Power-efficient 32-bit MCU with Arm Cortex-M0+ processor integrates liquid crystal driver

Seiko Epson Corporation has developed a new power-efficient flash microcontroller unit (MCU) with an ARM Corte -M0+ processor. The S1C31W65 is the latest addition to the popular S1C31W series of single-chip MCUs with an integrated liquid crystal driver. It is the first multipurpose microcontroller to support a segment liquid crystal display driver.

Industrial equipment and consumer electronics are increasingly IoT-enabled systems hosting a multitude of functions. They require high-performance processing while still maintaining low current consumption. To meet these market requirements, Epson has leveraged its low-leakage and low-current consumption technologies and used Arm Cortex-M0+ processors to expand and upgrade the S1C31 family of MCUs, which offer high performance yet consume minimal current.

The S1C31W65, operating at up to 33 MHz, delivers the highest performance in the S1C31 family. It consumes just 0.3 µA in sleep mode and operates at 130 µA/MHz. In addition, Epson leveraged its signature display driving technology to provide an LCD driver that can drive up to 416 segments. The bias power supply necessary for driving a liquid crystal panel can be generated by the internal power supply circuit, so display quality is not affected by the remaining battery power. In addition, drive voltage is software adjusted. The MCU supports LCD contrast adjustment and liquid crystal panels with different voltages.

The S1C31W65 has a host of peripheral circuits, including various timers, a real-time clock (RTC), R/F converter⁴, A/D converter, and a temperature sensor. It supports operating temperatures up to 105℃ and operating voltages ranging between 1.8 V and 5.5 V, making it ideal for industrial equipment and for consumer electronics that require sensing.

Key features

1. A large number of built-in circuits that simultaneously help customers add more functions to their products while reducing the number of parts
   • Self-programmable flash memory
   • Liquid crystal driver with integrated power supply circuit
   • Real-time clock
   • Supply voltage detector (SVD) circuit that does not require an external power supply supervisor
   • R/F converter, A/D converter, temperature sensor/reference voltage generator circuit
   • Universal port multiplexer (UPMUX): I/O pin assignments changed with software
2. Usable under a wide range of environmental conditions
   • Operating voltage range: 1.8 V to 5.5 V
   • Operating temperature range: -40℃ to 105℃
   • High-speed operation up to 33 MHz
   • Boot clock startup as fast as 2 µs⁵
   • Low-power 32.768 kHz crystal oscillator / 32 kHz built-in oscillation circuit