AD7755AN

Overview

The AD7755AN is a high-accuracy polyphase energy metering integrated circuit manufactured by Analog Devices Inc. It utilizes a 16-bit second-order sigma-delta ADC architecture to provide precise measurement of average and instantaneous active power. The device features three independent channels with integrated programmable gain amplifiers and phase correction capabilities, ensuring accurate multi-phase energy monitoring. Designed for robust performance in harsh environments, it includes internal relative matching circuits to maintain channel phase alignment regardless of filter configurations. The component operates on a single 5V supply within a voltage range of 4.75V to 5.25V, consuming typical power of 15mW. It offers a dynamic range of 500:1 with an error margin below 0.1%, exceeding IEC1036 standards. The unit is housed in a 24-pin DIP package.

Feature Summary

• Provides direct pulse output compatible with electromechanical counters or stepper motors for energy registration.
• Integrates internal power supply monitoring circuitry that maintains reset state during voltage anomalies to prevent erroneous counting.
• Features built-in empty load threshold characteristics to eliminate phantom rotation or creeping under no-load conditions.

Applications

• Core metering chip for electronic energy meters
• Multi-rate single-phase electricity meter designs
• Embedded remote automatic meter reading systems

Procurement Notes

Verify the specific suffix 'AN' corresponds to the 24-pin PDIP package variant when sourcing. Confirm availability status as this component has reached end-of-life; substitute models may exhibit different operational behaviors regarding power loss data retention.

Selection Notes

Select this component only for legacy system maintenance or specific historical design requirements due to its discontinued status. Evaluate alternative models if new designs require mitigation of potential pulse loss during power interruptions, as this original part lacks non-volatile counter storage.

Part Context

The AD7755 series was widely recognized for meeting IEC1036 accuracy standards and served as a foundational component in early electronic metering infrastructure. Its successor, the ADE7755, addresses linearity issues at low currents but retains similar architectural limitations regarding power-down data preservation.

Replacement Considerations

Public confirmed substitute part number: ADE7755.