MIC2778 _ BDTIC a Leading Distributor in China

MIC2778

The MIC2778 is a voltage monitor--uniquely designed to detect two separate voltage thresholds--combined with a delay generator and logic. It is designed for monitoring the battery supply of portable digital systems, particularly PDAs, pagers, and cellular telephones.

High- and low-voltage thresholds can be adjusted independently, allowing for wide hysteresis. Voltage detection thresholds are accurate to 2%.

If the battery voltage falls below the low-voltage threshold, the output (RST) is asserted and latched, preventing system operation until the battery is replaced or recharged. Internal logic prevents the output from chattering due to battery recovery or load removal. The output is asserted for 140ms (minimum) when a fresh battery is inserted. For applications not requiring built-in delay, see MIC841.

The IC's power supply input is separate from the detector inputs, allowing the MIC2778 to be powered from a downstream supply, such a boost converter. Supply current is extremely low (1µA, typical), making it ideal for portable applications. A high-precision 1% grade is available. The MIC2778 is supplied in Micrel's IttyBitty™ 5-lead SOT-23-5 package.

Features

Optimized for PDAs, cellular telephones, pagers, and other battery-powered devices
Independently adjustable high- and low-voltage thresholds
Internal logic prevents battery-voltage-fluctuation chatter
High ±2% voltage threshold accuracy; 1% available
Built in 140ms (minimum) delay deglitches output
Extremely low 1µA typical supply current
For applications not requiring built-in delay, see MIC841
Immune to brief power supply transients
5-lead SOT-23 package

Parameter

Parameter Name Value	Value
Typical Reset Pulse Width (ms) 140	140
Reset Type Active-Low/Open-Drain	Active-Low/Open-Drain
Typical Supply Current (uA) 1	1
Nominal Reset Voltage (V) 1.24 with adjustable hysteresis	1.24 with adjustable hysteresis
Product Type Single Voltage Monitor	Single Voltage Monitor