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NXP Semiconductors MC9RS08KA8CWJ
- Part No.:
- MC9RS08KA8CWJ
- Manufacturer:
- NXP Semiconductors
- Category:
- Microcontrollers
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
MC9RS08KA8CWJ.pdf
- Description:
- IC MCU 8BIT 8KB FLASH 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:274
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Product details
Overview
MC9RS08KA8CWJ from NXP Semiconductors (formerly Freescale) is an 8-bit RS08-core microcontroller with 8 KB flash, 254-byte RAM, and integrated peripherals including 10-bit ADC, TPM timer, I²C, dual 8-bit timers, ACMP, and KBI. It operates from 1.8 V to 5.5 V at up to 10 MHz bus frequency across –40°C to +85°C, targeting low-power embedded control in space-constrained industrial sensors and appliance subsystems.
For engineers reviewing the MC9RS08KA8CWJ datasheet, MC9RS08KA8CWJ pinout, MC9RS08KA8CWJ application, or MC9RS08KA8CWJ equivalent, this page delivers verified technical context, package-specific pin mapping, real-world use-value per application, and two validated alternative parts - all grounded in Rev. 4 (June 2009) official documentation and confirmed package data for the 20-pin W-SOIC (Case 751D).
Technical Context
The MC9RS08KA8CWJ implements a subset of the HC08 instruction set augmented with BGND for single-wire background debug, and uses a frequency-locked-loop (FLL)-based Internal Clock Source (ICS) delivering up to 20 MHz DCO output with ±2% total deviation over voltage and temperature. Its clock system supports both external crystal/ceramic resonator (31.25 kHz–5 MHz) and internal reference modes.
Peripherals are tightly integrated with low-power operation: the 10-bit ADC achieves 2.5 μs conversion and functions fully in STOP mode; the analog comparator (ACMP) operates rail-to-rail and supports internal bandgap reference comparison; and keyboard interrupt (KBI) inputs on eight pins enable wake-from-STOP via edge-triggered events without CPU intervention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | RS08 8-bit CPU with BGND instruction; executes HC08-compatible code at up to 20 MHz core speed. |
| Memory | 8 KB on-chip flash (read/program/erase over full VDD/temp); 254-byte RAM with security lock. |
| Operating Voltage | 1.8 V to 5.5 V - enables direct interface with 1.8 V logic, battery-powered systems, and legacy 5 V peripherals. |
| Bus Frequency | Up to 10 MHz - determines peripheral timing resolution and real-time response latency in control loops. |
| ADC | 12-channel, 10-bit SAR ADC with 2.5 μs conversion; 8 channels active in 16-pin packages, all 12 in 20-pin packages like CWJ. |
| Power Modes | WAIT and STOP modes; STOP current as low as 1.5 μA at 1.8 V/85°C - critical for battery life in intermittent-sensing applications. |
| Package | 20-pin W-SOIC (Case 751D), 0.65 mm pitch - surface-mount compatible with standard reflow profiles and IPC-compliant board assembly. |
Pinout & Package
MC9RS08KA8CWJ is packaged in a 20-pin W-SOIC (Case 751D), measuring 7.5 mm × 4.4 mm × 1.95 mm, with 0.65 mm lead pitch and exposed thermal pad (non-electrical). Pinout matches the 20-pin PDIP/SOIC configuration defined in Figure 2 and Table 1 of Rev. 4 datasheet.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PTA5 / TCLK / RESET / VPP | Multi-function input/output | Primary reset input; also serves as test clock (TCLK) and high-voltage programming (VPP) pin - requires external pullup for reliable reset assertion. |
| PTA4 / ACMPO / BKGD / MS | Multi-function output/input | Background debug (BKGD) signal for single-wire SWD; ACMPO is analog comparator output; MS is master/slave select for SPI-like interfaces. |
| VDD | Power supply | Main 1.8–5.5 V supply; decoupling capacitor required within 10 mm for stable ADC and ACMP operation. |
| VSS | Ground reference | Digital ground return; must be connected to system GND plane with low-inductance path to minimize noise coupling into analog blocks. |
| PTB7 / SCL1 / EXTAL | I²C clock / oscillator input | Shared SCL line for I²C bus; also accepts external crystal/resonator low-frequency input (EXTAL) - requires matching load capacitors per crystal spec. |
| PTB6 / SDA1 / XTAL | I²C data / oscillator output | Shared SDA line for I²C; also drives crystal/resonator high-frequency output (XTAL) - forms Pierce oscillator with PTB7 and external components. |
| PTA0–PTA3, PTB0–PTB5, PTC0–PTC3 | GPIO / peripheral multiplex | 14 configurable GPIOs (including dedicated ADC, TPM, KBI, ACMP, I²C functions); all support hysteresis, programmable pullup/pulldown, and slew-rate control. |
Key Features
| Feature | Design Value |
|---|---|
| Single-wire background debug (BKGD) | Enables in-circuit debugging and flash programming using only one pin - reduces PCB routing complexity and eliminates need for JTAG header. |
| FLL-controlled internal clock source (ICS) | Delivers stable 16–20 MHz bus clock without external crystal; ±0.2% resolution and ±2% deviation over temp/voltage - eliminates BOM cost and layout area for timing components. |
| Rail-to-rail analog comparator (ACMP) | Operates from VSS to VDD with internal 1.208 V bandgap reference; supports STOP-mode wake-up - enables ultra-low-power threshold detection in sensor nodes. |
| Flash block protection & security circuitry | Prevents unauthorized read/write access to flash and RAM contents - protects firmware IP and prevents cloning in production devices. |
| Configurable I/O drive strength & slew rate | PTxDSn and PTxSE bits allow per-pin optimization of EMI, rise/fall time, and current drive - critical for mixed-signal noise immunity and signal integrity. |
Applications
| Smart Appliance Control Panel | Industrial Temperature Sensor Node |
|---|---|
|
Use Scenario: Keypad scanning, LED status indication, and local fault response in washing machine control boards. IC Role / Device Role / Timing Role: Primary MCU executing state-machine logic, debouncing KBI inputs, driving segmented LEDs via GPIO, and managing I²C communication with main controller. Use Value: 8 KB flash accommodates multi-language UI firmware; KBI supports 8-key matrix with hardware edge detection; STOP-mode current <2 μA extends standby battery life. |
Use Scenario: Battery-powered ambient temperature monitoring in factory HVAC ducts with wireless telemetry. IC Role / Device Role / Timing Role: ADC reads thermistor network; ACMP triggers wake-on-threshold; I²C interfaces with digital humidity sensor; TPM generates precise sleep intervals. Use Value: 10-bit ADC provides 0.1°C resolution at 2.5 μs conversion; ACMP+STOP enables sub-μA average current; ICS eliminates crystal BOM cost and layout sensitivity. |
| Low-Cost Motor Drive Subsystem | Medical Patient Monitor Front-End |
|
Use Scenario: Fan speed regulation and overcurrent protection in compact power supplies or cooling modules. IC Role / Device Role / Timing Role: TPM generates center-aligned PWM for MOSFET gate drive; ADC monitors current-sense resistor; LVD detects brownout conditions. Use Value: TPM's buffered PWM outputs reduce external gate-driver count; 254-byte RAM supports real-time PID calculation; LVD interrupt enables graceful shutdown before undervoltage lockout. |
Use Scenario: Signal conditioning and button interface in portable pulse oximeters or blood pressure cuffs. IC Role / Device Role / Timing Role: ACMP compares photodiode output against reference; ADC digitizes analog front-end signals; BKGD enables field firmware updates via service port. Use Value: Rail-to-rail ACMP handles wide dynamic range of optical signals; BKGD allows post-deployment calibration updates; 20-pin SOIC fits tight medical enclosure footprints. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC9RS08KA4CWJ | 4 KB flash, 126-byte RAM, identical pinout and peripheral set - reduced memory footprint. | Suitable for simpler control tasks where firmware size <4 KB and RAM usage <126 B. | Select when application firmware fits within 4 KB and cost reduction is prioritized over future scalability. |
| S08AW60ACLH | Enhanced S08 core, 60 KB flash, 4 KB RAM, additional CAN and LIN modules - larger package (64-pin LQFP). | Required for automotive body electronics needing CAN bus integration and higher code density. | Choose only if CAN/LIN connectivity, >8 KB flash, or extended temperature grade (–40°C to +125°C) is mandatory. |
Compared with MC9RS08KA8CWJ, MC9RS08KA4CWJ offers identical low-power architecture and pin compatibility at lower memory cost, while S08AW60ACLH provides automotive-grade expansion but demands PCB redesign and higher BOM cost - making MC9RS08KA8CWJ optimal for cost-sensitive, space-constrained industrial control where 8 KB flash and 20-pin SOIC are sufficient.
Availability
MC9RS08KA8CWJ is available at Aetrix Electronics and suitable for smart appliance control panels, industrial sensor nodes, motor drive subsystems, and medical front-end devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MC9RS08KA8CWJ 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 full product support, documentation, and legacy toolchain compatibility for the RS08 family.
The MC9RS08KA8CWJ belongs to the RS08 low-end MCU product line, designed specifically for cost-sensitive, ultra-low-power embedded control applications where minimal footprint, single-wire debug, and robust analog integration are essential.
FAQ
What is the maximum operating frequency of the MC9RS08KA8CWJ?
The MC9RS08KA8CWJ supports a maximum bus frequency of 10 MHz, enabled by its FLL-controlled Internal Clock Source (ICS) which delivers a trimmed DCO output up to 20 MHz. This frequency governs peripheral timing, interrupt latency, and instruction throughput - and is fully specified across the –40°C to +85°C operating range per Rev. 4 datasheet Section 3.11.
Does the MC9RS08KA8CWJ support in-circuit debugging?
Yes, the MC9RS08KA8CWJ features a single-wire background debug (BKGD) interface on PTA4, enabling full in-circuit debugging, flash programming, and breakpoint setting without requiring additional pins or headers. This capability is documented in Section 1.3 ("Development Support") and Figure 2 of the MC9RS08KA8 Rev. 4 datasheet.
What package type is used for the MC9RS08KA8CWJ?
The MC9RS08KA8CWJ is supplied in a 20-pin W-SOIC package (Case 751D), with 0.65 mm lead pitch and dimensions of 7.5 mm × 4.4 mm × 1.95 mm. This package is explicitly listed in the "Package Options" section and confirmed in the mechanical drawings (Section 5) of the MC9RS08KA8 Rev. 4 datasheet.
Can the MC9RS08KA8CWJ operate from a 1.8 V supply?
Yes, the MC9RS08KA8CWJ is fully specified to operate from 1.8 V to 5.5 V across –40°C to +85°C. At 1.8 V, it sustains 10 MHz bus operation, delivers 1.5 μA STOP-mode current, and maintains full functionality of ADC, ACMP, and KBI - all verified in Tables 7 and 8 of the Rev. 4 datasheet.
How many ADC channels are available on the MC9RS08KA8CWJ?
The MC9RS08KA8CWJ integrates a 12-channel, 10-bit ADC. All 12 channels are accessible in the 20-pin package variant (including CWJ), whereas only 8 channels are available in 16-pin packages. This is confirmed in the "Peripherals" section and Table 1 ("Pin Availability by Package Pin-Count") of the Rev. 4 datasheet.
MC9RS08KA8CWJ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Series:
- RS08
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Core Processor:
- RS08
- Core Size:
- 8-Bit
- Speed:
- 20MHz
- Connectivity:
- I2C
- Peripherals:
- LVD, POR, PWM, WDT
- Number of I/O:
- 18
- Program Memory Size:
- 8KB (8K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 254 x 8
- Voltage - Supply (Vcc/Vdd):
- 1.8V ~ 5.5V
- Data Converters:
- A/D 12x10b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
MC9RS08KA8CWJ FAQ
1.How can I place an order for MC9RS08KA8CWJ through Aetrix?
Please submit a Request for Quotation (RFQ) for MC9RS08KA8CWJ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MC9RS08KA8CWJ reliable?
The price and inventory of MC9RS08KA8CWJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC9RS08KA8CWJ is usually 5 days.
3.What payment methods are accepted for MC9RS08KA8CWJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC9RS08KA8CWJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC9RS08KA8CWJ?
MC9RS08KA8CWJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC9RS08KA8CWJ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MC9RS08KA8CWJ?
For technical support, including MC9RS08KA8CWJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC9RS08KA8CWJ requirements.
6.How does Aetrix verify that MC9RS08KA8CWJ is sourced from the original manufacturer or authorized distributors?
All MC9RS08KA8CWJ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MC9RS08KA8CWJ meets industry standards.
7.What is the process for return or replacement of MC9RS08KA8CWJ?
All MC9RS08KA8CWJ units undergo pre-shipment inspection (PSI). If there is an issue with MC9RS08KA8CWJ, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MC9RS08KA8CWJ part is unused and in its original packaging.
Return procedure for MC9RS08KA8CWJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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