.hide-partial { max-height: none; } .show-more { display: none; }

AVR Core Microcontrollers - MCU

.catnav-wrapper { height: auto; overflow: visible; } .catalog-nav-tabs ul { white-space: normal; }

Types of Microcontrollers - MCU

List Images

Results: 2,140

Applied Filters:

Core = AVR

Mounting Style

Package/Case

Program Memory Size

Data Bus Width

ADC Resolution

Maximum Clock Frequency

Number of I/Os

Data RAM Size

Supply Voltage - Min

Supply Voltage - Max

Minimum Operating Temperature

Maximum Operating Temperature

Qualification

Packaging

Reset All

Search within results

In Stock

Normally Stocked

Active

New Products

RoHS Compliant

.search-refine-wrapper { display: inline-block; min-width: 100%; } .scroll-body { overflow-x: visible; } .search-table-wrapper { overflow: visible; } .hide-partial { max-height: none; } .show-more { display: none; }

Image	Part #	Mfr.	Description	Datasheet	Availability	Pricing (SGD) Filter the results in the table by unit price based on your quantity.	Qty.	Mounting Style	Package/Case	Core	Program Memory Size	Data Bus Width	ADC Resolution	Maximum Clock Frequency	Number of I/Os	Data RAM Size	Supply Voltage - Min	Supply Voltage - Max	Minimum Operating Temperature	Maximum Operating Temperature	Packaging
8-bit Microcontrollers - MCU 20MHz, 4KB, SOIC20, Ind 125C, Green ATTINY426-SF Microchip Technology 1: $1.58 828In Stock	Mfr. Part No. ATTINY426-SF Mouser Part No 579-ATTINY426-SF	Microchip Technology	8-bit Microcontrollers - MCU 20MHz, 4KB, SOIC20, Ind 125C, Green Learn More about Microchip Technology microchip attiny mcu	Datasheet	828In Stock	$1.58 $1.43 $1.31	Min.: 1 Mult.: 1	SMD/SMT	SOIC-20	AVR	4 kB	8 bit	12 bit	20 MHz	18 I/O	512 B	1.8 V	5.5 V	- 40 C	+ 125 C	Tube
8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX AVR16EB14T-E/ST Microchip Technology 1: $1.29 2,475In Stock New Product	Mfr. Part No. AVR16EB14T-E/ST Mouser Part No 579-AVR16EB14T-E/ST New Product	Microchip Technology	8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX Learn More about Microchip Technology microchip avr16eb14 20 28 32 mcus	Datasheet	2,475In Stock	Cut Tape $1.29 $1.27 Reel $1.07 MouseReel Available	Min.: 1 Mult.: 1 : 2,500	SMD/SMT	TSSOP-14	AVR	16 kB	8 bit	12 bit	20 MHz	12 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 125 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX AVR16EB14T-I/ST Microchip Technology 1: $1.17 2,482In Stock New Product	Mfr. Part No. AVR16EB14T-I/ST Mouser Part No 579-AVR16EB14T-I/ST New Product	Microchip Technology	8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX Learn More about Microchip Technology microchip avr16eb14 20 28 32 mcus	Datasheet	2,482In Stock	Cut Tape $1.17 $1.15 Reel $0.966 MouseReel Available	Min.: 1 Mult.: 1 : 2,500	SMD/SMT	TSSOP-14	AVR	16 kB	8 bit	12 bit	20 MHz	12 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C AVR32SD20T-I/SS Microchip Technology 1: $1.85 1,597In Stock New Product	Mfr. Part No. AVR32SD20T-I/SS Mouser Part No 579-AVR32SD20T-I/SS New Product	Microchip Technology	8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C Learn More about Microchip Technology microchip avr32sdx mcus	Datasheet	1,597In Stock	Cut Tape $1.85 $1.80 Reel $1.54 MouseReel Available	Min.: 1 Mult.: 1 : 1,600	SMD/SMT	SSOP-20	AVR	32 kB	8 bit	10 bit	20 MHz	15 I/O	4 kB	2.7 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C AVR32SD28T-I/SS Microchip Technology 1: $1.85 2,067In Stock New Product	Mfr. Part No. AVR32SD28T-I/SS Mouser Part No 579-AVR32SD28T-I/SS New Product	Microchip Technology	8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C Learn More about Microchip Technology microchip avr32sdx mcus	Datasheet	2,067In Stock	Cut Tape $1.85 $1.80 Reel $1.54 MouseReel Available	Min.: 1 Mult.: 1 : 2,100	SMD/SMT	SSOP-28	AVR	32 kB	8 bit	10 bit	20 MHz	21 I/O	4 kB	2.7 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C AVR32SD32T-I/PT Microchip Technology 1: $1.99 1,441In Stock New Product	Mfr. Part No. AVR32SD32T-I/PT Mouser Part No 579-AVR32SD32T-I/PT New Product	Microchip Technology	8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C Learn More about Microchip Technology microchip avr32sdx mcus	Datasheet	1,441In Stock	Cut Tape $1.99 $1.94 Reel $1.65 MouseReel Available	Min.: 1 Mult.: 1 : 1,600	SMD/SMT	TQFP-32	AVR	32 kB	8 bit	10 bit	20 MHz	25 I/O	4 kB	2.7 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C AVR32SD32T-I/QZB Microchip Technology 1: $2.05 4,986In Stock New Product	Mfr. Part No. AVR32SD32T-I/QZB Mouser Part No 579-AVR32SD32T-I/QZB New Product	Microchip Technology	8-bit Microcontrollers - MCU 32KB,ECC,2xCPU,20MHz,ERRCTRL,MVIO,PDID,2ADC,3Comp,2ZCD,2WDT,3USART,2SPI,2TWI,85C Learn More about Microchip Technology microchip avr32sdx mcus	Datasheet	4,986In Stock	Cut Tape $2.05 $2.00 Reel $1.71 MouseReel Available	Min.: 1 Mult.: 1 : 5,000	SMD/SMT	VQFN-32	AVR	32 kB	8 bit	10 bit	20 MHz	25 I/O	4 kB	2.7 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,20p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX AVR16EB20T-E/SS Microchip Technology 1: $1.47 1,585In Stock	Mfr. Part No. AVR16EB20T-E/SS Mouser Part No 579-AVR16EB20T-E/SS	Microchip Technology	8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,20p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX Learn More about Microchip Technology microchip avr16eb14 20 28 32 mcus	Datasheet	1,585In Stock	Cut Tape $1.47 $1.44 Reel $1.22	Min.: 1 Mult.: 1 : 1,600	SMD/SMT	SSOP-20	AVR	16 kB	8 bit	12 bit	20 MHz	17 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 125 C	Reel, Cut Tape
8-bit Microcontrollers - MCU 20 MHZ, QFN/MLF, 105C, GREEN, 5V, T&R ATmega168PB-MNR Microchip Technology 1: $2.01 4,659In Stock	Mfr. Part No. ATmega168PB-MNR Mouser Part No 579-ATMEGA168PBMNR	Microchip Technology	8-bit Microcontrollers - MCU 20 MHZ, QFN/MLF, 105C, GREEN, 5V, T&R Learn More about Microchip Technology microchip automotive 8bit mcus	Datasheet	4,659In Stock	Cut Tape $2.01 $1.96 Reel $1.96 MouseReel Available	Min.: 1 Mult.: 1 : 6,000	SMD/SMT	VQFN-32	AVR	16 kB	8 bit	10 bit	20 MHz	27 I/O	1 kB	1.8 V	5.5 V	- 40 C	+ 105 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU AVR 16KB FL 512B EE 1KB SRAM-20 MHz ATMEGA164A-MUR Microchip Technology 1: $5.70 4,000In Stock NRND	Mfr. Part No. ATMEGA164A-MUR Mouser Part No 556-ATMEGA164A-MUR NRND	Microchip Technology	8-bit Microcontrollers - MCU AVR 16KB FL 512B EE 1KB SRAM-20 MHz Learn More about Microchip Technology microchip megaavr 8 bit mcus	Datasheet	4,000In Stock	Cut Tape $5.70 $5.59 Reel $4.75 MouseReel Available	Min.: 1 Mult.: 1 : 4,000	SMD/SMT	QFN-44	AVR	16 kB	8 bit	10 bit	20 MHz	32 I/O	1 kB	1.8 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU AVR 32KB FLSH 1KB EE 2KB SRAM-20MHz, IND ATMEGA324A-MUR Microchip Technology 1: $6.42 3,575In Stock NRND	Mfr. Part No. ATMEGA324A-MUR Mouser Part No 556-ATMEGA324A-MUR NRND	Microchip Technology	8-bit Microcontrollers - MCU AVR 32KB FLSH 1KB EE 2KB SRAM-20MHz, IND Learn More about Microchip Technology microchip megaavr 8 bit mcus	Datasheet	3,575In Stock	Cut Tape $6.42 $6.27 Reel $5.33 MouseReel Available	Min.: 1 Mult.: 1 : 4,000	SMD/SMT	VQFN-44	AVR		8 bit		20 MHz			1.8 V	5.5 V			Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU AVR 32K FLSH 1K EE2K SRAM-20MHz IND ATMEGA328-AUR Microchip Technology 1: $3.41 10,092In Stock NRND	Mfr. Part No. ATMEGA328-AUR Mouser Part No 556-ATMEGA328-AUR NRND	Microchip Technology	8-bit Microcontrollers - MCU AVR 32K FLSH 1K EE2K SRAM-20MHz IND Learn More about Microchip Technology atmelatmega328	Datasheet	10,092In Stock	Cut Tape $3.41 $3.36 Reel $2.86 MouseReel Available	Min.: 1 Mult.: 1 : 2,000	SMD/SMT	TQFP-32	AVR	32 kB	8 bit	10 bit	20 MHz	23 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20 MHZ 105C ATMEGA328P-AN Microchip Technology 1: $3.81 6,839In Stock NRND	Mfr. Part No. ATMEGA328P-AN Mouser Part No 556-ATMEGA328P-AN NRND	Microchip Technology	8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20 MHZ 105C Learn More about Microchip Technology atmelatmega328	Datasheet	6,839In Stock	$3.81 $3.50 $3.16	Min.: 1 Mult.: 1	SMD/SMT	TQFP-32	AVR	32 kB	8 bit	10 bit	20 MHz	23 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 105 C	Tray
8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20 MHZ 105C ATMEGA328P-ANR Microchip Technology 1: $3.93 9,917In Stock NRND	Mfr. Part No. ATMEGA328P-ANR Mouser Part No 556-ATMEGA328P-ANR NRND	Microchip Technology	8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20 MHZ 105C Learn More about Microchip Technology atmelatmega328	Datasheet	9,917In Stock	Cut Tape $3.93 $3.84 Reel $3.25 MouseReel Available	Min.: 1 Mult.: 1 : 2,000	SMD/SMT	TQFP-32	AVR	32 kB	8 bit	10 bit	20 MHz	23 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 105 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20MHz IND ATMEGA328P-AUR Microchip Technology 1: $3.73 34,294In Stock NRND	Mfr. Part No. ATMEGA328P-AUR Mouser Part No 556-ATMEGA328P-AUR NRND	Microchip Technology	8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20MHz IND Learn More about Microchip Technology atmelatmega328	Datasheet	34,294In Stock	Cut Tape $3.73 $3.69 Reel $3.13 MouseReel Available	Min.: 1 Mult.: 1 : 2,000	SMD/SMT	TQFP-32	AVR	32 kB	8 bit	10 bit	20 MHz	23 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20 MHZ 105C ATMEGA328P-MN Microchip Technology 1: $3.81 11,593In Stock NRND	Mfr. Part No. ATMEGA328P-MN Mouser Part No 556-ATMEGA328P-MN NRND	Microchip Technology	8-bit Microcontrollers - MCU AVR 32K FLSH 2K SRAM 1KB EE-20 MHZ 105C Learn More about Microchip Technology atmelatmega328	Datasheet	11,593In Stock	$3.81 $3.50 $3.16	Min.: 1 Mult.: 1	SMD/SMT	VQFN-32	AVR	32 kB	8 bit	10 bit	20 MHz	23 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 105 C	Tray
8-bit Microcontrollers - MCU 4KB FLSH 256B EE256B SRAM-20MHz, IND ATTINY44A-MUR Microchip Technology 1: $1.41 22,880In Stock NRND	Mfr. Part No. ATTINY44A-MUR Mouser Part No 556-ATTINY44A-MUR NRND	Microchip Technology	8-bit Microcontrollers - MCU 4KB FLSH 256B EE256B SRAM-20MHz, IND Learn More about Microchip Technology microchip automotive 8bit mcus	Datasheet	22,880In Stock	Cut Tape $1.41 $1.33 $1.32 $1.17 Reel $1.17 MouseReel Available	Min.: 1 Mult.: 1 : 6,000	SMD/SMT	QFN-20	AVR	4 kB	8 bit	10 bit	20 MHz	12 I/O	256 B	1.8 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 20MHz Ind. Grade ATTINY84A-SSUR Microchip Technology 1: $1.47 23,331In Stock NRND	Mfr. Part No. ATTINY84A-SSUR Mouser Part No 556-ATTINY84A-SSUR NRND	Microchip Technology	8-bit Microcontrollers - MCU 20MHz Ind. Grade Learn More about Microchip Technology microchip automotive 8bit mcus	Datasheet	23,331In Stock	Cut Tape $1.47 Reel $1.22 MouseReel Available	Min.: 1 Mult.: 1 : 3,000	SMD/SMT	SOIC-14	AVR	8 kB	8 bit	10 bit	20 MHz	12 I/O	512 B	1.8 V	5.5 V	- 40 C	+ 85 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 16MHz, 16KB, SSOP20, 2xADC, PTC, EXT 125C, T/R ATTINY1616-XFR Microchip Technology 1: $1.39 1,470In Stock New Product	Mfr. Part No. ATTINY1616-XFR Mouser Part No 579-ATTINY1616-XFR New Product	Microchip Technology	8-bit Microcontrollers - MCU 16MHz, 16KB, SSOP20, 2xADC, PTC, EXT 125C, T/R Learn More about Microchip Technology microchip attiny1614 6 7	Datasheet	1,470In Stock	Cut Tape $1.39 $1.35 Reel $1.14 MouseReel Available	Min.: 1 Mult.: 1 : 1,600	SMD/SMT	SSOP-20	AVR	16 kB	8 bit	10 bit	16 MHz	18 I/O	2 kB	2.7 V	5.5 V	- 40 C	+ 125 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 20MHz, 16KB, SSOP20, 2xADC, PTC, EXT 105C, T/R ATTINY1616-XNR Microchip Technology 1: $1.25 1,007In Stock New Product	Mfr. Part No. ATTINY1616-XNR Mouser Part No 579-ATTINY1616-XNR New Product	Microchip Technology	8-bit Microcontrollers - MCU 20MHz, 16KB, SSOP20, 2xADC, PTC, EXT 105C, T/R Learn More about Microchip Technology microchip attiny1614 6 7	Datasheet	1,007In Stock	Cut Tape $1.25 $1.23 Reel $1.05 MouseReel Available	Min.: 1 Mult.: 1 : 1,600	SMD/SMT	SSOP-20	AVR	16 kB	8 bit	10 bit	16 MHz	18 I/O	2 kB	2.7 V	5.5 V	- 40 C	+ 105 C	Reel, Cut Tape, MouseReel
8-bit Microcontrollers - MCU 16MHz, 16KB, QFN20 Wettable flanks, Auto 125C, Green, Tray ATTINY1616-MZ-VAO Microchip Technology 1: $1.36 1,325In Stock New Product	Mfr. Part No. ATTINY1616-MZ-VAO Mouser Part No 579-ATTINY1616MZVAO New Product	Microchip Technology	8-bit Microcontrollers - MCU 16MHz, 16KB, QFN20 Wettable flanks, Auto 125C, Green, Tray Learn More about Microchip Technology microchip attiny1614 6 7	Datasheet	1,325In Stock	$1.36 $1.24 $1.13	Min.: 1 Mult.: 1	SMD/SMT	VQFN-20	AVR	16 kB	8 bit	10 bit	16 MHz	18 I/O	2 kB	2.7 V	5.5 V	- 40 C	+ 125 C	Tray
8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX AVR16EB14-E/ST Microchip Technology 1: $1.25 759In Stock New Product	Mfr. Part No. AVR16EB14-E/ST Mouser Part No 579-AVR16EB14-E/ST New Product	Microchip Technology	8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX Learn More about Microchip Technology microchip avr16eb14 20 28 32 mcus	Datasheet	759In Stock	$1.25 $1.14 $1.03	Min.: 1 Mult.: 1	SMD/SMT	TSSOP-14	AVR	16 kB	8 bit	12 bit	20 MHz	12 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 125 C	Tube
8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX AVR16EB14-I/ST Microchip Technology 1: $1.14 802In Stock New Product	Mfr. Part No. AVR16EB14-I/ST Mouser Part No 579-AVR16EB14-I/ST New Product	Microchip Technology	8-bit Microcontrollers - MCU 16KB RWW,2KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX Learn More about Microchip Technology microchip avr16eb14 20 28 32 mcus	Datasheet	802In Stock	$1.14 $1.05 $0.952	Min.: 1 Mult.: 1	SMD/SMT	TSSOP-14	AVR	16 kB	8 bit	12 bit	20 MHz	12 I/O	2 kB	1.8 V	5.5 V	- 40 C	+ 85 C	Tube
8-bit Microcontrollers - MCU 32KB RWW,3KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX AVR32EB14-E/ST Microchip Technology 1: $1.32 831In Stock New Product	Mfr. Part No. AVR32EB14-E/ST Mouser Part No 579-AVR32EB14-E/ST New Product	Microchip Technology	8-bit Microcontrollers - MCU 32KB RWW,3KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX Learn More about Microchip Technology microchip avrxeb mcus	Datasheet	831In Stock	$1.32 $1.21 $1.10	Min.: 1 Mult.: 1	SMD/SMT	TSSOP-14	AVR	32 kB	8 bit	12 bit	20 MHz	11 I/O	3 kB	1.8 V	5.5 V	- 40 C	+ 125 C	Tube
8-bit Microcontrollers - MCU 32KB RWW,3KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX AVR32EB14-I/ST Microchip Technology 1: $1.32 860In Stock New Product	Mfr. Part No. AVR32EB14-I/ST Mouser Part No 579-AVR32EB14-I/ST New Product	Microchip Technology	8-bit Microcontrollers - MCU 32KB RWW,3KB RAM,14p,20MHz,12-bit ADC,PGA,UART,SPI,I2C,2xTCB,TCEX,TCF,WEX Learn More about Microchip Technology microchip avrxeb mcus	Datasheet	860In Stock	$1.32 $1.21 $1.10	Min.: 1 Mult.: 1	SMD/SMT	TSSOP-14	AVR	32 kB	8 bit	12 bit	20 MHz	11 I/O	3 kB	1.8 V	5.5 V	- 40 C	+ 85 C	Tube