MC908GR8CDWE - 8-bit HC08 MCU, 7.5KB Flash, 28-SOIC | NXP
MPN: MC908GR8CDWE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.4 | $74.00 |
| 100 | $6.1 | $610.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.55 | $4,550.00 |
MC908GR8CDWE Overview
Background: An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data bus and a CISC (Complex Instruction Set Computer) or RISC instruction set, integrating CPU, non-volatile program memory (Flash/ROM), volatile data memory (RAM), and a set of peripherals such as timers, ADC, and communication controllers. Within the broader hierarchy, an MCU belongs to microcontrollers -> microcomputers -> embedded processors -> semiconductors. The Freescale/NXP HC08 family is a CISC architecture widely used in automotive body electronics, white goods, and industrial control where deterministic interrupt response and low cost matter more than raw throughput.
Key features include an 8 MHz internal bus, an on-chip oscillator, 7.5 KB of Flash, 384 bytes of RAM, and 17 GPIO pins. The wide operating voltage range (typically 3 V to 5.5 V) and a multi-channel timer make the part attractive for battery-backed and brown-out-sensitive applications. The 28-SOIC wide-body package simplifies hand-soldering and rework on through-hole-friendly 1.27 mm pitch footprints.
The HC08 core uses a Von Neumann architecture with a 16-bit stack pointer, allowing efficient C compilation and an upward migration path to the enhanced HCS08 family. The integrated Flash supports in-application programming via a background debug mode, simplifying field firmware updates.
Typical applications include appliance control boards, simple sensor signal conditioning nodes, automotive body controllers, HVAC actuators, and remote keyless entry transmitters. The wide 28-SOIC footprint and mature toolchain also make it suitable for legacy industrial PLC I/O modules where the part was originally designed in.
When designing with this part, ensure the supply decoupling network includes a 100 nF ceramic capacitor close to VDD/VSS plus a bulk capacitor of at least 4.7 uF, since the internal oscillator is sensitive to VDD ripple. Always verify oscillator trimming against the production temperature range, and budget for the 1.9 V minimum Flash programming voltage if in-circuit programming is used.
This page synthesizes distributor pricing, parametric alternatives, lifecycle status, and practical design notes that go beyond the manufacturer datasheet.
Drop-in alternatives for MC908GR8CDWE — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
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MC908GR8CFAE
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MC908GR16ACDWER
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MC908GR8CDWE Maximum Ratings & Electrical Characteristics
| Core | M68HC08 (8-bit CISC) |
| Program Memory | 7.5 KB Flash (7.5K x 8) |
| RAM Size | 384 bytes (384 x 8) |
| Maximum Clock Frequency | 8 MHz internal bus |
| Operating Voltage | 3.3 V / 5 V (3 V to 5.5 V range) |
| Number of I/O Pins | 17 |
| Package / Case | 28-SOIC (0.295 inch / 7.50 mm width) |
| Oscillator Type | Internal |
| Data Bus Width | 8-bit |
| Series | HC08 GR |
| Program Memory Type | FLASH |
| Mounting Type | Surface Mount |
| Packaging | Tube |
MC908GR8CDWE Pin Configuration
| Pin 1 | IRQ — External interrupt request input |
| Pin 2 | PTA0 — Port A bit 0 / general I/O |
| Pin 3 | PTA1 — Port A bit 1 / general I/O |
| Pin 4 | PTA2 — Port A bit 2 / general I/O |
| Pin 5 | PTA3 — Port A bit 3 / general I/O |
| Pin 6 | PTA4 — Port A bit 4 / general I/O |
| Pin 7 | PTA5 — Port A bit 5 / general I/O |
| Pin 8 | PTA6 — Port A bit 6 / general I/O |
| Pin 9 | PTA7 — Port A bit 7 / general I/O |
| Pin 10 | VSS — Ground |
| Pin 11 | OSC1 — Oscillator input / external clock |
| Pin 12 | OSC2 — Oscillator output |
| Pin 13 | VDD — Positive supply (3.3 V or 5 V) |
| Pin 14 | PTB0 — Port B bit 0 / general I/O |
| Pin 15 | PTB1 — Port B bit 1 / general I/O |
| Pin 16 | PTB2 — Port B bit 2 / general I/O |
| Pin 17 | PTB3 — Port B bit 3 / general I/O |
| Pin 18 | PTB4 — Port B bit 4 / general I/O |
| Pin 19 | PTB5 — Port B bit 5 / general I/O |
| Pin 20 | PTB6 — Port B bit 6 / general I/O |
| Pin 21 | PTB7 — Port B bit 7 / general I/O |
| Pin 22 | PTC0 — Port C bit 0 / general I/O |
| Pin 23 | PTC1 — Port C bit 1 / general I/O |
| Pin 24 | PTC2 — Port C bit 2 / general I/O |
| Pin 25 | PTC3 — Port C bit 3 / general I/O |
| Pin 26 | RST — Reset input (active low) |
| Pin 27 | BKGD — Background debug mode |
| Pin 28 | VPP — Flash programming voltage |
Typical Applications
MC908GR8CDWE is suitable for 7 applications: Appliance Control Boards, Automotive Body Controllers, HVAC Actuator Modules, Remote Keyless Entry (RKE) Transmitters, Sensor Signal Conditioning Nodes, Legacy Industrial PLC I/O Modules, Consumer Remote Control Handsets.
Appliance Control Boards
The MC908GR8CDWE's 7.5 KB Flash and 17 GPIO fit washing machine, dishwasher, and microwave control boards where deterministic interrupt response and low cost matter. Its internal oscillator eliminates the external crystal, reducing BOM cost on appliance mainboards that ship in millions of units per year. Place a 100 nF ceramic decoupling cap close to VDD and a 4.7 uF bulk capacitor on the supply rail to keep the internal oscillator stable across motor inrush events. With 8 MHz bus speed, the HC08 core easily services keypad scanning, relay drivers, and simple UART links to inverter modules.
Recommended
Automotive Body Controllers
For body electronics such as door modules, seat controllers, and lighting nodes, the MC908GR8CDWE provides the 5 V tolerance and HC08 CISC interrupt model used by legacy automotive firmware. With 17 GPIO the part can drive multiple relays, read switch matrices, and PWM dim lamps without external drivers. Although the standard grade is not AEC-Q100 qualified, the same die ships in automotive-qualified variants for under-hood and cabin applications. The 28-SOIC wide-body package simplifies conformal-coated board rework in vehicle service environments.
Recommended
HVAC Actuator Modules
Heating, ventilation, and air-conditioning damper and valve actuators benefit from the MC908GR8CDWE's compact 28-SOIC package and integrated timers for PWM motor control. The HC08's CISC instruction set simplifies the lookup tables and PID loops typical of damper control firmware. With 384 bytes of RAM the part can buffer ADC samples from thermistor sensors while simultaneously driving a stepper or brushless DC actuator. Brown-out detection protects the actuator against stalls and under-voltage events common in HVAC bus lines.
Recommended
Remote Keyless Entry (RKE) Transmitters
Battery-powered RKE key fobs use the MC908GR8CDWE for low-power button scanning and one-shot RF packet encoding. The HC08 core's fast wake-up from stop mode, combined with the integrated oscillator, keeps quiescent current low enough for multi-year coin-cell battery life. With 7.5 KB of Flash the part can hold rolling-code encryption tables and OEM pairing parameters for several vehicle models. The 28-SOIC package supports hand-assembly for prototype fobs while remaining compatible with high-volume reflow lines.
Recommended
Sensor Signal Conditioning Nodes
Industrial sensor hubs that read thermocouples, strain gauges, or 4-20 mA loops leverage the MC908GR8CDWE's GPIO and ADC-friendly 5 V supply rail. The HC08 core can implement linearization routines in firmware while 384 bytes of RAM buffer oversampled readings before UART/SPI forwarding. The wide 28-SOIC footprint simplifies field wiring termination boards where service technicians prefer through-hole-friendly 1.27 mm pitch. Wide operating voltage tolerance keeps the node functional across unregulated 24 V industrial rails when paired with an external LDO.
Recommended
Legacy Industrial PLC I/O Modules
Modicon-style PLC digital and analog I/O modules continue to use the MC908GR8CDWE as a per-channel coprocessor for filtering, debouncing, and diagnostic logging. With 17 GPIO the part can scan multiple isolated inputs through optocouplers while driving LEDs and relays on a single chip. The 8 MHz HC08 bus is fast enough to implement moving-average filters on noisy industrial signals. Engineers maintaining these modules should stock MC908GR8CDWE now, as the part is obsolete and lead time on new orders is no longer guaranteed by NXP.
Recommended
Consumer Remote Control Handsets
TV, set-top-box, and audio-system remote controls integrate the MC908GR8CDWE for matrix keypad scanning, IR or RF transmission, and low-power standby. The HC08's low-cost Flash and integrated oscillator let manufacturers ship sub-$3 BOMs while keeping firmware upgradeable through the background debug mode. With 7.5 KB of Flash, code space supports multiple device codesets and OEM brand tables for universal remote designs. The 28-SOIC package is friendly to hand-solder rework during prototyping and small-batch production.
Recommended
Recommended Products Summary
Engineering reference data for MC908GR8CDWE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC908GR8ACDWER | MC908GR8CFAE | MC908GR16ACDWER | MC908GR4ACDWER | MC9S08QE32CWL |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 28-SOIC (wide) | 28-SOIC (wide) - same | 32-QFP (different package) | 28-SOIC (wide) - same | 28-SOIC (wide) - same | 28-SOIC (wide) - same |
| Core | M68HC08 (8-bit CISC) | M68HC08 (same) | M68HC08 (same) | M68HC08 (same) | M68HC08 (same) | S08 (successor) |
| Program Memory (Flash) | 7.5 KB | 7.5 KB | 7.5 KB | 16 KB | 4 KB | 32 KB |
| RAM Size | 384 bytes | 384 bytes | 384 bytes | 512 bytes | 256 bytes | 2 KB |
| Maximum Bus Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 20 MHz |
| Operating Voltage | 3.3 V / 5 V | 3.3 V / 5 V | 3.3 V / 5 V | 3.3 V / 5 V | 3.3 V / 5 V | 1.8 V to 3.6 V |
| GPIO Count | 17 | 17 | 17 | 17 | 17 | 26 |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Active |
Key Differentiators
- Mature HC08 CISC core with broad legacy firmware base (vs MC908JL3ECDWE)
- Internal oscillator eliminates external crystal cost (vs MC9S08QE32CWL)
- 28-SOIC wide-body package simplifies hand rework (vs MC908GR8CFAE (32-QFP))
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 13) and a 4.7 uF or larger bulk capacitor on the same supply rail. The MC908GR8CDWE's internal oscillator is sensitive to VDD ripple; inadequate decoupling will manifest as baud-rate drift on the UART or timer period jitter on PWM outputs. For designs powered from a 24 V industrial rail, use an LDO such as the LM7805 or a modern equivalent to derive a clean 5 V supply.
Route the BKGD (pin 27) and RST (pin 26) traces away from high-current switching nodes such as relay coils or motor drivers. The 28-SOIC wide-body package has generous 1.27 mm pin pitch that tolerates hand routing, but keep analog ground and digital ground separated with a single-point tie at the MCU VSS pin to minimize ADC noise in mixed-signal designs.
Do not apply voltage to the VPP (pin 28) flash programming pin during normal operation beyond the datasheet limit; exceeding this voltage can latch-up the Flash charge pump and permanently damage the part. Always tie VPP to VDD through a 10 kohm resistor if in-circuit programming is not used, and verify the BKGD pin is not driven by external logic during reset. As a courtesy reminder, the part is obsolete - stock sufficient inventory for the product's expected lifetime.
When using the HC08 internal oscillator in EMI-sensitive environments (automotive, industrial), add a small ferrite bead in series with VDD and a 1 nF decoupling cap at the IC supply pin. Although the internal oscillator is robust, long PCB traces carrying the OSC1/OSC2 signals act as antennas; keep these traces short and shielded by a ground pour on adjacent layers.
Compliance Information
Compliance status not explicitly stated in the verified web data. Standard MC908GR8CDWE is commercial/industrial grade, not AEC-Q100; consult the manufacturer datasheet for RoHS/lead-free status before use in regulated markets.
