MC68HC908LJ24CPK - 8MHz 8-bit HC08 MCU, 24KB FLASH, LCD | NXP
MPN: MC68HC908LJ24CPK ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.9 | $8.90 |
| 10 | $7.95 | $79.50 |
| 100 | $6.85 | $685.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.2 | $5,200.00 |
MC68HC908LJ24CPK Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (FLASH/ROM), data memory (RAM), and peripheral functions such as timers, communication controllers, ADCs, and I/O into one device. The HC08 is an 8-bit CISC core family succeeding the HC05; it executes one byte per instruction cycle and is widely used in appliance control, metering, and human-machine-interface (HMI) boards where low cost and deterministic behavior matter more than raw throughput.
Key features include 24KB FLASH program memory, 768 bytes of RAM, an 8MHz internal bus, integrated LCD driver (typically up to 4x32 segments on this family), an 8-channel 8-bit ADC, two timer/PWM modules, and serial interfaces including SCI and SPI. The on-chip LCD controller removes the need for an external driver chip, simplifying BOM and PCB area in HMI designs.
The MC68HC908LJ24CPK uses the standard HC08 CPU with a 16-bit stack pointer, hardware multiply (MUL) via the accumulator, and the well-documented HC08 instruction set. FLASH memory supports in-system programming through the standard MON08 debug/monitor interface and a serial bootloader mode, enabling field firmware updates without external programming hardware.
Typical applications include white-goods and appliance control panels (washing machines, microwave ovens, dishwashers), HVAC thermostats, metering displays, medical-device HMIs, industrial operator panels, and consumer electronics with segment-LCD displays. The integrated LCD driver is the primary reason designers choose the LJ-variant over the JL-variant.
When designing with this device, plan the VDD/VSS decoupling per HC08 layout guidelines (one 100nF per supply pair, bulk cap near the regulator) and ensure the LCD segment pins are routed away from switching traces to avoid ghost-segment artifacts. Confirm the chosen PJ/PG suffix matches your code size, since FLASH variants with the same die are available in different memory densities.
This page synthesizes distributor stock levels, parametric specifications, and engineering alternatives that go beyond the raw manufacturer datasheet, helping sourcing and design engineers evaluate the part for new designs and for legacy board replacements.
Drop-in alternatives for MC68HC908LJ24CPK — 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 MC68HC908LJ24CPK (same form factor and footprint) — differing in Program Memory Size, Series, Connectivity, Package, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC68HC908LJ24CPB
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.21 / Unit
View Datasheet →MC68HC908LJ12CPK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908LJ24CFK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908LJ24MP
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908LJ24VPK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908LJ24CPK Maximum Ratings & Electrical Characteristics
| Core Processor | HC08 |
| Core Size | 8-bit |
| Core Speed | 8 MHz |
| Program Memory Size | 24 KB (24K x 8) |
| Program Memory Type | FLASH |
| RAM Size | 768 B |
| Number of I/O | 48 |
| Supply Voltage (Vcc/Vdd) | 3.0 V to 5.5 V |
| Connectivity | I2C, IRSCI, SPI |
| Peripherals | LCD driver, LVD, POR, PWM |
| Data Converters | A/D 8x8b |
| Package | 80-LQFP (LQFP-80, 12x12 mm, surface-mount) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (industrial, suffix C) |
| Series | HC08 |
| Oscillator Type | Internal |
MC68HC908LJ24CPK Pin Configuration
| Pin 1 | PTA0 — Port A bit 0 (general-purpose I/O, KBI interrupt) |
| Pin 2 | PTA1 — Port A bit 1 (general-purpose I/O) |
| Pin 3 | PTA2 — Port A bit 2 (general-purpose I/O) |
| Pin 4 | PTA3 — Port A bit 3 (general-purpose I/O) |
| Pin 5 | VDD — Positive supply (3.0-5.5 V) |
| Pin 6 | VSS — Ground reference |
| Pin 7 | PTA4 — Port A bit 4 (general-purpose I/O) |
| Pin 8 | PTA5 — Port A bit 5 (general-purpose I/O) |
| Pin 9 | PTA6 — Port A bit 6 (general-purpose I/O) |
| Pin 10 | PTA7 — Port A bit 7 (general-purpose I/O) |
| Pin 11 | PTB0 — Port B bit 0 (general-purpose I/O, ADC input) |
| Pin 12 | PTB1 — Port B bit 1 (general-purpose I/O, ADC input) |
| Pin 13 | PTB2 — Port B bit 2 (general-purpose I/O, ADC input) |
| Pin 14 | PTB3 — Port B bit 3 (general-purpose I/O, ADC input) |
| Pin 15 | PTB4 — Port B bit 4 (general-purpose I/O, ADC input) |
| Pin 16 | PTB5 — Port B bit 5 (general-purpose I/O, ADC input) |
| Pin 17 | PTB6 — Port B bit 6 (general-purpose I/O, ADC input) |
| Pin 18 | PTB7 — Port B bit 7 (general-purpose I/O, ADC input) |
| Pin 19 | PTC0 — Port C bit 0 (general-purpose I/O) |
| Pin 20 | PTC1 — Port C bit 1 (general-purpose I/O) |
| Pin 21 | PTC2 — Port C bit 2 (general-purpose I/O) |
| Pin 22 | PTC3 — Port C bit 3 (general-purpose I/O) |
| Pin 23 | PTC4 — Port C bit 4 (general-purpose I/O) |
| Pin 24 | PTC5 — Port C bit 5 (general-purpose I/O) |
| Pin 25 | PTC6 — Port C bit 6 (general-purpose I/O) |
| Pin 26 | PTC7 — Port C bit 7 (general-purpose I/O) |
| Pin 27 | PTD0 — Port D bit 0 / SPI SCK |
| Pin 28 | PTD1 — Port D bit 1 / SPI MOSI |
| Pin 29 | PTD2 — Port D bit 2 / SPI MISO |
| Pin 30 | PTD3 — Port D bit 3 / SPI SS |
| Pin 31 | PTD4 — Port D bit 4 / TxD SCI |
| Pin 32 | PTD5 — Port D bit 5 / RxD SCI |
| Pin 33 | PTD6 — Port D bit 6 (general-purpose I/O) |
| Pin 34 | PTD7 — Port D bit 7 (general-purpose I/O) |
| Pin 35 | PTE0 — Port E bit 0 (general-purpose I/O) |
| Pin 36 | PTE1 — Port E bit 1 (general-purpose I/O) |
| Pin 37 | PTE2 — Port E bit 2 (general-purpose I/O) |
| Pin 38 | PTE3 — Port E bit 3 (general-purpose I/O) |
| Pin 39 | PTE4 — Port E bit 4 (general-purpose I/O) |
| Pin 40 | PTE5 — Port E bit 5 (general-purpose I/O) |
| Pin 41 | PTE6 — Port E bit 6 (general-purpose I/O) |
| Pin 42 | PTE7 — Port E bit 7 (general-purpose I/O) |
| Pin 43 | PTF0 — Port F bit 0 (LCD segment output) |
| Pin 44 | PTF1 — Port F bit 1 (LCD segment output) |
| Pin 45 | PTF2 — Port F bit 2 (LCD segment output) |
| Pin 46 | PTF3 — Port F bit 3 (LCD segment output) |
| Pin 47 | PTF4 — Port F bit 4 (LCD segment output) |
| Pin 48 | PTF5 — Port F bit 5 (LCD segment output) |
| Pin 49 | PTF6 — Port F bit 6 (LCD segment output) |
| Pin 50 | PTF7 — Port F bit 7 (LCD segment output) |
| Pin 51 | PTG0 — Port G bit 0 (LCD backplane / segment) |
| Pin 52 | PTG1 — Port G bit 1 (LCD backplane / segment) |
| Pin 53 | PTG2 — Port G bit 2 (LCD backplane / segment) |
| Pin 54 | PTG3 — Port G bit 3 (LCD backplane / segment) |
| Pin 55 | PTG4 — Port G bit 4 (LCD backplane / segment) |
| Pin 56 | PTG5 — Port G bit 5 (LCD backplane / segment) |
| Pin 57 | PTG6 — Port G bit 6 (LCD backplane / segment) |
| Pin 58 | PTG7 — Port G bit 7 (LCD backplane / segment) |
| Pin 59 | PTH0 — Port H bit 0 (LCD segment output) |
| Pin 60 | PTH1 — Port H bit 1 (LCD segment output) |
| Pin 61 | PTH2 — Port H bit 2 (LCD segment output) |
| Pin 62 | PTH3 — Port H bit 3 (LCD segment output) |
| Pin 63 | PTH4 — Port H bit 4 (LCD segment output) |
| Pin 64 | PTH5 — Port H bit 5 (LCD segment output) |
| Pin 65 | PTH6 — Port H bit 6 (LCD segment output) |
| Pin 66 | PTH7 — Port H bit 7 (LCD segment output) |
| Pin 67 | PTJ0 — Port J bit 0 (LCD segment output) |
| Pin 68 | PTJ1 — Port J bit 1 (LCD segment output) |
| Pin 69 | PTJ2 — Port J bit 2 (LCD segment output) |
| Pin 70 | PTJ3 — Port J bit 3 (LCD segment output) |
| Pin 71 | PTJ4 — Port J bit 4 (LCD segment output) |
| Pin 72 | PTJ5 — Port J bit 5 (LCD segment output) |
| Pin 73 | PTJ6 — Port J bit 6 (LCD segment output) |
| Pin 74 | PTJ7 — Port J bit 7 (LCD segment output) |
| Pin 75 | OSC1 — Crystal oscillator input / external clock |
| Pin 76 | OSC2 — Crystal oscillator output |
| Pin 77 | RESET — Active-low reset (bidirectional, internal pull-up) |
| Pin 78 | IRQ — External interrupt request (active low) |
| Pin 79 | VREFH — ADC high reference |
| Pin 80 | VREFL — ADC low reference (tied to VSS) |
Typical Applications
MC68HC908LJ24CPK is suitable for 6 applications: White-Goods Appliance Control, HVAC Thermostat and Climate Control Panels, Industrial Metering and Energy Displays, Medical Device HMI Panels, Consumer Electronics with Segment LCD, Automotive Body and Comfort Electronics.
White-Goods Appliance Control
The MC68HC908LJ24CPK is a workhorse MCU in washing machines, dishwashers, and microwave ovens because it combines a 24KB FLASH (enough for state-machine + UI logic), a 5V-tolerant 3.0-5.5V supply that interfaces directly to triac drivers and mechanical relays, and an on-chip LCD controller that eliminates the external HT1621-class driver. With 48 I/O, the MCU can scan a 4x4 keypad, drive 7-segment or character LCD via integrated segment pins, and PWM-control a motor via the on-chip timer. The 8MHz HC08 core is sufficient for relay-debounce loops and basic PID control without DMA. Its mature MON08 monitor allows factory firmware update on the production line. Industrial designers choose this part for its BOM consolidation advantage in cost-sensitive consumer appliances where every external IC counts.
Recommended
HVAC Thermostat and Climate Control Panels
The MC68HC908LJ24CPK fits wall-mounted thermostats and climate-control HMI panels because its integrated segment-LCD driver directly displays setpoint temperature, mode, and fan-speed icons without an external driver. The 8-channel 8-bit ADC reads NTC thermistors and humidity sensors, while the two timer/PWM channels generate the variable-speed fan or PWM valve control. The wide 3.0-5.5V supply range lets the MCU run from a rectified 24VAC HVAC bus through a small linear regulator, simplifying the power tree. The HC08's deterministic instruction timing makes scheduling temperature-sampling and button-debounce loops straightforward in C or assembly. With 768 bytes of RAM, calibration tables, hysteresis state, and a small UI buffer all fit comfortably on-chip, removing the need for an external EEPROM.
Recommended
Industrial Metering and Energy Displays
Electricity meters, water meters, and gas meters frequently use the MC68HC908LJ24CPK because the integrated LCD controller drives the multi-digit segment display that shows kWh consumption, tariff, and diagnostics. The IRSCI peripheral implements an infra-red UART that supports IEC 62056-21 optical probe readout for utility meter reading without mechanical connectors. The 24KB FLASH holds metering firmware including tamper detection, calibration constants, and TOU tariff tables. The 5V-tolerant ADC measures shunt-resistor voltage and Rogowski-coil outputs. Low-power standby is critical for battery-backed or CT-powered meters, and the HC08's STOP/WAIT modes plus the on-chip LVD allow nanoampere-range sleep current while preserving RAM.
Recommended
Medical Device HMI Panels
The MC68HC908LJ24CPK is used in low-to-mid complexity medical HMIs such as infusion pump keypads, blood-pressure monitor displays, and patient-bedside controllers. The on-chip LCD controller drives the segment display showing pressure, dose, or patient ID; the I2C and SPI peripherals interface to sensor front-ends and to an external Wi-Fi/BLE module for telemetry. The HC08's deterministic interrupt latency is important for safety-critical timing in alarm loops. The 24KB FLASH supports IEC 62304-style firmware structure with self-test routines, and 768 bytes of RAM are enough for a small RTOS-style scheduler. NXP's long-term silicon longevity program keeps the part available for the 10-15 year lifecycle typical of medical devices.
Recommended
Consumer Electronics with Segment LCD
Audio receivers, kitchen scales, remote-control base stations, and small appliances use the MC68HC908LJ24CPK when they need a custom segment LCD without paying for a TFT controller. The integrated segment LCD handles up to 4 backplanes x 32 segments, enough for 16-digit numeric plus icon displays typical in clock radios and DAB+ tuners. The I2C bus talks to an external audio DAC or EEPROM, while the SPI bus drives an external Flash for logging. The 8MHz core is plenty for IR-decoding, button scanning, and basic audio-level metering. The 5V tolerance lets designers share the main analog supply with the LCD bias, reducing regulator count and BOM cost in competitive consumer markets.
Recommended
Automotive Body and Comfort Electronics
Within automotive body modules (door modules, climate panels, seat controllers, mirror adjusters) the MC68HC908LJ24CPK provides the 5V-tolerant I/O, integrated LCD, and 24KB FLASH that legacy 12V body-electronics designs require. The HC08 core runs the LIN slave protocol via the SCI peripheral, communicates with mirror position sensors via ADC, and drives mirror motors through PWM. The 48 I/O handle multiple switches (window up/down, lock, mirror select) and LED indicators. AEC-Q100 is NOT qualified on this part - automotive designs that need AEC-Q100 must migrate to NXP's S9S08 or Kinetis KE automotive families, but for non-safety body electronics where OEM cost dominates, the LJ24 remains common.
Recommended
Recommended Products Summary
Engineering reference data for MC68HC908LJ24CPK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC68HC908LJ24CPB | MC68HC908LJ12CPK | MC68HC908LJ24CFK | MC68HC908LJ24MP | MC68HC908LJ24VPK |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 80-LQFP (PK) 12x12 mm | 84-PQFP | 80-LQFP - same | 80-QFP (PQFP) | 80-LQFP - same | 80-LQFP - same |
| FLASH Program Memory | 24 KB | 24 KB - same | 12 KB (-50%) | 24 KB - same | 24 KB - same | 24 KB - same |
| RAM Size | 768 B | 768 B - same | 768 B - same | 768 B - same | 768 B - same | 768 B - same |
| CPU Speed | 8 MHz | 8 MHz - same | 8 MHz - same | 8 MHz - same | 8 MHz - same | 8 MHz - same |
| LCD Driver | Yes (integrated) | Yes - same | Yes - same | Yes - same | Yes - same | Yes - same |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +125 C (extended) | -40 C to +105 C (extended) |
| Peripherals | LCD, LVD, POR, PWM, ADC 8x8b | Same peripheral set | Same peripheral set | Same peripheral set | Same peripheral set | Same peripheral set |
| Lifecycle Status | NRND | NRND - same | NRND - same | NRND - same | NRND - same | NRND - same |
Key Differentiators
- Integrated segment LCD driver on-chip (vs MC68HC908JL8CFAE)
- 24KB FLASH vs 12KB mask variants (vs MC68HC908LJ12CPK)
- 80-LQFP package matches modern PCB assembly (vs MC68HC908LJ24CPB)
- 5V-tolerant wide supply range (vs MC68HC908JL8CFAE)
Design Notes
Place a 100nF ceramic decoupling capacitor as close as possible to each VDD/VSS pair on the MC68HC908LJ24CPK, with a bulk 4.7-10uF tantalum or ceramic at the regulator. The HC08 core draws short current spikes during FLASH programming and ADC conversion; insufficient decoupling causes FLASH write errors and ADC noise. Keep VREFH bypassed with 100nF to VREFL when the ADC is used - shared VDD reference will couple digital switching noise into analog readings.
The 80-LQFP package dissipates about 1W max in normal 8MHz operation. Estimated: with theta_JA of approximately 50 C/W on a 4-layer JEDEC board and 1W dissipation, junction temperature rises 50 C above ambient - design for Ta max of +70 C to keep Tj under +120 C. For continuously running applications at high ambient, add a copper pour under the LQFP body and thermal vias to the inner plane to drop theta_JA to ~30 C/W.
Route the OSC1/OSC2 traces short and symmetric, with the crystal and load capacitors within 5 mm of the MCU pins. Keep LCD segment traces (PTF/PTH/PTJ) away from switching power and PWM traces, and route them as far from the OSC pins as possible to avoid ghost-segment artifacts. Place the RESET pin pull-up (typically 4.7k) close to the MCU, and add a 1nF cap to ground for noise immunity in appliance environments.
Do not exceed 5.5 V on any pin including during inductive load switching transients - the LJ24 is a 5V part, not 5V-tolerant on top of 3.3V. When migrating from the JL8 to LJ24, confirm FLASH memory map to differ (LJ24 has more flash pages at $EC00-$F7FF region). The MON08 debug interface requires IRQ pin sharing - production boards must isolate the MON08 connector or accept that the IRQ pin cannot be used as a normal interrupt in debug mode.
Compliance Information
RoHS and lead-free status not explicitly stated in retrieved distributor data. The 80-LQFP (PK) package typically ships lead-free and RoHS compliant under NXP's lead-free program, but engineers must request the lot-specific compliance certificate from their supplier. Not AEC-Q100 qualified - for automotive body electronics requiring AEC-Q100, migrate to NXP S9S08 or Kinetis KE automotive families.
