MC9RS08KA2CPC174 - 8-bit RS08 MCU 2KB Flash 20MHz | NXP
MPN: MC9RS08KA2CPC174 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.76 | $17.60 |
| 100 | $1.56 | $156.00 |
| 500 | $1.4 | $700.00 |
| 1,000 | $1.25 | $1,250.00 |
MC9RS08KA2CPC174 Overview
An 8-bit microcontroller (MCU) is a single-chip computer whose data bus is 8 bits wide, integrating a processor core, program memory (FLASH), RAM, I/O ports, and system protection into one package. Within the MCU hierarchy, the RS08 family sits below the S08 and HC08 families as a simplified, cost-optimized core retaining S08-derived instruction efficiency.
Key features of the MC9RS08KA2 include the RS08 central processor unit with a simplified S08 instruction set augmented by high-performance LDA, STA, and CLR instructions, 2KB on-chip FLASH program memory, and 20MHz internal bus operation. System protection features and ultra-low-end cost positioning make it a direct drop for discrete logic and simple state-machine designs.
Technically, the RS08 core streamlines the classic HC08/S08 architecture, reducing gate count and die size while preserving code compatibility concepts familiar to HC08 developers. The internal oscillator removes the need for external crystals in many designs, lowering bill-of-materials cost and board area.
Typical applications include small appliance control, simple sensor interfacing, LED and indicator sequencing, low-cost battery chargers, and replacement of glue logic in industrial boards. The through-hole 8-PDIP package suits prototypes, legacy repair, and hand-soldered production.
Design consideration: verify the availability status of this Rochester Electronics-distributed suffix, as the original Freescale device is a legacy part; plan second sourcing accordingly.
This page synthesizes distributor pricing context, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, providing engineering value beyond a standard product listing.
Drop-in alternatives for MC9RS08KA2CPC174 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC9RS08KA2CPC174 (same form factor and footprint) — differing in Package, Mounting Type, Program Memory Size, Core Processor, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC9RS08KA1CSC
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View Datasheet →MC908QT2ACPE
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View Datasheet →MC9RS08KA2CPC174 Maximum Ratings & Electrical Characteristics
| Core Processor | RS08 |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 20 MHz |
| Program Memory Type | FLASH |
| Program Memory Size | 2KB (2K x 8) |
| Data Bus Width | 8 bit |
| Product Series | RS08KA |
| Package | 8-PDIP |
| Mounting Type | Through Hole |
| Packaging | Bulk |
| Product Category | Microcontrollers (MCU) |
MC9RS08KA2CPC174 Pin Configuration
| Pin 1 | VDD — Power supply positive |
| Pin 2 | VSS — Ground |
| Pin 3 | PTA0 — General-purpose I/O port A bit 0 |
| Pin 4 | PTA1 — General-purpose I/O port A bit 1 |
| Pin 5 | PTA2 — General-purpose I/O port A bit 2 |
| Pin 6 | PTA3 — General-purpose I/O port A bit 3 |
| Pin 7 | RESET — External reset input (bidirectional) |
| Pin 8 | BKGD/MS — Background debug / mode select |
Typical Applications
MC9RS08KA2CPC174 is suitable for 6 applications: Small Appliance Control, Discrete Logic Replacement, LED Indicator and Sequencing, Low-Cost Battery Chargers, Sensor Interfacing and Threshold Monitoring, Legacy Industrial Board Repair.
Small Appliance Control
The MC9RS08KA2CPC174 fits small appliance control boards such as coffee makers, fans, and simple kitchen devices where only a few buttons, LEDs, and one relay or triac drive are needed. Its 20MHz RS08 core easily handles button debouncing, LED sequencing, and timing loops, while the 2KB FLASH is sufficient for compact state-machine firmware typical of appliances. The 8-pin PDIP through-hole package simplifies hand assembly and repair, and internal clocking removes crystal cost. Designers should budget code space carefully and use the family's simplified instruction set to keep the compiled image within the 2KB limit while retaining responsive user-interface timing.
Recommended
Discrete Logic Replacement
The MC9RS08KA2CPC174 replaces multi-chip glue logic and timer circuits such as 555 timers, counters, and shift-register chains. A single 8-pin RS08KA2 consolidates timing, sequencing, and simple I/O expansion into one programmable device, reducing board area and component count while allowing firmware-based product revisions without PCB respins. The 20MHz internal clock provides microsecond-level timing resolution, far exceeding classic NE555 accuracy, and the FLASH program memory supports field rework during production. Because the device is through-hole PDIP, it can even be socketed in legacy industrial boards, enabling logic upgrades during maintenance without soldering rework on aging PCBs.
Recommended
LED Indicator and Sequencing
The MC9RS08KA2CPC174 drives multi-LED status indicators, chasers, and brightness sequencing in panels, chargers, and consumer products. Its port pins sink and source enough current for direct LED drive with series resistors, and the 20MHz core supports software PWM at flicker-free frequencies. The 2KB FLASH holds lookup tables for breathing effects and multi-pattern sequences with room to spare. The 8-pin PDIP suits both prototype breadboards and low-cost production panels. Engineers should verify per-port current limits in the NXP datasheet and, where multiple LEDs run concurrently, use multiplexing or external drivers to stay within package thermal and current ratings.
Recommended
Low-Cost Battery Chargers
The MC9RS08KA2CPC174 implements charge-state sequencing, termination detection, and LED status reporting in linear battery chargers for NiMH and simple Li-ion packs. The 20MHz core handles voltage-sampling loops and timer-based termination (such as -dV/dt and dT/dt detection) with simple external op-amp or comparator front ends. Software PWM can drive a pass transistor for crude current regulation in cost-sensitive designs. The 2KB FLASH accommodates multiple chemistry profiles selectable by a pin strap. Because chargers involve safety limits, designers must implement watchdog-based firmware fault handling and independent hardware overcharge protection, never relying on the MCU alone for safety compliance.
Recommended
Sensor Interfacing and Threshold Monitoring
The MC9RS08KA2CPC174 monitors simple analog or digital sensors - thermostats, float switches, photointerrupters - and drives outputs or communicates status. Its internal functions sample sensor inputs on a timed basis and apply threshold logic in firmware, replacing comparator-plus-timer discrete chains. The 20MHz core supports software averaging and basic digital filtering within the 2KB code budget, and the 8-pin PDIP allows placement near the sensor on small daughterboards. For legacy industrial equipment maintenance, socketed through-hole mounting eases field replacement. Designers should verify ADC availability in the NXP datasheet for the KA2 variant and use external comparators where precision thresholds are required.
Recommended
Legacy Industrial Board Repair
The MC9RS08KA2CPC174, supplied through Rochester Electronics' authorized legacy program, is a primary source for maintaining industrial equipment that originally used Freescale RS08KA2 devices. Rochester continues manufacturing the discontinued Freescale silicon under authorization, ensuring form-fit-function continuity for repair depots and MRO operations. The through-hole 8-PDIP package allows socketed replacement on 1990s-2000s era control boards without PCB modification. Maintenance teams should qualify a lifetime-buy quantity based on fleet analysis, store devices in moisture-barrier packaging per handling practice, and verify programming tool availability (RS08 background debug) before committing to long-term RS08-based service strategies for aging equipment.
Recommended
Recommended Products Summary
Engineering reference data for MC9RS08KA2CPC174 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC9RS08KA1 | MC908QY4AMPE | MC68HC908QY2CPE | MC908QT2ACPE |
|---|---|---|---|---|---|
| Package | 8-PDIP | 8-PDIP - same | 8-PDIP - same | 8-PDIP - same | 8-PDIP - same |
| Brand | NXP Semiconductors (Freescale) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core | RS08 | RS08 | M68HC08 | M68HC08 | M68HC08 |
| Max Clock Frequency | 20 MHz | 20 MHz | 8 MHz | 8 MHz | 8 MHz |
| Flash Memory | 2KB | 1KB | 4KB | 2KB | 2KB |
| Core Size | 8-Bit | 8-Bit | 8-Bit | 8-Bit | 8-Bit |
| Firmware Compatibility | RS08 instruction set | RS08 - compatible | HC08 - port required | HC08 - port required | HC08 - port required |
Key Differentiators
- Higher CPU clock in the 8-pin class (vs MC908QY4AMPE)
- Larger program memory headroom than the smallest family member (vs MC9RS08KA1)
- Authorized legacy availability through Rochester Electronics (vs MC68HC908QY2CPE)
Design Notes
Estimated: for a typical 5V supply on the 8-pin PDIP, place a 100nF ceramic decoupling capacitor directly across VDD (pin 1) and VSS (pin 2) with the shortest possible traces; add a 10uF bulk capacitor per board. The RS08KA2's internal regulator and oscillator remove external clock components, but supply ripple on motor-driving appliance boards can cause spurious resets - confirm the exact operating voltage range in the NXP RS08KA datasheet before finalizing the rail design.
The RS08 instruction set is a simplified subset of S08 - existing HC08/S08 firmware will NOT run unchanged on this core, and vice versa. When migrating between MC9RS08KA2 and HC08 8-pin devices (QY4, QY2, QT2), recompile from source, re-verify timing loops calibrated to the different maximum clocks (20MHz RS08 vs 8MHz HC08), and retest watchdog and reset behavior. Also verify that code size fits: the KA1 alternative offers only 1KB FLASH versus 2KB on the KA2.
On the 8-PDIP through-hole footprint, keep the RESET (pin 7) trace short and add an optional 10k pull-up plus 100nF to ground for noise immunity in electrically noisy appliance environments. Route LED or relay drive lines away from the BKGD/MS (pin 8) programming pin to avoid disturbing in-circuit debug connections. Leave the BKGD pin accessible via a test point for flash programming with the RS08 background debug interface.
Compliance Information
RoHS details for this legacy-program suffix were not stated in the verified web data; confirm compliance status with NXP/Rochester Electronics documentation before export-controlled or EU-market production use.
