MC68HC908JL3CP - 8MHz 8-bit HC08 MCU 4KB FLASH 28-PDIP | NXP
MPN: MC68HC908JL3CP ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.55 | $2,550.00 |
MC68HC908JL3CP Overview
Background: An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory (FLASH/ROM), working memory (RAM), and I/O peripherals into one package. The HC08 family is based on NXP's (formerly Motorola/Freescale) customer-specified integrated circuit (CSIC) design strategy, an upgrade path from the older HC05 architecture. The '908 prefix denotes a FLASH-based variant with on-chip in-system programming capability, while the JL3 sub-family denotes a low-cost, low-pin-count member aimed at consumer and appliance markets.
Key features include 4 KB FLASH program memory (4K x 8 organization), 128 bytes of RAM, an internal bus clock of up to 8 MHz, 23 general-purpose I/O pins, an 8-bit ADC with up to 12 channels depending on package, two 16-bit timers, a serial communications interface (SCI), and a serial peripheral interface (SPI). The CPU08 core provides upward source-level compatibility with the legacy HC05 and enhanced addressing modes including indexed with offset.
Architecture depth: The MC68HC908JL3CP uses a Von Neumann bus structure with a 16-bit program counter and 8-bit data bus. FLASH programming is supported via monitor ROM and a single-wire background debug interface, simplifying prototyping. The part includes a low-voltage inhibit module, computer operating properly (COP) watchdog, and external asynchronous interrupt inputs for robust field behavior.
Typical applications include white-goods motor control (washing machines, dishwashers), small appliance controllers, consumer remote controls, low-end security keypads, HVAC thermostat front-ends, and battery-powered sensor interfaces. Its wide operating voltage and CMOS low-power modes support both line-powered and portable designs.
When designing with this part, budget for an external crystal or RC oscillator source and consider programming the FLASH via monitor mode for low-volume production. For automotive-grade requirements, evaluate the equivalent -Q suffix variant.
Drop-in alternatives for MC68HC908JL3CP — 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 MC68HC908JL3CP (same form factor and footprint) — differing in Package Type, Program Memory Size, RAM Size, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC68HC908JL3ECP
✅ Drop-In✓ In Stock
$3.2 / Unit
View Datasheet →MC68HC908JL3MP
✅ Drop-In📋 Reference alternative (not in catalog)
MC68HC908JK3CP
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908JC3CP
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC9S08SG4CTG
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16F876A-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
MC68HC908JL3CP Maximum Ratings & Electrical Characteristics
| Core | HC08 / CPU08 |
| Data Bus Width | 8 bit |
| Maximum Clock Frequency | 8 MHz |
| Program Memory Size | 4 KB (4K x 8) FLASH |
| RAM Size | 128 bytes |
| Number of I/O Pins | 23 |
| ADC | 8-bit, up to 12 channels |
| Timers | 2 x 16-bit |
| Serial Interfaces | 1 x SCI, 1 x SPI |
| Watchdog | COP (Computer Operating Properly) |
| Package Type | 28-PDIP (0.600 inch / 15.24 mm) |
| Mounting Type | Through-Hole |
MC68HC908JL3CP Pin Configuration
| Pin 1 | IRQ — External interrupt request input |
| Pin 2 | PTA0 — Port A bit 0 / ADC channel 0 |
| Pin 3 | PTA1 — Port A bit 1 / ADC channel 1 |
| Pin 4 | PTA2 — Port A bit 2 / ADC channel 2 |
| Pin 5 | PTA3 — Port A bit 3 / ADC channel 3 |
| Pin 6 | PTA4 — Port A bit 4 / ADC channel 4 |
| Pin 7 | PTA5 — Port A bit 5 / ADC channel 5 |
| Pin 8 | VDD — Positive supply voltage |
| Pin 9 | VSS — Ground reference |
| Pin 10 | PTB0 — Port B bit 0 |
| Pin 11 | PTB1 — Port B bit 1 |
| Pin 12 | PTB2 — Port B bit 2 |
| Pin 13 | PTB3 — Port B bit 3 |
| Pin 14 | PTB4 — Port B bit 4 |
| Pin 15 | PTB5 — Port B bit 5 |
| Pin 16 | PTB6 — Port B bit 6 |
| Pin 17 | PTB7 — Port B bit 7 |
| Pin 18 | PTC0 — Port C bit 0 |
| Pin 19 | PTC1 — Port C bit 1 |
| Pin 20 | PTC2 — Port C bit 2 |
| Pin 21 | PTC3 — Port C bit 3 |
| Pin 22 | PTC4 — Port C bit 4 |
| Pin 23 | PTC5 — Port C bit 5 |
| Pin 24 | PTC6 — Port C bit 6 |
| Pin 25 | PTC7 — Port C bit 7 |
| Pin 26 | OSC1 — Crystal oscillator input |
| Pin 27 | OSC2 — Crystal oscillator output |
| Pin 28 | RST — Reset input (active low) |
Typical Applications
MC68HC908JL3CP is suitable for 6 applications: White Goods Motor Control, Consumer Appliance Remote Control, HVAC Thermostat Front-End, Security Keypad / Access Control, Battery Sensor Interface Module, Small Fan / Pump Controller.
White Goods Motor Control
The MC68HC908JL3CP's 8 MHz CPU08 core, two 16-bit timers (TPM1/TPM2), and 23 GPIO pins fit washing-machine and dishwasher motor-control boards where 8-bit processing is sufficient for TRIAC phase-angle control, tachometer feedback, and user-keypad scanning. The 12-channel 8-bit ADC monitors line voltage, current, and thermistor sensors directly without external signal conditioning. Its 4 KB FLASH holds modest state-machine control code plus EEPROM emulation for user settings, while the SCI interface connects to the appliance's main display module. Compared with newer S08 parts, the JL3CP remains attractive for legacy white-goods designs where cost dominates and toolchain familiarity is high.
Recommended
Consumer Appliance Remote Control
The MC68HC908JL3CP's HC08 STOP/WAIT low-power modes, 128 bytes RAM, and integrated SCI are well-matched to handheld IR/RF remote-control transmitters. The 8 MHz internal bus is fast enough for protocol bit-banging (RC5, NEC, SIRC) while STOP mode drops quiescent current to single-digit microamps, preserving coin-cell life. The COP watchdog and external IRQ inputs ensure field robustness against ESD-induced hangs. Although the JL3CP's FLASH is limited at 4 KB, that is plenty for fixed-protocol remotes; more elaborate learning remotes should step up to JL8 or S08SG4.
Recommended
HVAC Thermostat Front-End
The MC68HC908JL3CP's 8-bit ADC samples thermistor, humidity, and set-point potentiometer signals at the required slow rates, while its 4 KB FLASH holds HVAC state-machine firmware and EEPROM emulation for schedule storage. The two 16-bit timer channels drive TRIAC zero-crossing switching for relay-based fan and compressor control. Wide operating voltage supports 24 VAC thermostats when rectified and regulated to 5 V. For full HVAC system controllers, upgrade to JL16/GT16 with more memory; the JL3CP is well-suited to low-end battery-only thermostat displays.
Recommended
Security Keypad / Access Control
The MC68HC908JL3CP's 23 GPIO pins accommodate a 4x4 matrix keypad without external scanning logic, and its SCI links to a downstream host controller or wireless module. The HC08 COP watchdog prevents lockup during keypad entry sequences. With its 8 MHz bus the part debounces keypad inputs and runs PIN verification code within the 4 KB FLASH limit. For higher-security designs with encrypted credentials, step up to S08 or Kinetis parts - the JL3CP is best for simple numeric-keypad door locks and alarm-panel keypads.
Recommended
Battery Sensor Interface Module
The MC68HC908JL3CP's low STOP-mode current and 8-bit ADC suit wireless battery-monitor nodes that wake periodically to sample cell voltage, current, and temperature. Its 4 KB FLASH handles simple state-machine logic and low-power RF command handling via SPI to an external transceiver such as an NRF24L01 or SX1276. The part's wide supply range (verify exact limits in datasheet) supports 2x AA alkaline or 1S Li-ion packs directly. For industrial wireless sensor networks, consider migrating to S08PL/KE parts with integrated radios.
Recommended
Small Fan / Pump Controller
The MC68HC908JL3CP's two 16-bit timer channels generate PWM for brushless DC or brushed motor speed control, while the 8-bit ADC reads back tachometer or current sense for closed-loop regulation. Its 23 GPIO pins drive status LEDs, button inputs, and fault signals without external expanders. The 4 KB FLASH fits speed-profiling tables and fault-handling state machines. COP watchdog and external IRQ guard against motor-stall-induced software lockup. This combination is ideal for low-cost CPU-fan, aquarium-pump, and small-appliance fan designs.
Recommended
Recommended Products Summary
Engineering reference data for MC68HC908JL3CP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC68HC908JL3ECP | MC68HC908JL3MP | MC68HC908JK3CP | PIC16F876A-I/SP |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | Microchip Technology |
| Package | 28-PDIP | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same footprint, different pinout |
| Core | HC08 CPU08, 8-bit | HC08 CPU08, 8-bit | HC08 CPU08, 8-bit | HC08 CPU08, 8-bit | PIC16 RISC, 8-bit |
| Max Clock Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 20 MHz |
| Program Memory | 4 KB FLASH | 4 KB FLASH | 4 KB FLASH | 4 KB FLASH (smaller RAM) | 14 KB FLASH |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 368 bytes |
| GPIO Pins | 23 | 23 | 23 | 20 (lower pin-count variant) | 22 |
| ADC | 8-bit, up to 12 channels | 8-bit, up to 12 channels | 8-bit, up to 12 channels | 8-bit, up to 12 channels | 10-bit, 8 channels |
| Operating Temperature | -40 C to +85 C (commercial) | -40 C to +85 C | -40 C to +125 C (extended) | -40 C to +85 C | -40 C to +85 C (I suffix) |
| Lifecycle Status | NRND | NRND / active | NRND / active | NRND / active | Active |
Key Differentiators
- Wide operating voltage headroom over PIC16F876A (vs PIC16F876A-I/SP)
- Extended temperature option in same footprint (vs MC68HC908JL3MP)
- Monitor-mode in-system programming (vs MC9S08SG4CTG)
Design Notes
The MC68HC908JL3CP requires a regulated VDD between approximately 2.7 V and 5.5 V; verify the exact range in the datasheet for your specific mask revision. A 100 nF decoupling capacitor should be placed within 5 mm of the VDD pin, and a bulk 10 uF capacitor near the supply entry point. For noisy motor-control applications, add a ferrite bead between the +5 V rail and the MCU VDD pin. The HC08 STOP mode reduces quiescent current to single-digit microamps but requires an interrupt or reset to wake.
Place the external crystal (or ceramic resonator) within 10 mm of OSC1/OSC2 to minimize stray capacitance and stray EMI pickup. Route the RST line away from high-current switching traces (motor drivers, TRIAC outputs) and add a 10 kohm pull-up to VDD. Keep ADC input traces short and shield them with a ground guard ring when sampling low-level analog signals. The IRQ line is sensitive to noise - debounce with an RC network when used with mechanical contacts.
Estimated: programming the JL3 FLASH via monitor mode requires the part to be clocked and the IRQ pin held high during the programming sequence. Failing to enter monitor mode correctly can leave the device locked - keep a known-good monitor firmware available. Also note that the COP watchdog must be serviced periodically; disable it explicitly if your application loop can stall longer than the watchdog timeout. Do not exceed 5.5 V on any pin, including ADC inputs, or permanent damage may result.
Compliance Information
RoHS/REACH status not confirmed in available data; treat as 'unknown' until verified against the latest NXP product PCN. The CP package is a legacy plastic PDIP not targeted at AEC-Q100 automotive qualification - use MP or AE suffix variants for automotive.
