MC908JK1ECDWE - 8-bit HC08 MCU 1.5KB Flash 8MHz 20-SOIC | NXP
MPN: MC908JK1ECDWE ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.32 | $7.32 |
| 10 | $6.85 | $68.50 |
| 100 | $6.1 | $610.00 |
| 500 | $5.4 | $2,700.00 |
| 1,000 | $4.75 | $4,750.00 |
MC908JK1ECDWE Overview
What is an HC08 microcontroller? An HC08 (also written HC908 or HCS08 family predecessor) is a low-cost, high-performance 8-bit CISC microcontroller architecture originally developed by Motorola and continued by NXP/Freescale. The HC08 family uses a customer-specified integrated circuit (CSIC) design strategy, meaning memory sizes, peripherals and package options are configurable per family member. The HC908JK sub-family is the entry-level, small-package tier targeting cost-sensitive, low-pin-count embedded applications in appliance control, lighting, sensors, and human-interface devices.
Key features of the MC908JK1ECDWE include 1.5 KB Flash with security, 128 bytes RAM, 8-channel 8-bit ADC, 14 general-purpose I/O pins, two 16-bit timers, a computer-operating-properly (COP) watchdog, low-voltage reset, and an external interrupt. The device operates from 3.0V to 5.5V and is qualified for -40C to +85C industrial temperature range.
The HC08JK/JL families are based on an enhanced M68HC08 CPU08 core that supports 16 addressing modes and a multiply/accumulate-like instruction set. The on-chip Flash provides in-system programmability and security, enabling field firmware updates and IP protection. The integrated ADC with 8 analog channels allows direct sensor interfacing without external components.
Typical applications include appliance control boards, white goods and HVAC controls, simple motor drives, smart lighting controllers, battery chargers, security keypads, sensor signal conditioning, and general-purpose low-cost embedded control.
When designing with this device, pay attention to the supply voltage range (3.0V to 5.5V) and decoupling requirements. Place a 100 nF decoupling capacitor close to each VDD pin. For ADC accuracy, add an RC filter on analog inputs and ensure the analog supply is well-bypassed.
This page synthesizes NXP distributor pricing, drop-in pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for MC908JK1ECDWE — 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 MC908JK1ECDWE (same form factor and footprint) — differing in Package, Program Memory Size, Core, Core Architecture, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC68HC908JK1CDWE
✅ Drop-In📋 Reference alternative (not in catalog)
MC68HC908JK1CDWE2
✅ Drop-In📋 Reference alternative (not in catalog)
MC908JK3ECDWE
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →MC908QL3CDWE
✅ Drop-In✓ In Stock
$6.2 / Unit
View Datasheet →MC68HC908JK3CDWE
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908JK8CDWE
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC908JK1ECDWE Maximum Ratings & Electrical Characteristics
| Manufacturer | NXP Semiconductors (formerly Freescale) |
| Series | HC08JK |
| Core | CPU08 (HC08 CISC) |
| Data Bus Width | 8 bit |
| Maximum Clock Frequency | 8 MHz |
| Program Memory Size | 1.5 KB Flash |
| RAM Size | 128 B |
| ADC | 8-channel 8-bit |
| Supply Voltage | 3.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C |
| I/O Pins | 14 |
| Timers | 2 x 16-bit |
| Watchdog | COP (Computer Operating Properly) |
| Package | 20-SOIC (SO-20W, 7.50 mm width) |
| Mounting Type | Surface Mount |
MC908JK1ECDWE Pin Configuration
| Pin 1 | IRQ — External interrupt request input |
| Pin 2 | PTA0/ADC0 — GPIO / ADC channel 0 |
| Pin 3 | PTA1/ADC1 — GPIO / ADC channel 1 |
| Pin 4 | PTA2/ADC2 — GPIO / ADC channel 2 |
| Pin 5 | PTA3/ADC3 — GPIO / ADC channel 3 |
| Pin 6 | PTA4/ADC4 — GPIO / ADC channel 4 |
| Pin 7 | PTA5/ADC5 — GPIO / ADC channel 5 |
| Pin 8 | PTA6/ADC6 — GPIO / ADC channel 6 |
| Pin 9 | PTA7/ADC7 — GPIO / ADC channel 7 |
| Pin 10 | VSS — Ground |
| Pin 11 | PTB0/TCH0 — GPIO / Timer channel 0 |
| Pin 12 | PTB1/TCLK — GPIO / Timer clock input |
| Pin 13 | PTB2 — GPIO |
| Pin 14 | PTB3 — GPIO |
| Pin 15 | PTB4 — GPIO |
| Pin 16 | PTB5 — GPIO |
| Pin 17 | PTB6 — GPIO |
| Pin 18 | PTB7 — GPIO |
| Pin 19 | RESET — Reset input (active low) |
| Pin 20 | VDD — Positive supply voltage |
Typical Applications
MC908JK1ECDWE is suitable for 7 applications: Appliance Control Board, HVAC Thermostat and Climate Control, Smart Lighting and LED Driver Controller, Battery Charger and Power Management Controller, Security Keypad and Access Control Panel, Industrial Sensor Signal Conditioning, General-Purpose Low-Cost Embedded Control.
Appliance Control Board
The MC908JK1ECDWE's 1.5 KB Flash, 128 B RAM, 14 GPIOs, and 8-channel 8-bit ADC make it ideal for low-cost appliance control boards such as washing machine control panels, dishwasher user interfaces, microwave oven controllers, and refrigerator temperature displays. The HC08 CPU08 core runs at 8 MHz, providing sufficient instruction throughput for keypad scanning, sensor reading, relay driving, and basic state-machine control. The integrated ADC eliminates the need for an external A/D chip, reducing BOM cost. Per NXP application guidance, the part operates from 3.0V-5.5V, allowing direct interface with 5V relays and triacs.
Recommended
HVAC Thermostat and Climate Control
The MC908JK1ECDWE's 8-channel 8-bit ADC and industrial temperature range (-40C to +85C) suit it well for HVAC thermostat, fan controller, and zone-valve actuator designs. The 14 GPIO pins handle keypad input, LCD segment driving, relay/triac output, and serial communication to remote sensors. The HC08's deterministic interrupt response and on-chip COP watchdog enable reliable long-term unattended operation. Per the NXP datasheet, the part's low-voltage-reset circuit ensures clean startup after brownout events common in HVAC line-powered systems.
Recommended
Smart Lighting and LED Driver Controller
The MC908JK1ECDWE drives smart-lighting controllers, dimmer circuits, and LED driver controllers with PWM outputs from its two 16-bit timer channels. The 8 MHz CPU08 core executes dimming curves, color-mixing algorithms, and DMX-512-like protocols in real time. The 1.5 KB Flash stores lighting scenes, ramp tables, and color presets. Per NXP, the 14 GPIOs handle zero-cross detection, TRIAC gate drive, button inputs, and status LEDs, while the 8-bit ADC reads ambient light sensors for daylight harvesting.
Recommended
Battery Charger and Power Management Controller
The MC908JK1ECDWE serves as a low-cost charger controller for lead-acid, NiCd, NiMH, and Li-ion battery packs. Its 8-bit ADC monitors battery voltage, charge current, and temperature thermistor values, while the COP watchdog and timer interrupts implement charge-state timing. Per the NXP datasheet, the 3.0V-5.5V supply range allows direct 3-cell NiMH or single-cell Li-ion operation without level shifting. The 14 GPIOs drive charge/ discharge FETs, status LEDs, and safety relay cutoffs.
Recommended
Security Keypad and Access Control Panel
The MC908JK1ECDWE is well suited for security keypad, RFID reader controller, and access-control panel designs where compact code footprint, deterministic response, and low cost matter most. The 1.5 KB Flash stores PIN validation logic, encrypted credential data, and lock-release debounce timers. The 14 GPIOs drive matrix keypads, piezo buzzers, electromagnetic locks, and Wiegand interface lines to card readers. Per NXP, the on-chip Flash security feature prevents firmware IP from being read out, protecting access-control algorithms.
Recommended
Industrial Sensor Signal Conditioning
The MC908JK1ECDWE conditions and linearizes analog signals from thermocouples, RTDs, strain gauges, and 4-20 mA current loops in industrial sensor-transmitter designs. The 8-channel 8-bit ADC samples multiple sensor inputs while the COP watchdog ensures fault recovery. Per NXP, the 8-bit resolution is adequate for process-control applications with 1% accuracy requirements (e.g., tank-level, flow-rate, or temperature monitoring). The 20-SOIC wide-body package tolerates industrial PCB temperature swings and is easy to hand-prototype.
Recommended
General-Purpose Low-Cost Embedded Control
The MC908JK1ECDWE serves as a general-purpose low-cost 8-bit MCU for toys, educational electronics, hobby robotics, and consumer gadgets where BOM cost is paramount. The 1.5 KB Flash, 128 B RAM, 14 GPIOs, and ADC provide enough capability for sensor fusion, motor PWM, LED animation, and serial communication. Per the NXP datasheet, the part's HC08 CISC instruction set and 16 addressing modes deliver good code density, allowing more functionality per byte of Flash. The 20-SOIC package is breadboard-friendly via SOIC-to-DIP adapters.
Recommended
Recommended Products Summary
Engineering reference data for MC908JK1ECDWE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC68HC908JK1CDWE | MC68HC908JK1CDWE2 | MC908JK3ECDWE | MC908QL3CDWE |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 20-SOIC (SO-20W) | 20-SOIC - same | 20-SOIC - same | 20-SOIC - same | 20-SOIC - same |
| Core | HC08 CPU08 CISC 8-bit | HC08 CPU08 CISC 8-bit | HC08 CPU08 CISC 8-bit | HC08 CPU08 CISC 8-bit | HC08 CPU08 CISC 8-bit |
| Max Clock Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| Program Memory | 1.5 KB Flash | 1.5 KB Flash | 1.5 KB Flash | 4 KB Flash | 4 KB Flash |
| RAM | 128 B | 128 B | 128 B | 128 B | 128 B |
| ADC | 8-ch 8-bit | 8-ch 8-bit | 8-ch 8-bit | 12-ch 8-bit | 10-ch 8-bit |
| Supply Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 2.7 V to 5.5 V |
| Lifecycle | Last-time-buy (EOL) | Obsolete / last-time-buy | Obsolete / last-time-buy | Last-time-buy | Last-time-buy |
Key Differentiators
- Compact 20-SOIC package with full HC08 peripheral set (vs MC68HC908JK1CDWE)
- 1.5 KB Flash upgrade path to 4 KB same-package JK3 variant (vs MC908JK3ECDWE)
- Industrial-grade temperature range with on-chip LVR and COP (vs PIC16F876A (28-pin competitor))
Design Notes
The MC908JK1ECDWE requires a clean 3.0V-5.5V supply rail. Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 20), with a 10 uF bulk capacitor on the same supply node within 1 cm. Per the NXP datasheet, the on-chip low-voltage-reset (LVR) circuit holds the part in reset when VDD drops below the LVR threshold, eliminating the need for external POR circuitry. For noisy industrial supplies, add a ferrite bead or pi-filter (LC) between the upstream regulator and VDD.
Route the RESET pin (pin 19) away from high-frequency switching nodes and adjacent to a 10 kohm pull-up resistor. The 20-SOIC wide-body footprint allows generous trace widths for power pins; use at least 0.5 mm traces for VDD/VSS. Place the ADC reference decoupling capacitor (1 nF ceramic) within 5 mm of the analog supply. For ADC accuracy, keep analog input traces short and guarded by ground pours to minimize digital switching noise coupling.
Do not exceed absolute maximum supply voltage of 6.0V on VDD, or the part will suffer permanent damage. Ensure unused GPIO pins are configured as outputs (not floating inputs) to avoid spurious interrupt wake-ups. When using the ADC, allow at least 10 us acquisition time between channel switching and conversion start, or sample-hold settling will degrade accuracy. Per NXP, programming the Flash requires the proper BDM clock frequency; verify the programmer settings match the bus frequency (8 MHz internal / divided external).
The HC08 CPU08 core generates significant edge-rate noise on GPIO transitions during port writes. When the part interfaces with analog sensors via the ADC, insert 100 ohm series resistors on digital GPIO traces near the MCU to dampen ringing. For ADC channels adjacent to high-frequency digital lines, use ground traces as shields between the analog and digital sections. The on-chip ADC has a typical input leakage of <100 nA at 25C, allowing direct connection to high-impedance sensor dividers without buffers.
Compliance Information
Compliance information not explicitly listed in the verified web data; the NXP product page does not provide current RoHS/REACH declarations for this EOL part. Industrial temperature grade -40C to +85C is confirmed by datasheet. AEC-Q100 is not applicable - this is a general industrial MCU, not automotive-qualified.
