Description

The AS1927 microprocessor supervisory circuits were designed to generate a reset when the monitored supply voltage falls below a factory-trimmed threshold. The reset remains asserted for a minimum timeout period after the supply voltage stabilizes. AS1927 only consumes 170nA current.

Guaranteed to be in the correct state for VCC higher than +1.0V, these devices are ideal for portable and batterypowered systems with strict monitoring requirements. The devices feature factory-trimmed thresholds to monitor a supply voltage between 1.575V and 4.625V. The devices are available with the reset output types

The AS1927 include a manual-reset input for systems that never fully power down the microprocessor. Additionally, these devices feature a watchdog timer to ensure that the processor is operating within proper code boundaries.

A watchdog disable feature allows to turn off the watchdog if not required or unwanted, as in boot up conditions of microcontrollers. The AS1927 are available in a 6-pin TDFN (2x2mm) package.

Key Features

• 170nA Ultra-Low Supply Current
• Operating Range: 1.0V to 5.5V
• Threshold range: 1.57V to 4.62V
• Guaranteed Reset Valid Down to VCC = 1.0V
• Six Minimum Reset Timeout Period Options from: 10ms to 1.2s
• Manual Reset Input
• Watchdog Timeout Period: 1.5s or 1.5min
• Three Reset Output Types
•  - Active-Low Push/Pull (AS1927L)
•  - Active-High Push/Pull (AS1927H)
•  - Active-Low Open-Drain (AS1927D)
• Operating Temperature Range: -40 to +85°C
• 6-pin TDFN (2x2mm) Package

Applications

The devices are ideal for low-power portable and battery-powered systems, metering devices, embedded controllers, intelligent instruments, automotive systems, and critical CPU monitoring applications.

Block diagram for AS1927 Supervisor IC