W79E825AW - 8-Bit MCU, 16KB ISP Flash, 18 I/O Ports | Nuvoton
MPN: W79E825AW ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.38 | $138.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $0.99 | $990.00 |
W79E825AW Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, volatile RAM, and peripheral interfaces into one package; 8-bit MCUs such as the W79E825AW remain widely used in cost-sensitive embedded designs where the processing workload (sensing, key handling, simple state machines, motor pulse trains) fits comfortably within an 8-bit data path. Within the broader semiconductor taxonomy, an MCU belongs to the microcontrollers sub-category of Integrated Circuits, sitting above Logic ICs and beneath microprocessors in capability. The 4T core architecture positions the W79E825AW for one-instruction-per-four-clock operation, providing up to several MIPS per MHz depending on the selected clock source.
Key features of the W79E825AW include ISP Flash that supports in-application firmware updates without removing the part from the board, a configurable 4-/2-channel 10-bit PWM block for motor or LED control, a 10-bit ADC that can be routed to multiple I/O pins, and a Brown-out / Watchdog combination for unsupervised recovery from power or code faults. The four-level interrupt controller lets time-critical events preempt background tasks, and the Enhanced UART supports 9-bit address-mode communications for RS-485 multi-drop networks.
Typical applications include white-goods control boards, low-end motor drives, simple sensor hubs, IR remote transceivers, and consumer-electronic user-interface modules. The 18 I/O budget covers keypad scanning, LED driving, and small display interfaces without external expanders.
When designing with this part, leave at least one UART accessible as a serial debug / ISP window and verify the ISP entry sequence against the In-System Programming section of the manufacturer datasheet to avoid lock-out conditions.
Drop-in alternatives for W79E825AW — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
W79E825ASN
✅ Drop-In📋 Reference alternative (not in catalog)
W79E832ADG
✅ Drop-In📋 Reference alternative (not in catalog)
N79E825ASG
✅ Drop-In📋 Reference alternative (not in catalog)
N79E825ASG
✅ Drop-In📋 Reference alternative (not in catalog)
W79E825ASG
✅ Drop-In📋 Reference alternative (not in catalog)
W79E825AW Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit CMOS, 4T (4 clocks per instruction cycle) |
| Program Memory (Flash) | 16 KB ISP Flash EPROM |
| Data Memory (RAM) | 256 bytes on-chip SRAM |
| Data Flash NVM | 256 bytes on-chip |
| I/O Ports | 18 multi-function I/O |
| Timers / Counters | 2 × 16-bit |
| Interrupt Sources | 13 sources, 4 priority levels |
| UART | 1 Enhanced full-duplex |
| I2C | 1 channel |
| PWM Channels | 4 channels, 10-bit |
| ADC | 4 channels, 10-bit (multiplexed) |
| Watchdog Timer | Programmable |
| On-chip Oscillator | Yes (internal clock circuitry) |
W79E825AW standard Pin Configuration Guide
Pin configuration for W79E825AW (standard package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for W79E825AW.
Refer to the datasheet for full pin configuration.
Typical Applications
W79E825AW is suitable for 6 applications: Home Appliance Control Boards, Small Motor / DC-Fan Speed Control, IR Remote Control & Consumer IR Receivers, Sensor Hub / Data-Logger Front End, User-Interface Keypad / Display Modules, RS-485 Sensor / Multi-Drop Slave Nodes.
Home Appliance Control Boards
The W79E825AW fits home-appliance control boards including washing-machine sub-modules, microwave key/display controllers, and rice-cooker / induction-cooker user-interface boards. Its 16 KB ISP Flash accommodates small RTOS-less state machines plus menu/parameter storage, while 256 bytes of on-chip data Flash NVM preserve user-set timings across power cycles. Four channels of 10-bit PWM drive buzzer tones and LED backlight dimming without external timers, and the 4-channel 10-bit ADC reads temperature sensors or potentiometers directly. The 18 I/O budget easily covers a 4x4 keypad matrix plus a multiplexed 7-segment display, and the Enhanced UART enables diagnostic links to factory test rigs or to a higher-level display main-board - reducing BOM cost for the appliance tier below $1.50 per control module.
Recommended
Small Motor / DC-Fan Speed Control
For brushed-DC fans, vibration pumps, and small unipolar stepper motor control the W79E825AW offers the right mix of PWM and ADC without excess. Four 10-bit PWM channels drive up to four low-side or H-bridge gate signals for two small DC motors or one bipolar stepper; the four-channel 10-bit ADC multiplexes back-EMF or shunt-sense feedback to close a software PI loop. The Enhanced UART relays motor telemetry (RPM, current, fault codes) to a host controller, while ISP Flash permits field firmware updates for tuning PID gains per motor lot. Compared with a 32-bit Cortex-M0, the W79E825AW cuts BOM cost in cost-sensitive consumer fans, but cannot handle sinusoidal BLDC or FOC algorithms above a few hundred Hz electrical.
Recommended
IR Remote Control & Consumer IR Receivers
In IR remote controls and consumer IR learning receivers the W79E825AW's 256-byte SRAM, single Enhanced UART, and 13 interrupts with four-level priority cover RC5/RC6/ NEC protocol decoding along with low-power standby operation. The 4T core decodes edge timings of 9-13 kHz carrier bursts deterministically; 256 bytes of on-chip data Flash NVM store learned device codes across battery swaps. The 18 I/O budget drives multiple LED indicators plus a 3x4 keypad matrix, and ISP Flash allows factory re-flashing of protocol tables without disassembling the remote. Compared with dedicated IR-decoder ASICs, this part gives the manufacturer the flexibility to add features (e.g., RF4CE gateway logic) by repacking firmware rather than re-spinning an ASIC.
Recommended
Sensor Hub / Data-Logger Front End
In simple sensor-hub and data-logger front ends the W79E825AW aggregates 1-4 analog sensors through its 4-channel 10-bit ADC and forwards results over I2C or UART to a host processor. Its 256-byte SRAM buffers short bursts of samples; the on-chip data Flash stores calibration coefficients; and ISP Flash supports remote firmware updates for sensor-fusion changes. The Watchdog timer recovers from sensor-noise-induced hangs, important for unattended sensors in industrial areas. Compared with discrete AFE + microcontroller solutions, this part integrates ADC + MCU + NVM into one die, reducing footprint and BOM in retrofit sensor modules.
Recommended
User-Interface Keypad / Display Modules
For keypad-plus-display sub-assemblies the W79E825AW supplies the timing and I/O budget to scan up to an 8x8 button matrix (or smaller) and drive a multiplexed character LCD or 7-segment display. The 18 I/O pins are more than sufficient for the keypad columns/rows plus a 4-common/8-segment display; the timer/counter provides precise multiplexed refresh without CPU overhead; and the 256-byte SRAM holds debounce buffers. ISP Flash enables late-stage menu customization without reflashing the master MCU. Compared with LED-driver companion ICs, this part eliminates a chip and reduces BOM cost.
Recommended
RS-485 Sensor / Multi-Drop Slave Nodes
In RS-485 multi-drop sensor networks the W79E825AW acts as a slave node responding to a Modbus/RTU master. The Enhanced UART supports the 9-bit address-mode required by Modbus, and the 13 interrupts with four priority levels keep the address-matching latency low. The programmable Watchdog Timer resets the node if the master goes silent for too long, and ISP Flash allows in-field firmware upgrades via the same UART. Compared with isolated RS-485 transceiver solutions, this MCU adds node-level compute without adding a separate logic device, keeping each remote node under $2 BOM.
Recommended
Recommended Products Summary
Engineering reference data for W79E825AW — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | W79E825ASN | W79E832ADG | N79E825ASG | W79E825ASG |
|---|---|---|---|---|---|
| Brand | Nuvoton (formerly Winbond) | Nuvoton | Nuvoton | Nuvoton | Nuvoton |
| Core Architecture | 8-bit, 4T | 8-bit, 4T | 8-bit, 4T | 8-bit, 4T | 8-bit, 4T |
Key Differentiators
- ISP Flash on same die as 256 B NVM data flash (vs N79E825ASG)
- Enhanced UART with 9-bit address-mode support (vs W79E832ADG)
- 13 interrupts in a four-level priority scheme (vs N79E825ASG)
Design Notes
When laying out the W79E825AW PCB, place a 0.1 µF decoupling capacitor within 5 mm of each VDD pin and a bulk capacitor (4.7 µF or larger) on the regulator output. The device's ISP programming sequence relies on a specific reset-state pattern on designated pins; if external reset or brown-out circuitry holds the device in a non-ISP state, in-system firmware updates can be locked out until the next power cycle.
Route any ADC analog input traces away from PWM or digital switching lines; crosstalk of more than 20 mV from a PWM edge into the 10-bit ADC input reduces the dynamic range by at least 3 LSB at 5 V VDD. A grounded guard ring around the ADC pin plus a small RC filter (1 kΩ + 100 pF) at the input yields ~10 dB improvement in noisy environments like brushed-motor PCBs.
Estimated: at 5 V VDD with all peripherals active and CPU running at the maximum oscillator rate, the W79E825AW draws roughly 5-10 mA (exact figure depends on the chosen clock mode and active peripheral count). For battery-backed designs, gate the W79E825AW supply with an external load switch controlled from a host MCU to drop standby current to the µA range when the device is not actively scanning or transmitting.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status for the W79E825AW were not stated explicitly in the verified web data; request the latest material declaration from Nuvoton (or its franchised distributor) before designing the part into any product with substance-restriction requirements.
