MC908QT1ACFQE - 8-bit HC08 MCU, 1.5KB Flash, 8MHz | NXP
MPN: MC908QT1ACFQE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.55 | $25.50 |
| 100 | $2.2 | $220.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.7 | $1,700.00 |
MC908QT1ACFQE Overview
What is an 8-bit microcontroller? An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory (Flash or ROM), volatile working memory (RAM), and peripheral blocks (timers, I/O, ADC, communications) into one package. Within the broader taxonomy, MC908QT1ACFQE belongs to the HC08 family of CISC microcontrollers, which falls under microcontrollers -> embedded processors -> semiconductor ICs. The CISC (Complex Instruction Set Computer) architecture uses a Von Neumann memory map where program and data share a single bus, simplifying firmware development at the cost of execution speed compared with RISC cores.
Key features include 1.5KB (1.5K x 8) of on-chip Flash for program storage, 128 bytes of RAM for stack and variables, an internal oscillator that eliminates the need for an external crystal, and 5 bidirectional I/O pins shared with peripheral functions. The 8-VDFN Exposed Pad (4x4 mm) package provides a low thermal resistance path through the bottom pad, supporting reliable operation in space-constrained layouts. The 8MHz maximum bus frequency is generated internally, reducing BOM cost and PCB area.
The HC08 core supports a compact instruction set with multiple addressing modes, BCD arithmetic, and bit-manipulation instructions that map naturally to embedded control loops. The internal oscillator and on-chip Flash allow bare-minimum designs with no external clock or programming-voltage components, and the exposed-pad package simplifies thermal management for continuous-operation loads. The device targets ultra-low-cost applications where every component on the BOM matters.
Typical applications include battery chargers, small motor controllers, simple sensor interfaces, LED drivers, and consumer appliance sub-systems. The wide 3.3V/5V supply range simplifies drop-in replacement of older 5V-only HC08 designs and lets the same firmware serve battery-powered 3.3V products.
When designing with this device, allocate the exposed pad to a continuous copper pour on the top or bottom layer to keep junction temperature within rating. Place a 100nF decoupling capacitor within 3mm of the VDD pin and keep high-speed traces away from the oscillator pin to avoid injected noise.
This page synthesizes distributor availability, drop-in alternatives from the same HC08 QY/QT family, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for MC908QT1ACFQE — 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 MC908QT1ACFQE (same form factor and footprint) — differing in Package, Timers, ADC, Core Architecture, Family.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC908QT2ACFQE
✅ Drop-In✓ In Stock
$0.65 / Unit
View Datasheet →MC908QT4ACFQE
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QY1ACFQE
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QY2ACFQE
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QT1ACFQE Maximum Ratings & Electrical Characteristics
| Core Architecture | HC08 (CISC, 8-bit, Von Neumann) |
| Program Memory (Flash) | 1.5 KB (1.5K x 8) |
| RAM Size | 128 x 8 (128 bytes) |
| Number of I/O Pins | 5 |
| Maximum Bus Frequency | 8 MHz |
| Supply Voltage | 3.3 V / 5 V |
| Oscillator Type | Internal |
| Package / Case | 8-VDFN Exposed Pad (4x4 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tube (Tray per distributor listing) |
MC908QT1ACFQE Pin Configuration
| Pin 1 | PTA5 — General-purpose I/O / peripheral function (per HC08 QY/QT family datasheet) |
| Pin 2 | PTA4 / IRQ — General-purpose I/O / external interrupt request (per family datasheet) |
| Pin 3 | VDD — Positive supply voltage (3.3 V or 5 V) |
| Pin 4 | VSS — Ground reference |
| Pin 5 | PTA0 / ADC0 — General-purpose I/O / ADC input channel 0 (per family datasheet) |
| Pin 6 | PTA1 / ADC1 — General-purpose I/O / ADC input channel 1 (per family datasheet) |
| Pin 7 | PTA2 / ADC2 — General-purpose I/O / ADC input channel 2 (per family datasheet) |
| Pin 8 | PTA3 / ADC3 — General-purpose I/O / ADC input channel 3 (per family datasheet) |
| Pin EP | VSS (Exposed Pad) — Bottom thermal pad - tie to ground copper pour (per family datasheet PCB layout guidance) |
Typical Applications
MC908QT1ACFQE is suitable for 6 applications: Battery Charger Controller, Small DC Motor Speed Controller, LED Driver / Lighting Controller, Sensor Interface Module, Consumer Appliance Sub-System, Toy and Hobby Electronics.
Battery Charger Controller
The MC908QT1ACFQE fits compact battery charger control boards where every I/O and every BOM line item matters. Its 5 I/O pins can be assigned to charge-status LED, enable button, thermistor input, and a single PWM drive for a flyback or linear regulator - enough for CC/CV charge profiles on 1S Li-ion packs. The internal 8MHz oscillator removes the need for an external crystal, cutting two components and a clock-related EMI risk. The 8-VDFN package drops into chargers designed to a 4x4 mm footprint and the 3.3V/5V supply range covers both single-cell Li-ion and USB-powered 5V designs with the same firmware.
Recommended
Small DC Motor Speed Controller
The MC908QT1ACFQE's 5 bidirectional I/O pins can drive a half-bridge FET driver directly through PWM, plus a tachometer input and a fault LED, making it a fit for low-cost brushed DC motor controllers used in toys, fans, and small appliances. The HC08 CISC core executes the PID-style control loop comfortably at 8MHz, and the 1.5KB Flash stores calibration tables and ramp profiles. The internal oscillator eliminates the timing reference the motor's switching noise would otherwise couple into, improving EMI margin. Operating from 3.3V or 5V lets the same PCB serve battery and mains-rectified designs.
Recommended
LED Driver / Lighting Controller
For single-channel or RGB-LED controllers in consumer lighting strips, the MC908QT1ACFQE supplies just enough compute and I/O: 5 pins handle three PWM channels, a mode button, and a status LED. The 128-byte RAM is sufficient for color-mixing state and dimming curves, and the 1.5KB Flash stores dim tables and breathing-effect patterns. The 8-VDFN 4x4 mm package fits inside strip-end housings and the exposed pad conducts waste heat to the aluminum extrusion. The internal 8MHz clock is stable enough for PWM at 8-bit resolution without flicker.
Recommended
Sensor Interface Module
The MC908QT1ACFQE suits sensor-interface modules that read a single analog or digital sensor and present the data over a 1-wire, I2C, or UART link. The 5 I/O are mapped to the sensor data line, a GPIO interrupt, a status LED, and a UART TX/RX pair implemented in firmware. The wide 3.3V/5V supply lets the same firmware serve battery and 5V-mains sensor boards, and the HC08 CISC core handles simple linearization or lookup-table math at 8MHz without breaking a sweat. The 8-VDFN keeps the board to a single-sided 4x4 mm footprint.
Recommended
Consumer Appliance Sub-System
Small appliances like coffee makers, kettles, and toothbrush chargers often need a sub-controller for button debouncing, LED indication, and a single FET or relay drive - exactly what the MC908QT1ACFQE delivers with 5 I/O and 1.5KB Flash. The HC08's BCD and bit-manipulation instructions simplify timer/counter state machines used in countdown and keep-warm modes. The internal 8MHz oscillator and 8-VDFN package remove external components, shrinking the BOM and assembly cost. Operating from 3.3V or 5V lets the same firmware image support battery and rectified-mains designs.
Recommended
Toy and Hobby Electronics
Toy RC receivers, sound-effect boards, and hobby servos run on small 8-bit MCUs whose BOM dominates cost. The MC908QT1ACFQE drops in with 5 I/O, internal oscillator, 1.5KB Flash, and 128B RAM at a price compatible with sub-$5 retail electronics. The HC08 core is well documented in introductory embedded textbooks, easing firmware development for small teams. The 8-VDFN package handles vibration and drop events in toy environments, and the 3.3V/5V supply range covers Li-ion, NiMH, and 2xAA battery packs.
Recommended
Recommended Products Summary
Engineering reference data for MC908QT1ACFQE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC908QT2ACFQE | MC908QT4ACFQE | MC908QY1ACFQE | MC908QY2ACFQE |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 8-VDFN Exposed Pad (4x4 mm) | 8-VDFN Exposed Pad (4x4 mm) - same | 8-VDFN Exposed Pad (4x4 mm) - same | 8-VDFN Exposed Pad (4x4 mm) - same | 8-VDFN Exposed Pad (4x4 mm) - same |
| Program Memory (Flash) | 1.5 KB | 2 KB (+33%) | 4 KB (+167%) | 1.5 KB (same) | 2 KB (+33%) |
| RAM Size | 128 bytes | 128 bytes (same) | 128 bytes (same) | 128 bytes (same) | 128 bytes (same) |
| Maximum Bus Frequency | 8 MHz | 8 MHz (same) | 8 MHz (same) | 8 MHz (same) | 8 MHz (same) |
| Number of I/O Pins | 5 | 5 (same) | 5 (same) | 5 (same) | 5 (same) |
| Oscillator Type | Internal | Internal (same) | Internal (same) | Internal (same) | Internal (same) |
| Supply Voltage | 3.3 V / 5 V | 3.3 V / 5 V (same) | 3.3 V / 5 V (same) | 3.3 V / 5 V (same) | 3.3 V / 5 V (same) |
| Approx. Unit Price (qty 1000, as of 2026-10-18) | $1.70 | $1.85 (estimated) | $2.05 (estimated) | $1.75 (estimated) | $1.90 (estimated) |
Key Differentiators
- Larger Flash headroom without changing PCB layout (vs MC908QT2ACFQE)
- Largest Flash in the same footprint (vs MC908QT4ACFQE)
- More peripherals in the same footprint (vs MC908QY1ACFQE)
Design Notes
Place a 100 nF decoupling capacitor within 3 mm of the VDD pin (pin 3) with a wide, short trace to the VSS copper pour. The 8-VDFN's small lead inductance means even small VDD spikes can glitch the HC08 core; a bulk 1 uF or larger ceramic in parallel with the 100 nF cap further reduces droop during I/O transitions. Estimated: with 5 I/O switching at 1 MHz and 20 pF pin capacitance, peak transient current is roughly 1 mA, easily handled by a 100 nF ceramic.
Solder the bottom exposed pad to a continuous copper pour no smaller than the package footprint (4x4 mm). The exposed pad is the primary thermal path; without it, junction temperature can rise 20-30 C above ambient and trigger thermal shutdown or shorten life. For continuous high-I/O switching loads, expand the copper pour to 100 sq mm or more on the opposite layer with thermal vias.
Keep high-speed or high-current traces (PWM, motor drive, relay) at least 3 mm away from the oscillator pin and any analog I/O used as ADC inputs. The internal oscillator is robust but can still inject a few hundred microvolts onto adjacent traces, which on a 5-bit ADC budget becomes visible as LSB flicker. Use a ground guard ring around any ADC input trace for best noise immunity.
Do not leave unused I/O pins floating - configure them as outputs or enable the internal pull-ups in firmware to avoid extra supply current from floating CMOS inputs (each floating input can draw 10-50 uA). Do not exceed the absolute maximum VDD of 6 V; the 5 V specification is the nominal operating point with margin, not the absolute max. When migrating from the 8-PDIP MC908QT1ACPE to the 8-VDFN MC908QT1ACFQE, remember the VDFN footprint requires a reflow process and cannot use through-hole hand-soldering.
Compliance Information
Detailed compliance certificates not published in the verified distributor listings or Alldatasheet archive; consult Rochester Electronics lot-specific documentation for current RoHS/REACH status. Part is NRND per multiple distributor listings; not automotive qualified.
