MC908SR12CBE - 8MHz 8-Bit HC08 MCU 12KB Flash 42-PDIP | NXP
MPN: MC908SR12CBE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.67 | $4.67 |
| 10 | $4.2 | $42.00 |
| 100 | $3.65 | $365.00 |
| 500 | $3.1 | $1,550.00 |
| 1,000 | $2.75 | $2,750.00 |
MC908SR12CBE Overview
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.
Drop-in alternatives for MC908SR12CBE — 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 MC908SR12CBE (same form factor and footprint) — differing in ADC, Core, Package, RAM Size, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC908SR12CFAE
✅ Drop-In✓ In Stock
$4.31 / Unit
View Datasheet →MC908AP32CFAE
✅ Drop-In✓ In Stock
$7.4 / Unit
View Datasheet →MC908JK3ECDWE
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →MC908QY4ACDTE
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →MC68HC711E9
✅ Drop-In📋 Reference alternative (not in catalog)
MC908SR12CBE Maximum Ratings & Electrical Characteristics
| Core | HC08 (M68HC08) |
| Data Bus Width | 8 bit |
| Maximum Clock Frequency | 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 |
| Operating Temperature Range | -40C to +85C |
| Package / Case | 42-PDIP (0.600 in, 15.24 mm) |
| Mounting Type | Through Hole |
| Oscillator Type | Internal |
| Packaging | Tube |
| RoHS Status | RoHS3 Compliant |
| Family | HC08SR |
MC908SR12CBE Pin Configuration
| Pin 1 | IRQ — External interrupt request input |
| Pin 2 | PTA0 — Port A bit 0 / ADC input |
| Pin 3 | PTA1 — Port A bit 1 / ADC input |
| Pin 4 | PTA2 — Port A bit 2 / ADC input |
| Pin 5 | PTA3 — Port A bit 3 / ADC input |
| Pin 6 | PTA4 — Port A bit 4 / ADC input |
| Pin 7 | PTA5 — Port A bit 5 / ADC input |
| Pin 8 | PTA6 — Port A bit 6 / ADC input |
| Pin 9 | PTA7 — Port A bit 7 / ADC input |
| Pin 10 | VDD — Supply voltage (2.7 V to 5.5 V) |
| Pin 11 | VSS — Ground |
| Pin 12 | OSC1 — Oscillator input / external clock |
| Pin 13 | OSC2 — Oscillator output |
| Pin 14 | PTB0 — Port B bit 0 / timer channel |
| Pin 15 | PTB1 — Port B bit 1 / timer channel |
| Pin 16 | PTB2 — Port B bit 2 / timer channel |
| Pin 17 | PTB3 — Port B bit 3 / timer channel |
| Pin 18 | PTB4 — Port B bit 4 / timer channel |
| Pin 19 | PTB5 — Port B bit 5 / timer channel |
| Pin 20 | PTB6 — Port B bit 6 / timer channel |
| Pin 21 | PTB7 — Port B bit 7 / timer channel |
| Pin 22 | PTC0 — Port C bit 0 |
| Pin 23 | PTC1 — Port C bit 1 |
| Pin 24 | PTC2 — Port C bit 2 |
| Pin 25 | PTC3 — Port C bit 3 |
| Pin 26 | PTC4 — Port C bit 4 |
| Pin 27 | PTC5 — Port C bit 5 |
| Pin 28 | PTC6 — Port C bit 6 |
| Pin 29 | PTC7 — Port C bit 7 |
| Pin 30 | PTD0 — Port D bit 0 / SPI |
| Pin 31 | PTD1 — Port D bit 1 / SPI |
| Pin 32 | PTD2 — Port D bit 2 / SPI |
| Pin 33 | PTD3 — Port D bit 3 / SPI |
| Pin 34 | PTD4 — Port D bit 4 / UART |
| Pin 35 | PTD5 — Port D bit 5 / UART |
| Pin 36 | PTD6 — Port D bit 6 / UART |
| Pin 37 | PTD7 — Port D bit 7 / UART |
| Pin 38 | RST — Reset input (active low) |
| Pin 39 | VPP — Programming voltage input |
| Pin 40 | VDD — Supply voltage |
| Pin 41 | VSS — Ground |
| Pin 42 | NC — Not connected (per datasheet) |
Typical Applications
MC908SR12CBE is suitable for 6 applications: 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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
Recommended Products Summary
Engineering reference data for MC908SR12CBE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 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 |
Key Differentiators
- Largest Flash in HC08SR 42-PDIP family at low cost (vs MC908JK3ECDWE)
- Modern HC08 CPU versus older HC11 instruction set (vs MC68HC711E9)
- Same 42-PDIP pinout as MC908SR12CFAE (vs MC908AP32CFAE)
Design Notes
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.
Compliance Information
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.
