AD2S44-UM18B

Overview

The AD2S44-UM18B is a low-cost, 14-bit dual-channel synchro/resolver-to-digital converter housed in a 32-lead bottom-brazed ceramic DIP hybrid package. It provides independent Type II servo loop tracking for two channels with ±4.0 arc minute accuracy over the -55°C to +125°C temperature range. The device utilizes a ratiometric conversion technique for noise immunity and features independent reference inputs allowing different frequencies per channel. Digital output is accessed via three-state transparent latches controlled by A/B and OE lines, supporting parallel natural binary coding.

Feature Summary

• Dual-channel architecture with independent signal and reference conditioning circuits
• 14-bit resolution (1 LSB = 1.3 arc minutes) with ±4.0 arc minute accuracy
• Built-in test (BIT) facility for fault detection and failsafe indication
• High tracking rate of 20 rev/sec and acceleration constant of 62,000 sec⁻²

Applications

• Gimbal and gyro control systems
• Military servo control and fire control systems
• Avionic systems and antenna monitoring
• CNC machine tooling and robotics

Procurement Notes

Verify the specific voltage configuration suffix '18' corresponds to 11.8 V signal and 26 V resolver inputs as defined in the ordering guide. Confirm the 'B' suffix indicates high-reliability processing including MIL-STD-883 screening. Ensure the package option DH-32E matches the required 32-lead bottom-brazed ceramic DIP form factor for the target application.

Selection Notes

Select this model when space, weight, and cost are critical constraints requiring dual-channel capability. The UM variant offers ±4.0 arc minute accuracy across the full military temperature range (-55°C to +125°C). Consider external resistor scaling if input signals deviate from standard 11.8 V or 26 V levels, noting that resistor matching impacts common-mode rejection and accuracy.

Part Context

This component belongs to the AD2S44 family of synchro/resolver-to-digital converters manufactured by Analog Devices. It is distinct from monolithic alternatives like the AD2S80A series and hybrid isolating converters like the SDC/RDC1740. The device employs BiMOS II process technology for low power consumption and high reliability within a hermetically sealed hybrid package.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. The datasheet references other products such as the SD C/RDC1740 and AD2S80A series but does not explicitly list them as direct replacements for the AD2S44-UM18B.