Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Controls/MCUs

AVR MCUs combine USB controller, analog features

Posted: 11 Mar 2008 ?? ?Print Version ?Bookmark and Share

Keywords:USB controller? AVR MCU? analog?

Atmel Corp. has announced new AVR MCUs that combine USB controller and high-performance analog features. The ATmega16U4 and ATmega32U4 promise to reduce system cost in battery-powered devices such as gaming accessories.

Battery-powered devices can take advantage of being connected to a USB port to recharge. However, modern batteries require sophisticated algorithms to accelerate and optimize charging, while USB brings further constraints on the battery charging since it is limited both in the voltage and the maximum current it can provide.

The new AVR devices allow optimized battery charging combined with USB functions. The ADC can be used to sense motion or pressure in the end application and the high-speed PWM is suitable for low-cost motor control.

Gaming peripherals, such as sophisticated joysticks, also require a number of ADC channels and several PWM channels to drive force-feedback motors. The new devices have a rich feature set that address those needs and optimize the global system cost. This includes a 10bit ADC with 12 channels; a built-in temperature sensor allowing compensating thermal effects on analog performance; and, a programmable gain x1, x10, x40 and x200, giving more flexibility to measure differential voltages for current monitoring. A high-speed timer with three PWM channels with complementary outputs and programmable dead-times allows 8bit resolution PWM with an industry-best frequency of 500kHz, up to 11bit resolution PWM with a frequency over 60kHz.

A hardware flow control on the USART eases the connection to other devices when bridging with USB at high baud rates. Digital inputs with TTL thresholds ease interface with 3V devices in mixed 5/3V applications. A on-chip 3.3V regulator can deliver up to 50mA and supply external devices in USB powered applications. Jitter and accuracy of the on-chip 8MHz calibrated RC oscillator can support serial communication without crystal. All devices include a hardware multiplier, one USART, one SPI, one TWI, two 8bit and two 16bit timers with PWM and 26 programmable I/Os.

ATmega16U4 features 16Kbytes of In-System Programmable (ISP) flash, 1Kbyte of RAM and 512bytes of EEPROM. ATmega32U4 features 32Kbytes of ISP flash, 2.5Kbytes of RAM and 1Kbyte of EEPROM. They are available in 44-pin packages.

"The new microcontrollers complement the existing family of AVR USB microcontrollers serving a variety of embedded host or peripheral USB applications," said Jean-Christophe Lawson, Atmel's AVR product marketing manager. "Smaller footprint and enhanced analog performance was requested for several USB-based applications and we are pleased to introduce a new combination of features that will optimize the performance and cost of the customer's applications."

An extensive software library is offered to support the most-relevant USB classes for the embedded market.

The parts are supported by the latest release of AVR Studio, which is available from the Atmel Website. Both JTAGICE MkII at $299 and AVR Dragon at $49 allow in-system programming and emulation through on-chip debug resources. The STK600-TQFP44 includes a dedicated adapter board so these specific devices can connect on the generic STK600 Starter Kit. By June 2008, this will be complemented by the EVK527 a standalone evaluation kit allowing the evaluation of HID, mass storage, audio and battery-charging applications.

ATmega32U4 engineering samples are available and both devices will be shipping in volume in Q2 08. ATmega32U4 is offered in TQFP44 and QFN/MLF44 packages at $2.65 in quantities of 10,000 units and ATmega16U4 is offered in a QFN44 package at $2.40 in quantities of 10,000 units.

Article Comments - AVR MCUs combine USB controller, ana...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top