NXP Semiconductors MC33FS8420G0ESR2

Overview

MC33FS8420G0ESR2 from NXP Semiconductors is an ASIL B–capable automotive fail-safe system basis chip (SBC) integrating a VPRE synchronous buck controller, two low-voltage synchronous buck converters (BUCK1 and BUCK2), one boost converter, and two LDOs. It delivers up to 3.6 A peak per buck rail, supports 60 V DC input, and features SPI/I²C control with CRC, fail-safe output, and power-up sequencing for radar and ADAS domain controllers.

For engineers reviewing the MC33FS8420G0ESR2 datasheet, MC33FS8420G0ESR2 pinout, MC33FS8420G0ESR2 application, or MC33FS8420G0ESR2 equivalent, key selection criteria include its dual-buck architecture with multi-phase capability (up to 7.2 A peak on BUCK1+BUCK2), ASIL B safety certification per ISO 26262, AEC-Q100 Grade 1 qualification, and integrated voltage supervision with six monitoring inputs (VMON1–VMON4, VCOREMON, VDDIOMON).

Technical Context

The MC33FS8420G0ESR2 implements a hierarchical power management architecture: VPRE controls external high-side/low-side MOSFETs for primary 12 V/24 V conversion; BUCK1 supplies MCU core (configurable 1.025–1.8 V, 2.6–4.5 A); BUCK2 supplies auxiliary loads (1.2–1.8 V, up to 4.5 A); BOOST provides 5.0–5.74 V at ≤1.5 A peak; LDO1/LDO2 deliver 1.2–5.0 V at ≤400 mA each. All regulators support programmable soft-start and thermal shutdown with DFS (fail-safe state machine activation).

Safety logic includes dedicated watchdog (simple WD), FCCU interface for MCU error monitoring, PGOOD/RSTB/INTB outputs, and fail-safe output FS0B (open-drain, active-low). Power synchronization (PSYNC) enables coordinated operation with a second FS85 device or external PMIC, while FSYNC input/output supports system-level EMC optimization via frequency synchronization and spread spectrum.

Key Specifications

Pinout & Package

MC33FS8420G0ESR2 is housed in a HVQFN56 package: plastic thermal-enhanced very thin quad flat package with wettable flank, 56 terminals, 0.5 mm pitch, 8 mm × 8 mm × 0.85 mm body, and exposed pad (EP) connected to GNDFS/GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive SBC applications.

Compared with MC33FS8420G0ESR2, MC33FS8425G0ESR2 adds FCCU-based MCU error correlation without changing power architecture, while MC33FS8520A0ESR2 upgrades safety integrity to ASIL D with enhanced watchdog and fail-safe depth - both retain pin-to-pin compatibility but differ in OTP-configured safety features and monitoring scope.

Availability

MC33FS8420G0ESR2 is available at Aetrix Electronics and suitable for radar sensor modules, ADAS domain controllers, and automotive vision systems requiring stable component supply, long-term automotive lifecycle support, and AEC-Q100 qualified power management ICs.

Supply support for MC33FS8420G0ESR2 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

NXP Semiconductors is a global semiconductor company specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with leadership in automotive MCUs, radar transceivers, and functional safety power management.

The FS84 product line delivers ASIL B–certified system basis chips optimized for radar, vision, and domain controller power architectures - integrating multiple SMPS, LDOs, safety monitors, and fail-safe logic in a single HVQFN package.

FAQ

What is the safety qualification level of the MC33FS8420G0ESR2?

The MC33FS8420G0ESR2 is ASIL B–capable and developed in compliance with ISO 26262 for automotive functional safety. It is qualified per AEC-Q100 Grade 1 (−40 °C to +125 °C) and includes integrated fail-safe state machine, PGOOD/RSTB outputs, and voltage supervision with programmable OV/UV thresholds - all verified for ASIL B diagnostic coverage requirements.

Does the MC33FS8420G0ESR2 support multi-phase operation between BUCK1 and BUCK2?

Yes, the MC33FS8420G0ESR2 supports multi-phase operation between BUCK1 and BUCK2 to extend peak current capability to 7.2 A on a single rail. Phase shifting is configurable via OTP programming (e.g., delay 0 or delay 2), and both regulators share synchronized switching frequency (2.22 MHz) and soft-start ramp rates (7.81 mV/µs) to minimize input ripple and thermal imbalance.

What are the key differences between MC33FS8420G0ESR2 and MC33FS8425G0ESR2?

The MC33FS8425G0ESR2 adds FCCU (Fault Collection and Control Unit) functionality for advanced MCU error monitoring, supports up to four voltage monitoring inputs (VMON1–VMON4), and includes additional safety diagnostics versus MC33FS8420G0ESR2. Both share identical regulator topology, pinout, and ASIL B rating, but MC33FS8425G0ESR2 enables higher diagnostic coverage for complex safety partitions.

Can the MC33FS8420G0ESR2 be used in 24 V commercial vehicle applications?

Yes, the MC33FS8420G0ESR2 supports up to 60 V DC input and is qualified for automotive environments including 24 V commercial vehicles. External reverse-battery protection diodes are mandatory on VSUP1 and VSUP2 pins, and thermal design must accommodate ambient temperatures up to +125 °C per AEC-Q100 Grade 1 requirements.

How is the fail-safe output (FS0B) triggered on the MC33FS8420G0ESR2?

The FS0B output on MC33FS8420G0ESR2 is asserted active-low by the integrated fail-safe state machine upon detection of internal faults (e.g., thermal shutdown, overvoltage), external supervision violations (VCOREMON/VMONx), or MCU-reported errors via FCCU inputs. It remains latched until cleared by power cycle or SPI command, providing deterministic safe-state signaling to downstream systems.