AS1973

Overview

The AS1973 is a low-voltage dual comparator manufactured by ams-OSRAM USA INC. It operates with single supplies from 2.5V to 5.5V or dual supplies of ±1.25V to ±2.75V. The device features an open-drain output stage capable of pulling beyond VCC up to 5.5V > VEE, making it suitable for logic-level translation. Key electrical characteristics include a quiescent supply current as low as 8.5µA per comparator, a typical propagation delay of 300ns, and internal hysteresis of 3mV. The common-mode input voltage range extends 250mV above the rails, and the package type is an 8-pin MSOP.

Feature Summary

• Open-drain output stage allows voltage extension beyond VCC for level shifting applications
• Internal hysteresis ensures clean switching with slow input signals
• Common-mode input voltage range extends 250mV beyond supply rails
• Low power consumption with minimal propagation delay

Applications

• Battery-powered systems
• Logic-level translators (3V/5V)
• Zero-crossing detectors
• Threshold detectors and discriminators

Procurement Notes

Verify the specific ordering suffix (e.g., -T) to confirm the delivery form, as the datasheet lists both tube and tape-and-reel options for the AS1973. Confirm the manufacturer origin, noting that technical content originates from austriamicrosystems AG, now ams AG. Ensure the application environment stays within the specified operating temperature range of -40°C to +85°C. Check for any recent product change notices regarding packaging or assembly site transfers.

Selection Notes

Select the AS1973 when a dual comparator configuration with open-drain outputs is required for interfacing with different logic voltage levels. This model is appropriate for designs needing rail-to-rail input capability extending slightly beyond the supply rails. Consider this part for space-limited applications due to its compact 8-pin MSOP package. Evaluate if the 3mV internal hysteresis meets noise immunity requirements without external feedback components.

Part Context

The AS1973 belongs to the AS1970–AS1975 family of low-voltage comparators. While the AS1970/AS1972/AS1974 feature push/pull outputs, the AS1973 variant specifically utilizes an open-drain output structure. This family is designed for 3V and 5V applications, offering low supply current and high speed. The AS1973 serves as the dual-channel counterpart to the single-channel AS1971 and the quad-channel AS1975.

Replacement Considerations

Direct functional substitutes within the same series include the AS1971 (single channel, open-drain) and AS1975 (quad channel, open-drain). For push/pull output requirements, consider the AS1972 (dual channel) or AS1974 (quad channel). Verify pin compatibility and output drive capabilities when substituting.