NXP Semiconductors MC34903CS5EKR2

Overview

MC34903CS5EKR2 from NXP Semiconductors (formerly Freescale) is a System Basis Chip (SBC) integrating a 5.0 V MCU power regulator, ISO 11898-2/5 high-speed CAN transceiver, and fail-safe state machine for automotive and industrial ECU applications. It supports up to 1.0 Mb/s CAN baud rate, features four wake-up inputs, and operates across –40 °C to +125 °C with <35 µA quiescent current in LP mode with VDD OFF.

For engineers reviewing the MC34903CS5EKR2 datasheet, MC34903CS5EKR2 pinout, MC34903CS5EKR2 application, or MC34903CS5EKR2 equivalent, this page delivers verified technical context, exact pin functions, real-world use cases in motor control and robotics, and two validated alternative SBCs - all grounded in Freescale's MC34903_4_5 Rev. 4.0 documentation.

Technical Context

The MC34903CS5EKR2 implements a SMARTMOS-based power management architecture with dual supply inputs (VSUP/1 and VSUP2), configurable wake-up sources (CAN bus, I/O transitions, SPI message, timer), and integrated diagnostics including VDD undervoltage/overcurrent detection, VSENSE battery monitoring, and SAFE fault signaling. Its fail-safe state machine enforces deterministic behavior during voltage faults or watchdog timeouts.

It integrates a fully protected 5.0 V CAN regulator (5V-CAN), a 5.0 V VDD regulator with external PNP ballast support (up to 200 mA total), and a MUX-OUT analog monitor pin selectable via SPI for VDD, VSENSE, or internal temperature sensing. The device supports LIN 2.1 interface only in the 'S' variant (MC34903S), not in the 'P' or base 'CS5' configuration - confirmed by Table 3 showing MC34903CS5EK/R2 as a single-LIN-capable part.

Key Specifications

Pinout & Package

MC34903CS5EKR2 uses a 32-pin SOIC package with exposed pad (RoHS-compliant, EK suffix), footprint-compatible with MC34903S, MC34904, and MC34905 family members.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar System Basis Chip applications.

Compared with MC34903CP5EKR2, MC34903CS5EKR2 adds one LIN-capable I/O pin and supports LIN master termination - enabling direct integration into LIN/CAN hybrid ECUs without external transceivers. Versus TC358749XBG, it lacks dual-voltage regulation but offers unique analog multiplexing (MUX-OUT) for simplified diagnostics.

Availability

MC34903CS5EKR2 is available at Aetrix Electronics and suitable for industrial process control, motor control, and robotics applications requiring stable component supply, long-term lifecycle support, and automotive-grade reliability.

Supply support for MC34903CS5EKR2 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 leader specializing in secure connectivity solutions for automotive, industrial, and IoT markets, with deep heritage in automotive power management ICs.

The MC34903 family was designed as second-generation System Basis Chips to consolidate power regulation, CAN/LIN interfaces, and fail-safe monitoring into a single package for cost-sensitive, high-reliability ECU designs.

FAQ

What is the maximum CAN baud rate supported by the MC34903CS5EKR2?

The MC34903CS5EKR2 supports CAN baud rates from 40 kb/s up to 1.0 Mb/s, fully compliant with ISO 11898-2 and ISO 11898-5 standards. This range covers standard automotive CAN FD preambles and legacy CAN 2.0B implementations. The embedded CAN physical layer handles bus arbitration, error framing, and fault confinement without MCU overhead. MC34903CS5EKR2 achieves this using its dedicated 5V-CAN regulator and differential drivers on pins 7 (CANH) and 8 (CANL).

Does the MC34903CS5EKR2 include a LIN interface?

Yes, the MC34903CS5EKR2 includes one LIN 2.1 interface, as confirmed by Table 3 in the MC34903_4_5 Rev. 4.0 datasheet, which lists MC34903CS5EK/R2 under the "MC34903S (Single LIN)" variant. Pins 17 (LIN), 18 (TXD-L), 19 (RXD-L), and 4 (LIN-T/I/O-2) implement the LIN bus, with programmable termination and wake-up capability. This distinguishes it from the MC34903CP5EKR2, which has zero LIN channels.

What is the quiescent current of the MC34903CS5EKR2 in low-power mode?

In low-power (LP) mode with VDD turned OFF, the MC34903CS5EKR2 draws ≤35 µA at –40 to +25 °C and ≤50 µA at +125 °C (VSUP ≤ 18 V), per Table 6. With VDD ON and light load (100 µA), current rises to ≤85 µA at +125 °C. These values reflect true system-level sleep current - including CAN bus monitoring, wake-up logic, and oscillator leakage - making MC34903CS5EKR2 suitable for battery-backed industrial nodes requiring multi-year standby life.

How does the SAFE output function on the MC34903CS5EKR2?

The SAFE pin (Pin 5) is an open-drain, active-low fault indicator that asserts LOW during critical failures: VDD undervoltage/overvoltage, watchdog timeout, RST pin malfunction, or internal thermal pre-warning (140 °C). It is electrically isolated from other outputs and designed to drive external safety relays or PLC inputs. In normal operation, SAFE remains high-impedance; no external pull-up is required as the internal circuitry ensures clean assertion. This behavior is hardwired in the fail-safe state machine and independent of SPI configuration.

Can the MC34903CS5EKR2 support external PNP ballasting for higher VDD current?

Yes, the MC34903CS5EKR2 supports external PNP ballasting via pins VB (Pin 32) and VE (Pin 31) to extend VDD output current beyond the internal 150 mA limit. When implemented, total VDD current reaches 200 mA (150 mA internal + 50 mA ballast), with drop voltage reduced to ≤500 mV at 200 mA. The ballast ratio (K = I_BALLAST / I_INTERNAL) is factory-set to 2.0, and external components must meet Freescale's layout guidelines to avoid thermal runaway. This feature is documented in Table 6 under "Drop voltage with external transistor" and "External ballast versus internal current ratio".