MC9S08QA2CDNE - 8-Bit 20MHz 2KB Flash MCU | NXP 8-SOIC
MPN: MC9S08QA2CDNE ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.38 | $138.00 |
| 500 | $1.12 | $560.00 |
| 1,000 | $0.95 | $950.00 |
MC9S08QA2CDNE Overview
An 8-bit microcontroller (MCU) is a single-chip computer integrating a CPU, volatile memory (RAM), non-volatile memory (Flash/ROM), and programmable peripherals. 8-bit MCUs sit at the entry-level of the microcontroller hierarchy (8-bit -> 16-bit -> 32-bit -> SoC) within the broader semiconductor category, and they remain dominant in cost- and power-constrained designs such as appliance controls, sensor nodes, and human-interface replacement of discrete logic. The HCS08 core executes the legacy HC08 instruction set with the added BGND instruction for background debug.
Key features of the MC9S08QA2CDNE include the HCS08 CPU delivering up to 20 MHz bus speed, 2 KB Flash program memory, on-chip RAM for data, two very low-power stop modes for battery life extension, an integrated low-voltage detection (LVD) module with reset or interrupt capability, and a background debugging system (BDCS) with breakpoint capability for in-circuit debug. The 8-pin SOIC package enables compact PCB layouts in space-constrained designs.
The part uses a Freescale/NXP S08 CISC architecture with HC08 upward compatibility, easing migration from legacy HC08 designs. The architecture combines a 16-bit stack pointer and index register (H:X) with 8-bit data paths, balancing code density against throughput. On-chip peripherals and the integrated LVD reduce external component count.
Typical applications include low-cost appliance controllers, battery-powered sensor interfaces, simple user-interface replacements, and industrial sensor signal conditioning where the 8-bit core, low-power stop modes, and small Flash footprint are sufficient for the firmware image.
When designing with this device, ensure the supply rail is held within the 1.8 V to 3.3 V range (3.6 V absolute maximum) and that bulk decoupling is placed close to the VDD pin. LVD should be configured for the application brown-out threshold to prevent Flash corruption during supply dips.
Drop-in alternatives for MC9S08QA2CDNE — 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 MC9S08QA2CDNE (same form factor and footprint) — differing in Package, ADC, Flash Memory, Supply Voltage Range, RoHS Status.
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View Datasheet →MC9S08QA2CDNE Maximum Ratings & Electrical Characteristics
| Core | HCS08 (S08) |
| Data Bus Width | 8 bit |
| Instruction Set | HC08 + BGND |
| Maximum Clock Frequency | 20 MHz |
| Core Speed | 40 MHz |
| Program Memory Size | 2 KB (2K x 8) Flash |
| Supply Voltage Range | 1.8 V to 3.3 V (3.6 V abs max) |
| Package | 8-pin SOIC |
| Mounting Type | Surface Mount |
| Low-Power Modes | Two very low-power stop modes |
| Low-Voltage Detection | Yes (reset or interrupt) |
| Background Debug | BDCS with breakpoint capability |
MC9S08QA2CDNE Pin Configuration
| Pin 1 | PTB5/KBIP5/ADP5 — Port B bit 5 / Keyboard interrupt / ADC input |
| Pin 2 | VDD — Supply voltage (1.8 V to 3.6 V) |
| Pin 3 | VSS — Ground |
| Pin 4 | BKGD/MS — Background Debug / Mode Select |
| Pin 5 | PTA2/TCLK/RESET — Port A bit 2 / Timer clock / Reset |
| Pin 6 | PTA3/SDA/TXD — Port A bit 3 / SDA / UART TXD |
| Pin 7 | PTA4/SCL — Port A bit 4 / SCL |
| Pin 8 | PTB4/KBIP4/ADP4 — Port B bit 4 / Keyboard interrupt / ADC input |
Typical Applications
MC9S08QA2CDNE is suitable for 6 applications: Low-Cost Appliance Controller, Battery-Powered Sensor Node, User Interface Replacement, Industrial Sensor Signal Conditioning, Automotive Body Electronics (Non-Safety), Consumer Toy and Hobby Electronics.
Low-Cost Appliance Controller
The MC9S08QA2CDNE suits low-cost appliance controllers (washing machines, microwaves, simple HVAC controls) where 2 KB Flash is ample for state-machine firmware and the HCS08 core delivers 20 MHz bus speed for responsive user-interface polling. Its two very low-power stop modes reduce standby drain to a few microamps, helping meet energy-star idle budgets. The integrated low-voltage detection prevents Flash corruption during brown-outs common in motor-driven loads, and the 8-pin SOIC keeps the BOM small on crowded appliance PCBs.
Recommended
Battery-Powered Sensor Node
For battery-powered sensor nodes (remote environmental sensors, wireless thermometers, simple IoT endpoints), the MC9S08QA2CDNE's 1.8 V to 3.3 V supply range and two low-power stop modes enable multi-year battery life on a single coin cell. The HCS08 core at 20 MHz is fast enough to wake, sample a sensor, run a brief decision algorithm, and return to stop mode within milliseconds. The LVD module issues a reset before the rail collapses, protecting 2 KB of Flash against in-application corruption during end-of-life battery voltage decay.
Recommended
User Interface Replacement
When replacing discrete logic or a 555-timer-based user interface (button debouncers, LED sequencers, simple keypad scanners), the MC9S08QA2CDNE consolidates the design into a single 8-pin SOIC device. Its 8-bit CISC core and HC08 instruction set deliver tight code density, so a multi-button debouncer plus PWM-driven LED chase fits within 2 KB Flash. The HCS08's BGND instruction and BDCS breakpoints simplify firmware bring-up versus pure-logic prototypes.
Recommended
Industrial Sensor Signal Conditioning
In industrial 4-20 mA loop-powered transmitters and simple sensor conditioning front-ends, the MC9S08QA2CDNE handles linearization, range scaling, and HART-like modulation on a tight power budget. Its 1.8 V minimum supply suits 3.3 V-derived rails, while the two low-power stop modes let the MCU idle between samples to stay within loop-compliance budgets. The integrated LVD guards Flash during inductive load transients common on plant floors, and the 8-pin SOIC package survives hand-solder rework on legacy boards.
Recommended
Automotive Body Electronics (Non-Safety)
For non-safety automotive body modules (interior lighting controllers, mirror adjusters, simple seat controllers), the MC9S08QA2CDNE's HCS08 core and 8-pin SOIC deliver compact code in a small footprint. Note that this part lacks explicit AEC-Q100 qualification - for safety-relevant or AEC-Q100-required designs, select an AEC-Q100-qualified S08 variant. The LVD and stop modes support crank-undervoltage ride-through required by body electronics.
Recommended
Consumer Toy and Hobby Electronics
The MC9S08QA2CDNE is a strong fit for consumer toys, hobby robotics, and educational electronics kits where unit cost and PCB area dominate BOM decisions. Its 2 KB Flash holds simple behaviour trees, the HCS08 20 MHz bus speed drives hobby servos and PWM channels with low jitter, and the 8-SOIC package hand-solders easily on through-hole-friendly adapter boards. The 1.8 V minimum supply enables direct Li-ion or 2xAA operation.
Recommended
Recommended Products Summary
Engineering reference data for MC9S08QA2CDNE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC9S08QA4CDNE | MC9S08QG4CDNE | MC9S08QD2VSC | MC9S08QE32CLCR | MC9RS08KA1CDBR | MCHC908QT4VDWER |
|---|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| Core | HCS08 | HCS08 | HCS08 | HCS08 | HCS08 | RS08 | HC908 |
| Max Clock Frequency | 20 MHz bus / 40 MHz core | 20 MHz bus | 20 MHz bus | 10 MHz bus | 20 MHz bus | 10 MHz bus | 8 MHz bus |
| Program Memory | 2 KB Flash | 4 KB Flash | 4 KB Flash | 2 KB Flash | 32 KB Flash | 1 KB Flash | 4 KB Flash |
| Supply Voltage | 1.8 V to 3.3 V | 1.8 V to 3.3 V | 1.8 V to 3.3 V | 1.8 V to 3.3 V | 1.8 V to 3.3 V | 1.8 V to 5.5 V | 2.4 V to 5.5 V |
| Low-Power Stop Modes | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
Key Differentiators
- Compact 2 KB Flash with HCS08 core at 20 MHz bus speed (vs MC9RS08KA1CDBR)
- Same-family upgrade path within 8-SOIC (vs MC9S08QA4CDNE)
- Active-lifecycle S08 family alternative (vs MC9S08QE32CLCR)
Design Notes
The MC9S08QA2CDNE operates from 1.8 V to 3.3 V (3.6 V absolute maximum). Place a 100 nF decoupling capacitor as close as possible to the VDD pin and a 4.7 uF bulk capacitor on the supply rail. Enable the on-chip low-voltage detection (LVD) to issue a reset before the supply collapses below safe Flash programming voltage, preventing code corruption during battery end-of-life or motor-induced brown-outs.
Do not assume any GPIO pin can source/sink more than the datasheet-rated current. Avoid using the BKGD/MS pin as a regular GPIO during normal operation, since this pin carries the background debug mode-select function. Use BGND for BDM debug sessions only. The HC08 instruction set with BGND requires a Freescale/NXP-compatible BDM pod for in-circuit debug - JTAG is not supported on this part.
Layout the 8-SOIC on a 0.65 mm pitch land pattern with thermal relief on the VDD/VSS pads. Keep the BKGD/MS trace short (<= 25 mm) and route away from switching nodes to avoid debug-session glitches. For battery applications, place the MCU and its decoupling network on the same ground island to avoid ground loops through the LVD sense path.
Compliance Information
Compliance fields could not be confirmed from the verified web data; refer to the official NXP/Freescale datasheet for RoHS, lead-free, and halogen-free status. The part is not AEC-Q100 qualified per its End-of-Life product page.