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Ultra Low Power MCU HT32L522x1 Series by Holtek

Ultra Low Power MCU HT32L522x1 Series: With the HT32L522x1 microcontrollers, the Taiwanese manufacturer Holtek offers a solution for applications where minimising power consumption is the top priority.

In deep power down mode, these MCUs require just 120nA (typical) at 3.3V VDD.

Ultra Low Power MCU HT32L522x1 series in brief

The HT32L522x1 MCUs are based on an ARM Cortex-M0+ core and run with up to 48MHz main clock. The operating temperature range covers -40°C to +105°C. As for other HT32 MCUs, Holtek offers UL/IEC 60730-1 Class B certification with self-test routines and a safety test library also for this family.

The two derivatives differ in the size of the integrated memory:

  • HT32L52231: 32kB Flash / 4kB SRAM
  • HT32L52241: 64kB Flash / 8kB SRAM

They are each available in 3 different package types:

  • QFN32 (4mm x 4mm) with 25 GPIO
  • QFN46 (4,5mm x 6,5mm) with 37 GPIO
  • LQFP48 (7mm x 7mm) with 39 GPIO

With 16 different pin mapping options, the pin-out of the HT32L522x1 can be flexibly adapted to the needs of the intended application.

Serial interfaces such as SPI, USART, UART and I2C are available as standard.

Interesting peripherals – ADC & Motor Control Timer

The integrated 12-bit SAR ADC converts at up to 1 Msps. Interestingly, the ADC has an analogue watchdog to trigger an interrupt depending on the upper or lower set limit. This allows, for example, batteries and accumulators or sensors of all kinds to be monitored. In particular, the internal temperature sensor of the MCU can be connected directly (cold chain logger, overheating warning…).

The 16-bit motor control timer is also worth to be mentioned. It offers 4 capture/compare registers, complementary outputs and programmable dead time. This means that 3-phase motors can also be controlled. A ‘break’ signal input is also available.

Details of the other peripherals can be found in the data sheet.

Datasheet HT32L522x1

Low power performance of HT32L522x1 MCUs

Compared to Cortex-M0+ MCUs from other manufacturers, the HT32L522x1 with a valid operating voltage of 1.65V to 3.6V offers a significant reserve in battery-operated applications.

In RUN mode in a while(1) loop, the power consumption at room temperature and 48 MHz clock is only 3.9mA typical (4.2mA max.), at 8MHz 0.82mA typical (0.89mA max.) and at 32kHz in low-power RUN mode 3.5µA.

In sleep mode, it is typically 0.81mA (48MHz), 0.56mA (16MHz), 296µA (8MHz) or 1.41 µA (32kHz), depending on the main clock. These values refer to the core with the peripherals switched off.

There are 3 further deep sleep modes below the sleep mode. In these modes, all clock sources – apart from the internal 32kHz oscillator (LSI) – are stopped. The integrated ultra low power LDO is used in these modes. The real-time clock (RTC) runs in DSM1 and DSM2, which further reduces the current requirement to 1.15µA typical.

In DSM3, the internal 32kHz oscillator is also switched off in addition to the RTC, meaning that only 540nA typical is required.

With the Ultra Low Power MCU HT32L522x1 Series, Holtek now offers the right platform for very power-efficient designs. Are you preparing one? Contact us directly or send us your enquiry here. We would also be happy to offer you expertise on other energy-saving components and technologies.

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