Part: ATmega16U4/ATmega32U4 — Atmel Type: 8-bit Microcontroller with USB Controller Description: High-performance, low-power 8-bit AVR microcontroller with 16/32KB In-System Self-Programmable Flash, 1.25/2.5KB SRAM, 512Bytes/1KB EEPROM, and a USB 2.0 Full-speed/Low Speed Device Module.

Operating Conditions:

• Supply voltage: 2.7–5.5V
• Operating temperature: -40 to +85°C
• Max frequency: 16MHz at 4.5V

Absolute Maximum Ratings:

Key Specs:

• CPU: AVR 8-bit RISC
• Max throughput: Up to 16 MIPS at 16MHz
• Flash memory: 16/32KB In-System Self-Programmable
• SRAM: 1.25/2.5KB Internal
• EEPROM: 512Bytes/1KB Internal
• USB data rates: Up to 12Mbit/s (Full-speed), 1.5Mbit/s (Low Speed)
• I/O lines: 26 Programmable
• ADC: 12-channels, 10-bit
• Data retention: 20 years at 85°C / 100 years at 25°C

Features:

• Advanced RISC Architecture with 135 instructions
• On-chip 2-cycle Multiplier
• JTAG (IEEE std. 1149.1 compliant) Interface
• USB 2.0 Full-speed/Low Speed Device Module
• On-chip PLL for USB and High Speed Timer (32 up to 96MHz)
• Multiple Timer/Counters (8-bit, 16-bit, 10-bit High-Speed)
• Multiple PWM Channels (8-bit, 2-16 bit programmable resolution, 2-11 bit high speed)
• Programmable Serial USART with Hardware Flow Control
• Master/Slave SPI Serial Interface
• Byte Oriented 2-wire Serial Interface
• Programmable Watchdog Timer with Separate On-chip Oscillator
• On-chip Analog Comparator
• On-chip Temperature Sensor
• Power-on Reset and Programmable Brown-out Detection
• Internal 8MHz Calibrated Oscillator
• Six Sleep Modes

Applications:

• Embedded control applications

Package:

• 44-lead TQFP Package, 10x10mm
• 44-lead QFN Package, 7x7mm

• High Performance, Low Power AVR ® 8-Bit Microcontroller
• Advanced RISC Architecture
• 135 Powerful Instructions - Most Single Clock Cycle Execution
• 32 x 8 General Purpose Working Registers
• Fully Static Operation
• Up to 16 MIPS Throughput at 16MHz
• On-Chip 2-cycle Multiplier
• Non-volatile Program and Data Memories
• 16/32KB of In-System Self-Programmable Flash
• 1.25/2.5KB Internal SRAM
• 512Bytes/1KB Internal EEPROM
• Write/Erase Cycles: 10,000 Flash/100,000 EEPROM
• Data retention: 20 years at 85 C/ 100 years at 25 C (1)
• Optional Boot Code Section with Independent Lock Bits In-System Programming by On-chip Boot Program True Read-While-Write Operation Parts using external XTAL clock are pre-programed with a default USB bootloader
• Programming Lock for Software Security
• JTAG (IEEE ® std. 1149.1 compliant) Interface
• Boundary-scan Capabilities According to the JTAG Standard
• Extensive On-chip Debug Support
• Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface
• USB 2.0 Full-speed/Low Speed Device Module with Interrupt on Transfer Completion
• Complies fully with Universal Serial Bus Specification Rev 2.0
• Supports data transfer rates up to 12Mbit/s and 1.5Mbit/s
• Endpoint 0 for Control Transfers: up to 64-bytes
• Six Programmable Endpoints with IN or Out Directions and with Bulk, Interrupt or Isochronous Transfers
• Configurable Endpoints size up to 256 bytes in double bank mode
• Fully independent 832 bytes USB DPRAM for endpoint memory allocation
• Suspend/Resume Interrupts
• CPU Reset possible on USB Bus Reset detection
• 48MHz from PLL for Full-speed Bus Operation
• USB Bus Connection/Disconnection on Microcontroller Request
• Crystal-less operation for Low Speed mode
• Peripheral Features
• On-chip PLL for USB and High Speed Timer: 32 up to 96MHz operation
• One 8-bit Timer/Counter with Separate Prescaler and Compare Mode

ATmega32U4-AU – TQFP-44 Pinout

Notes

• Pin diagram shows 44-pin QFN/QFP package for both ATmega32U4 and ATmega16U4; this table is specific to ATmega32U4-AU.
• USB-related pins (UVcc, D-, D+, UGnd, UCap, VBus) are dedicated to USB functionality.
• Multiple power (VCC, AVCC, AVC2) and ground (GND, UGnd) pins distributed throughout package.
• Port pins support multiple alternate functions (SPI, UART, PWM, ADC, etc.) as indicated in descriptions.
• PE6 and PE2 have special functions (INT6/AIN0 and HWB respectively).

*NOTICE:

Stresses beyond those listed under 'Absolute Maximum Ratings' may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Table 29-1. DC Characteristic, TA = -40°C to 85°C, VCC = 2.7V to 5.5V (unless otherwise noted)

Table 29-1. DC Characteristic, TA = -40°C to 85°C, VCC = 2.7V to 5.5V (unless otherwise noted)

1. "Max" means the highest value where the pin is guaranteed to be read as low
2. "Min" means the lowest value where the pin is guaranteed to be read as high
3. Although each I/O port can sink more than the test conditions (20mA at V CC = 5V, 10mA at V CC = 3V) under steady state conditions (non-transient), the following must be observed:

ATmega16U4/ATmega32U4:

• 1.)The sum of all IOL, for ports A0-A7, G2, C4-C7 should not exceed 100mA.

2.)The sum of all IOL, for ports C0-C3, G0-G1, D0-D7 should not exceed 100mA.

• 3.)The sum of all IOL, for ports G3-G5, B0-B7, E0-E7 should not exceed 100mA.
• 4.)The sum of all IOL, for ports F0-F7 should not exceed 100mA.

If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition.

1. Although each I/O port can source more than the test conditions (20mA at V CC = 5V, 10mA at V CC = 3V) under steady state conditions (non-transient), the following must be observed:

ATmega16U4/ATmega32U4:

Note:

• 1)The sum of all IOH, for ports A0-A7, G2, C4-C7 should not exceed 100mA.
• 2)The sum of all IOH, for ports C0-C3, G0-G1, D0-D7 should not exceed 100mA.
• 3)The sum of all IOH, for ports G3-G5, B0-B7, E0-E7 should not exceed 100mA.
• 4)The sum of all IOH, for ports F0-F7 should not exceed 100mA.

1. All DC Characteristics contained in this datasheet are based on simulation and characterization of other AVR microcontrollers manufactured in the same process technology. These values are preliminary values representing design targets, and will be updated after characterization of actual silicon
2. Values with 'Power Reduction Register 1 - PRR1' disabled (0x00).
3. Maximum regulator output current should be reduced by the USB buffer current required when USB is active (about 25mA). The remaining regulator output current can be used for the external application.
4. As specified on the USB Electrical chapter, the D+/D- pads can withstand voltages down to -1V applied through a 39 resistor

Depending on the target application power supply, the ATmega16U4/ATmega32U4 requires different hardware typical implementations.

Figure 21-2. Operating Modes versus Frequency and Power-supply