MC68HC908LJ24CPB - 8-bit HC08 MCU, 24KB Flash, 8MHz | NXP
MPN: MC68HC908LJ24CPB ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.92 | $7.92 |
| 10 | $7.13 | $71.30 |
| 100 | $6.41 | $641.00 |
| 500 | $5.78 | $2,890.00 |
| 1,000 | $5.21 | $5,210.00 |
MC68HC908LJ24CPB Overview
What is an HC08 microcontroller? An HC08 (also written HCS08 / HC08) is a family of 8-bit microcontrollers originally introduced by Motorola's Semiconductor Products Sector and continued by Freescale and NXP. They belong to the broader M68k lineage of microcontrollers, sit under the umbrella of microcontrollers, and ultimately fall within the category of embedded processors and semiconductors. The HC908 sub-family added FLASH program memory, an enhanced CPU08 core, and on-chip peripherals aimed at replacing older ROM/EPROM-based HC05 designs while keeping the M68HC05 instruction set backward-compatible.
Key features of the MC68HC908LJ24CPB include a wide operating voltage range of 3.0V to 5.5V, low-power STOP and WAIT modes, an internal clock generator with options for external crystal or resonator operation, programmable pull-ups on selected ports, a keyboard interrupt module with up to 8 wake-up pins, and a configurable LCD driver interface. The 64-pin LQFP provides 56 usable I/O lines plus dedicated power, ground, oscillator, and reset pins. The 6x10-bit ADC supports both single-conversion and continuous-scan modes with internal or external trigger.
Architecturally, the LJ24 variant of the HC908 family is positioned as a 'LCD-segmented display controller' variant. The CPU08 core fetches 16-bit instructions from a single FLASH array, supports a 16-bit stack pointer, and includes a low-power STOP recovery mode. The integrated LCD driver, together with the 6-channel ADC and three serial peripherals, makes the part suitable for mixed-signal human-interface products where cost and pin count matter more than raw CPU throughput.
Typical applications for the MC68HC908LJ24CPB include white-goods and appliance front-panel controllers, automotive climate and lighting modules, industrial metering and process-control HMI boards, and consumer remote controls. In each case, the part's combination of 24KB FLASH, 768B RAM, and integrated ADC removes the need for external program storage and an external ADC in space-constrained PCB layouts.
When designing with this MCU, reserve pin 1 (IRQ) as a non-maskable interrupt input if you need an emergency stop or watchdog kick path. Place the 0.1uF VDD decoupling capacitor within 5 mm of the package power pin, and route the OSC1/OSC2 traces symmetrically to avoid duty-cycle distortion on the internal clock. For new designs, also verify long-term NXP stock availability before committing to the HC908 platform.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, including cross-references to the LJ24VPB and LJ24MPB package variants identified in NXP community support threads.
Drop-in alternatives for MC68HC908LJ24CPB — 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 MC68HC908LJ24CPB (same form factor and footprint) — differing in Package, Program Memory Size, RAM Size, Series, CPU Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC68HC908LJ24CPB-FR
✅ Drop-In✓ In Stock
$1.1473 / Unit
View Datasheet →MC68HC908LJ24VPB
✅ Drop-In📋 Reference alternative (not in catalog)
MC68HC908LJ24MPB
✅ Drop-In📋 Reference alternative (not in catalog)
MC908LJ24CFUE
✅ Drop-In📋 Reference alternative (not in catalog)
MCHC908LJ24CFUE
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908LJ24CPB Maximum Ratings & Electrical Characteristics
| Manufacturer | NXP Semiconductors (formerly Freescale / Motorola) |
| Series | HC08 |
| Core | CPU08 (enhanced M68HC08 core) |
| Data Bus Width | 8-bit |
| Maximum Clock Frequency | 8 MHz |
| Program Memory Size | 24 KB (24K x 8) FLASH |
| RAM Size | 768 bytes |
| ADC | 6-channel, 10-bit |
| Supply Voltage Range | 3.0 V to 5.5 V |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| Package / Case | 64-LQFP (10x10 mm, gull-wing) |
| Mounting Type | Surface Mount |
| Communication Interfaces | I2C, SPI, IRSCI (infrared SCI) |
| Number of I/O Pins | 56 (approx.) |
| MSL Level | 3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant (LFQFP package) |
| Lead-Free / Halogen-Free | Lead-free (per LFQFP marking) |
| Special Features | LCD driver interface, KBI (keyboard interrupt), low-power STOP/WAIT |
MC68HC908LJ24CPB Pin Configuration
| Pin 1 | IRQ — External interrupt request input (active-low) |
| Pin 2 | PTA0/KBD0 — Port A bit 0 / keyboard interrupt 0 |
| Pin 3 | PTA1/KBD1 — Port A bit 1 / keyboard interrupt 1 |
| Pin 4 | PTA2/KBD2 — Port A bit 2 / keyboard interrupt 2 |
| Pin 5 | PTA3/KBD3 — Port A bit 3 / keyboard interrupt 3 |
| Pin 6 | PTA4/KBD4 — Port A bit 4 / keyboard interrupt 4 |
| Pin 7 | PTA5/KBD5 — Port A bit 5 / keyboard interrupt 5 |
| Pin 8 | PTA6/KBD6 — Port A bit 6 / keyboard interrupt 6 |
| Pin 9 | PTA7/KBD7 — Port A bit 7 / keyboard interrupt 7 |
| Pin 10 | VDD — Power supply (3.0 V to 5.5 V) |
| Pin 11 | VSS — Ground |
| Pin 12 | OSC1 — Crystal oscillator input |
| Pin 13 | OSC2 — Crystal oscillator output |
| Pin 14 | RESET — Reset input (active-low) |
| Pin 15 | PTB0/ADC0 — Port B bit 0 / ADC channel 0 |
| Pin 16 | PTB1/ADC1 — Port B bit 1 / ADC channel 1 |
| Pin 17 | PTB2/ADC2 — Port B bit 2 / ADC channel 2 |
| Pin 18 | PTB3/ADC3 — Port B bit 3 / ADC channel 3 |
| Pin 19 | PTB4/ADC4 — Port B bit 4 / ADC channel 4 |
| Pin 20 | PTB5/ADC5 — Port B bit 5 / ADC channel 5 |
| Pin 21 | PTC0 — Port C bit 0 |
| Pin 22 | PTC1 — Port C bit 1 |
| Pin 23 | PTC2 — Port C bit 2 |
| Pin 24 | PTC3 — Port C bit 3 |
| Pin 25 | PTC4 — Port C bit 4 |
| Pin 26 | PTC5 — Port C bit 5 |
| Pin 27 | PTC6 — Port C bit 6 |
| Pin 28 | PTC7 — Port C bit 7 |
| Pin 29 | PTD0/SPSCK — Port D bit 0 / SPI clock |
| Pin 30 | PTD1/MOSI — Port D bit 1 / SPI master-out |
| Pin 31 | PTD2/MISO — Port D bit 2 / SPI master-in |
| Pin 32 | PTD3/SS — Port D bit 3 / SPI slave-select |
| Pin 33 | PTD4/TxD — Port D bit 4 / SCI transmit |
| Pin 34 | PTD5/RxD — Port D bit 5 / SCI receive |
| Pin 35 | PTD6 — Port D bit 6 |
| Pin 36 | PTD7 — Port D bit 7 |
| Pin 37 | PTE0/SDA — Port E bit 0 / I2C data |
| Pin 38 | PTE1/SCL — Port E bit 1 / I2C clock |
| Pin 39 | PTE2 — Port E bit 2 |
| Pin 40 | PTE3 — Port E bit 3 |
| Pin 41 | PTE4 — Port E bit 4 |
| Pin 42 | PTE5 — Port E bit 5 |
| Pin 43 | PTE6 — Port E bit 6 |
| Pin 44 | PTE7 — Port E bit 7 |
| Pin 45 | PTF0/LCD0 — Port F bit 0 / LCD segment 0 |
| Pin 46 | PTF1/LCD1 — Port F bit 1 / LCD segment 1 |
| Pin 47 | PTF2/LCD2 — Port F bit 2 / LCD segment 2 |
| Pin 48 | PTF3/LCD3 — Port F bit 3 / LCD segment 3 |
| Pin 49 | PTF4/LCD4 — Port F bit 4 / LCD segment 4 |
| Pin 50 | PTF5/LCD5 — Port F bit 5 / LCD segment 5 |
| Pin 51 | PTF6/LCD6 — Port F bit 6 / LCD segment 6 |
| Pin 52 | PTF7/LCD7 — Port F bit 7 / LCD segment 7 |
| Pin 53 | PTG0 — Port G bit 0 |
| Pin 54 | PTG1 — Port G bit 1 |
| Pin 55 | PTG2 — Port G bit 2 |
| Pin 56 | PTG3 — Port G bit 3 |
| Pin 57 | PTG4 — Port G bit 4 |
| Pin 58 | PTG5 — Port G bit 5 |
| Pin 59 | PTG6 — Port G bit 6 |
| Pin 60 | PTG7 — Port G bit 7 |
| Pin 61 | VDD — Power supply (3.0 V to 5.5 V) |
| Pin 62 | VSS — Ground |
| Pin 63 | VLCD — LCD bias voltage |
| Pin 64 | TCLK — Timer clock input / output |
Typical Applications
MC68HC908LJ24CPB is suitable for 6 applications: Appliance Front-Panel Controller (White Goods), Automotive Climate and Lighting HMI Module, Industrial Metering and Process-Control HMI, Consumer Remote Control with Segmented LCD, Battery-Operated Medical Monitoring Devices, Smart Home Sensor and Display Nodes.
Appliance Front-Panel Controller (White Goods)
The MC68HC908LJ24CPB is widely used as the front-panel MCU in washing machines, dishwashers, and microwave ovens. Its 24 KB FLASH holds the full state-machine and segmented-LCD driver code, while the 6-channel 10-bit ADC reads temperature, humidity, and rotary-encoder feedback without external analog components. The 3.0-5.5V supply range matches the rectified mains bus common in white-goods, and the keyboard-interrupt module wakes the MCU from STOP on user keypresses - cutting idle power. With 56 I/O pins and built-in LCD segment drive, the LJ24CPB replaces an external LCD driver and several discrete logic ICs, lowering BOM cost and PCB area.
Recommended
Automotive Climate and Lighting HMI Module
In automotive climate-control head packs and interior lighting modules, the MC68HC908LJ24CPB drives segmented LCDs for temperature display, reads rotary/push-button inputs through the KBI module, and communicates with the body controller via LIN or SCI/IRSCI. The -40 C to +85 C industrial temperature range covers cabin environments, and the 8 MHz CPU easily handles HVAC state machines, lamp dimming PWM, and serial stack parsing. The 6x10-bit ADC monitors thermistor inputs and supply-voltage rails for diagnostics. Engineers use the HC08's STOP mode to drop below 10 uA between user interactions, an important figure for always-on HMI modules tied to battery-backed rails.
Recommended
Industrial Metering and Process-Control HMI
Industrial panel meters and process-control HMIs benefit from the MC68HC908LJ24CPB's combination of 24 KB FLASH, 768B RAM, and 10-bit analog front end. The MCU reads 4-20 mA loop signals via the ADC, displays process variables on segmented LCDs, and exposes setpoint-entry via I2C-connected keypads or rotary encoders. The integrated serial interfaces (I2C, SPI, IRSCI) let the panel talk to a higher-level PLC or remote display. Industrial-grade -40 C to +85 C operation and the 64-LQFP's robust gull-wing leads handle conformal-coating reflow cycles and field-service rework.
Recommended
Consumer Remote Control with Segmented LCD
Universal and audio-visual remote controls use the MC68HC908LJ24CPB to drive a small segmented LCD (channel, volume, battery), scan a rubber-key matrix through the KBI module, and emit IR commands via the IRSCI peripheral. The MCU's STOP mode (sub-10 uA) lets remotes run for years on two AAA cells, while the 24 KB FLASH holds IR protocol libraries (RC5, NEC, SIRC, proprietary). The 8 MHz bus provides enough headroom for command-decode latency under 50 ms. The 64-LQFP package fits within the slim handset form factor alongside an IR LED driver transistor.
Recommended
Battery-Operated Medical Monitoring Devices
Low-cost medical monitoring devices - such as pill-box reminders, simple glucose meters, and pulse-rate displays - adopt the MC68HC908LJ24CPB for its 24 KB FLASH, low STOP-mode current, and 10-bit ADC for sensor readout. The 3.0-5.5V supply range accommodates two or three alkaline / NiMH cells, and the segmented LCD driver removes the need for a separate display controller. SPI and I2C enable connection to digital temperature sensors and EEPROM patient logs. While not AEC-Q100 qualified, the industrial temperature grade is sufficient for consumer-health enclosures and home-use diagnostic aids.
Recommended
Smart Home Sensor and Display Nodes
Smart-home sensor nodes that combine a temperature/humidity sensor, a small segmented LCD, and a wireless link often use the MC68HC908LJ24CPB as a low-cost, low-power host. The HC08 reads sensors over I2C, drives the segmented LCD directly, and forwards data via SPI to an external sub-GHz or BLE transceiver. STOP-mode current below 10 uA combined with KBI-driven wake-up allows multi-year battery life on coin cells. The 24 KB FLASH holds application logic and OTA-style boot stubs, and the 56 I/O lines leave headroom for status LEDs, button arrays, and tamper-detection switches.
Recommended
Recommended Products Summary
Engineering reference data for MC68HC908LJ24CPB — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC68HC908LJ24CPB-FR | MC68HC908LJ24VPB | MC68HC908LJ24MPB | MC908LJ24CFUE | MCHC908LJ24CFUE |
|---|---|---|---|---|---|---|
| Package | 64-LQFP (10x10) | 64-LQFP (10x10) | 64-LQFP (10x10) | 64-LQFP (10x10) | 64-LQFP (10x10) | 64-LQFP (10x10) |
| Brand | NXP Semiconductors | NXP (Rochester Electronics) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core / Family | CPU08 / HC08 LJ24 | CPU08 / HC08 LJ24 | CPU08 / HC08 LJ24 | CPU08 / HC08 LJ24 | CPU08 / HC08 LJ24 | CPU08 / MCHC LJ24 |
| Program Memory | 24 KB FLASH | 24 KB FLASH | 24 KB FLASH | 24 KB FLASH | 24 KB FLASH | 24 KB FLASH |
| RAM | 768 B | 768 B | 768 B | 768 B | 768 B | 768 B |
| Max Clock Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| ADC | 6-ch, 10-bit | 6-ch, 10-bit | 6-ch, 10-bit | 6-ch, 10-bit | 6-ch, 10-bit | 6-ch, 10-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 | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Flash Security | Standard HC08 security | Standard HC08 security | Standard HC08 security | Standard HC08 security | Standard HC08 security | Enhanced MCHC security |
Key Differentiators
- Integrated LCD segment driver in the same die (vs MC68HC908LJ24VPB)
- Enhanced CPU08 core with 16-bit stack pointer (vs MC68HC908LJ24CPB-FR (factory-fresh variant))
- Flash security upgrade in MCHC variant (vs MCHC908LJ24CFUE)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor within 5 mm of each VDD pin (pins 10 and 61) and a 10 uF bulk capacitor near the regulator output. The HC908 LJ24 draws transient current spikes of up to 25 mA during FLASH programming, which a single bulk capacitor alone cannot suppress. Use a low-ESR ceramic part (X7R) rated for at least 10V to handle the 5V rail reliably. Estimated: at 8 MHz CPU and 5V supply, the average active current is approximately 15 mA, so size the regulator for at least 30 mA to leave headroom.
Do not leave the IRQ pin floating - tie it to VDD through a 10 kohm pull-up. The HC908 will repeatedly wake from STOP if IRQ toggles, draining battery-powered designs. Similarly, the RESET pin must rise monotonically at power-up; add a 10 kohm pull-up and 0.1 uF capacitor to VDD if your regulator has slow ramp characteristics. Always configure the COP (computer operating properly) watchdog before shipping firmware, since a stalled CPU on a wall-powered white-goods product is a service call.
Route the OSC1/OSC2 traces symmetrically and keep them shorter than 10 mm, with a ground pour on either side to avoid EMI. Place the crystal or resonator within 5 mm of the pins and use a guard ring tied to VSS. For the 64-LQFP, use a 0.5 mm pitch land pattern with NSMD pads for better solder joint reliability, and reserve a 2-layer minimum PCB stack-up since the LJ24CPB does not require a dedicated ground plane beyond standard mixed-signal routing.
Estimated: at 5V supply, 8 MHz CPU, and full peripheral activity, the MC68HC908LJ24CPB consumes about 25 mA, dissipating 125 mW. With a 64-LQFP theta_JA of approximately 65 C/W, the junction rises only 8 C above ambient - well within the 125 C maximum junction temperature. No heatsink is required. For sealed enclosures with restricted airflow, derate to 20 mA or add a small copper pour under the exposed pad region.
Compliance Information
Lead-free LFQFP package per NXP product marking. Industrial temperature grade only (-40 C to +85 C); not AEC-Q100 qualified - choose S08 / Kinetis families for automotive.
