased reliability and 2% accuracy across the full industrial temperature range.

The SC1437, in a 5-lead SOT-23 package, is available through Semtech's network of direct sales representatives and distributors, and is priced at $0.45 in production quantities of 1000 pieces.