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- TOKYO, Japan, November 19, 2025 -

Seiko Epson Corporation (TSE: 6724, "Epson") has developed and begun shipping samples of the S1C17W11, a new 16-bit microcontroller featuring low power consumption and high-precision resistance measurement capabilities.

The growing aging population, expansion of home healthcare, increasing demand for environmental monitoring, and global efforts to achieve the Sustainable Development Goals are fueling the need for battery-powered personal healthcare devices and compact measurement instruments capable of long-term operation. These devices must offer high measurement accuracy and an extended operating life while being compact and affordable. Conventional designs that combine a general-purpose microcontroller with external analog and display circuits have higher parts counts and consume more power, costing more time and money for design, evaluation, and mass production.

To address these challenges, Epson developed the S1C17W11, a single-chip microcontroller that integrates Epson's proprietary low-power technology, measurement circuits including a CR oscillator-based A/D converter (RFC)¹, and display and interface functions. This integration reduces the number of external components, enabling smaller devices that consume less power while also saving users time and effort for evaluation and development.

Epson will continue to address diverse social challenges and contribute to building a sustainable society by delivering energy-saving, highly reliable microdevices based on its efficient, compact, and precise technologies.

1. CR oscillator-based high-precision A/D converter (RFC)

By converting resistance values into frequency and measuring that frequency with a high-precision counter² equivalent to 24 bits, the device supports enhanced accuracy for sensing applications that rely on resistance, such as thermometers and water quality meters.

2. Energy-efficient design

Low standby current (109nA Typ.) in SLEEP mode enables long-life operation. The device, which is designed to run on an LR41 button cell or other small battery, requires only infrequent battery replacement.

3. Built-in display and notification circuits

The built-in LCD driver (20 SEG × 1-4 COM) reduces the need for external LCD driving circuits. The microcontroller also incorporates a voltage booster circuit (CHREG)³ for driving a buzzer or LED, eliminating the external circuitry required in previous products. This enables a louder buzzer and brighter LED, ensuring reliable user notifications even when covered or in noisy environments.

4. Memory security features

The device is equipped with built-in Flash (48 KB) and EEPROM⁴ (128 B), enabling storage of calibration data and measurement history. Supports on-board rewriting and improved maintainability.

• ¹ A measurement circuit that converts resistance changes into oscillation frequency and compares the difference between the measurement oscillator and the reference oscillator, enabling high-precision measurement equivalent to up to 24 bits with ease.
• ² A circuit that measures frequency with high precision by counting pulses (oscillation frequency) output from the oscillator within a fixed time interval.
• ³ Previously, the applied voltage was limited to the supply voltage VDD (approximately 3.6V max), but this circuit boosts VDD to generate up to 5.0V, enabling higher-output drive for buzzers and LEDs.
• ⁴ A type of non-volatile memory that allows data to be electrically rewritten and erased, while retaining data even when the power is turned off.

Thermometers, non-contact/contact biometric devices, portable water/salinity meters, food and beverage inspection terminals, industrial handheld measuring instruments, and IoT sensor devices.

Product name	S1C17W11
CPU core	Epson original 16-bit RISC CPU core S1C17
Flash memory capacity	48 KB
RAM capacity	2 KB
EEPROM capacity	128 bytes
R/F converter	CR oscillator type, 24-bit counter Number of conversion channels: 1 channel
	Compatible sensors and number of connectable sensors DC bias resistive sensors: 2 (max.) AC bias resistive sensors: 1 (max.)
	Reference power supply for measurement: Internally generated by a dedicated power circuit
Oscillator circuit	Built-in oscillator circuit: 700 kHz (Typ.) Built-in oscillator circuit: 32 kHz (Typ.) 4 M (max.) / 2 M / 1 M / 500 k / 384 k / 250 kHz built-in oscillator circuit Rectangular or sine wave input: 4.2 MHz (max.)
LCD driver	20 segments × 1-4 commons
LCD power supply	Built-in 1/3 bias power supply (selectable internal boost or resistor divider) External voltage applicable (external voltage can be divided by internal resistors)
Sound generator	Buzzer output function: Output Frequency 512 Hz to 16 kHz, One-shot output capability
	Melody Generation Function
Booster circuit for driving a buzzer or LED	Output voltage: VDD × 2 ≦ 5.0 V (Typ.) I/O voltage for SNDA2 output terminals (BZOUT, #BZOUT) Can also be used as power supply for an LED, output current: 10 mA (max.)
Serial interface	UART：1ch / SPI：1ch / I²C：1ch
Input/Output ports	Input/Output ports: Up to 24 bits Output port: Up to 1 Bit
Power supply voltage detection circuit	VDD or External Voltage: 32 Levels (1.15 V to 3.2 V)
Timer	16-bit timer: 3 channels 16-bit PWM timer: 2 channels Watchdog timer
Current consumption (typical)	SLEEP mode: 109 nA HALT mode: 1.3 µA(32 kHz built-in oscillator) RUN mode: 90 µA(IOSC=ON) 4 µA (OSC1=ON) 160 µA(OSC3=ON)
Supply voltage	VDD operating voltage: 1.2 V to 3.6 V VDD operating voltage during Flash rewrite: 2.2 V to 3.6 V (Flash programming voltage VPP: 7.5 V external application or internal generation) EEPROM programming voltage: 2.2 V to 3.6 V (Programming voltage VPP internally generated)
Packaging type	P-VQFN048-0707-0.50 (terminal pitch: 0.5 mm), bare chip

Please see the link below for further product details.

https://global.epson.com/products_and_drivers/semicon/products/micro_controller/16bit/#ac08

For requests and inquiries regarding microcontroller-related materials, please refer to the following page.
By requesting materials, you will be able to download microcontroller-related documents.

https://global.epson.com/products_and_drivers/semicon/offer/mcu.html

Seiko Epson Corporation

MD Sales Department

https://global.epson.com/products_and_drivers/semicon/information/support.html

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