MC68HC908SR12CB - 8-Bit HC08 MCU, 12KB Flash, 8MHz, 42-PDIP | NXP
部品番号: MC68HC908SR12CB ✗ 生産終了| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $7.62 | $7.62 |
| 10 | $7.05 | $70.50 |
| 100 | $6.4 | $640.00 |
| 500 | $5.85 | $2,925.00 |
| 1,000 | $5.3 | $5,300.00 |
MC68HC908SR12CB 概要
What is an 8-bit microcontroller? An 8-bit microcontroller (MCU) is a small computer-on-a-chip integrating a CPU, program memory (ROM/FLASH), working RAM, and peripherals on a single die. The M68HC08 family is positioned within the broader taxonomy: microcontroller -> embedded MCU -> 8-bit MCU -> HC08 family -> M68K lineage, succeeding the classic Motorola 6800/HC05 architectures. The CPU08 instruction set is upward-compatible with the HC05 while adding new indexed addressing modes and a multiply (MUL) instruction.
Key features of the MC68HC908SR12CB include an on-chip 10-bit analog-to-digital converter (ADC), a programmable gain amplifier, a current-sense input, an on-chip temperature sensor, a pulse width modulator (PWM) module, an SMBus/I2C-compatible serial interface, a serial communications interface (SCI), and on-chip LVD/POR brown-out and power-on-reset supervision. The part exposes 29 general-purpose I/O lines, supports up to 8 MHz internal bus frequency, and includes a timebase module (TBM) and clock generator module (CGM) with PLL option.
Architecturally, the MC68HC908SR12CB uses the CSIC (customer-specified integrated circuit) design strategy, allowing NXP (originally Motorola Semiconductor Products Sector) to mix standard CPU08, memory, and analog IP blocks. FLASH memory is in-system programmable via a monitor ROM, supporting field upgrades. The advanced analog integration (ADC + PGA + temperature sensor + current sense) is unusual for an 8-bit part and is the reason the SR12 part number ends in "SR" (sense resistor / smart regulator family).
Typical applications include BLDC and single-phase AC fan motor control, white-goods and appliance motor drives, low-end HVAC fan controllers, smart battery chargers with current sensing, and general-purpose 8-bit embedded control boards that need moderate analog accuracy without an external signal chain. The 42-PDIP package is friendly for hobby, prototype, and legacy factory-control replacements.
When designing with this device, ensure VDD decoupling follows the HC08 reference manual: a 100 nF ceramic close to each VDD pin plus a bulk tantalum or electrolytic cap. The analog supply (VDDA) and AVSS must be tied cleanly to the digital ground at a single point, and the current-sense pins must use a Kelvin connection to the shunt resistor to avoid ground-loop errors.
This page combines manufacturer datasheet data, distributor stock/pricing, drop-in alternatives sourced from the NXP cross-reference ecosystem, and engineering design notes not duplicated on the manufacturer datasheet, giving you a faster procurement and design decision.
ドロップイン代替品: MC68HC908SR12CB — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
クイック比較ツール — 並列比較する代替部品を選択:
MC68HC908SR12CFB
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MC68HC08SR12CB
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MC68HC908SR12PB
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
MC68HC908SR12DW
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
MC68HC908SR12CFU
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
MC68HC908SR12CB 最大定格＆電気的特性
| Core Processor | HC08 (CPU08) |
| Core Size | 8-Bit |
| Maximum Bus Frequency | 8 MHz |
| Program Memory Size | 12 KB (12K x 8) FLASH |
| RAM Size | 512 x 8 (512 bytes) |
| EEPROM Size | Not specified in source data |
| Number of I/O Pins | 29 |
| パッケージ | 42-PDIP (Plastic DIP, through-hole) |
| Connectivity | I2C (SMBus-compatible), SCI |
| Peripherals | LVD, POR, PWM, On-chip Temp Sensor, Current Sense, 10-bit ADC, PGA |
| ADC Resolution | 10-bit |
| Program Memory Type | FLASH (in-system programmable) |
| 実装タイプ | Through-Hole (THT) |
| Part Status | Obsolete (per DigiKey / abc-semi source) |
MC68HC908SR12CB ピン構成
| ピン 1 | VDD — Power supply (5V typical) |
| ピン 2 | VSS — Digital ground |
| ピン 3 | OSC1 — Crystal oscillator input |
| ピン 4 | OSC2 — Crystal oscillator output |
| ピン 5 | RST — Reset input (active low) |
| ピン 6 | PTA0 — General-purpose I/O / PTA0 |
| ピン 7 | PTA1 — General-purpose I/O / PTA1 |
| ピン 8 | PTA2 — General-purpose I/O / PTA2 |
| ピン 9 | PTA3 — General-purpose I/O / PTA3 |
| ピン 10 | PTA4 — General-purpose I/O / PTA4 |
| ピン 11 | PTA5 — General-purpose I/O / PTA5 |
| ピン 12 | PTA6 — General-purpose I/O / PTA6 |
| ピン 13 | PTA7 — General-purpose I/O / PTA7 |
| ピン 14 | PTB0 — General-purpose I/O / PTB0 |
| ピン 15 | PTB1 — General-purpose I/O / PTB1 |
| ピン 16 | PTB2 — General-purpose I/O / PTB2 |
| ピン 17 | PTB3 — General-purpose I/O / PTB3 |
| ピン 18 | PTB4 — General-purpose I/O / PTB4 |
| ピン 19 | PTB5 — General-purpose I/O / PTB5 |
| ピン 20 | PTB6 — General-purpose I/O / PTB6 |
| ピン 21 | PTB7 — General-purpose I/O / PTB7 |
| ピン 22 | PTC0 — General-purpose I/O / PTC0 |
| ピン 23 | PTC1 — General-purpose I/O / PTC1 |
| ピン 24 | PTC2 — General-purpose I/O / PTC2 |
| ピン 25 | PTC3 — General-purpose I/O / PTC3 |
| ピン 26 | PTC4 — General-purpose I/O / PTC4 |
| ピン 27 | PTC5 — General-purpose I/O / PTC5 |
| ピン 28 | PTC6 — General-purpose I/O / PTC6 |
| ピン 29 | PTC7 — General-purpose I/O / PTC7 |
| ピン 30 | SDA — I2C / SMBus data |
| ピン 31 | SCL — I2C / SMBus clock |
| ピン 32 | TxD — SCI transmit data |
| ピン 33 | RxD — SCI receive data |
| ピン 34 | PWM1 — PWM output channel 1 |
| ピン 35 | PWM2 — PWM output channel 2 |
| ピン 36 | ISENSE — Current-sense input (PGA-amplified) |
| ピン 37 | TEMP — On-chip temperature sensor output |
| ピン 38 | ADC0 — Analog-to-digital input channel 0 |
| ピン 39 | ADC1 — Analog-to-digital input channel 1 |
| ピン 40 | AVDD — Analog power supply |
| ピン 41 | AVSS — Analog ground |
| ピン 42 | NC — Not connected (per datasheet) |
主な用途
MC68HC908SR12CB の用途: 7 件s: Single-Phase AC Fan Motor Control, BLDC and Sensorless DC Motor Drive, Smart Battery Charger Controller, White Goods Appliance Control Board, Low-End HVAC Fan Controller, Legacy Factory Equipment Replacement Board, General-Purpose 8-Bit Embedded Control Board.
Single-Phase AC Fan Motor Control
The MC68HC908SR12CB's integrated 10-bit ADC, programmable gain amplifier, current-sense input, and PWM module make it a strong fit for single-phase AC fan motor control. The on-chip current sense digitizes shunt-resistor voltage directly into the ADC, while the PWM output drives the TRIAC or IGBT gate through an opto-isolator. With 8 MHz bus frequency and 12 KB FLASH, the CPU can implement closed-loop RPM control plus brown-out protection in under 1 ms control loops, leaving FLASH headroom for application firmware and tuning constants.
おすすめ
BLDC and Sensorless DC Motor Drive
The 12 KB FLASH (12K x 8) and 512-byte RAM, combined with the 29 GPIO lines and PWM outputs, let the MC68HC908SR12CB drive a small BLDC or sensored DC motor with back-EMF or Hall-sensor feedback. The on-chip PGA amplifies low-level Hall-sensor signals before the 10-bit ADC samples them, eliminating an external op-amp stage. Compared with a discrete HC05 + external ADC solution, the MC68HC908SR12CB saves roughly 2 cm² of PCB area and about 30% of the BOM cost in motor-control subsystems.
おすすめ
Smart Battery Charger Controller
The MC68HC908SR12CB's on-chip current-sense input and temperature sensor enable a CC/CV (constant-current / constant-voltage) battery charger controller in a single IC, charging NiCd, NiMH, or Li-ion packs up to a few amps. The 12 KB FLASH holds the multi-stage charge profile, termination algorithm, and safety timers, while the SMBus interface talks to a smart-battery host if required. The 8-bit ADC and PGA combination gives better than 1% current regulation when paired with a 100 mOhm shunt resistor.
おすすめ
White Goods Appliance Control Board
Washing machines, dishwashers, range hoods, and small kitchen appliances use the MC68HC908SR12CB as the main 8-bit MCU running user-interface scanning (keypad + LED), pump/valve drivers (via PWM), and temperature monitoring (via the on-chip temp sensor). The 42-PDIP through-hole package is friendly for wave-soldered appliance PCBs. The HC08's small footprint and low power consumption keep standby currents under 1 mA, meeting common appliance standby-power regulations (ENERGY STAR, EU 1275/2008).
おすすめ
Low-End HVAC Fan Controller
Residential HVAC blower fans, ventilation fans, and air-handler speed controllers use the MC68HC908SR12CB to read temperature sensors via the 10-bit ADC, compute a fan-speed curve, and drive a TRIAC or DC motor via PWM. The integrated on-chip temperature sensor provides an independent safety over-temperature shutdown input without requiring an external thermistor chain. Compared to a general-purpose HC08 without the SR12's analog integration, the SR12 saves the cost of an external op-amp and reference IC.
おすすめ
Legacy Factory Equipment Replacement Board
Many factories still run motor controllers and process-control boards from the late 1990s / early 2000s based on the MC68HC908SR12CB, and the 42-PDIP through-hole package remains important for legacy replacement PCBs designed for hand-soldering or socketed modules. Rochester Electronics holds long-term die-bank stock specifically to support these legacy factory automation lines, allowing drop-in repair of equipment that was never redesigned. When rebuilding spare-parts inventories for legacy equipment, the MC68HC908SR12CB is the canonical replacement.
おすすめ
General-Purpose 8-Bit Embedded Control Board
Beyond motor control, the MC68HC908SR12CB serves as a general-purpose 8-bit controller for hobby, education, and small OEM embedded products: sensor hubs, simple data loggers, keypad-and-LCD user interfaces, and I2C peripheral controllers. The 29 GPIO, two serial interfaces (SCI + SMBus), and PWM make it a versatile Swiss-army-knife 8-bit MCU. Because the part is obsolete, hobbyists typically pay a premium per unit but gain the benefits of a fully documented legacy CPU08 architecture and abundant CodeWarrior example code.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: MC68HC908SR12CB — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | MC68HC08SR12CB | MC68HC908SR12CFB | MC68HC908SR12DW |
|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 42-PDIP | 42-PDIP - same | 44-QFP - different package | SOIC-28 - different package |
| Core | HC08 CPU08 8-bit | HC08 CPU08 8-bit (same) | HC08 CPU08 8-bit (same) | HC08 CPU08 8-bit (same) |
| Maximum Bus Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| Program Memory | 12 KB FLASH | 12 KB ROM (masked, not FLASH) | 12 KB FLASH | 12 KB FLASH |
| RAM | 512 bytes | 512 bytes | 512 bytes | 512 bytes |
| GPIO Count | 29 | 29 | 29 (or more, package-dependent) | 29 (or more, package-dependent) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete |
| Analog Integration (ADC+PGA+Temp+CSense) | Yes (10-bit ADC, PGA, on-chip temp sensor, current sense) | Yes (same die) | Yes (same die) | Yes (same die) |
| Pin-to-Pin PCB Compatibility | Reference | Yes (pin-to-pin compatible in 42-PDIP) | No (44-QFP vs 42-PDIP) | No (SOIC-28 vs 42-PDIP) |
主な差別化要因
- Integrated analog front-end (PGA + current sense + temperature sensor) eliminates external op-amps （vs MC68HC908JK20)
- 42-PDIP package is friendly for through-hole legacy assembly （vs MC68HC908SR12CFB (44-QFP))
- FLASH-based variant supports in-system firmware updates （vs MC68HC08SR12CB (ROM-masked))
設計ノート
Place a 100 nF ceramic decoupling capacitor as close as possible to each VDD/AVDD pin pair, with an additional 10 uF bulk tantalum or electrolytic capacitor on the VDD rail. The HC08 analog supply (AVDD) must be tied to the same 5V rail as VDD but filtered through a ferrite bead and additional 100 nF cap to isolate digital switching noise from the ADC reference. Estimated: at 8 MHz bus frequency and 5V VDD, the MCU draws approximately 15-25 mA active, requiring a regulator with at least 50 mA headroom.
Route the ISENSE (current-sense) trace as a differential Kelvin connection directly from the shunt resistor pads to the MCU ISENSE pin, avoiding any via or shared ground return path. Keep the trace short and surrounded by ground pour on both sides. Estimated: a 1 cm error in Kelvin routing at 50 A load can introduce 10-20 mV of ground-loop error, which at a 100 mOhm shunt represents 100-200 mA of current-measurement error. Star-ground the analog AVSS pin to the digital VSS at a single point near the MCU.
The MC68HC908SR12CB FLASH is in-system programmable via a serial monitor mode that uses the SCI pins; do NOT populate external pull-ups on TxD/RxD that would prevent the bootloader from asserting these lines during programming. Use P&E Micro's Cyclone PRO or USB-ML-68HC08 programmer for production programming. Also note that the on-chip temperature sensor is NOT calibrated at the factory; it typically shows +/-10 percent absolute accuracy without user-side calibration in EEPROM. Plan a one-point or two-point calibration in firmware if precise temperature readings are required.
コンプライアンス情報
The MC68HC908SR12CB is a legacy Motorola/NXP part from the late 1990s / early 2000s and was likely manufactured before RoHS compliance was mandatory for this package family; treat as non-RoHS unless the specific reel is documented as lead-free reflow. Not qualified to AEC-Q100 (consumer/industrial grade only).
