Example: ATmega48-20AU, without "V", working voltage is 2.7-5.5V.
2. The numerical part of the suffix indicates the highest supported system clock.
For example: ATmega48-20AU, "20" means that it can support the system clock up to 20MHZ.
3. Add a suffix after the first (second) letter to indicate encapsulation. "p": dip package, "a": tqfp package, "m": mlf package.
For example: ATmega48-20AU, "A" stands for TQFP packaging.
4. Add a suffix after the last letter to indicate the application level. "C" stands for commercial grade, "I" stands for industrial grade (containing lead) and "U" stands for industrial grade (containing no lead).
For example: ATmega48-20AU, and "u" stands for lead-free industrial grade. ATmega48-20AI, "I" stands for lead industrial grade.
The biggest feature of AVR 8-bit single chip microcomputer
Compared with other 8-bit single-chip microcomputer, the biggest feature of AVR 8-bit single-chip microcomputer is:
Harvard structure, high-speed operation processing ability1MIPS/MHz;
Ultra-functional Reduced Instruction Set (RISC), with 32 general working registers, overcomes the bottleneck phenomenon caused by single ACC processing for 805 1 MCU;
Fast access register group and one-cycle instruction system greatly optimize the size and execution efficiency of the target code, and some models of FLASH are very large, especially suitable for development in high-level languages.
When the output is the same as the HI/LOW of PIC, it can output 40mA (single output), and it can be set as tri-state high resistance input or pull-up resistor input, which has the current injection ability of 10mA-20mA;
On-chip integration of multi-frequency RC oscillator, power-on automatic reset, watchdog, startup delay and other functions makes the peripheral circuit simpler and the system more stable and reliable;
Most AVR chips are rich in resources: E2PROM, PWM, RTC, SPI, UART, TWI, ISP, AD, analog comparator, WDT, etc.
In addition to ISP function, most AVRs also have IAP function, which is convenient for upgrading or destroying applications.
Application field of AVR single chip microcomputer
At present, AVR has been widely used in:
Air conditioning control panel
Printer control panel
Smart electric meter
Intelligent flashlight
LED control panel
Medical equipment
Global (satellite) positioning system
Viewing AVR single chip microcomputer from market point of view
Cost performance: Most models of AVR have high cost performance. The models with outstanding cost performance are: atmega48, atmega8, atmega 16, atmega 169P.
Supply: the supply of general AVR is relatively stable, but there are still problems with the samples and supply of unconventional AVR.
Market share: At present, the market share of AVR is still not as good as PIC and 5 1. However, the advantages of AVR make the market share of AVR expand all the time, and the annual usage is also increasing.