SPI bus isolator with seven unidirectional channels
The Analog Devices ADUM3153ARSZ-RL7 is a dedicated SPI digital isolator from the iCoupler® SPIsolator™ family, using magnetic coupling to provide 3750 Vrms galvanic isolation for serial peripheral interface (SPI) buses. It offers seven unidirectional channels arranged as three on side 1 and four on side 2, which maps directly to the clock, data, and chip-select signals of a standard SPI link plus an extra signal line for interrupts or handshaking. The part is rated for a 2 Mbps data rate, sufficient for the majority of SPI peripherals such as ADCs, DACs, and digital temperature sensors.
2 Mbps data rate — what it covers
The 2 Mbps data rate handles typical SPI clock frequencies up to 2 MHz, which covers most industrial sensors, data converters, and configuration interfaces. If your application requires faster throughput — for example, streaming from a high-speed ADC or driving a display — you would need a higher-rate isolator such as the ADuM3154 series (up to 40 Mbps). For the common case of reading a 16-bit ADC at 100 kSPS, 2 Mbps leaves plenty of margin.
There is no announced end-of-life or last-time-buy schedule. This part is ROHS3 compliant and available in Tape & Reel (RL7 suffix) or Cut Tape options.
Package and footprint — 20-SSOP
Housed in a 20-SSOP package (0.209" body width, 5.30 mm), the part uses a standard surface-mount footprint shared with many other ADI SPI isolators. Mounting is surface mount only.
Temperature range and transient immunity
The minimum common-mode transient immunity of 25 kV/µs ensures data integrity in noisy environments with fast-switching power stages. Propagation delay is 25 ns max (both directions), and pulse-width distortion is held to 3 ns max, which keeps the SPI clock edge timing tight.