1.8V MCUs connect to 3.3V power domains

June 12, 2014 // By Graham Prophet
This series of STM32 microcontrollers are specific low-voltage devices that help overcome the challenges designers face when adding a companion chip to a low-voltage host processor.

These focused low-voltage microcontrollers connect to the same digital power domain as the host, such as a 1.8V power supply, while allowing on-chip peripherals to operate from higher voltages such as 3.3V, giving freedom from the usual performance trade-offs that come with lower supply voltages.

STM32F038/48/58/78 and STM32F318/28/58/78 are low-voltage companion MCUs that enable flexible design partitioning. The combination of 1.8V digital supply voltage and independent analogue domain is particularly strong where a wide analogue dynamic range is required, or for connecting directly to USB devices. STM32F0x8 I/Os allow bridging between different voltages without using level shifters: the ADC peripheral of STM32F3x8 devices is fully functional down to 1.8V.

These devices combine the ARM Cortex-M0 core with up to 128 kByte on-chip Flash, while the STM32F3x8 based on the ARM Cortex-M4 core with DSP instruction set and floating-point unit have up to 512 kByte. Extensive pin, peripheral, and software compatibility between the two new low-voltage families, and with the mainstream STM32 F0 and STM32 F3 series, ensure design flexibility and scalability.

The low-voltage product lines allow designers to take advantage of the same features as mainstream STM32 F0 and STM32 F3 product series with no compromise or degradation in processing performance when operating at the lower voltage. Moreover, by enabling a simplified hardware implementation, these devices deliver an immediate cost advantage.

Use them, ST suggests, in portable consumer applications such as smartphones, accessories and media devices; they come in low-profile CSP, UQFN or UFBGA package styles as well as TSSOP and LQFP. The full range of package options spans configurations from 20 pins to 100 pins.

Prices start from $0.66 (10,000) for STM32F038F6P6 in 20-pin TSSOP with 32 kByte Flash, or $0.92 for the STM32F318K8U6 in UQFN32 with 64 kByte Flash.

STMicroelectronics; www.st.com/stm32