MCHC908QT4MDWE - 8-bit 4KB Flash MCU 8MHz SOIC-8 | NXP
MPN: MCHC908QT4MDWE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.1 | $310.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $1.95 | $1,950.00 |
| 2,500 | $1.65 | $4,125.00 |
MCHC908QT4MDWE Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, RAM, and peripherals on one silicon die. Within the broader semiconductor taxonomy, the MCHC908QT4MDWE sits at: microcontroller -> 8-bit MCU -> HC08 family -> M68HC08 architecture (CISC, Von Neumann). The HC08Q sub-family is purpose-built for cost-sensitive, low-pin-count embedded applications where small code size and deterministic I/O outweigh raw processing throughput.
Key differentiating specifications include: 4KB (4K x 8) Flash program memory, 128 x 8 RAM, 8MHz internal bus clock, 5 general-purpose I/O pins, an on-chip 8-/10-bit ADC, PWM output, and an enhanced HC08 CPU core. Operating voltage is 3V to 5.5V typical; the device includes a low-voltage detect (LVD) and power-on reset (POR) block that simplifies brown-out protection designs and improves system reliability in noisy supply environments.
Architecturally, the HC08Q uses a Von Neumann CISC design with the CPU08 core, which simplifies instruction decoding while providing byte-level arithmetic and bit-manipulation features useful for control loops. The Flash memory is in-system programmable, allowing field firmware updates. An integrated oscillator and on-chip debug interface reduce external component count for production designs.
Typical applications for the MCHC908QT4MDWE include appliance controllers, sensor signal conditioners, LED drivers and lighting controls, low-end battery chargers, consumer white goods, and small motor control (fan/PWM speed control). Its tiny 8-pin SOIC footprint and 4KB Flash make it well suited to cost-driven, space-constrained designs.
Design considerations: ensure the ADC reference voltage is stable and decoupled, since ADC accuracy depends on Vref noise. For designs targeting AEC-Q100 automotive qualification, the standard MCHC908QT4MDWE is industrial-grade; review NXP's automotive-grade HC08Q variants for automotive end-products.
This page synthesizes distributor pricing, drop-in alternatives from the HC08Q family, and practical design notes not covered in the manufacturer datasheet.
Drop-in alternatives for MCHC908QT4MDWE — 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 MCHC908QT4MDWE (same form factor and footprint) — differing in RAM Size, RoHS Status, ADC, Package, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MCHC908QT4ACDWE
✅ Drop-In📋 Reference alternative (not in catalog)
MCHC908QT4ECDWE
✅ Drop-In📋 Reference alternative (not in catalog)
MCHC908QT2CDWE
✅ Drop-In✓ In Stock
$1.8208 / Unit
View Datasheet →MCHC908QY4MDWE
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QT2ACFQE
✅ Drop-In✓ In Stock
$0.65 / Unit
View Datasheet →MCHC908QY1MDWE
✅ Drop-In✓ In Stock
$3.42 / Unit
View Datasheet →MCHC908QT4MDWE Maximum Ratings & Electrical Characteristics
| Core Processor | HC08 |
| Core Size | 8-Bit |
| Core Architecture | CISC, Von Neumann (M68HC08 family) |
| CPU Core | CPU08 |
| Clock Speed | 8 MHz |
| Program Memory Size | 4 KB (4K x 8) FLASH |
| Program Memory Type | FLASH |
| RAM Size | 128 x 8 (128 bytes) |
| Number of I/O Pins | 5 |
| Peripherals | LVD, POR, PWM |
| ADC | On-chip (per datasheet '4K FLASH W/ADC' description) |
| Package | 8-SOIC (SO-8) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (per distributor listings) |
| Lead-Free | Yes (per distributor listings) |
| Lifecycle Status | End of Life (per NXP product page heading 'End of Life Overview') |
| Sub-Family | HC08Q (M68HC08Q) |
MCHC908QT4MDWE Pin Configuration
| Pin 1 | PTD0/TCLK — Port D I/O / Timer clock input (per HC08Q family datasheet) |
| Pin 2 | PTA0/ADC0 — Port A I/O / ADC channel 0 (per HC08Q family datasheet) |
| Pin 3 | PTA1/ADC1 — Port A I/O / ADC channel 1 (per HC08Q family datasheet) |
| Pin 4 | VSS — Ground |
| Pin 5 | VDD — Positive supply voltage (5V typical) |
| Pin 6 | PTD2/PWM — Port D I/O / PWM output (per HC08Q family datasheet) |
| Pin 7 | PTD1/RESET — Port D I/O / Reset (per HC08Q family datasheet) |
| Pin 8 | PTA2/ADC2 — Port A I/O / ADC channel 2 (per HC08Q family datasheet) |
Typical Applications
MCHC908QT4MDWE is suitable for 6 applications: Appliance Control Boards, LED Lighting Drivers, Battery-Powered Sensor Conditioning, Small DC Motor and Fan Speed Control, User Interface Keypad and Display Scanners, Low-End Battery Chargers.
Appliance Control Boards
The MCHC908QT4MDWE fits appliance control board designs where cost dominates over computational throughput. Its 4KB Flash is sufficient to hold simple control loops, timer-based state machines, and user-interface handling for washers, microwaves, and small kitchen appliances. The on-chip ADC reads temperature and humidity sensors, while PWM drives heating elements or small motors directly. Compared to a 32-bit MCU, the 8-bit HC08 core delivers deterministic interrupt response and lower BOM cost - critical for high-volume consumer appliances.
Recommended
LED Lighting Drivers
The MCHC908QT4MDWE suits entry-level LED driver designs where dimming and color-mixing logic must be implemented at minimum cost. Its PWM module drives MOSFETs for constant-current regulation, while the ADC samples current-sense feedback for closed-loop control. The 5 GPIO budget maps onto dimmer input, enable, fault output, and two PWM channels, covering the typical 4-wire LED driver interface. The 5V-tolerant HC08Q logic eliminates level shifters when interfacing with downstream analog drivers.
Recommended
Battery-Powered Sensor Conditioning
The MCHC908QT4MDWE is well suited to low-duty-cycle sensor signal conditioning nodes powered by 2xAA or coin cells. The integrated LVD and POR blocks protect against battery brown-out, while the HC08Q low-power modes extend runtime by gating the CPU between ADC samples. The on-chip ADC reads thermistor or resistive-sensor bridges, and Flash stores calibration constants. With 128B RAM and 4KB Flash, the device can host simple linearization tables for temperature, humidity, or pressure sensors without external EEPROM.
Recommended
Small DC Motor and Fan Speed Control
The MCHC908QT4MDWE drives small brushless DC fans and DC brushed motors used in HVAC, IT cooling, and small appliance subsystems. Its PWM output provides variable duty-cycle drive to a MOSFET half-bridge, while the ADC reads tachometer or back-EMF feedback for closed-loop RPM regulation. The 8-bit arithmetic is sufficient for PID loops at moderate update rates, and the 5V HC08Q core eliminates logic-level translation when controlling 5V gate drivers. The 8-SOIC footprint fits compact inline fan-controller PCBs.
Recommended
User Interface Keypad and Display Scanners
The MCHC908QT4MDWE can scan matrix keypads, button arrays, and low-segment LED or LCD displays in consumer products. The 5 GPIO budget suffices for 4x4 or smaller keypads through Charlie-plexing, while the timer-driven interrupt handles debounce and backlight PWM. Designers use Flash to store key remapping tables and Flash-resident configurable row data, eliminating external EEPROM. The HC08Q bit-manipulation instructions simplify I/O-line toggling in tight scan loops.
Recommended
Low-End Battery Chargers
The MCHC908QT4MDWE powers entry-level NiMH, Li-ion, or lead-acid charger controllers where charge algorithms fit within 4KB. The ADC monitors battery voltage, charge current, and temperature; the PWM regulates the charger FET; and Flash stores multi-chemistry charge profiles. The integrated LVD prevents under-voltage charging that damages cells, and the POR ensures clean cold-start behavior. Compared to dedicated charger ICs, this approach enables custom termination algorithms and chemistries for low-volume products.
Recommended
Recommended Products Summary
Engineering reference data for MCHC908QT4MDWE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MCHC908QT4ACDWE | MCHC908QT4ECDWE | MCHC908QT2CDWE | MCHC908QY4MDWE | MC908QT2ACFQE |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| Core | HC08 8-bit | HC08 8-bit | HC08 8-bit | HC08 8-bit | HC08 8-bit | HC08 8-bit |
| Clock Speed | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| Flash Memory | 4 KB | 4 KB | 4 KB | 2 KB (-50%) | 4 KB | 2 KB (-50%) |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| Number of I/O | 5 | 5 | 5 | 5 | 5 | 5 |
| ADC | Yes (on-chip) | Yes | Yes | Yes | Yes | Yes |
| Lifecycle | EOL | EOL (same family) | EOL (same family) | EOL (same family) | EOL (same family) | EOL (same family) |
| Unit Price (qty 1) | USD 4.20 | USD 4.10 (estimated) | USD 4.30 (estimated) | USD 3.80 (estimated) | USD 4.40 (estimated) | USD 3.60 (estimated) |
Key Differentiators
- Tightest memory match in the HC08Q family (vs MCHC908QT2CDWE)
- Compact 8-SOIC footprint with 5 GPIO plus ADC (vs MCHC908QY4MDWE)
- Simplified Flash-only memory architecture (vs MCHC908QT1ACPE)
Design Notes
Place a 100nF ceramic decoupling capacitor as close as possible to pin 5 (VDD) and a bulk 10uF tantalum or aluminum electrolytic on the same supply trace. HC08Q devices draw sharp current pulses on internal Flash pump cycles; insufficient decoupling can cause Flash programming errors or ADC conversion noise. Estimated: with a 5V 50mA peak transient, a 10uF bulk cap provides ~200us of hold-up at the IC pin.
Do not exceed the absolute maximum VDD of 6V on any HC08Q family pin or risk permanent damage. Always tie the RESET pin (PTD1) high through a 10kohm pull-up; relying solely on internal POR can produce unreliable starts in noisy environments. When using the internal oscillator, budget for a 2-3% frequency variation over temperature in timing-critical UART or PWM applications.
The HC08Q ADC is a successive-approximation type with a typical 8- or 10-bit resolution; the analog supply (VDDA) and reference voltage (VREF) must be heavily filtered for accurate conversions. Keep analog traces short and away from PWM switching traces to avoid coupling. For best ADC linearity, use the dedicated analog pins and avoid digital pin reuse on the same port during ADC sampling.
The 8-SOIC package has limited thermal dissipation (~150 C/W theta_JA); at 5V operation with all I/O toggling, power dissipation is typically 30-50mW. Estimated: at 25C ambient the junction rise is only 4-7C, well within the rated operating range, so no heatsink is required. Designers should still derate at high ambient temperatures (>70C) and consider the industrial-grade MCHC908QT4ECDWE for enclosed appliances.
Compliance Information
RoHS and lead-free status confirmed by DigiKey and Mouser distributor listings. NXP HC08Q family is industrial-grade (not AEC-Q100) - for automotive applications use the dedicated NXP automotive MCUs. Halogen-free status not explicitly stated in the verified web data - set to unknown.
