Analog Devices Inc. AD7478AWARMZ-RL

Overview

AD7478AWARMZ-RL from Analog Devices is an 8-bit, 1.2 MSPS successive-approximation ADC in a 6-lead SC70 package, operating from 2.35 V to 5.25 V supply. It delivers 49 dB SINAD at 100 kHz input, 7 ns minimum SCLK-to-data hold time (VDD > 3.6 V), and 1 μA max standby current-enabling high-speed data acquisition in space-constrained battery-powered instrumentation.

For engineers reviewing the AD7478AWARMZ-RL datasheet, AD7478AWARMZ-RL pinout, AD7478AWARMZ-RL application, or AD7478AWARMZ-RL equivalent, key selection factors include its 12-cycle serial interface timing, internal VDD-referenced full-scale range (0 V to VDD), guaranteed no-missed-codes performance, and automotive-qualified SC70 thermal profile (θJA = 340.2°C/W).

Technical Context

The AD7478AWARMZ-RL implements a standard SAR architecture with track-and-hold acquisition synchronized to the falling edge of CS. Conversion is initiated on CS fall and completed in exactly 12 SCLK cycles, with no pipeline delay and deterministic timing control via external clock.

Its reference is derived directly from VDD, eliminating external reference components and fixing the analog input range to 0 V to VDD. Digital interface complies with SPI/QSPI/MICROWIRE/DSP protocols, supporting MSB-first serial output with four leading zeros followed by eight data bits and four trailing zeros.

Key Specifications

Pinout & Package

AD7478AWARMZ-RL is housed in a 6-lead SC70 package (2.2 mm × 1.35 mm × 0.95 mm height), optimized for ultra-compact PCB layouts and low thermal resistance (θJC = 228.9°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7478ARTZ-REEL7, AD7478AWARMZ-RL offers superior thermal performance in constrained spaces and automotive qualification; versus ADS7822U, it eliminates reference design complexity and doubles throughput-but requires strict adherence to SC70 layout guidelines for noise control.

Availability

AD7478AWARMZ-RL is available at Aetrix Electronics and suitable for portable medical devices, industrial motor controllers, optical sensor modules, and automotive cabin monitoring systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7478AWARMZ-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 AD7476A/AD7477A/AD7478A family was designed to deliver high-speed, low-power SAR ADC functionality in the smallest possible packages-targeting battery-operated, space-constrained instrumentation and sensor interface applications.

FAQ

What is the maximum sampling rate supported by the AD7478AWARMZ-RL?

The AD7478AWARMZ-RL supports a maximum throughput rate of 1.2 MSPS, achieved when using a 20 MHz SCLK and operating within its specified supply (2.35 V to 5.25 V) and temperature (−40°C to +85°C) ranges. This rate corresponds to a minimum conversion time of 600 ns, defined by exactly 12 SCLK cycles. At lower clock frequencies, throughput scales linearly-for example, 10 MHz SCLK yields 1 MSPS.

Does the AD7478AWARMZ-RL require an external voltage reference?

No, the AD7478AWARMZ-RL uses an internal reference derived from the VDD supply, establishing a full-scale input range of 0 V to VDD. This eliminates the need for external reference components, reduces BOM count, and ensures automatic tracking of supply variations-though it also means input dynamic range scales directly with VDD stability and noise.

How does the serial interface of the AD7478AWARMZ-RL format its output data?

The AD7478AWARMZ-RL outputs data in MSB-first order on the SDATA pin as a 16-bit frame: four leading zeros, followed by eight data bits, followed by four trailing zeros. This fixed-length format simplifies firmware parsing and ensures consistent timing across conversions, regardless of input value. Data is latched on the falling edge of SCLK, with valid hold time as low as 7 ns (VDD > 3.6 V).

Is the AD7478AWARMZ-RL suitable for automotive applications?

Yes-the AD7478AWARMZ-RL is qualified for automotive applications per AEC-Q200, rated for operation from −40°C to +85°C (A grade), and packaged in a robust 6-lead SC70 with verified thermal performance (θJA = 340.2°C/W). Its 1 µA max standby current and VDD-referenced architecture further support energy-efficient, reliable operation in vehicle cabin and body-control modules.

What is the guaranteed DC accuracy of the AD7478AWARMZ-RL?

The AD7478AWARMZ-RL guarantees ±0.3 LSB integral nonlinearity (INL), ±0.3 LSB differential nonlinearity (DNL), ±0.3 LSB offset error, and ±0.3 LSB gain error over temperature. These specifications ensure monotonicity (no missed codes) and predictable transfer function behavior-critical for closed-loop control and calibrated sensor interfaces where linearity directly impacts system accuracy.