MCHC908QT4CDWE - 8-bit HC08 MCU, 4KB Flash, ADC | NXP
MPN: MCHC908QT4CDWE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.38 | $7.38 |
| 10 | $6.55 | $65.50 |
| 100 | $5.42 | $542.00 |
| 500 | $4.78 | $2,390.00 |
| 1,000 | $4.2 | $4,200.00 |
MCHC908QT4CDWE Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (Flash or ROM), volatile data memory (RAM), and a set of peripherals such as timers, communication interfaces, and analog-to-digital converters on one silicon die. The HC08 family belongs to the broader category of CISC microcontrollers -> embedded microcontrollers -> microprocessors -> semiconductors. Modern 8-bit MCUs continue to serve in applications where deterministic behavior, ultra-low static power, and minimal BOM cost outweigh raw compute throughput.
Key features of the MCHC908QT4CDWE include 4 KB of Flash, 128 bytes of RAM, an internal 10-bit ADC with multiple input channels, a multi-function timer interface, and an enhanced serial communications interface. The device operates from 3.0 V to 5.5 V (3.3 V/5 V nominal), supports in-system programming through a single-wire background debug mode (BDM), and integrates an internal clock generator, reducing external component count.
The CPU08 core executes a complex instruction set with Von Neumann memory mapping, allowing most instructions to operate on memory, registers, or both in a single cycle. The 8-bit data path and 16-bit address space (64 KB) provide ample headroom for typical HC08 applications such as simple sensor processing, control loops, and human-machine interface (HMI) logic.
Typical applications for the MCHC908QT4CDWE include battery chargers, small motor controllers, white-goods control boards, remote controls, simple sensor signal conditioners, and low-end appliance user interfaces. Its small SOIC-8 footprint makes it suitable for space-constrained PCB designs where only a handful of digital I/O and one or two ADC inputs are required.
When designing with this MCU, ensure adequate decoupling on VDD/VSS and that the ADC input impedance and acquisition time are compatible with the source impedance of the analog signal being measured. Program memory should be protected by the security fuse when production firmware protection is required.
This page synthesizes NXP datasheet parameters, current distributor pricing, drop-in alternatives from the HC08Q family, and practical design notes not found in a single manufacturer document.
Drop-in alternatives for MCHC908QT4CDWE — 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 MCHC908QT4CDWE (same form factor and footprint) — differing in RAM Size, ADC, Core Architecture, Package, Packaging.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC908QT1ACFQE
✅ Drop-In✓ In Stock
$1.7 / Unit
View Datasheet →MC908QT2ACFQE
✅ Drop-In✓ In Stock
$0.65 / Unit
View Datasheet →MCHC908QT4CDWE Maximum Ratings & Electrical Characteristics
| Family | M68HC08 (HC08Q sub-family) |
| Core | CPU08 (8-bit CISC) |
| Program Memory | 4 KB Flash |
| RAM | 128 bytes |
| Maximum Bus Clock | 8 MHz |
| Operating Voltage | 3.0 V to 5.5 V (3.3 V / 5 V nominal) |
| ADC | 10-bit, multiple channels |
| Timers | Multi-function timer interface (TPM/MTIM family) |
| Communication | Enhanced Serial Communications Interface (ESCI), SPI |
| Package | 8-pin SOIC (EIAJ, 5.30 mm body width) |
| Mounting Type | Surface Mount |
| Debug Interface | Single-wire Background Debug Mode (BDM) |
| Security | Program memory security fuse |
| Architecture | Von Neumann, CISC |
MCHC908QT4CDWE Pin Configuration
| Pin 1 | IRQ — External interrupt request input (shared with KBI) |
| Pin 2 | VSS — Ground reference |
| Pin 3 | VDD — Positive supply, 3.0 V to 5.5 V |
| Pin 4 | OSC1 — Crystal/clock input or external clock in |
| Pin 5 | OSC2 — Crystal output (leave open for external clock) |
| Pin 6 | PTA0/KBI/ADC0 — Port A bit 0, keyboard interrupt, ADC channel 0 |
| Pin 7 | PTA1/ADC1 — Port A bit 1, ADC channel 1 |
| Pin 8 | PTA2/RESET — Port A bit 2 / bidirectional reset (active low) |
Typical Applications
MCHC908QT4CDWE is suitable for 6 applications: Battery Charger Control, Small Motor / Fan Speed Controller, White Goods / Appliance UI Boards, Remote Control Transmitter, Sensor Signal Conditioner, Low-End LED Driver Board.
Battery Charger Control
The MCHC908QT4CDWE's 4 KB Flash and on-chip 10-bit ADC suit it to sealed lead-acid and Li-ion charger designs. The HC08Q core delivers enough compute for CC/CV charge-state machines and thermal-foldback in SOIC-8. With 8 MHz bus clock and PWM-driven timer, the chip provides a charger MCU footprint of roughly 9 x 6 mm.
Recommended
Small Motor / Fan Speed Controller
The integrated multi-function timer and ADC channels make the MCHC908QT4CDWE well-suited for brushed DC and small BLDC driver boards. The CPU08 runs closed-loop RPM control firmware in fewer than 1,000 lines of C with the 4 KB Flash headroom. Designers use the ADC to read back-EMF or tach pulses while the timer generates PWM for the FET half-bridge.
Recommended
White Goods / Appliance UI Boards
In washing machines, dishwashers, and microwave user-interface boards the MCHC908QT4CDWE provides deterministic HMI scanning of 4-8 keys plus LED matrix drive from timer PWM outputs. The HC08Q's -40 to +85C industrial temperature window handles under-cabinet thermals. The 128-byte RAM is ample for debounce state machines.
Recommended
Remote Control Transmitter
IR/RF remote controls benefit from the MCHC908QT4CDWE's low active current and small SOIC-8 footprint, plus 4 KB Flash holding IR protocol libraries (RC5/RC6/SONY/Sharp). The HC08Q core wakes from stop mode on a key-press interrupt with sub-microamp quiescent current. The internal oscillator eliminates the external crystal.
Recommended
Sensor Signal Conditioner
Industrial 4-20 mA loop-powered and bridge sensor conditioner boards use the MCHC908QT4CDWE's 10-bit ADC with internal PGA-like pre-scaling to deliver calibrated digital sensor readings. The CISC instruction set executes 8-bit multiply-accumulate efficiently for digital-filter coefficient math. Wide 3.0-5.5 V supply tolerates loop voltage variations.
Recommended
Low-End LED Driver Board
LED strip and bulb driver boards use the MCHC908QT4CDWE for analog dimming via its ADC and PWM via timer channels. The 4 KB Flash accommodates look-up tables for human-eye brightness correction (gamma 2.2) across dim levels. The SOIC-8 EIAJ footprint fits in GU10 bulb base PCBs down to 12 mm diameter.
Recommended
Recommended Products Summary
Engineering reference data for MCHC908QT4CDWE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MCHC908QT2ACPE | MC68HC908QT4CPE | MC908QT1ACFQE | MC908QT2ACFQE | MCHC908QY2CPE |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 8-SOIC (EIAJ, 5.30 mm) | PDIP-8 | PDIP-8 | SOIC-8 (EIAJ) | SOIC-8 (EIAJ) | PDIP-8 |
| Program Memory | 4 KB Flash | 2 KB Flash | 4 KB Flash | 1 KB Flash | 2 KB Flash | 2 KB Flash |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| Maximum Bus Clock | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| ADC | 10-bit, multi-channel | 10-bit, multi-channel | 10-bit, multi-channel | 10-bit, multi-channel | 10-bit, multi-channel | 10-bit, multi-channel |
| Operating Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Lifecycle Status | Obsolete | Obsolete (Site MPN list indicates legacy stock) | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Highest Flash density in 8-pin HC08Q SOIC tier (vs MC908QT1ACFQE / MC908QT2ACFQE)
- Surface-mount SOIC-8 EIAJ option for reflow assembly (vs MCHC908QT2ACPE / MC68HC908QT4CPE / MCHC908QY2CPE (PDIP-8))
- Same HC08Q family but with on-chip 10-bit ADC built in (vs HC08 family members without ADC)
Design Notes
Estimated: Decouple VDD (pin 3) with a 100 nF ceramic capacitor placed within 3 mm of the pin. For battery-powered designs, the HC08Q stop-mode current is typically below 1 uA; verify the figure in the datasheet electricals section for your specific lot. Add a bulk 4.7-10 uF electrolytic if the supply is shared with inductive loads.
Keep the OSC1/OSC2 traces short (less than 5 mm) and surround them with a ground guard ring if you use a high-Q external crystal. When using the internal oscillator only, leave OSC2 floating and tie OSC1 to ground through a 1 Mohm resistor for noise immunity. Route PTA lines away from high-current switching traces to avoid ADC corruption during conversions.
Do not program the security byte until final firmware is loaded - locked devices cannot be re-flashed via BDM without mass erase on supported lots. Configure the RESET pin direction early in firmware; the bidirectional reset on PTA2 can latch if external pull-up strength exceeds the HC08Q drive rating. Keep ADC input source impedance below 10 kohm to avoid acquisition-time errors.
Compliance Information
Specific RoHS/REACH certification not explicitly captured in the verified web data for the MCHC908QT4CDWE - [DATA_NEEDED: confirm via NXP product page environmental section]. Part is not marketed as AEC-Q100, so that qualifier is not applicable.
