Milpitas, Calif. Aimed at portable electronics applications, Linear Technology Corp. has introduced the LTC2934 and LTC2935 ultra-low-current monitors that draw only 500 nA of quiescent current. Suitable for compact, single-cell applications, the single-channel LTC2934 and LTC2935 supply voltage monitors are housed in 2 x 2-mm, DFN or ThinSOT packages.
The unique features of the LTC2934 and LTC2935 differentiate them in the low-power monitor market and make them suitable choices for single Li+ coin cell, AA, AAA and other compact battery-powered or “green” applications, Linear said. The LTC2935 offers three binary inputs that allow selection of one of eight integrated reset thresholds, from 3.3 V to 2.25 V in 150-mV increments. The device's internal precision attenuators allow the part to maintain only 500 nA of supply current.
The LTC2934 allows an external resistive divider to finely set the reset threshold anywhere from 1.6 V to 6 V. The reset thresholds in both devices are +/-1.5% accurate over temperature. An early warning of a low-voltage condition is provided via a power-fail output. The supervisory circuits monitor VCC and pull the reset output low if the supply voltage drops below the configured reset threshold. The LTC2934 includes two reset timeout-periods of 15 ms or 200 ms, settable via a time-out selection pin, while the LTC2935 offers a fixed 200-ms timeout. A manual reset pin is also provided on both devices for optional use of a pushbutton switch to force a system reset.
Reset and power-fail outputs are available with open drain or active pull-up circuits. Commercial and industrial versions offer different operating temperature ranges from 0°C to 70°C (LTC2934) and -40°C to 85°C (LTC2935). Both devices are RoHS compliant.
Linear Technology , www.linear.com