Analog Devices Inc. AD7770ACPZ

Overview

AD7770ACPZ from Analog Devices is an 8-channel, 24-bit simultaneous sampling sigma-delta ADC with per-channel programmable gain (1/2/4/8), internal 2.5 V reference, and dual operating modes (high-resolution: 103 dB DR at 32 kSPS; low-power: 4.75 mW/channel). It supports true differential or single-ended inputs and integrates a diagnostic 12-bit SAR ADC for functional safety validation in protection relays.

For engineers reviewing the AD7770ACPZ datasheet, AD7770ACPZ pinout, AD7770ACPZ application, or AD7770ACPZ equivalent, key selection criteria include simultaneous 24-bit sampling across eight channels, ±4 nA differential input bias current enabling direct sensor interfacing, sinc3 filter latency, and SPI-controlled sample rate converter for coherent line-frequency sampling.

Technical Context

The AD7770ACPZ implements eight independent sigma-delta modulators with sinc3 digital filters and a programmable sample rate converter (SRC) enabling ODR resolution down to 15.2 µSPS. Each channel includes a capacitive PGA with four fixed gain settings and configurable input topology (true differential, pseudo-differential, or single-ended).

Dual power modes are implemented via internal LDO control and clock gating: high-resolution mode uses 8.192 MHz MCLK and delivers 103 dB dynamic range at 32 kSPS; low-power mode uses 4.096 MHz MCLK and reduces per-channel dissipation to 4.75 mW while maintaining 103 dB DR at 8 kSPS.

Key Specifications

Pinout & Package

The AD7770ACPZ is housed in a 64-lead LFCSP (9 mm × 9 mm, 0.8 mm pitch) with exposed thermal pad. Pin functions include eight differential analog input pairs (AIN0± to AIN7±), dedicated SYNC_IN/SYNC_OUT for multi-device synchronization, three GPIOs for SRC update control, and separate analog/digital supply domains (AVDD1x/AVSSx, AVDD2x/AVSSx, IOVDD, DGND).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel high-precision ADC applications.

Compared with AD7779ACPZ, the AD7770ACPZ adds integrated diagnostics and programmable SRC for safety-critical and grid-tied applications; compared with LTC2378-20IUK#PBF, it provides true simultaneous sampling and per-channel gain control essential for phase-accurate power quality analysis.

Availability

AD7770ACPZ is available at Aetrix Electronics and suitable for protection relays, industrial process control systems, and general-purpose data acquisition requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7770ACPZ 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7770ACPZ belongs to Analog Devices' precision Σ-Δ ADC product line, designed specifically for high-fidelity, multi-channel data acquisition in electric utility infrastructure and factory automation where synchronization, low noise, and functional safety are mandatory.

FAQ

What is the maximum simultaneous sampling rate supported by the AD7770ACPZ?

The AD7770ACPZ supports up to 32 kSPS per channel in high-resolution mode with all eight channels active. This rate is achieved using an 8.192 MHz master clock and sinc3 filtering. At this ODR, the device delivers 103 dB dynamic range and maintains ±9 ppm INL. The AD7770ACPZ also supports lower rates (e.g., 8 kSPS in low-power mode) via its programmable sample rate converter, which allows fine-grained adjustment down to 15.2 µSPS for grid-coherent applications.

Does the AD7770ACPZ require an external reference voltage?

No, the AD7770ACPZ includes an internal 2.5 V reference with ±0.2% initial accuracy and ±10 ppm/°C typical temperature coefficient. REFOUT provides a buffered output usable by external circuitry. An external reference (1 V to 3.6 V) may be used via REFx± pins if higher initial accuracy or custom voltage is needed, but the internal reference eliminates BOM cost and layout complexity in most industrial DAQ designs.

How does the AD7770ACPZ support functional safety compliance in protection relay designs?

The AD7770ACPZ supports functional safety through its integrated 12-bit SAR ADC, which operates independently of the main Σ-Δ channels. This SAR ADC can validate Σ-Δ measurements using internal node sensing or external multiplexed signals, enabling periodic self-diagnostics without interrupting real-time acquisition. Combined with adjustable phase synchronization and deterministic latency, the AD7770ACPZ helps meet IEC 61508 SIL-2 requirements for hardware fault tolerance in protection relays.

What are the power supply requirements for the AD7770ACPZ analog section?

The AD7770ACPZ analog section requires two supply domains: AVDD1x/AVSSx (±1.65 V bipolar or 3.3 V unipolar) for the PGA and Σ-Δ modulators, and AVDD2x/AVSSx (2.2 V to 3.6 V) for digital filtering and interface logic. AVDD4/AVSSx (AVDD1x − 0.3 V to AVDD1x) powers the SAR ADC. All analog supplies must be well-decoupled; the datasheet specifies 10 µF + 100 nF per domain. Total analog supply current ranges from 3.9 mA (low-power mode, buffers disabled) to 26.7 mA (high-resolution mode, buffers enabled).

Can the AD7770ACPZ operate over the full industrial temperature range?

Yes, the AD7770ACPZ is specified for performance from −40°C to +105°C and remains functional up to +125°C. Key specifications-including dynamic range, INL, and reference stability-are guaranteed across the −40°C to +105°C range. At temperatures above +105°C, slight parameter degradation may occur, but typical performance plots in the datasheet confirm stable operation through +125°C, making the AD7770ACPZ suitable for harsh environments such as transformer monitoring and motor drive cabinets.