MC908QB8VDWE - 8KB Flash 8MHz HC08 MCU 16-SOIC | NXP
MPN: MC908QB8VDWE ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.5 | $6.50 |
| 10 | $5.85 | $58.50 |
| 100 | $5.2 | $520.00 |
| 500 | $4.55 | $2,275.00 |
| 1,000 | $3.95 | $3,950.00 |
MC908QB8VDWE Overview
An 8-bit microcontroller (MCU) is a microprocessor optimized for embedded control, integrating CPU, memory (Flash/ROM/RAM), and peripherals on a single chip. The HC08 family is a Complex Instruction Set Computer (CISC) family with Von Neumann architecture (unified program/data bus), positioned as the low-cost, high-performance successor to the M68HC05 line within NXP's legacy 8-bit portfolio. The QB sub-family targets applications requiring small package count, low pin count (16 pins), and integrated analog/digital peripherals with minimal external components.
Key features include 8KB (8K x 8) on-chip Flash program memory, 256 bytes RAM, 14 general-purpose I/O lines, an internal bus clock up to 8MHz (32MHz oscillator with divide-by-4), 5V operation (4.5V to 5.5V supply), and integrated peripherals including a 6-channel 10-bit ADC, timer interface, and serial communication interface. The 16-SOIC package provides surface-mount compatibility for standard reflow processes and supports industrial operating temperature ranges.
The HC08QB8 architecture uses an enhanced M68HC08 central processor unit (CPU) with 16-bit stack pointer, 16-bit index register, and 8-bit accumulator. Memory addressing supports up to 64KB linear space, with security and protection features to prevent unauthorized Flash access. The integrated oscillator, brownout reset, low-voltage reset, and watchdog timer provide system-level robustness for unattended industrial installations.
Typical applications include home appliances, white goods motor control, simple sensor interfaces, low-end consumer electronics, industrial control modules, lighting control, and battery chargers. The compact 16-SOIC footprint and integrated peripherals make it well-suited for replacing discrete logic plus analog front-end designs with a single MCU.
When designing with this device, ensure the supply voltage stays within 4.5V to 5.5V and place decoupling capacitors (100 nF + 10 uF) close to the VDD/VSS pins. The oscillator and reset pins should be configured per the reference manual to guarantee clean startup, and unused I/O pins should be configured as outputs to minimize current draw.
This page synthesizes distributor pricing, drop-in alternatives from the HC08 family, and practical design notes for the MC908QB8VDWE that go beyond the manufacturer datasheet, helping engineers select the right variant and design the surrounding support circuitry with confidence.
Drop-in alternatives for MC908QB8VDWE — 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 MC908QB8VDWE (same form factor and footprint) — differing in Architecture, Core, Mounting Type, Package, RAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC908QB8CDWE
✅ Drop-In✓ In Stock
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View Datasheet →MC908QB8VDW
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QB8CDWER
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QY8VDWE
✅ Drop-In✓ In Stock
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View Datasheet →MCHC908QB8MDWE
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QB8VDWE Maximum Ratings & Electrical Characteristics
| Core | HC08 (8-bit CISC) |
| Architecture | Von Neumann |
| Program Memory | 8 KB Flash (8K x 8) |
| RAM | 256 bytes |
| CPU Clock Speed | 8 MHz (internal bus) |
| Oscillator Frequency | 32 MHz max (with internal divide-by-4) |
| Supply Voltage (VDD) | 4.5 V to 5.5 V |
| I/O Pins | 14 |
| Package | 16-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount (Gull Wing) |
| Operating Temperature | -40C to +85C (Industrial) |
| Temperature Grade | Industrial |
| ADC | 6-channel 10-bit (per family reference) |
| Timers | Yes (TIM/ICM1, per family reference) |
| RoHS Status | Compliant |
| Terminal Form | GULL WING |
| Number of Terminals | 16 |
MC908QB8VDWE Pin Configuration
| Pin 1 | VDD — Positive supply voltage (4.5V-5.5V) |
| Pin 2 | OSC1 — Oscillator input / external clock |
| Pin 3 | OSC2 — Oscillator output |
| Pin 4 | PTA0 — General-purpose I/O / ADC channel |
| Pin 5 | PTA1 — General-purpose I/O / ADC channel |
| Pin 6 | PTA2 — General-purpose I/O / ADC channel |
| Pin 7 | PTA3 — General-purpose I/O / ADC channel |
| Pin 8 | VSS — Ground reference |
| Pin 9 | PTA4 — General-purpose I/O / timer channel |
| Pin 10 | PTA5 — General-purpose I/O / timer channel |
| Pin 11 | PTB0 — General-purpose I/O |
| Pin 12 | PTB1 — General-purpose I/O |
| Pin 13 | PTB2 — General-purpose I/O |
| Pin 14 | PTB3 — General-purpose I/O |
| Pin 15 | RST — Reset input (active low) |
| Pin 16 | IRQ — External interrupt / general-purpose I/O |
Typical Applications
MC908QB8VDWE is suitable for 6 applications: Home Appliance Control, Lighting Control Modules, Industrial Sensor Interface, Battery Chargers (Low-Cost Lead-Acid / NiMH), Simple Motor Control (Relays / Solenoids), Consumer Electronics Keypads / Remote Controls.
Home Appliance Control
The MC908QB8VDWE fits home appliance control boards (washing machines, dishwashers, microwave ovens) where 8KB Flash holds the user-interface state machine, ADC reads temperature/level sensors, and GPIO drives relay triacs. Its 4.5-5.5V supply matches the 5V rails common in white-goods SMPS designs, and the 16-SOIC footprint fits compact appliance PCBs. The -40C to +85C industrial rating covers under-counter and garage installations. With 14 GPIO, designers can scan 4x4 keypads without external expanders, while the HC08 CISC core handles simple PWM for indicator LED dimming. The integrated brownout and watchdog timer add reliability for unattended operation.
Recommended
Lighting Control Modules
For dimmable LED drivers and lighting control modules, the MC908QB8VDWE provides 8KB Flash for dimming curves, 6-channel 10-bit ADC for ambient-light sensing, and timer channels for PWM generation. The 8MHz CPU clock computes logarithmic dimming curves in real time, and the 5V supply simplifies integration with TRIAC dimmer interfaces. Designers can implement occupancy sensing, daylight harvesting, and DMX-style addressing in a single 16-SOIC part. The HC08's deterministic interrupt latency keeps PWM jitter low for flicker-free dimming, while the watchdog timer protects against firmware lockup in unattended installations.
Recommended
Industrial Sensor Interface
Industrial sensor-interface boards benefit from the MC908QB8VDWE's 6-channel 10-bit ADC and 5V analog supply compatibility with 4-20mA current-loop sensors, thermistors, and bridge transducers. The 8KB Flash holds linearization tables and MODBUS-RTU framing for sensor hubs, while 14 GPIO handle digital sensors and alarm outputs. Industrial -40C to +85C operation supports factory-floor deployments, and the integrated brownout reset protects against unstable factory power. The HC08 architecture provides deterministic response for safety-critical sensor trips, and the 16-SOIC footprint suits dense multi-signal PCB layouts.
Recommended
Battery Chargers (Low-Cost Lead-Acid / NiMH)
The MC908QB8VDWE drives low-cost battery chargers for lead-acid and NiMH packs where 8KB Flash stores multi-stage charging profiles (bulk/absorption/float for lead-acid; -delta-V for NiMH), the 10-bit ADC reads pack voltage and current shunt, and timers generate PWM for the buck converter. The 5V VDD aligns with typical charger auxiliary rails, and 14 GPIO control FET drivers, status LEDs, and temperature sensors. Industrial temperature rating supports garage and outdoor charger installations. Designers can implement timer-based safety cutoffs and watch-dog-protected fault recovery in firmware without external supervisor ICs.
Recommended
Simple Motor Control (Relays / Solenoids)
For relay and solenoid control in HVAC valves, washing-machine dispensers, and small pump drivers, the MC908QB8VDWE provides deterministic HC08 interrupt handling for safe switching and 14 GPIO to drive opto-isolated triac/relay stages. The 8MHz CPU computes debounce, sequencing, and feedback loops, while the integrated ADC reads motor current for stall detection. Industrial temperature rating covers outdoor HVAC installations, and the 16-SOIC footprint suits compact control boards. Watchdog timer and brownout reset add reliability for unattended motor-control applications.
Recommended
Consumer Electronics Keypads / Remote Controls
Consumer remote controls, keypads, and IR/RF transmitters benefit from the MC908QB8VDWE's low pin count (16-SOIC), 8KB Flash for protocol stacks (RC5/RC6, NEC, proprietary), and 5V operation matched to IR LED driver circuits. The 14 GPIO support 4x4 key matrices, while timers generate 38 kHz carrier for IR transmission. Industrial temperature rating extends to outdoor keypads and gate controls, and the integrated brownout reset survives battery-low conditions. Designers can implement wake-on-keypad interrupts and deep-sleep modes (per family reference) to extend battery life in remote controls.
Recommended
Recommended Products Summary
Engineering reference data for MC908QB8VDWE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC908QB8CDWE | MC908QB8VDW | MC908QB8CDWER | MC908QY8VDWE | MCHC908QB8MDWE |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 16-SOIC | 16-SOIC - same | 16-SOIC - same | 16-SOIC - same | 16-SOIC - same | 16-SOIC - same |
| Program Memory (Flash) | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| CPU Clock | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| Temperature Grade | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| I/O Pins | 14 | 14 | 14 | 14 | 14 | 14 |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| Lifecycle Status | Active | Active | Active | Active | Active | Active |
Key Differentiators
- Industrial temperature grade in 16-SOIC (vs MC908QB8CDWE)
- Industrial temperature grade in tube packaging (vs MC908QB8CDWER)
- Lower BOM cost vs QY family with LCD (vs MC908QY8VDWE)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 1) and a 10 uF bulk tantalum or aluminum electrolytic capacitor on the same VDD trace, within 10 mm of the MCU. The HC08 core draws brief current spikes during Flash programming and ADC conversions; insufficient bulk capacitance can trigger brownout reset and abort writes. Tie VSS (pin 8) directly to the ground plane with a via or short trace to minimize ground bounce.
Configure OSC1/OSC2 (pins 2 and 3) per the HC908QB8 family reference manual. For external crystal operation, add the manufacturer-recommended load capacitors (typically 15-33 pF) on each oscillator pin to ground; for ceramic resonators, use the resonator's built-in capacitors. For external clock input, drive OSC1 with a CMOS-level source and leave OSC2 floating. The internal divide-by-4 reduces a 32 MHz crystal to the 8 MHz bus clock.
Route the RST pin (pin 15) with a short trace and place the reset pull-up resistor (typically 4.7 kohm) close to the MCU. Long reset traces pick up noise that can cause spurious resets in industrial environments. For in-circuit programming via BDM, group the BKGD and related pins on a header accessible at the board edge for production-line firmware updates.
Compliance Information
RoHS and REACH compliance per NXP product declarations on DigiKey/Mouser listings. Not AEC-Q100 qualified (legacy HC08 family predates automotive qualification program for this MCU tier); contact NXP for automotive-grade alternatives in S08/S12 families.
