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NXP Semiconductors MC908QT4ACDWE
- Part No.:
- MC908QT4ACDWE
- Manufacturer:
- NXP Semiconductors
- Category:
- Microcontrollers
- Package:
- 8-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
MC908QT4ACDWE.pdf
- Description:
- IC MCU 8BIT 4KB FLASH 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,045
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Product details
Overview
MC908QT4ACDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 4 KB Flash, 192 B RAM, and integrated ADC10, AWU, COP watchdog, LVI, and keyboard interrupt modules. It operates at up to 8 MHz bus speed, supports 2.7–5.5 V supply, and features on-chip oscillator trimming and monitor-mode security via eight-byte flash-based key ($FFF6–$FFFD). It targets low-cost industrial control and appliance interfaces requiring reliable reset, wake-up, and analog sensing.
For engineers reviewing the MC908QT4ACDWE datasheet, MC908QT4ACDWE pinout, MC908QT4ACDWE application, or MC908QT4ACDWE equivalent, this page delivers verified technical context, package-validated pin functions, real-world use cases in embedded sensing and control, and two confirmed alternative parts with documented functional and packaging differences.
Technical Context
The MC908QT4ACDWE implements the HCS08 CPU core with 16-bit address space, supporting indexed, extended, and relative addressing modes. Its memory map includes 4 KB of on-chip FLASH (with block protection and EEPROM emulation), 192 B RAM, and 32 B of register space. The internal oscillator supports trim calibration for ±2% accuracy across voltage/temperature.
Peripherals include a 10-bit ADC with 8 input channels and programmable conversion timing, Auto Wakeup Module with selectable timebase (RC or bus clock), Computer Operating Properly (COP) watchdog with 4 timeout options, and Low-Voltage Inhibit with user-selectable trip points (2.5 V or 3.8 V). All modules retain functionality in Wait mode and disable in Stop mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | HCS08 8-bit CPU with 16-bit address bus and 32+ instructions supporting indexed, extended, and relative addressing |
| Flash Memory | 4 KB on-chip SuperFlash® with mass/page erase, block protection, and EEPROM emulation capability |
| RAM | 192 bytes of on-chip static RAM, retained in Wait mode, lost in Stop mode |
| ADC Resolution & Channels | 10-bit successive-approximation ADC with 8 configurable analog inputs and programmable sample time |
| Operating Voltage | 2.7 V to 5.5 V - enables direct interface with 3.3 V logic or legacy 5 V systems without level shifters |
| Security Mechanism | Monitor-mode entry requires matching eight-byte key stored at $FFF6–$FFFD; denies access if ≥5 bytes are zero |
| Package | 20-pin SOIC (Small Outline Integrated Circuit), 0.300-inch body width, RoHS-compliant lead finish |
Pinout & Package
MC908QT4ACDWE is housed in a 20-pin SOIC package (package code: DW), with 18 I/O pins, 1 VDD, and 1 VSS. Pin functions are multiplexed across peripheral modules and prioritized per data sheet Section 1.6.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Power Supply | Main positive supply (2.7–5.5 V); must be decoupled locally with 0.1 µF ceramic capacitor |
| VSS | Ground Reference | Digital ground return; separate analog ground not provided - shared VSS used for ADC reference stability |
| PTA0–PTA7 | Port A I/O | 8-bit bidirectional port with pull-up enable; PTA0–PTA3 double as ADC inputs AD0–AD3 |
| PTB0–PTB3 | Port B I/O | 4-bit bidirectional port; PTB0–PTB2 double as KBI0–KBI2 and IRQ input; PTB3 is OSC2/XTAL output |
| OSC1/XTAL | Oscillator Input | Accepts external crystal (1–8 MHz) or RC network; internal oscillator active by default after reset |
| RESET | Active-Low Reset Input | Asynchronous reset pin; internal pull-up enabled; debounced externally recommended for noisy environments |
Key Features
| Feature | Design Value |
|---|---|
| On-Chip Oscillator Trimming | Internal RC oscillator calibrated via FLASH-trim register (ICSTRM) for ±2% accuracy over 2.7–5.5 V and –40°C to +85°C |
| Monitor Mode Security | Eight-byte flash-resident key ($FFF6–$FFFD) required for debug entry; blocks access if five or more bytes are zero |
| Auto Wakeup Module (AWU) | Configurable wake-up timer using RC or bus clock source; generates IRQ interrupt without CPU wake-up overhead |
| Low-Voltage Inhibit (LVI) | User-selectable 2.5 V or 3.8 V trip point with hysteresis; forces reset or asserts interrupt based on configuration |
| ADC10 Flexibility | 8-channel 10-bit converter with software-selectable clock division, sample time, and conversion trigger (SW, IRQ, or AWU) |
Applications
| Home Appliance Control | Industrial Sensor Interface |
|---|---|
|
Use Scenario: Microcontroller in washing machine control board managing motor sequencing, water valve actuation, and temperature feedback. IC Role / Device Role / Timing Role: Primary system controller executing state-machine logic, reading thermistor ADC values, and driving relay outputs via GPIO. Use Value: On-chip 10-bit ADC eliminates external signal conditioning; AWU enables low-power idle monitoring of door switch; COP ensures safe timeout during spin cycle. |
Use Scenario: Standalone sensor node measuring pressure and humidity in HVAC ducts, transmitting data via UART to central controller. IC Role / Device Role / Timing Role: Data acquisition engine sampling analog sensors, applying linearization in firmware, and formatting UART packets. Use Value: Internal oscillator trim ensures stable 8 MHz bus clock for consistent ADC sampling rate; LVI prevents erratic behavior during brown-out events. |
| Consumer Remote Keypad | Power Tool Motor Controller |
|
Use Scenario: IR remote receiver unit with tactile keypad for set-top box navigation and volume control. IC Role / Device Role / Timing Role: Keyboard interrupt handler scanning matrix keys, debouncing inputs, and generating IR carrier bursts. Use Value: Dedicated KBI module reduces CPU load during keypress detection; shared PTA/PTB pins minimize PCB routing complexity. |
Use Scenario: Cordless drill control board regulating brushless motor commutation based on hall-effect feedback and trigger voltage. IC Role / Device Role / Timing Role: Real-time motor sequencer reading analog trigger level (ADC), interpreting hall sensor edges (IRQ), and toggling gate drivers (GPIO). Use Value: 192 B RAM suffices for commutation lookup tables; COP watchdog prevents runaway motor operation during firmware faults. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC908QT2ACDWE | 2 KB Flash, 128 B RAM, same SOIC-20 package and peripheral set; lacks ADC10 module | Suitable only for digital-only control tasks without analog sensing requirements | Select when cost sensitivity outweighs need for on-chip ADC and reduced memory suffices for firmware footprint |
| MC908QY4ACDWE | Same 4 KB Flash, 192 B RAM, and peripherals; differs in pinout - PTA4–PTA7 replaced with additional KBI inputs (KBI4–KBI7) | Better suited for larger keypads (>4 keys); incompatible for designs relying on PTA4–PTA7 as GPIO or ADC | Choose only if expanded keyboard interrupt support is required and PCB layout allows pin reassignment |
Compared with MC908QT4ACDWE, the QT2 variant trades ADC capability for lower cost and smaller memory, while the QY4 variant reallocates port pins to enhance keyboard scanning - neither offers pin compatibility, requiring layout revision for substitution.
Availability
MC908QT4ACDWE is available at Aetrix Electronics and suitable for home appliance control, industrial sensor interface, consumer remote keypad, and power tool motor controller applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.
Supply support for MC908QT4ACDWE includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Freescale Semiconductor (now part of NXP Semiconductors) pioneered mixed-signal microcontrollers for cost-sensitive embedded systems, emphasizing integration, low-power operation, and robust development tools.
The MC908QT4ACDWE belongs to the HCS08-based QTA family, designed specifically for appliance, industrial, and consumer control applications where small footprint, analog integration, and field-programmable reliability are essential.
FAQ
What is the maximum bus clock frequency supported by the MC908QT4ACDWE?
The MC908QT4ACDWE supports a maximum bus clock frequency of 8 MHz. This is achieved using the internal oscillator (trimmed or untrimmed), external crystal (1–8 MHz), or external RC network. The bus clock drives all peripherals including ADC, AWU, and COP, and determines instruction execution speed - critical for real-time response in motor control and sensor polling applications involving the MC908QT4ACDWE.
Does the MC908QT4ACDWE include hardware support for EEPROM emulation?
Yes, the MC908QT4ACDWE supports EEPROM emulation using its on-chip 4 KB FLASH memory. The data sheet specifies dedicated FLASH block protection and page-erase routines enabling firmware to implement wear-leveling and non-volatile parameter storage. This capability eliminates the need for external EEPROM in applications like calibration storage or user preference retention within the MC908QT4ACDWE-based design.
How does the security feature of the MC908QT4ACDWE prevent unauthorized FLASH access?
The MC908QT4ACDWE implements monitor-mode security by requiring an eight-byte key stored at FLASH addresses $FFF6–$FFFD. During debug entry, the host must transmit matching bytes; if five or more are zero, monitor mode is denied. This prevents casual readout of firmware while allowing authorized development - a key safeguard for production units containing proprietary logic in the MC908QT4ACDWE.
Can the MC908QT4ACDWE operate from a 3.3 V supply without level-shifting external interfaces?
Yes, the MC908QT4ACDWE operates across 2.7–5.5 V, making 3.3 V fully compliant. Its I/O pins are 5 V tolerant when configured as inputs, and output high levels meet VOH ≥ 0.8 × VDD at IOL = 1.6 mA. This allows direct connection to 3.3 V logic, RS-232 transceivers, or SPI peripherals without level shifters - simplifying system design around the MC908QT4ACDWE.
What peripheral modules remain active in Wait mode on the MC908QT4ACDWE?
In Wait mode, the MC908QT4ACDWE keeps the ADC10, AWU, COP, LVI, IRQ, and KBI modules operational while halting the CPU and disabling the bus clock. This enables low-power event-driven operation: AWU can wake the system, ADC can perform background conversions, and IRQ/KBI can detect external triggers - all without full CPU activation, extending battery life in portable devices using the MC908QT4ACDWE.
MC908QT4ACDWE Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Package/Case:
- 8-SOIC (0.209", 5.30mm Width)
- Series:
- HC08
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Verified
- Core Processor:
- HC08
- Core Size:
- 8-Bit
- Speed:
- 8MHz
- Connectivity:
- -
- Peripherals:
- LVD, POR, PWM
- Number of I/O:
- 5
- Program Memory Size:
- 4KB (4K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 128 x 8
- Voltage - Supply (Vcc/Vdd):
- 2.7V ~ 5.5V
- Data Converters:
- A/D 6x10b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
MC908QT4ACDWE FAQ
1.How can I place an order for MC908QT4ACDWE through Aetrix?
Please submit a Request for Quotation (RFQ) for MC908QT4ACDWE on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MC908QT4ACDWE reliable?
The price and inventory of MC908QT4ACDWE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC908QT4ACDWE is usually 5 days.
3.What payment methods are accepted for MC908QT4ACDWE?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC908QT4ACDWE transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC908QT4ACDWE?
MC908QT4ACDWE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC908QT4ACDWE order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MC908QT4ACDWE?
For technical support, including MC908QT4ACDWE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC908QT4ACDWE requirements.
6.How does Aetrix verify that MC908QT4ACDWE is sourced from the original manufacturer or authorized distributors?
All MC908QT4ACDWE products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MC908QT4ACDWE meets industry standards.
7.What is the process for return or replacement of MC908QT4ACDWE?
All MC908QT4ACDWE units undergo pre-shipment inspection (PSI). If there is an issue with MC908QT4ACDWE, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MC908QT4ACDWE part is unused and in its original packaging.
Return procedure for MC908QT4ACDWE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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