DS1238AS-5

Supervisors Overview

The DS1238AS-5 is a MicroManager supervisory circuit designed for single-input voltage monitoring in commercial temperature ranges. It integrates power-fail detection, manual reset control, and watchdog timer functions within a 16-pin SOIC package. The device operates between 4.5 V and 5.5 V with a typical threshold of 4.5 V. Key electrical parameters include a reset delay of 150 ms, a power-fail threshold of 4.25 V, and an overvoltage threshold of 4.5 V. It consumes 4 mA during operation and supports active high/low, open-drain, and push-pull outputs.

Supervisors Feature Summary

• Provides orderly shutdown capabilities by detecting impending power failures to allow microprocessor data preservation.
• Converts standard CMOS SRAM into nonvolatile memory through automatic write protection when supply voltage drops below tolerance.
• Includes a hardware watchdog timer that halts and restarts out-of-control microprocessors to ensure system reliability.

Supervisors Applications

• Microprocessor systems requiring reliable power management and reset sequencing
• Embedded applications utilizing CMOS SRAM for nonvolatile memory conversion
• Industrial control units needing watchdog functionality for fault recovery

Supervisors Procurement Notes

Verify the specific suffix 'AS' indicates the industrial or extended temperature range variant if required, as standard versions may differ. Confirm the '5' suffix corresponds to the 5V threshold specification. Check current lifecycle status as this component series may be discontinued or subject to limited availability from Analog Devices/Maxim Integrated distributors.

Supervisors Selection Notes

Select this component when a single-supervisory input with integrated watchdog and battery backup switching is required. Ensure the 16-pin SOIC package fits the board layout constraints. Verify that the 4.5 V to 5.5 V operating range matches the system's main rail voltage. Consider the 150 ms reset delay timing against the microprocessor startup requirements.

Supervisors Part Context

This part belongs to the DS1238A family of MicroManager circuits, which combine voltage supervision with memory protection features. It is pin-for-pin compatible with older MAX691 designs but offers enhanced integration. The AS designation typically denotes specific packaging or temperature grade variations within the Maxim Integrated portfolio.

Supervisors Replacement Considerations

DS1238S+T&R; serves as a surface-mount alternative within the same functional family. The DS1236AS-5 is a related supervisory circuit with similar thresholds but potentially different feature sets. Verify pin compatibility and output drive capabilities before substituting.