The NXP MCZ33996EK is a 16-output low-side power switch designed for multiplexed load control in automotive body electronics, industrial PLC outputs, and general-purpose solenoid or lamp drivers. It integrates a 16-bit SPI interface to shift serial data into parallel output control, reducing microcontroller pin count to four wires (CS, SCK, SI, SO) for sixteen independent N-channel switches. Each output can sink up to 900 mA continuously with a typical on-resistance of 550 mΩ, and the load supply range spans 5 V to 27 V while the logic supply runs from 3.1 V to 5.5 V. The 1:16 input-to-output ratio means one serial command updates all sixteen outputs simultaneously, making it a fit for applications where a single SPI bus controls a bank of loads — think automotive door modules, seat adjusters, or industrial valve banks.
550 mΩ Rds(on) and 900 mA per channel — thermal budget for the exposed-pad package
The 550 mΩ typical Rds(on) at 900 mA per channel yields about 0.45 W dissipation per fully loaded output. For designs running fewer than sixteen outputs simultaneously, the per-channel current can be pushed closer to the 900 mA limit without exceeding the package thermal ceiling.
Fault protection — what is built in and what still needs external parts
The MCZ33996EK integrates current limiting (fixed), open-load detection, over-temperature shutdown, and over-voltage protection. Open-load detect works when the output is off — it pulls the output low through a current source and monitors the voltage — useful for diagnosing broken lamp filaments or disconnected solenoids. Over-temperature and over-voltage are self-resetting; the device latches off until the fault clears and the SPI command re-enables the output. No external current-sense resistor or comparator is needed for these diagnostics, which saves board space and BOM cost. The fixed current limit is not programmable, so if the load inrush exceeds the limit threshold, the output will current-limit rather than latch off — something to consider for capacitive loads like incandescent lamps or large electrolytic capacitors.