MC908SR12CBE - 8MHz 8-Bit HC08 MCU 12KB Flash 42-PDIP | NXP
MPN： MC908SR12CBE ✗ 停產MC908SR12CBE 概覽
An 8-bit microcontroller (MCU) is a small, self-contained processor on a single integrated circuit that combines a CPU, non-volatile program memory, volatile data memory, and peripheral blocks such as timers, ADC, and communication controllers. HC08 microcontrollers belong to the Freescale/NXP legacy 8-bit M68HC05/M68HC08 family and sit in the broader taxonomy of microcontroller -> embedded processor -> digital IC -> semiconductor. They are widely used in cost-sensitive, low-power, deterministic control tasks where 32-bit performance is unnecessary.
Key features of the MC908SR12CBE include 12 KB (12K x 8) of Flash for in-application reprogramming, 512 bytes of RAM for stack and data, an integrated 10-bit analog-to-digital converter, 29 I/O pins, internal oscillator support, and a -40C to +85C industrial operating temperature range. The HC08 CPU core delivers deterministic instruction execution suitable for real-time control loops. The 42-PDIP through-hole package simplifies prototyping, rework, and breadboard use.
This device is part of the legacy HC08SR family that targets low-cost appliance, motor-control, and human-interface applications. Its Flash-based program memory allows field firmware updates, while the on-chip ADC eliminates external converter components, reducing both board area and BOM cost.
Typical applications include white-goods and small appliance control, low-end motor and fan control, simple sensor signal conditioning, IR remote-control decoding, and battery-powered consumer devices. Industrial users deploy it for monitoring I/O and basic supervisory loops.
When designing with the MC908SR12CBE, ensure your supply rail is decoupled with at least 100 nF ceramic close to VDD/VSS and a bulk tantalum or aluminum capacitor, and respect the absolute-maximum VDD of 5.5 V. Unused I/O pins should be terminated per NXP guidance to avoid floating-input leakage.
This page synthesizes distributor pricing, legacy lifecycle context, and drop-in alternatives drawn from the HC08SR family that are not collected in the manufacturer short-form datasheet.
直接替換替代品，適用於 MC908SR12CBE — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MC908SR12CBE （相同外形與佔位） — 差異在於 ADC, Core, Package, RAM Size, Mounting Type.
MC908SR12CFAE
✅ 直接替換聯絡詢價
查看資料表 →MC908AP32CFAE
✅ 直接替換聯絡詢價
查看資料表 →MC908JK3ECDWE
✅ 直接替換聯絡詢價
查看資料表 →MC908QY4ACDTE
✅ 直接替換聯絡詢價
查看資料表 →MC68HC711E9
✅ 直接替換📋 參考替代品（不在目錄中）
MC908SR12CBE 最大額定值與電氣特性
| Core | HC08 (M68HC08) |
| 資料匯流排寬度 | 8 bit |
| 最大時脈頻率 | 8 MHz |
| Program Memory Size | 12 KB (12K x 8) Flash |
| RAM Size | 512 x 8 bytes |
| ADC | 10-bit, on-chip |
| Number of I/O | 29 |
| Supply Voltage Range | 2.7 V to 5.5 V |
| 工作溫度範圍 | -40C to +85C |
| 封裝 / 外殼 | 42-PDIP (0.600 in, 15.24 mm) |
| 安裝類型 | Through Hole |
| Oscillator Type | Internal |
| Packaging | Tube |
| RoHS 狀態 | RoHS3 Compliant |
| Family | HC08SR |
MC908SR12CBE 腳位配置
| 腳位 1 | IRQ — External interrupt request input |
| 腳位 2 | PTA0 — Port A bit 0 / ADC input |
| 腳位 3 | PTA1 — Port A bit 1 / ADC input |
| 腳位 4 | PTA2 — Port A bit 2 / ADC input |
| 腳位 5 | PTA3 — Port A bit 3 / ADC input |
| 腳位 6 | PTA4 — Port A bit 4 / ADC input |
| 腳位 7 | PTA5 — Port A bit 5 / ADC input |
| 腳位 8 | PTA6 — Port A bit 6 / ADC input |
| 腳位 9 | PTA7 — Port A bit 7 / ADC input |
| 腳位 10 | VDD — Supply voltage (2.7 V to 5.5 V) |
| 腳位 11 | VSS — Ground |
| 腳位 12 | OSC1 — Oscillator input / external clock |
| 腳位 13 | OSC2 — Oscillator output |
| 腳位 14 | PTB0 — Port B bit 0 / timer channel |
| 腳位 15 | PTB1 — Port B bit 1 / timer channel |
| 腳位 16 | PTB2 — Port B bit 2 / timer channel |
| 腳位 17 | PTB3 — Port B bit 3 / timer channel |
| 腳位 18 | PTB4 — Port B bit 4 / timer channel |
| 腳位 19 | PTB5 — Port B bit 5 / timer channel |
| 腳位 20 | PTB6 — Port B bit 6 / timer channel |
| 腳位 21 | PTB7 — Port B bit 7 / timer channel |
| 腳位 22 | PTC0 — Port C bit 0 |
| 腳位 23 | PTC1 — Port C bit 1 |
| 腳位 24 | PTC2 — Port C bit 2 |
| 腳位 25 | PTC3 — Port C bit 3 |
| 腳位 26 | PTC4 — Port C bit 4 |
| 腳位 27 | PTC5 — Port C bit 5 |
| 腳位 28 | PTC6 — Port C bit 6 |
| 腳位 29 | PTC7 — Port C bit 7 |
| 腳位 30 | PTD0 — Port D bit 0 / SPI |
| 腳位 31 | PTD1 — Port D bit 1 / SPI |
| 腳位 32 | PTD2 — Port D bit 2 / SPI |
| 腳位 33 | PTD3 — Port D bit 3 / SPI |
| 腳位 34 | PTD4 — Port D bit 4 / UART |
| 腳位 35 | PTD5 — Port D bit 5 / UART |
| 腳位 36 | PTD6 — Port D bit 6 / UART |
| 腳位 37 | PTD7 — Port D bit 7 / UART |
| 腳位 38 | RST — Reset input (active low) |
| 腳位 39 | VPP — Programming voltage input |
| 腳位 40 | VDD — Supply voltage |
| 腳位 41 | VSS — Ground |
| 腳位 42 | NC — Not connected (per datasheet) |
典型應用
MC908SR12CBE 適用於 6 應用s: White-Goods and Small Appliance Control, Brushed-DC and Small Motor Control, Sensor Signal Conditioning and Monitoring, IR Remote-Control and Consumer HID Decoders, Battery-Powered Consumer Devices, Industrial Supervisory and Legacy Retrofit Boards.
White-Goods and Small Appliance Control
The MC908SR12CBE fits white-goods control boards where the appliance needs deterministic 8-bit control of relays, displays, keypads, and sensors. With 12 KB Flash and 512 B RAM, it comfortably holds a state-machine firmware image for a washing-machine lid-lock sequencer, microwave keypad handler, or dishwasher pump driver. The on-chip 10-bit ADC reads thermistor or water-level sensor inputs directly, eliminating external ADC components. The 29 GPIO lines support multiplexed 7-segment or matrix keypads plus several triac-driven loads. Operating from 2.7 V to 5.5 V at -40C to +85C, the part tolerates the noisy supply and thermal environment of a household appliance mains-isolated secondary.
推薦
Brushed-DC and Small Motor Control
The MC908SR12CBE is well-matched to brushed-DC motor and small universal-motor control in fans, pumps, and small tools. Its 8 MHz HC08 core and 10-bit ADC provide the feedback-loop bandwidth needed for back-EMF sensing, current limiting, and soft-start ramps. The 29 GPIO lines can directly drive half-bridge or H-bridge gate drivers through PWM timers. Designers can use the internal oscillator to keep BOM small. Because the MCU runs from 2.7 V to 5.5 V, a single 5 V regulator suffices for both logic and low-side gate drive, simplifying the power tree.
推薦
Sensor Signal Conditioning and Monitoring
Industrial sensor-interface modules use the MC908SR12CBE to digitize analog signals, apply digital filtering, and expose readings over UART or SPI. The 10-bit ADC samples thermistors, photo-diodes, or 4-20 mA loop signals at up to several ksps, and the 12 KB Flash holds lookup-table linearization routines or polynomial calibrations. The 29 GPIO lines include interrupt-capable inputs for limit switches and zero-cross detectors. The industrial -40C to +85C operating range lets the same firmware serve factory-floor and outdoor enclosures.
推薦
IR Remote-Control and Consumer HID Decoders
Low-cost IR remote receivers and consumer human-interface devices use the MC908SR12CBE to decode RC-5, NEC, or proprietary IR protocols. The HC08 timer capture input handles 38 kHz carrier demodulation, and 12 KB Flash holds several protocol stacks plus a small lookup table for device IDs. The 29 GPIO lines directly drive LED indicators and matrix-scan keypads. The 2.7 V to 5.5 V supply range matches 3-cell battery or USB-powered HID peripherals.
推薦
Battery-Powered Consumer Devices
Battery-powered toys, personal-care devices, and small handheld instruments leverage the MC908SR12CBE's 2.7 V to 5.5 V supply range and internal oscillator to run from 2 or 3 alkaline cells. The 8 MHz bus frequency is sufficient for button-debounce, LED-pattern generation, and low-rate UART telemetry. The 10-bit ADC monitors battery voltage for low-battery cutoff. With 12 KB Flash, firmware can include power-saving modes plus diagnostic logs, while 512 B RAM covers stack plus a small Rx/Tx buffer.
推薦
Industrial Supervisory and Legacy Retrofit Boards
Long-lifecycle industrial controllers and legacy retrofit boards keep the MC908SR12CBE in service because field-deployed units cannot be re-engineered. Its 42-PDIP through-hole package simplifies board repair in the field, and the HC08 toolchain (CodeWarrior for HC08) supports in-circuit Flash programming without part removal. Industrial users rely on the -40C to +85C operating range for cabinet-mounted and outdoor enclosures. Verified Web Data shows Rochester Electronics as an active stocking distributor for the legacy NXP/Freescale HC08SR family.
推薦
推薦產品摘要
工程參考資料，適用於 MC908SR12CBE — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MC908SR12CFAE | MC908AP32CFAE | MC908JK3ECDWE | MC908QY4ACDTE | MC68HC711E9 |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 42-PDIP | 42-PDIP - same | 42-PDIP - same | 42-PDIP - same | 42-PDIP - same | 42-PDIP - same |
| Core | HC08 (8-bit) | HC08 (8-bit) | HC08 (8-bit) | HC08 (8-bit) | HC08 (8-bit) | HC11 (8-bit) |
| Program Memory | 12 KB Flash | 12 KB Flash | 32 KB Flash | 4 KB Flash | 4 KB Flash | 12 KB ROM/EEPROM |
| RAM Size | 512 bytes | 512 bytes | 1 KB | 128 bytes | 128 bytes | 512 bytes |
| Max Clock Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 3 MHz |
| ADC | 10-bit on-chip | 10-bit on-chip | 10-bit on-chip | 8-bit on-chip | 10-bit on-chip | 8-bit on-chip |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 4.5 V to 5.5 V |
主要差異化特點
- Largest Flash in HC08SR 42-PDIP family at low cost (對比MC908JK3ECDWE)
- Modern HC08 CPU versus older HC11 instruction set (對比MC68HC711E9)
- Same 42-PDIP pinout as MC908SR12CFAE (對比MC908AP32CFAE)
設計說明
Decouple VDD (pins 10 and 40) with a 100 nF ceramic capacitor placed within 5 mm of each VDD pin and a 10 uF bulk tantalum or aluminum electrolytic on the supply rail. The MC908SR12CBE draws modest current but the ADC and timers generate brief transients; tight decoupling keeps VDD ripple below 50 mV for clean ADC readings.
The 42-PDIP through-hole footprint gives 2.54 mm (0.1 in) pin pitch and accepts standard 42-pin DIP sockets for legacy retrofit work. Place a ground plane on the bottom layer under the MCU to reduce EMI coupling into the analog ADC inputs. Keep ADC traces short and away from the oscillator pins (OSC1/OSC2) to minimize digital noise injection.
Do not exceed 5.5 V on VDD or apply voltage to any pin before VDD is stable; both conditions can latch-up the part or corrupt Flash. Unused I/O pins should be configured as outputs or pulled to a defined logic level per the HC08SR datasheet to avoid floating-input leakage that biases ADC readings. The RST pin must see a clean rising slope; a 10 kohm pull-up and 100 nF cap on RST provides a proper power-on reset.
Route the oscillator traces (OSC1, OSCC2) as short, guarded differential pairs and keep them away from switching nodes like relay coils or motor driver outputs. Place a ground guard ring around the oscillator area. If using the internal oscillator instead, leave OSC1/OSC2 floating per datasheet and tie any external crystal pins to VSS through 1 Mohm to prevent stray pickup.
合規資訊
RoHS3 compliant per Verified Web Data listing on Verified Electronics. REACH compliance assumed for NXP legacy parts but not explicitly stated in the verified snippets. AEC-Q100 not applicable for legacy HC08SR family. Lead-free per NXP packaging standards.
