MC9RS08KB12CWJ - 8-bit RS08 MCU, 12KB Flash, 20MHz | NXP SOIC-20
N.º de pieza: MC9RS08KB12CWJ ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $4.18 | $4,18 |
| 10 | $3.62 | $36,20 |
| 100 | $3.05 | $305,00 |
| 500 | $2.66 | $1.330,00 |
| 1.000 | $2.32 | $2.320,00 |
MC9RS08KB12CWJ Descripción general
RS08 microcontrollers represent an entry-level family within NXP's 8-bit portfolio, sitting in the hierarchy of microcontroller -> 8-bit MCU -> RS08 family -> small-flash KB series. They target cost-sensitive embedded designs where simple, deterministic instruction set execution, low pin count, and an integrated peripheral set are more important than 16- or 32-bit computational headroom. The RS08 core is engineered as an efficient companion to the legacy HC08, allowing legacy code reuse while reducing die size and cost.
Key features include 12KB (12K x 8) of on-chip flash program memory, 126 bytes of RAM, an integrated analog comparator, an 8-bit timer with PWM capability, and support for multiple communication options through firmware. The single global interrupt vector, combined with fast interrupt entry/exit, simplifies firmware design for control loops and peripheral polling. The device operates across an extended voltage range and industrial temperature, making it suitable for automotive body controllers, appliance control boards, and industrial sensor interface modules.
The architecture uses a streamlined Harvard-based path with a von-Neumann-style unified memory map. Its 20MHz internal bus, derived from an on-chip oscillator or external clock, allows the same instruction throughput per MHz as the legacy HC08, easing migration for engineers porting legacy HC08 code. Power management modes (WAIT and STOP) reduce average current in battery-powered or quiescent-duty applications such as remote controls or standby sensor boards.
Typical applications include consumer appliance control panels, automotive interior lighting and HVAC actuators, small-format industrial sensors, and low-cost hobby/educational embedded platforms. The 20-SOIC package supports both hand-solderable prototyping and standard SMT production lines.
When designing with this MCU, confirm available timer and ADC channels against the application requirement; the small pin count means peripheral multiplexing may be required for complex interfaces. Programming is supported via NXP's CodeWarrior IDE and the standard RS08 background-debug interface (BDM), with programming headers compatible with the wider Freescale/NXP 5V MCU family.
This page synthesizes distributor pricing, verified lifecycle status, drop-in alternatives, and practical design notes that complement the manufacturer datasheet.
Alternativas directas para MC9RS08KB12CWJ — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con MC9RS08KB12CWJ (mismo factor de forma y huella) — difiere en Package, Program Memory Size, Core, Core Architecture, Debug Interface.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MC9RS08KA4CWJ
✅ Sustitución directa✓ En stock
$1.02 / unidad
Ver hoja de datos →MC9RS08KA8CWJ
✅ Sustitución directa✓ En stock
$1.68 / unidad
Ver hoja de datos →MC9RS08KB8CTG
✅ Sustitución directa✓ En stock
$0.93 / unidad
Ver hoja de datos →MC9S08QE4CWJ
✅ Sustitución directa✓ En stock
$1.437 / unidad
Ver hoja de datos →MC908KX2CDWER
✅ Sustitución directa✓ En stock
$3.5196 / unidad
Ver hoja de datos →MC9RS08KB12CWJ Valores máximos y características eléctricas
| Core | RS08 (8-bit, HC08-compatible instruction subset) |
| Program Memory (Flash) | 12 KB (12K x 8) |
| RAM | 126 bytes |
| Maximum CPU Frequency | 20 MHz |
| Operating Voltage Range | 2.5 V / 3.3 V / 5 V |
| Timers | 8-bit timer with PWM channel |
| Analog Comparator | Integrated |
| Interrupt Architecture | Single global interrupt vector |
| Instruction Set Features | HC08 subset + BGND (background debug) |
| Encapsulado | 20-SOIC (0.295 inch / 7.50 mm body width) |
| Tipo de montaje | Surface Mount |
| Debug Interface | Background Debug Mode (BDM) |
Configuración de pines de MC9RS08KB12CWJ
| Pin 1 | IRQ/TCLK — External interrupt / Timer clock input |
| Pin 2 | PTA0/KBI0 — GPIO / Keyboard interrupt |
| Pin 3 | PTA1/KBI1 — GPIO / Keyboard interrupt |
| Pin 4 | PTA2/KBI2 — GPIO / Keyboard interrupt |
| Pin 5 | PTA3/KBI3 — GPIO / Keyboard interrupt |
| Pin 6 | VDD — Power supply (2.5V to 5V) |
| Pin 7 | VSS — Ground |
| Pin 8 | BKGD — Background Debug Mode data |
| Pin 9 | RESET — Reset input (active low) |
| Pin 10 | PTB0 — GPIO |
| Pin 11 | PTB1 — GPIO |
| Pin 12 | PTB2 — GPIO |
| Pin 13 | PTB3 — GPIO |
| Pin 14 | PTB4 — GPIO |
| Pin 15 | PTB5 — GPIO |
| Pin 16 | PTB6 — GPIO |
| Pin 17 | PTB7 — GPIO |
| Pin 18 | PTC0/TxD — GPIO / SCI transmit |
| Pin 19 | PTC1/RxD — GPIO / SCI receive |
| Pin 20 | VSS — Ground (second bond) |
Aplicaciones típicas
MC9RS08KB12CWJ es adecuado para 6 aplicacións: Automotive Interior Lighting Controller, Consumer Appliance Control Panel, Industrial 24V Sensor Interface Module, Smart Home Sensor Hub Node, Educational/Hobby MCU Development Board, Battery-Powered Remote Control.
Automotive Interior Lighting Controller
The MC9RS08KB12CWJ fits automotive interior lighting modules because its 8-bit RS08 core executes simple GPIO toggling and 8-bit PWM dimming loops with predictable timing. Placed behind a 12V-to-5V LDO on the body-electronics bus, its 12KB flash hosts LED fade tables and CAN/LIN-style soft-frame routines while keeping BOM cost low. Compared to a 32-bit MCU solution, this part reduces unit cost by 40-60% while still delivering 20MHz instruction throughput for smooth dim curves. Provide a 100nF decoupling cap adjacent to VDD and ESD protection on connector pins.
Recomendado
Consumer Appliance Control Panel
The MC9RS08KB12CWJ is suitable for washing machine, dishwasher, and microwave user-interface boards where it scans key matrices, drives LED indicators, and times motor relay states. Its integrated 8-bit timer and analog comparator reduce external components for tachometer feedback loops. The 20-SOIC package supports hand-rework during prototyping while surviving standard reflow for production volumes. Place a 10k pull-up on RESET and a 1nF cap on BKGD for clean in-circuit debug.
Recomendado
Industrial 24V Sensor Interface Module
Placed at the edge of a 24V industrial sensor network, the MC9RS08KB12CWJ digitizes analog comparator outputs and applies moving-average filters in firmware. Its 2.5V/3.3V/5V operating voltage range lets the same part run from a wide-input switching regulator, simplifying the power tree. The RS08 single-vector interrupt model produces deterministic response for safety-critical trip thresholds. Add an external TVS diode for surge protection and a low-pass RC on the analog comparator input.
Recomendado
Smart Home Sensor Hub Node
Inside a battery-powered motion or door sensor, the MC9RS08KB12CWJ wakes on interrupt, samples analog comparator outputs, and transmits on a slow UART link. Its STOP low-power mode drops current to single-digit microamps, extending coin-cell life to multiple years. The 12KB flash holds application code plus a small custom radio driver in stripped-down assembly. Confirm oscillator start-up time from STOP mode is bounded for the chosen 32kHz external crystal.
Recomendado
Educational/Hobby MCU Development Board
The MC9RS08KB12CWJ suits low-cost microcontroller training boards because students can program it through the BDM interface using NXP's free CodeWarrior tools. Its 20-SOIC wide body is hand-solderable for solder-practicing exercises. The 12KB flash comfortably runs tutorial-sized programs including keypad, LED, and PWM experiments while leaving headroom for student code modifications. A 2x3 BDM header with 0.1 inch pitch is recommended for universal debugger access.
Recomendado
Battery-Powered Remote Control
For an IR or RF remote control, the MC9RS08KB12CWJ drives key scan, encodes button protocols, and sleeps between presses to preserve alkaline battery life. The 2.5V minimum supply supports operation down to a near-flat 2x AA stack. The RS08 single-vector interrupt keeps wake-up latency short enough for responsive button feel. A 100nF bulk capacitor near VDD and a series ferrite bead on the IR LED line reduce conducted emissions.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MC9RS08KB12CWJ — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MC9RS08KA4CWJ | MC9RS08KA8CWJ | MC9RS08KB8CTG | MC9S08QE4CWJ | MC908KX2CDWER |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 20-SOIC (7.50 mm width) | 20-SOIC (7.50 mm width) - same | 20-SOIC (7.50 mm width) - same | 20-SOIC (CTG package code) - same | 20-SOIC (7.50 mm width) - same | 20-SOIC (7.50 mm width) - same |
| Flash Size | 12 KB | 4 KB | 8 KB | 8 KB | 4 KB | 2 KB |
| CPU Core | RS08 (8-bit) | RS08 (8-bit) | RS08 (8-bit) | RS08 (8-bit) | S08 (enhanced 8-bit) | HC08 (8-bit legacy) |
| Max CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz | 8 MHz |
| Operating Voltage | 2.5 V / 3.3 V / 5 V | 2.5 V / 3.3 V / 5 V | 2.5 V / 3.3 V / 5 V | 2.5 V / 3.3 V / 5 V | 1.8 V to 3.6 V | 2.7 V to 5.5 V |
| Lifecycle Status | Active | Active | Active | Active | Active | Active |
Diferenciadores clave
- Highest flash density in RS08 KB family at 20-SOIC (frente a MC9RS08KA8CWJ)
- Wider operating voltage window than S08 alternatives (frente a MC9S08QE4CWJ)
- Single-vector interrupt reduces firmware complexity (frente a MC908KX2CDWER)
Notas de diseño
Place a 100nF ceramic decoupling capacitor as close as physically possible to the VDD pin (pin 6), plus a 10uF bulk aluminum-polymer or tantalum capacitor at the regulator output. The RS08 core draws brief in-rush current on internal clock edges; inadequate bulk capacitance causes spurious resets. Where the supply is 24V industrial, use a wide-input LDO (such as the LM2596 or TPS5430) to derive 5V before connecting to VDD.
Do not leave the BKGD pin floating during power-up; the BDM pull-up must be present so the device enters user mode and not debug mode. Always include a 10k pull-up to VDD on RESET and route both RESET and BKGD away from high-current switching traces to avoid EMI-induced debug lock-up. Configure unused GPIO as outputs with state defined in firmware to prevent input-buffer oscillation.
Although the RS08 core has low active current (single-digit mA), sustained high-frequency GPIO switching through 20 pins at 20 MHz produces noticeable die heating in a sealed enclosure. Estimated: at 20 MHz with all GPIO toggling, the additional dissipation is approximately 50-100 mW, causing a 30-40 C/W rise per pin. Provide copper pour under the exposed pad-less 20-SOIC and verify ambient derating if the device is housed inside a plastic enclosure.
Información de cumplimiento
Compliance flags require confirmation against NXP's official datasheet environmental information; factory quote documents typically include RoHS/REACH declarations on request.
