Analog Devices Inc. AD7655ACP

Overview

AD7655ACP from Analog Devices is a low-cost, 4-channel, 16-bit, simultaneous-sampling SAR analog-to-digital converter with dual track-and-hold amplifiers, 500 kSPS throughput in normal mode, 0 V to 5 V unipolar input range, and parallel/serial 3 V/5 V interface. It serves as the core data acquisition front-end in multichannel industrial motor control and power monitoring systems.

For engineers reviewing the AD7655ACP datasheet, AD7655ACP pinout, AD7655ACP application, or AD7655ACP equivalent, key selection criteria include simultaneous dual-channel sampling capability, impulse-mode power scaling (2.6 mW at 10 kSPS), no pipeline delay, SPI/QSPI/MICROWIRE compatibility, and LQFP/LFCSP package options for layout flexibility in space-constrained embedded designs.

Technical Context

The AD7655ACP implements a charge redistribution SAR architecture with internal error correction and an integrated conversion clock. Its two independent track-and-hold circuits support true simultaneous sampling across four analog inputs via A0-controlled multiplexing of INA1/INB1 or INA2/INB2 pairs.

It operates in two distinct modes: normal mode delivers 500 kSPS with 120 mW typical power dissipation, while impulse mode reduces throughput to 444 kSPS and scales power linearly down to 2.6 mW at 10 kSPS-enabling dynamic power management without sacrificing timing determinism or introducing pipeline latency.

Key Specifications

Pinout & Package

AD7655ACP is available in a 48-lead LQFP package (7 mm × 7 mm, 0.5 mm pitch) with exposed thermal pad connected to AGND. Pin functions are validated per Analog Devices Rev. E datasheet Figure 4 and Table 6.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel, simultaneous-sampling ADC applications.

Compared with AD7654ACPZ, AD7655ACP adds 4-channel capability via integrated multiplexing and dual T/H without increasing footprint; versus AD7606BSTZ, it trades channel count for higher throughput, lower latency, and dual-interface support-making it optimal for real-time control where timing determinism and interface adaptability outweigh raw channel count.

Availability

AD7655ACP is available at Aetrix Electronics and suitable for AC motor control, 3-phase power monitoring, and 4-channel industrial data acquisition requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for AD7655ACP includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7655ACP belongs to the PulSAR® family of precision SAR ADCs designed specifically for industrial automation, energy metering, and motor control applications demanding simultaneous sampling, low latency, and robust operation from −40°C to +85°C.

FAQ

What is the maximum sampling rate of the AD7655ACP in normal mode?

The AD7655ACP achieves a maximum throughput rate of 500 kSPS in normal mode, corresponding to a complete dual-channel conversion cycle time of 2 µs. This specification is guaranteed over the full operating temperature range (−40°C to +85°C) with AVDD = DVDD = 5 V and VREF = 2.5 V, as confirmed in the Rev. E datasheet Table 2. The AD7655ACP maintains this rate without pipeline delay or latency penalties.

Does the AD7655ACP support both parallel and serial digital interfaces?

Yes, the AD7655ACP supports both parallel and serial interfaces via the SER/PAR pin. When SER/PAR = LOW, it operates in 16-bit parallel mode with D[0:15] outputs. When SER/PAR = HIGH, the same pins function as a serial port compatible with SPI, QSPI, MICROWIRE, and DSP protocols. This dual-mode capability is explicitly documented in the General Description and Product Highlights sections of the AD7655ACP datasheet Rev. E.

What is the purpose of the A0 pin on the AD7655ACP?

The A0 pin on the AD7655ACP selects which pair of analog inputs is simultaneously sampled: A0 = LOW activates INA1/INB1, while A0 = HIGH activates INA2/INB2. This hardware-controlled multiplexing enables flexible 4-channel acquisition without external analog switches or additional timing logic. The function is defined in the Functional Block Diagram, General Description, and Pin Function Descriptions (Table 6) of the AD7655ACP Rev. E datasheet.

Can the AD7655ACP operate from a single 5 V supply?

Yes, the AD7655ACP operates from a single 5 V supply applied to AVDD and DVDD, with OVDD supporting 2.7 V to 5.25 V logic levels. This single-supply operation simplifies power design in industrial systems and eliminates need for dual-rail regulators. The Rev. E datasheet specifies AVDD and DVDD min/max at 4.75 V to 5.25 V, and confirms single-supply functionality in the General Description and Power Supplies sections.

How does impulse mode affect power consumption in the AD7655ACP?

In impulse mode (IMPULSE = HIGH), the AD7655ACP scales power dissipation proportionally with throughput: 120 mW at 500 kSPS, 114 mW at 444 kSPS, and only 2.6 mW at 10 kSPS. This dynamic scaling is achieved by reducing internal clock frequency and bias currents during idle periods, as verified in the Power Dissipation row of Table 2 and the Impulse Mode description in the General Description section of the AD7655ACP Rev. E datasheet.