NXP Semiconductors MC33298P

Overview

MC33298P from Freescale Semiconductor is an eight-channel low-side power switch IC with SPI serial interface, designed for automotive load control. It features 0.4 Ω R_DS(ON) @ 25°C, 3.0 A transient current capability per output, 5.5–26.5 V wide VPWR supply range, and integrated open-load/over-temperature/over-current fault reporting via SO pin. It is used to drive solenoids, relays, lamps, and small DC motors in vehicle body electronics.

For engineers reviewing the MC33298P datasheet, MC33298P pinout, MC33298P application, or MC33298P equivalent, key selection considerations include its 24-pin SOICW package, SPI-compatible 2.0 MHz (up to 8.5 MHz) operation, 65 V output clamp voltage, sleep current of 25 µA, and independent per-output fault detection without external components.

Technical Context

The MC33298P integrates an 8-bit serial-in shift register driving an 8-bit parallel latch, enabling microcontroller-controlled ON/OFF switching of eight independent low-side MOSFETs. Each output uses updrain DMOS transistors with internal 65 V clamping and self-limiting current (3.0–6.0 A) during overloads.

Fault management is fully autonomous: over-voltage shutdown at 28–36 V VPWR, over-temperature shutdown at 155–185 °C per channel, and open-load detection when outputs are OFF. Serial diagnostics report faults on the tri-state SO pin, synchronized to CS and SCLK, supporting daisy-chained configurations.

Key Specifications

Pinout & Package

MC33298P is housed in a 24-pin Small Outline Integrated Circuit Wide-body (SOICW) package with exposed thermal pad (Case 738), optimized for automotive PCB thermal performance and high-voltage isolation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-side power switch applications.

Compared with MC33298P, MC33879 offers higher integration density but reduced voltage robustness and different logic-level support, while TPS27081A provides simpler single-channel control without serial configurability or comprehensive fault reporting - making MC33298P uniquely suited for scalable, diagnostic-rich automotive body electronics.

Availability

MC33298P is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC I/O expansion, commercial vehicle lighting systems, and under-hood power distribution requiring stable component supply across extended temperature and voltage ranges.

Supply support for MC33298P 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

Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in automotive and industrial analog/mixed-signal ICs, known for high-reliability power management and system basis chips.

The MC33298P belongs to Freescale's SMARTMOS™ automotive power switch family, engineered specifically for intelligent, fault-aware load control in vehicle body electronics and distributed power systems.

FAQ

What is the maximum continuous current per output for MC33298P when all eight outputs are active?

The MC33298P supports 0.5 A continuous current per output when all eight outputs are simultaneously ON on a typical PCB layout. This rating assumes TA = 25°C and accounts for thermal derating due to shared junction-to-ambient thermal resistance (RθJA = 31 °C/W). At higher ambient temperatures or with fewer active outputs, higher per-output current is possible - consult Figure 22 in the datasheet for thermal modeling.

Does MC33298P require an external charge pump for gate drive?

No, MC33298P does not require an external charge pump. Its DMOS output transistors are logic-level compatible and fully enhanced with VDD ≤ 5.5 V, enabling direct gate drive from standard 5 V CMOS microcontrollers. This eliminates external boost circuitry and reduces board space and cost.

How does MC33298P report an open-load condition?

MC33298P reports an open-load condition only when an output is commanded OFF: it sources 30–100 µA through the load and monitors voltage at the OPx pin. If the voltage exceeds 0.6–0.8×VDD, the SO pin asserts a fault code during the next SPI read cycle. No open-load detection occurs when the output is ON.

Can MC33298P be used in 24 V commercial vehicle systems?

Yes, MC33298P is explicitly rated for VPWR up to 26.5 V steady-state and withstands transient peaks to 60 V, making it suitable for 24 V commercial vehicle applications. Its over-voltage shutdown activates at 28–36 V, providing protection during load-dump events common in heavy-duty truck electrical systems.

What is the function of the SFPD pin on MC33298P?

The SFPD (Short Fault Protect Disable) pin on MC33298P controls over-current response behavior: when grounded, an over-current event causes the affected output to latch OFF after 25–100 ms; when pulled to 5 V, the same event places the output in current-limit mode without shutdown - allowing continued operation during temporary overload conditions.