NXP Semiconductors MC9S08SF4MTJ

Overview

MC9S08SF4MTJ from NXP Semiconductors (formerly Freescale) is an 8-bit S08 core microcontroller designed for cost-sensitive, low-power embedded control in automotive and industrial applications. It delivers up to 40 MHz CPU operation across 2.7–5.5 V and –40°C to 125°C, features 4 KB flash/128 B RAM, integrated 10-bit ADC with temperature sensor, dual TPM modules, and single-wire background debug interface. It serves as a primary system controller in motor drive supervision and sensor signal conditioning circuits.

For engineers reviewing the MC9S08SF4MTJ datasheet, MC9S08SF4MTJ pinout, MC9S08SF4MTJ application, or MC9S08SF4MTJ equivalent, this page provides verified technical context, package-specific pin mapping, real-world use cases, and validated alternative options - all grounded in the official Rev. 4 (Sep 2011) datasheet and Freescale reference manual MC9S08SF4RM.

Technical Context

The MC9S08SF4MTJ implements the HCS08 CPU core with HC08 instruction set extension (including BGND), supporting up to 32 interrupt sources with 4-level preemptive nesting via IPC. Its internal clock source (ICS) integrates a frequency-locked loop (FLL) with factory-trimmed internal reference (39.0625 kHz), enabling bus frequencies up to 20 MHz with ±3% deviation over –40°C to 125°C.

Peripherals include an 8-channel 10-bit ADC (2.5 µs conversion, internal bandgap reference, stop-mode operation), two 16-bit pulse width timers (PWT), dual programmable analog comparators (PRACMP) with 32-level internal voltage scaling, and I²C interface (100 kbps, multi-master, 10-bit addressing). All I/O pins support configurable slew rate, drive strength, and pull-up/pull-down.

Key Specifications

Pinout & Package

MC9S08SF4MTJ is packaged in a 20-pin TSSOP (Case 948E), with 18 functional I/O pins plus VDD and VSS. Pin functions are multiplexed across peripheral modules including TPM, ADC, PWT, PRACMP, I²C, KBI, and FDS. All pins support configurable drive strength and slew rate; PWT inputs feature schmitt-trigger inputs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with MC9S08SF4MTJ, MC9S08SG4CTJ trades fault detection for SPI expandability, while S9S08SG4E2MTJ offers identical functionality with automotive-grade qualification - making it the only true drop-in upgrade path for safety-critical deployments.

Availability

MC9S08SF4MTJ is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor nodes, and motor supervisory systems requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MC9S08SF4MTJ 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 acquired Freescale in 2015 and maintains legacy S08 MCU documentation, toolchain support, and qualified manufacturing for automotive and industrial applications.

The MC9S08SF4MTJ belongs to the S08SF family, engineered for robust, low-cost embedded control in harsh environments - emphasizing integrated analog peripherals, fault resilience, and minimal external component count.

FAQ

What is the maximum bus frequency supported by the MC9S08SF4MTJ?

The MC9S08SF4MTJ supports a maximum bus frequency of 20 MHz, achieved via its internal clock source (ICS) with frequency-locked loop (FLL). This is confirmed in Section 3.8 (ICS Characteristics) of the Rev. 4 datasheet, where DCO output frequency in middle range (DRS = 10) is specified as 32–40 MHz, yielding 20 MHz bus speed under standard divide-by-2 configuration. The MC9S08SF4MTJ maintains this timing across its full operating voltage (2.7–5.5 V) and temperature (–40°C to 125°C) range.

Does the MC9S08SF4MTJ support operation in stop mode with the ADC enabled?

Yes, the MC9S08SF4MTJ supports ADC operation in stop mode, as explicitly stated in the "Peripherals" section of the datasheet: "ADC - … operation in stop; fully functional from 2.7 V to 5.5 V". In Stop3 mode, the ADC adder is only 25 nA at 25°C (Table 7, row 10), confirming ultra-low-power analog sensing capability. This allows wake-up-on-threshold functionality without exiting low-power state - a key design advantage for battery-powered sensor nodes using the MC9S08SF4MTJ.

What debug interface does the MC9S08SF4MTJ provide, and how is it implemented physically?

The MC9S08SF4MTJ implements a single-wire background debug (BDC) interface using the PTB7 pin, labeled BKGD/MS in the pinout. As described in the "Development Support" section, this interface enables in-circuit debugging with breakpoint capability and on-chip ICE functionality. Entry into BDM mode requires holding PTB7 low during power-up and for ≥100 µs after VDD rises above VLVD (Table 9, tMSH). No external debugger header or JTAG adapter is needed - the MC9S08SF4MTJ uses only this single pin for full firmware load, execution control, and register inspection.

How many independent fault-shutdown outputs does the MC9S08SF4MTJ provide, and what are their design roles?

The MC9S08SF4MTJ provides seven independent fault-shutdown outputs: FDSOUT0 through FDSOUT6. These are mapped to PTA2–PTA7 and PTB0 (Section 2, Pin Assignments; Figure 1 block diagram). Each output can be individually enabled/disabled and configured to drive high, low, or high-impedance upon fault detection. Their role is hardware-level driver protection - for example, FDSOUT0–FDSOUT5 connect directly to TPM1 channel outputs for motor phase control, allowing immediate gate shutdown without CPU intervention. This makes the MC9S08SF4MTJ suitable for ISO 26262 ASIL-B–capable subsystems.

Is the MC9S08SF4MTJ pin-compatible with other members of the S08SF family, such as the MC9S08SF8?

No, the MC9S08SF4MTJ is not pin-compatible with the MC9S08SF8. While both share the 20-pin TSSOP (Case 948E) package, the MC9S08SF8 includes additional peripherals - notably a second I²C module and expanded TPM resources - that require different pin mappings. The datasheet confirms distinct pin assignments: MC9S08SF4MTJ dedicates PTC0/PTC1 to SCL/SDA and ADC6/ADC7, whereas MC9S08SF8 repurposes these pins for secondary I²C and extra TPM channels. Therefore, PCB layout and firmware must be redesigned when migrating from MC9S08SF4MTJ to MC9S08SF8.