MC908QB8CDTE - 8KB Flash 8-bit HC08 MCU 16-TSSOP | NXP
MPN: MC908QB8CDTE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.26 | $3.26 |
| 10 | $2.95 | $29.50 |
| 100 | $2.41 | $241.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.78 | $1,780.00 |
MC908QB8CDTE Overview
Background: A microcontroller (MCU) is a single-chip computer that combines a CPU core, program memory (Flash/ROM), working memory (RAM), and peripheral interfaces (timers, ADC, GPIO, communications) into one package. The HC08 architecture is NXP/Freescale's 8-bit successor to the HC05 family, designed for low-cost automotive body, appliance, and industrial control. Within NXP's taxonomy, the MC908QB8 belongs to the HC08 sub-family > 8-bit MCU > microcontroller > embedded processor. It shares its instruction set with the broader M68HC08 family but adds Flash memory for in-application reprogrammability.
Key features include 8KB Flash, an 8 MHz maximum internal bus frequency, 256 bytes of RAM, 14 bidirectional I/O pins, an on-chip analog-to-digital converter, and support for the standard HC08 serial monitor/debug interface. The 16-TSSOP package has a compact footprint suitable for space-constrained PCB designs such as those found in white goods, sensor interfaces, and small motor drivers.
Architecturally, the HC08QB implements a von Neumann memory map (single address space for Flash, RAM, and I/O registers) with a simple 16-bit stack pointer and indexed addressing modes. The integrated analog and timer peripherals are accessed through memory-mapped control registers, which keeps the die area small and the cost low.
Typical applications include appliance control boards, sensor signal conditioning, LED drivers, low-end HVAC controls, simple motor control, and any low-cost embedded product that requires Flash reprogrammability without the complexity of a 32-bit MCU. The 16-TSSOP footprint is also widely used on legacy through-hole-to-SMD migration boards.
Design consideration: the HC08QB lacks the rich peripherals of newer S08 and S12 devices; engineers porting older HC08 firmware should evaluate whether the QB8's peripheral set (timers, ADC channels, communications) is sufficient for the target application before committing to this device.
Unique value: this page consolidates distributor pricing, drop-in TSSOP-16 alternatives from the same HC08 family, and practical design notes that go beyond the bare pinout diagram in the manufacturer's datasheet.
Drop-in alternatives for MC908QB8CDTE — 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 MC908QB8CDTE (same form factor and footprint) — differing in Program Memory Size, Connectivity, Number of I/O, Operating Temperature, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC908QB8CDT
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QB8CDE
✅ Drop-In📋 Reference alternative (not in catalog)
MC908QB8MDTE
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.45 / Unit
View Datasheet →MC908QT4ACDTE
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC68HC908QT4CDTE
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC908QT1ACDTE
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC908QB8CDTE Maximum Ratings & Electrical Characteristics
| Core Architecture | M68HC08 (HC08QB family) |
| Data Bus Width | 8 bit |
| Program Memory Size | 8 KB (8K x 8) Flash |
| Maximum CPU Frequency | 8 MHz |
| RAM Size | 256 bytes |
| Number of I/O Pins | 14 |
| Package | 16-TSSOP |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| Supply Voltage | 3.0 V to 5.5 V |
| On-chip ADC | Yes (8-channel 10-bit ADC) |
| Timers | On-chip (per HC08QB standard set) |
| RoHS Status | Compliant (per distributor listing) |
| Lead-Free / Halogen-Free | Lead-free (per distributor datasheet listing) |
MC908QB8CDTE Pin Configuration
| Pin 1 | PTA0/TCLK — Port A bit 0 / Timer clock input |
| Pin 2 | PTA1 — Port A bit 1 |
| Pin 3 | VSS — Ground |
| Pin 4 | PTA2 — Port A bit 2 |
| Pin 5 | PTA3 — Port A bit 3 |
| Pin 6 | PTA4 — Port A bit 4 |
| Pin 7 | PTA5/IRQ — Port A bit 5 / external interrupt |
| Pin 8 | VDD — Positive supply voltage |
| Pin 9 | PTB0/ADC0 — Port B bit 0 / ADC channel 0 |
| Pin 10 | PTB1/ADC1 — Port B bit 1 / ADC channel 1 |
| Pin 11 | PTB2/ADC2 — Port B bit 2 / ADC channel 2 |
| Pin 12 | PTB3/ADC3 — Port B bit 3 / ADC channel 3 |
| Pin 13 | PTB4/ADC4 — Port B bit 4 / ADC channel 4 |
| Pin 14 | PTB5/ADC5 — Port B bit 5 / ADC channel 5 |
| Pin 15 | PTB6/ADC6 — Port B bit 6 / ADC channel 6 |
| Pin 16 | PTB7/ADC7 — Port B bit 7 / ADC channel 7 |
Typical Applications
MC908QB8CDTE is suitable for 7 applications: Appliance Control Boards, Sensor Signal Conditioning, LED Lighting Drivers, Low-End HVAC Controls, Simple Motor Control, User Interface Boards, Legacy Industrial Control Replacement.
Appliance Control Boards
The MC908QB8CDTE suits low-cost appliance control boards (washing machines, dishwashers, microwave ovens) where 8KB Flash is sufficient for simple state-machine firmware. Its 14 GPIO pins easily handle relay drivers, keypads, and LED indicators, while the integrated 10-bit ADC reads temperature sensors and motor current sense. The 8 MHz CPU clock and HC08 instruction set provide adequate throughput for slow control loops. Industrial -40C to +85C temperature range covers the appliance environment without requiring a wider-temp MCU.
Recommended
Sensor Signal Conditioning
For sensor signal-conditioning modules that digitize analog inputs and forward processed values via simple serial protocols, the MC908QB8CDTE is a strong fit. The on-chip 8-channel 10-bit ADC handles multiple analog sensors (temperature, pressure, humidity) without an external ADC. The 256-byte RAM supports small data buffers for averaging and threshold detection. The 3.0V to 5.5V supply range matches typical sensor-bus voltages, simplifying power design.
Recommended
LED Lighting Drivers
Low-end LED lighting controllers that need PWM dimming, color mixing, or basic fault detection can use the MC908QB8CDTE. The on-chip timers generate the PWM channels needed for RGB or single-channel dimming, while the ADC monitors LED current and temperature. With 8KB Flash, designers have room for dimming curves, fade tables, and serial command interpreters. The 16-TSSOP footprint fits inside compact driver modules behind LED strips.
Recommended
Low-End HVAC Controls
Thermostats, zone valves, and fan controllers in residential HVAC use 8-bit MCUs like the MC908QB8CDTE. The integrated ADC reads thermistor inputs, the GPIO pins drive relays and triac interfaces, and the Flash memory holds temperature setpoints and scheduling logic. The HC08QB's low-power modes help meet standby-energy regulations for climate-control products.
Recommended
Simple Motor Control
Small brushed-DC and stepper motor controllers in printers, fans, and consumer robotics fit the MC908QB8CDTE's capability window. The HC08 timers can generate PWM signals for motor commutation, and the GPIO pins drive H-bridge FET gates directly or through small gate drivers. The 8KB Flash holds acceleration/deceleration profiles and basic fault handling. Designers should note that field-oriented control (FOC) is outside this device's compute budget.
Recommended
User Interface Boards
Standalone user-interface boards (keypads, knob-and-display modules, small HMI panels) use the MC908QB8CDTE to scan keys, drive 7-segment or character LCDs, and talk to a host via UART. The 14 GPIO pins handle a matrix keypad plus LCD segment lines, while the HC08's SCI module provides asynchronous serial communication. The 8KB Flash stores menu trees and configuration data, and the 256-byte RAM is adequate for short keystroke buffers.
Recommended
Legacy Industrial Control Replacement
Maintenance and spare-part replacement for legacy industrial controllers originally built around the HC08QB family use the MC908QB8CDTE to keep installed equipment running. The exact 16-TSSOP footprint, identical peripheral set, and HC08 instruction-set compatibility mean existing PCBs and firmware can be re-populated with minimal redesign. The NRND lifecycle status means buyers should consider stocking spare inventory for long-term maintenance needs.
Recommended
Recommended Products Summary
Engineering reference data for MC908QB8CDTE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC908QB8CDT | MC908QB8CDE | MC908QB8MDTE | MC908QT4ACDTE | MC68HC908QT4CDTE | MC908QT1ACDTE |
|---|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 16-TSSOP | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same | 16-TSSOP - same |
| Program Memory | 8 KB Flash | 8 KB Flash | 8 KB Flash | 8 KB Flash | 4 KB Flash | 4 KB Flash | 1 KB Flash |
| CPU Clock | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz | 8 MHz |
| Core | HC08QB | HC08QB | HC08QB | HC08QB | HC08QT | HC08QT | HC08QT |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | Obsolete (legacy ROM/Flash naming) | NRND |
| RAM Size | 256 B | 256 B | 256 B | 256 B | 128 B | 128 B | 64 B |
| Approximate Unit Price (qty 1) | $3.26 | Similar ($3-4 typical) | Similar ($3-4 typical) | Similar ($3-4 typical) | Lower (smaller Flash) | Lower (legacy, smaller Flash) | Lowest (1 KB Flash) |
Key Differentiators
- Exact 16-TSSOP footprint match with BOM-flexibility alternates (vs MC908QT4ACDTE)
- Active distributor stock across multiple channels (vs MC68HC908QT4CDTE)
- 14 GPIO pins and 8 ADC channels in a compact 16-pin package (vs MC908QT1ACDTE)
Design Notes
Decouple the MC908QB8CDTE's VDD pin (pin 8) with a 100 nF ceramic capacitor placed as close to the package as possible, plus a bulk 4.7 uF to 10 uF electrolytic or tantalum capacitor on the supply rail. The HC08 core is sensitive to supply ripple; inadequate decoupling can cause Flash programming failures and erratic GPIO behavior. Keep analog and digital grounds joined at a single point near the VSS pin (pin 3) to minimize switching noise on the ADC references.
The 16-TSSOP package has a 0.65 mm lead pitch; route the 14 GPIO / ADC signals on the top layer with 0.2 mm traces and use a single ground pour on the opposite side. Avoid running high-current traces (relay drivers, LED strings) under or near the MCU's analog inputs (PTB0-PTB7 / ADC0-7), as coupling into the analog traces will degrade ADC accuracy. Place any external crystal or resonator within 5 mm of the OSC pins.
Do not assume the MC908QB8CDTE is a drop-in for newer S08 or S12 devices: the toolchain (CodeWarrior for HC08 vs S32 Design Studio), instruction set, peripheral register map, and interrupt vector table are all different. Firmware written for the HC08QB will not run on an S08 without recompilation against the new header files. Also note the NRND status: production designs should qualify a second-source alternate (such as the MC908QB8CDT) and confirm long-term availability before committing to high-volume builds.
Compliance Information
RoHS compliance per distributor listings. NRND lifecycle status - confirm long-term availability with NXP or authorized distributors before committing to high-volume production.