Analog Devices Inc. AD7658BSTZ-1-RL

Overview

AD7658BSTZ-1-RL from Analog Devices is a 12-bit, 6-channel simultaneous-sampling SAR ADC with true bipolar ±10 V/±5 V input ranges, 250 kSPS throughput, on-chip 2.5 V reference, and iCMOS process technology - deployed in power line monitoring systems requiring high channel density and synchronized acquisition across multiple phases.

For engineers reviewing the AD7658BSTZ-1-RL datasheet, AD7658BSTZ-1-RL pinout, AD7658BSTZ-1-RL application, or AD7658BSTZ-1-RL equivalent, key selection criteria include its 6 independent track-and-hold circuits, daisy-chain serial interface compatibility with SPI/QSPI/MICROWIRE, ±10 V analog input capability, and 64-lead LQFP package with AGND/DGND separation for noise-sensitive measurement designs.

Technical Context

The AD7658BSTZ-1-RL implements six independent 12-bit successive approximation register (SAR) ADCs sharing a common on-chip 2.5 V reference and reference buffers, each with dedicated REFCAP pins (REFCAPA–C) for local decoupling. Its iCMOS process enables ±16.5 V analog supply rails (VDD/VSS) while maintaining 5 V digital logic compatibility via separate AVCC, DVCC, and VDRIVE supplies.

Conversion control uses three independent CONVST inputs (A/B/C) to trigger simultaneous sampling of channel pairs (V1/V2, V3/V4, V5/V6), supporting hardware- or software-selectable input ranges (±4×VREF or ±2×VREF). It supports parallel, serial, and daisy-chain readout modes with twos-complement output coding and 3.1 µs conversion time.

Key Specifications

Pinout & Package

AD7658BSTZ-1-RL is housed in a 64-lead LQFP (10 mm × 10 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated per Analog Devices Rev. D datasheet Figure 3 and Table 7.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7656BSTZ-1-RL and AD7657BSTZ-1-RL, the AD7658BSTZ-1-RL trades resolution and SNR for lower BOM cost and relaxed layout constraints - making it optimal for high-volume power quality monitors where 12-bit accuracy meets IEC 62053-22 Class 0.5S requirements.

Availability

AD7658BSTZ-1-RL is available at Aetrix Electronics and suitable for power line monitoring, industrial motor control, multiaxis positioning systems, and test & measurement equipment requiring stable component supply across extended product lifecycles.

Supply support for AD7658BSTZ-1-RL 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, headquartered in Norwood, MA.

The AD7656-1/AD7657-1/AD7658-1 family was designed specifically for industrial data acquisition systems demanding simultaneous sampling, true bipolar inputs, and integrated reference stability - targeting power infrastructure, factory automation, and precision instrumentation markets.

FAQ

What is the maximum analog input voltage range supported by the AD7658BSTZ-1-RL?

The AD7658BSTZ-1-RL supports true bipolar analog input ranges of ±10 V (±4 × VREF) and ±5 V (±2 × VREF), selected either by the RANGE pin or via software configuration of the RNGx bits. Operation at ±10 V requires VDD = +10 V to +16.5 V and VSS = −10 V to −16.5 V per Table 8 in the Rev. D datasheet. The device's iCMOS process enables this wide range without external level-shifting circuitry.

Does the AD7658BSTZ-1-RL require an external reference voltage?

No, the AD7658BSTZ-1-RL includes an on-chip 2.5 V reference with ±1% initial accuracy, 6 ppm/°C temperature coefficient, and 150 ppm long-term stability. It can operate in internal reference mode (REFEN/DIS = 1) using REFCAPA/B/C decoupling capacitors, eliminating the need for external references in most applications. External reference mode is supported via the REFIN/REFOUT pin if higher precision or custom voltage is required.

How many channels does the AD7658BSTZ-1-RL sample simultaneously, and how is synchronization achieved?

The AD7658BSTZ-1-RL samples all six analog inputs (V1–V6) simultaneously in groups of two per conversion start signal: CONVST A triggers V1/V2, CONVST B triggers V3/V4, and CONVST C triggers V5/V6. Aperture delay matching is guaranteed at ≤4 ns across all channels, ensuring phase-coherent acquisition critical for power quality analysis and multiaxis control. Independent CONVST control allows flexible interleaved or fully synchronized sampling patterns.

What digital interface options does the AD7658BSTZ-1-RL support, and which is recommended for space-constrained designs?

The AD7658BSTZ-1-RL supports high-speed parallel (16-bit bus), serial (SPI/QSPI/MICROWIRE-compatible), and daisy-chain modes. For space-constrained designs, the serial interface with daisy-chain capability is recommended - it uses only 4–5 pins (CS, SCLK, DOUTx, DCINx, DCEN) to connect multiple AD7658BSTZ-1-RL devices, reducing PCB routing complexity and host processor pin count versus parallel mode.

What is the power consumption of the AD7658BSTZ-1-RL in active and standby modes?

In normal operational mode at 250 kSPS with AVCC = DVCC = VDRIVE = +5.25 V and VDD/VSS = ±16.5 V, the AD7658BSTZ-1-RL consumes 140 mW (26 mA total supply current). In full power-down mode (STBY = high), it draws just 315 µW - ideal for battery-backed data loggers or systems requiring periodic wake-up sampling. Partial power-down mode reduces consumption to 40 mW while retaining register settings.