MC68HC908LB8MDWE - 8KB Flash 8MHz HC08 MCU 20-SOIC | NXP
MPN: MC68HC908LB8MDWE ✗ Akhir HidupMC68HC908LB8MDWE Ringkasan
An 8-bit microcontroller (8-bit MCU) is a single-chip computer that integrates an 8-bit CPU core, program memory, working RAM, and peripheral interfaces (timers, ADC, I/O, communications) into one package. The M68HC08 family is part of the broader MCU hierarchy: 8-bit microcontroller -> microcontroller -> embedded processor -> semiconductor IC. The HC08 is a CISC architecture that succeeded the HC05, adding a higher-throughput instruction set while keeping the same programming model, which simplified migration for existing HC05 firmware bases.
Key features of the MC68HC908LB8MDWE include an 8-channel 8-bit ADC with linear successive approximation, a multi-channel timer with PWM capability, an internal oscillator that reduces external BOM, and on-chip peripherals including a Low-Voltage Reset (LVR), Power-On Reset (POR), and PWM module. The integrated peripherals reduce system cost by eliminating external glue logic, and the 8KB Flash supports in-application reprogramming for field upgrades.
The device is fabricated on Freescale/NXP's mature HC08 process and uses an internal oscillator that eliminates one or two external crystal components compared to HC05 designs. The architecture balances cost-sensitive 8-bit throughput with deterministic interrupt response for event-driven control loops, and the part is qualified for consumer and industrial environments where 5V tolerance and ESD robustness are required.
Typical applications include remote keyless entry (RKE) key fobs, simple motor and valve controllers, low-end consumer appliances, security keypads, IR/RF transmitters, and battery-powered sensor interface boards. The 18 I/O pins are sufficient to drive a small keypad, an LED indicator, a piezo sounder, and a transmitter FET directly.
When designing with this device, ensure the supply decoupling network uses a 100nF ceramic capacitor close to the VDD/VSS pins and that the reset pin is held low during power ramp-up. Note that the part is marked obsolete by some distributors (NXP/Freescale) and may have long lead times - plan inventory accordingly or evaluate the cross-referenced alternatives listed on this page.
This page synthesizes distributor pricing, parametric specifications, drop-in alternatives, and design notes not consolidated on any single manufacturer or distributor page.
Alternatif penggantian untuk MC68HC908LB8MDWE — paket yang sama, pin-pada-pin kompatibel. Bagian paket yang berbeda memerlukan kerja ulang PCB diabaikan.
Variasi di dalam seri ini
Model-series yang sama yang kompatibel dengan penggantian MC68HC908LB8MDWE (sama faktor bentuk dan footprint) — berbeda di dalam Program Memory Size, Package, RAM Size, Series, Supply Voltage.
MC908JB8JDWE
✅ Drop-InKontak untuk harga
Lihat Datasheet →MC908QY8CDWE
✅ Drop-InKontak untuk harga
Lihat Datasheet →MC68HC705J1ACP
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MC68HC705J1ACDW
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MC68HC908LB8MPE
✅ Drop-In ⚠️ Spesifikasi Tidak Disahkan📋 Alternatif referensi (tidak dalam katalog)
MC68HC908LB8CDWE
✅ Drop-In ⚠️ Spesifikasi Tidak DisahkanKontak untuk harga
Lihat Datasheet →MC68HC908LB8MDWE Rating Maksimal & Karakteristik Listrik
| Manufacturer | NXP / Freescale Semiconductor |
| Series | HC08 |
| Core Processor | HC08 |
| Core Size | 8-Bit |
| Core Architecture | CISC |
| Maximum Clock Speed | 8 MHz |
| Program Memory Size | 8 KB (8K x 8) |
| Program Memory Type | FLASH |
| RAM Size | 128 x 8 (128 bytes) |
| Number of I/O | 18 |
| ADC | 8-bit, 7-channel (per datasheetbank excerpt) |
| Peripherals | LVR, POR, PWM |
| Oscillator Type | Internal |
| Supply Voltage (Vcc) | 5 V |
| Paket / Case | 20-SOIC (0.295 inch / 7.50 mm width) |
| Tipe Mounting | Surface Mount |
| Packaging | Tube |
| Part Status | Obsolete (per abc-semi listing) |
Konfigurasi Pin MC68HC908LB8MDWE
| Pin produk 1 | IRQ — External interrupt request input |
| Pin produk 2 | PTA0 — Port A bit 0 (general-purpose I/O) |
| Pin produk 3 | PTA1 — Port A bit 1 (general-purpose I/O) |
| Pin produk 4 | VDD — Supply voltage (5V) |
| Pin produk 5 | VSS — Ground |
| Pin produk 6 | PTA2 — Port A bit 2 (general-purpose I/O) |
| Pin produk 7 | PTA3 — Port A bit 3 (general-purpose I/O) |
| Pin produk 8 | PTA4 — Port A bit 4 (general-purpose I/O) |
| Pin produk 9 | PTA5 — Port A bit 5 (general-purpose I/O) |
| Pin produk 10 | PTA6 — Port A bit 6 (general-purpose I/O) |
| Pin produk 11 | PTA7 — Port A bit 7 (general-purpose I/O) |
| Pin produk 12 | PTB0 — Port B bit 0 (general-purpose I/O) |
| Pin produk 13 | PTB1 — Port B bit 1 (general-purpose I/O) |
| Pin produk 14 | PTB2 — Port B bit 2 (general-purpose I/O) |
| Pin produk 15 | PTB3 — Port B bit 3 (general-purpose I/O) |
| Pin produk 16 | PTB4 — Port B bit 4 (general-purpose I/O) |
| Pin produk 17 | PTB5 — Port B bit 5 (general-purpose I/O) |
| Pin produk 18 | PTB6 — Port B bit 6 (general-purpose I/O) |
| Pin produk 19 | PTB7 — Port B bit 7 (general-purpose I/O) |
| Pin produk 20 | RST — Reset input (active low) |
Aplikasi Umum
MC68HC908LB8MDWE cocok untuk 6 aplikasis: Remote Keyless Entry (RKE) Transmitter, Low-End Appliance Controller, Security Keypad and Access Controller, Battery-Powered IR/RF Transmitter Module, Simple Motor and Valve Controller, Consumer Toy and Hobby Electronics.
Remote Keyless Entry (RKE) Transmitter
The MC68HC908LB8MDWE is purpose-built for remote keyless entry key fobs. The 8KB Flash holds rolling-code encryption firmware, the 18 I/O drives a 4x3 keypad plus LED and piezo sounder, the internal oscillator eliminates external crystal cost, and 5V-tolerant I/O handles direct FET drive for the UHF transmitter stage. The PWM module dims indicator LEDs at low duty cycle for battery life, and the 128-byte RAM is sufficient for transient stack and key-debounce buffers. Compared to newer S08 MCUs, the LB8 retains the legacy HC08 instruction set so existing rolling-code libraries port without rework, a major benefit for long-life automotive aftermarket SKUs.
Direkomendasikan
Low-End Appliance Controller
For cost-sensitive white-goods sub-modules such as a coffee maker's brew-cycle timer or a microwave's keypad interface, the MC68HC908LB8MDWE provides adequate compute in a small 20-SOIC footprint. The 8-channel 8-bit ADC reads thermistor or humidity sensors, the timer/PWM drives a relay or triac, and the 18 I/O handles a matrix keypad and seven-segment LED display. The HC08's deterministic interrupt latency ensures the brew cycle and safety interlocks respond within bounded time. Power consumption is dominated by the external relay coil; the MCU itself draws single-digit mA at 8MHz/5V which suits wall-powered appliances.
Direkomendasikan
Security Keypad and Access Controller
Wired security keypads for door access control use the MC68HC908LB8MDWE to scan a 3x4 matrix, debounce entries, compare against stored PIN codes, and drive a relay or Wiegand output. The 8KB Flash comfortably fits lookup tables for several hundred PIN slots plus encryption, and the 128-byte RAM buffers entry sequences. The internal oscillator removes a crystal that would otherwise be a tampering target, increasing physical security. The 5V supply rails match common 12V->5V regulator outputs in security panels, simplifying integration.
Direkomendasikan
Battery-Powered IR/RF Transmitter Module
Handheld IR/RF remote controls benefit from the MC68HC908LB8MDWE's low-power 8-bit core, internal oscillator (no external crystal drain), and PWM for IR carrier generation at 36-40kHz. The 18 I/O supports a matrix keypad, multiple LEDs, and the transmitter FET driver. The 128-byte RAM and 8KB Flash are sufficient for protocol stacks (RC5, NEC, or simple proprietary RF OOK). Sleep current is dominated by external circuitry, but the HC08 core itself supports low-power wait and stop modes for battery-life extension on coin cells.
Direkomendasikan
Simple Motor and Valve Controller
The MC68HC908LB8MDWE drives small brushed DC motors or solenoid valves in industrial sensor-actuator nodes. The PWM output provides speed or proportional valve control, the 8-bit ADC reads a position feedback potentiometer or pressure transducer, and the 18 I/O handles limit switches, enable inputs, and status LEDs. The HC08's CISC instruction set executes arithmetic and PID loops efficiently at 8MHz. The 20-SOIC wide package is well-suited to hand-soldered prototyping and low-volume industrial modules where active production MCUs are unnecessary.
Direkomendasikan
Consumer Toy and Hobby Electronics
Mass-market RC toys, hobby servos, and educational electronics kits use the MC68HC908LB8MDWE because the 5V 8-bit HC08 platform is inexpensive, well-documented, and supported by legacy development tools. The 8KB Flash fits simple behavior trees, the PWM drives servo or motor outputs, and the ADC reads analog sensors such as IR distance or temperature. The wide SOIC package is easy for hobbyists to hand-solder on perfboard, and the internal oscillator removes one BOM line item to keep kit costs low.
Direkomendasikan
Ringkasan Produk Direkomendasikan
Data referensi engineering untuk MC68HC908LB8MDWE — pembandingan, panduan desain, dan informasi konformitas.
Panduan Pemilihan
Pembandingan dengan Alternatif
| Parameter Umum | Produk Ini | MC908JB8JDWE | MC908QY8CDWE | MC68HC705J1ACP | MC68HC705J1ACDW |
|---|---|---|---|---|---|
| Package | 20-SOIC (wide, 7.50mm) | 20-SOIC (wide, 7.50mm) - same | 20-SOIC (wide, 7.50mm) - same | 20-SOIC (wide, 7.50mm) - same | 20-SOIC (wide, 7.50mm) - same |
| Brand | NXP Semiconductors (Freescale) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core | HC08 (8-bit, CISC) | HC08 (8-bit, CISC) | HC08 (8-bit, CISC) | HC05 (8-bit, predecessor) | HC05 (8-bit, predecessor) |
| USB Connectivity | No | Yes (USB 2.0 full-speed device) | No | No | No |
| Primary Application | RKE transmitter, low-power control | USB HID / general-purpose | General-purpose 8-bit control | Legacy HC05 applications | Legacy HC05 applications |
Diferensiator Kunci
- Tuned for low-power RKE transmitter designs with PWM and ADC focus (vsMC908QY8CDWE)
- Same SOIC-20W footprint as the broader NXP HC08 family (vsMC68HC705J1ACP)
- Flash-based, in-application reprogrammable (vsMC68HC705J1ACDW)
- No USB peripheral - simpler firmware and lower BOM (vsMC908JB8JDWE)
Catatan Desain
Place a 100nF ceramic decoupling capacitor as close as possible to the VDD (pin 4) and VSS (pin 5) pins. For battery-powered applications such as RKE key fobs, add a bulk 10uF tantalum or aluminum polymer cap on the supply rail to handle the transmit burst current. The HC08 core draws single-digit mA at 8MHz/5V; in STOP mode current drops to microamp range, suitable for coin-cell applications.
Route the reset pin (pin 20) with a short trace to a 10k pull-up to VDD and a 100nF cap to VSS for clean power-on-reset behavior. Avoid routing the internal oscillator traces near switching nodes such as the PWM outputs or the IR/RF transmitter FET - the HC08's internal oscillator is more susceptible to EMI than an external crystal, so good PCB grounding is essential. Estimated: PCB area should provide at least 1 square inch of ground plane for thermal and EMI reasons.
Do not assume the part is RoHS compliant without checking the exact suffix; some HC08 lots were built in Pb-bearing process lines. Verify the RoHS status of the specific lot before use in any RoHS-bound design. Also note that the part is listed as obsolete by some distributors - confirm longevity of supply with NXP/Freescale distributors before committing to a production design, or select the MC908QY8CDWE cross-reference instead.
The 20-SOIC wide package has a junction-to-ambient thermal resistance in the 80-100 C/W range. At 5V/8MHz the HC08 core dissipates well under 100mW, so thermal rise is not a concern even in sealed enclosures. Estimated: at 25C ambient the junction temperature stays below 35C under normal operation, leaving ample margin for industrial-temperature environments up to 85C ambient without derating.
Informasi Konformitas
RoHS/REACH compliance status was not stated in the verified web data; mark as unknown pending direct manufacturer confirmation. The part is not AEC-Q100 qualified - it is targeted at consumer/industrial applications. Refer to NXP/Freescale product page for full compliance documentation.
