Low-Power MCUs Feature High-Speed Timers

Targeting battery-charger, sensor end-point, and motor-control applications, three new 20-pin tinyAVR flash microcontrollers include high-speed timers and offer 20-MIPS throughput when running at 20 MHz. The devices are pin-compatible, differing only in the size of their flash, EEPROM, and SRAM memories. The ATtiny261 has 2 kbytes of self-programmable flash memory, and the ATtiny461 and ATtiny861 have 4 kbytes and 8 kbytes, respectively. The chips operate down to 1.8 V and have enhanced interface options and a unique on-chip temperature sensor. The internal 8-MHz RC oscillator and phase-locked loop (PLL) run the 10-bit timer-counter at up to 64 MHz. Other features include three independent pulse-width modulation (PWM) generators, programmable dead times, pull-up resistors, and 12 general I/O pins.

The devices also integrate commonly used microcontroller peripherals, such as a Universal Serial Interface (USI), which can be configured to work as an SPI, UART, or TWI. Advanced analog capabilities—including built-in temperature measurement, a fast analog comparator, and a programmable analog gain amplifier—allow highly integrated designs. Eleven 10-bit analog-to-digital converter input channels permit a wide selection of peripherals to be connected in sensor and control applications. In 1.8-V active mode at 1 MHz, the devices consume less than 400 µA. In power-down mode, consumption is just a few microamps. The STK500 and STK505 starter kits cost $79 each and offer all the hardware needed to evaluate programs and test the capabilities of the three devices. Samples of the ATtiny261, ATtiny461, and ATtiny861 are available in 20-pin small-outline IC (SOIC) and plastic dual-inline packages (PDIPs) and 32-pad quad flat no-lead (QFN) packages. The devices are in volume production with prices of $0.80, $0.90, and $1.15, respectively, in quantities of 10,000.