Analog Devices Inc. AD7278ARMZ-RL

Overview

AD7278ARMZ-RL from Analog Devices is an 8-bit, 4 MSPS successive approximation analog-to-digital converter (ADC) in a 6-lead TSOT package, operating from a single 2.35 V to 3.6 V supply. It delivers 74 MHz full-power bandwidth, −67 dB THD at 1 MHz input, and 49 dB SINAD, enabling high-fidelity sampling in space-constrained industrial sensor interfaces and motor control feedback loops.

For engineers reviewing the AD7278ARMZ-RL datasheet, AD7278ARMZ-RL pinout, AD7278ARMZ-RL application, or AD7278ARMZ-RL equivalent, this page provides verified technical context, real-world timing behavior, validated package mapping, confirmed serial interface compatibility (SPI/QSPI/MICROWIRE/DSP), and precise power-down current (0.1 μA typical) for low-duty-cycle embedded data acquisition systems.

Technical Context

The AD7278ARMZ-RL implements a standard SAR architecture with no pipeline delay, using CS falling edge to initiate sampling and SCLK as both conversion clock and serial interface clock. Its internal VDD-referenced ADC enables 0 V to VDD analog input range without external reference components.

Conversion requires exactly 10 SCLK cycles (at up to 48 MHz), yielding a maximum throughput of 4 MSPS. The track-and-hold amplifier achieves 60 ns acquisition time and supports input frequencies up to 74 MHz (−3 dB), with aperture jitter specified at 18 ps typical.

Key Specifications

Pinout & Package

AD7278ARMZ-RL is housed in a 6-lead TSOT package (2.9 mm × 1.6 mm × 0.8 mm), optimized for high-density PCB layouts and thermal performance (θ_JA = 230°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit high-speed ADC applications.

Compared with AD7278ARMZ-RL, the AD7278BRMZ-RL adds guaranteed high-temp performance without layout or firmware changes, while AD7478ARTZ-REEL7 trades integration for reference flexibility-making AD7278ARMZ-RL optimal for compact, self-contained, single-supply sensing nodes.

Availability

AD7278ARMZ-RL is available at Aetrix Electronics and suitable for industrial motor control, portable sensor nodes, and switch-mode power supply feedback requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for AD7278ARMZ-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7276/AD7277/AD7278 family was designed for space-constrained, low-power, high-throughput data acquisition in industrial automation, motor control, and portable instrumentation-emphasizing integration, temperature robustness, and serial interface flexibility.

FAQ

What is the maximum sampling rate supported by the AD7278ARMZ-RL?

The AD7278ARMZ-RL achieves a maximum throughput rate of 4 MSPS when operated with a 48 MHz SCLK. This is enabled by its fixed 10 SCLK-cycle conversion time, as confirmed in Table 4 of the Rev. E datasheet. At lower SCLK frequencies, the throughput scales linearly-for example, 24 MHz yields 2 MSPS. The part guarantees no pipeline delay, ensuring deterministic timing critical for real-time control loops.

Does the AD7278ARMZ-RL require an external voltage reference?

No, the AD7278ARMZ-RL uses an internal reference derived from VDD, supporting an analog input range of 0 V to VDD. This eliminates the need for external reference components, simplifying design and reducing bill-of-materials cost. The internal reference architecture is explicitly stated in the General Description section and validated across the full 2.35 V to 3.6 V supply range.

What serial interface protocols is the AD7278ARMZ-RL compatible with?

The AD7278ARMZ-RL supports SPI, QSPI, MICROWIRE, and DSP-compatible serial interfaces. Its SDATA output is MSB-first, framed by CS, and synchronized to the falling edge of SCLK. The datasheet confirms compatibility across all four protocols in the FEATURES section and timing diagrams (Figures 5–7), with no mode pins or configuration registers required.

How does the power consumption of the AD7278ARMZ-RL compare between active and power-down modes?

In normal operational mode at 3 V and 3 MSPS, the AD7278ARMZ-RL draws 3.5 mA typical (10.5 mW). In full power-down mode, it consumes just 0.1 μA typical-reducing power to 360 nW at 3.6 V. This 35,000× reduction is validated in Table 4 (Power Requirements section) and enables ultra-low-duty-cycle operation in energy-harvesting or battery-powered systems.

Is the AD7278ARMZ-RL pin-compatible with other members of the AD7276/AD7277/AD7278 family?

Yes-the AD7278ARMZ-RL shares identical 6-lead TSOT pinout with AD7276ARMZ-RL and AD7277ARMZ-RL, as shown in Figure 8 and Table 7 of the datasheet. All three variants use VDD, GND, VIN, SCLK, SDATA, and CS in the same physical locations, allowing hardware reuse across resolution grades without PCB redesign.