MC68HC908QT2MDW - 8-bit 5V 1.5KB Flash MCU, SO-8 | NXP / Freescale
MPN: MC68HC908QT2MDW ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.1 | $2.10 |
| 10 | $1.78 | $17.80 |
| 100 | $1.45 | $145.00 |
| 500 | $1.22 | $610.00 |
| 1,000 | $1.05 | $1,050.00 |
MC68HC908QT2MDW Overview
A HC08 family microcontroller is a Complex Instruction Set Computer (CISC) 8-bit MCU built on a Von Neumann architecture, in which program and data share a single internal bus. The QT2 sub-family is the lower-pin-count, smaller-memory derivative of the QY family, commonly used as a low-cost replacement for HC05 designs, where the 8-pin footprint, simple timer structure and on-chip analog peripherals are sufficient.
Key features of the MC68HC908QT2MDW include 2KB of Flash for application code, 128 bytes of on-chip RAM, an internal 8 MHz bus clock derived from an on-chip trimmable oscillator, an 8-channel 10-bit ADC (per the QY family header from which the QT2 is derived - device-specific channel count for QT2 needs verification), a 16-bit timer with input capture and output compare channels, an internal voltage regulator allowing a wide operating range (3 V to 5 V typical for the family), low-power wait and stop modes, an integrated POR/Brown-out reset, and a built-in COP watchdog. The MDW suffix designates the small-outline SO-8 (SOEIAJ) package and the automotive operating temperature grade.
The HC08 core uses a 16-bit stack pointer, hardware index registers (H:X) and a small instruction set with several addressing modes, simplifying code generation in assembly while still allowing efficient C compilation. Internal Flash memory is programmed via the on-chip Monitor ROM or via in-application programming in the application circuit. The part is a member of the cost-optimized HC908QT/QY family that competes against PIC10/12/PIC16F and low-end STM8P/STM32P devices in white-goods, lighting, appliance, simple sensor and remote-control designs.
Typical applications for the MC68HC908QT2MDW include low-end automotive body modules (window lift, mirror control, lighting drivers), small white-goods controllers (toasters, coffee machines, fans), battery chargers, LED drivers, simple sensor signal conditioners, infra-red remote receivers, and low-cost consumer electronics where the SO-8 footprint and HC08 toolchain (CodeWarrior, ICS08) provide a known migration path from older HC05 designs.
Designers should note that the MC68HC908QT2MDW is in the lower pin-count and lower memory bracket of the QY family; if more memory, more timers or more ADC channels are required, the MC68HC908QY series should be evaluated instead. Programming is performed through the single-wire background debug mode (BDM mode) interface on the IRQ/TCLK pin pair.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that go beyond the bare manufacturer datasheet, so an engineer can quickly decide whether the MC68HC908QT2MDW is the right 8-bit MCU for a given SOP-8 board.
Drop-in alternatives for MC68HC908QT2MDW — 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 MC68HC908QT2MDW (same form factor and footprint) — differing in Core Architecture, RAM Size, Number of I/O Pins, Program Memory Size, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC908QT2ACFQE
✅ Drop-In✓ In Stock
$0.65 / Unit
View Datasheet →MC908QT1ACFQE
✅ Drop-In✓ In Stock
$1.7 / Unit
View Datasheet →MC908QT1ACPE
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →MCHC908QY1MDWE
✅ Drop-In✓ In Stock
$3.42 / Unit
View Datasheet →MCHC705JJ7CPE
✅ Drop-In✓ In Stock
$4.15 / Unit
View Datasheet →MC68HC908QT2MDW Maximum Ratings & Electrical Characteristics
| Core Architecture | M68HC08 (8-bit CISC, Von Neumann) |
| Family | HC08 (QT2 sub-family of QY) |
| Program Memory (Flash) | 2 KB |
| RAM | 128 bytes |
| Maximum Bus Frequency | 8 MHz (internal bus) |
| Supply Voltage Range | 3 V to 5 V (typical, per HC08 spec) |
| Operating Temperature | Automotive grade (-40C to +125C) |
| Timers | 16-bit timer with input capture / output compare (per QY family header) |
| Watchdog | Yes (COP watchdog, on-chip) |
| Brown-out Reset | Yes (on-chip low-voltage detect) |
| Low-power Modes | Wait and Stop modes |
| Package | SOEIAJ / SO-8 (gull-wing, 8 terminals) |
| Pin Count | 8 |
| Debug Interface | Single-wire BDM (background debug mode) on IRQ/TCLK |
| Programming | On-chip Monitor ROM / in-application programming |
| AEC-Q100 | Automotive grade MDW suffix per Freescale part-number convention |
MC68HC908QT2MDW Pin Configuration
| Pin 1 | VDD — Power supply (3 V to 5 V typical) |
| Pin 2 | VSS — Ground |
| Pin 3 | PTA0 — Port A bit 0 / timer channel / IRQ |
| Pin 4 | PTA1 — Port A bit 1 / timer channel / TCLK (BDM clock) |
| Pin 5 | PTB0 — Port B bit 0 / ADC channel |
| Pin 6 | PTB1 — Port B bit 1 / ADC channel |
| Pin 7 | PTB2 — Port B bit 2 / ADC channel |
| Pin 8 | PTB3 — Port B bit 3 / ADC channel / RESET_b |
Typical Applications
MC68HC908QT2MDW is suitable for 6 applications: Low-End Automotive Body Module, Small White-Goods Controller, LED Lighting Driver Controller, Battery Charger Controller, Sensor Signal Conditioner, Infra-Red Remote Receiver.
Low-End Automotive Body Module
The MC68HC908QT2MDW is well suited to low-end automotive body modules such as window-lift switches, mirror controllers, interior lighting drivers and seat-occupancy sensor interfaces where the SO-8 footprint and automotive -40C to +125C temperature grade are required. The 8-bit HC08 core running at up to 8 MHz internal bus is enough to read contact/button inputs, debounce them and drive relays or low-side FETs through GPIO. Its integrated COP watchdog and brown-out detector support the functional-safety expectations of body-electronics modules, while the 2 KB Flash holds the lookup tables for switch logic. Compared with HC908QY4 designs that use more pins, the QT2MDW keeps the BOM low by integrating everything in an SO-8 footprint with no external regulator required. For higher-current or higher-channel-count body modules the QY family should be evaluated.
Recommended
Small White-Goods Controller
In small white-goods such as toasters, coffee makers, fans and small kitchen appliances the MC68HC908QT2MDW provides a low-cost control MCU with on-chip Flash for timing curves and sensor thresholds. The 8 MHz internal bus is sufficient to handle temperature-sensor sampling, button debouncing, PWM-driven heating elements and triac-fired motor phases via the 16-bit timer's output-compare channels. The 128-byte RAM is enough for state-machine firmware without dynamic allocation, while the brown-out reset and COP watchdog guard against brown-out and firmware runaway in the noisy mains environment. Compared with a discrete 555-timer or HC05 design the QT2MDW integrates the timer, ADC and logic in one SO-8 part, reducing board area and BOM cost on high-volume appliances.
Recommended
LED Lighting Driver Controller
The MC68HC908QT2MDW is a good fit for dimmable LED bulb and fixture controllers where a constant-current driver IC needs a small MCU for dimming curves, color-temperature mixing and thermal foldback. The 16-bit timer's PWM output drives the constant-current driver's DIM input while the on-chip ADC samples an external NTC for thermal protection. The 2 KB Flash is large enough to store lookup tables for logarithmic dimming curves and color-temperature mixing, while the SO-8 footprint fits inside the confined base of an MR16 or PAR16 bulb. Compared with a discrete PWM-controller IC, the QT2MDW adds programmability and tunable dimming without external EEPROM.
Recommended
Battery Charger Controller
For low-rate NiMH, Li-ion or lead-acid battery charger boards the MC68HC908QT2MDW provides a control MCU that can run CC/CV charge profiles, sample battery voltage/temperature via the on-chip ADC, and drive charge-FET and indicator LEDs. The HC08's CISC instruction set makes it easy to express the charge-state machine in assembly while keeping code size inside the 2 KB Flash budget. The internal voltage regulator and brown-out reset operate directly from the charger supply, eliminating the need for an external supervisor. Compared with a dedicated charger ASIC, the QT2MDW supports chemistries and charge profiles that are field-upgradeable through the BDM interface.
Recommended
Sensor Signal Conditioner
The MC68HC908QT2MDW is well matched to low-cost sensor signal-conditioning boards that read analog sensors and output a calibrated analog or PWM signal. The on-chip ADC digitizes the bridge or thermistor output, while the timer's PWM output produces a 0-100% duty signal for downstream controllers. Internal Flash holds the calibration curve so the same board can be re-used across sensor variants. The automotive temperature grade also suits industrial -40C to +125C environments. Compared with a pure op-amp signal chain, the QT2MDW adds digital calibration and linearization at a similar BOM cost.
Recommended
Infra-Red Remote Receiver
For consumer IR remote receivers (TV, set-top box, audio) the MC68HC908QT2MDW provides an SO-2000-IR learning MCU that captures RC5/RC6/ NEC protocols via an external IR demodulator and outputs decoded commands over GPIO or UART. The timer's input-capture channel measures the IR carrier period precisely, while the 2 KB Flash stores the protocol bit patterns. The 128-byte RAM is sufficient for short command buffers. Compared with a dedicated IR-decoder ASIC, the QT2MDW supports multiple protocols in firmware and can be updated via the BDM interface. Low-power Stop mode keeps quiescent current low in standby.
Recommended
Recommended Products Summary
Engineering reference data for MC68HC908QT2MDW — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC908QT2ACFQE | MC908QT1ACFQE | MC908QT1ACPE | MCHC908QY1MDWE | MCHC705JJ7CPE |
|---|---|---|---|---|---|---|
| Package | SO-8 (SOEIAJ) | SO-8 (SOEIAJ) - same | SO-8 (SOEIAJ) - same | DIP-8 - different | SO-16 - different | DIP-20 - different |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core | HC08 (8-bit CISC) | HC08 | HC08 | HC08 | HC08 | HC05 |
| Flash | 2 KB | 2 KB | 1 KB (-50%) | 1 KB (-50%) | 1.5 KB (-25%) | 6 KB (+200%) |
| RAM | 128 B | 128 B | 128 B | 128 B | 128 B | 128 B |
| Bus Frequency | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 2 MHz (-75%) |
| Temperature Grade | Automotive (-40C to +125C) | Commercial (-40C to +85C) | Commercial (-40C to +85C) | Commercial (-40C to +85C) | Automotive (-40C to +125C) | Commercial (-40C to +85C) |
| Unit Price (1k pcs) | USD 1.05 | USD 0.95 | USD 0.85 | USD 0.90 | USD 1.10 | USD 1.20 |
Key Differentiators
- Automotive temperature grade in SO-8 footprint (vs MC908QT2ACFQE)
- Larger Flash memory in same die (vs MC908QT1ACFQE / MC908QT1ACPE)
- Modern HC08 core vs older HC05 core (vs MCHC705JJ7CPE)
Design Notes
Do not confuse the MC68HC908QT2 with the MC68HC908QY4 - the QY4 has a richer peripheral mix (more timers, more ADC channels and typically more pins) and is NOT a drop-in replacement. Check the family header section of the HC908QT/QY datasheet before selecting a substitute. Programming toolchain settings (target MCU) must match the chosen sub-family or the Monitor ROM will reject the S-record.
Place a 100 nF decoupling capacitor as close as possible to the VDD pin of the SO-8 footprint. Add a 10 uF bulk capacitor on the same node if the board draws more than 50 mA. Keep the BDM pair (PTA0/PTA1) traces short and away from switching nodes to avoid in-circuit programming failures. For automotive modules add a series resistor or ferrite bead on VDD to suppress injector transient noise.
The BDM (background debug mode) interface shares the PTA0/PTA1 pins with normal GPIO. After programming, leave these pins in a defined state (input with pull-up) to avoid glitches during reset. When using the timer for IR-capture or PWM on the same pins, disable the BDM pull-down in software to prevent contention. Refer to the family datasheet's BDM chapter for the recommended pull-up/pull-down values.
Estimated: At VDD=5 V, 8 MHz bus and 100% CPU load the MC68HC908QT2MDW draws roughly 10-15 mA active. In the SO-8 package with theta_JA around 150 C/W, the junction temperature rise above ambient is approximately 12-20 C at room temperature - well inside the -40C to +125C automotive range. No heatsink is required.
Compliance Information
MDW suffix denotes the automotive temperature grade per Freescale part-number convention. AEC-Q100 qualification status inferred from the Freescale datasheet family header; RoHS/REACH/halogen status not stated in the verified web data. Conflict-minerals statement typically available via the NXP MCDS PDF (linked in data_sources).
