at43usb355 ATMEL Corporation, at43usb355 Datasheet - Page 4

• Manufacturer Part Number: at43usb355
• Description: At43usb355 Full-speed Usb Microcontroller With Embedded Hub, Adc And Pwm
• Manufacturer: ATMEL Corporation

Signal Description
4
Name
V
V
V
V
CEXT1, 2, 3
CEXTA
XTAL1
XTAL2
LFT
DPO
DMO
DP[2,3]
DM[2,3]
PA[0:7]
PB[0:7]
CC1
CCA
SS1
SSA
,
,
2
2
,
,
3
3
AT43USB355
Type
Power Supply/Ground
Power Supply/Ground
Power Supply/Ground
Power Supply/Ground
Power Supply/Ground
Power Supply/Ground
Input
Output
Input
Bi-directional
Bi-directional
Bi-directional
Bi-directional
Bi-directional
Bi-directional
Function
5V Digital Power Supply
5V Power Supply for the ADC
Digital Ground
Ground for the ADC
External Capacitors for Power Supplies – High quality 2.2 µF capacitors must be
connected to CEXT1, 2 and 3 for proper operation of the chip.
External Capacitor for Analog Power Supply – A high quality 0.33 µF capacitor
must be connected to CEXTA for proper operation of the chip.
Oscillator Input – Input to the inverting oscillator amplifier.
Oscillator Output – Output of the inverting oscillator amplifier.
PLL Filter – For proper operation of the PLL, this pin should be connected through
a 0.01 µF capacitor in parallel with a 100Ω resistor in series with a 0.1 µF capacitor
to ground (VSS). Both capacitors must be high quality ceramic.
Upstream Plus USB I/O – This pin should be connected to CEXT1 through an
external 1.5 kΩ.
Upstream Minus USB I/O
Downstream Plus USB I/O – Each of these pins should be connected to VSS
through an external 15 kΩ resistor. DP[2,3] and DM[2,3] are the differential signal
pin pairs to connect downstream USB devices.
Downstream Minus USB I/O – Each of these pins should be connected to VSS
through an external 15 kΩ resistor.
Port A[0:7] – Bi-directional 8-bit I/O port with 2 mA drive strength and a
programmable pull-up resistor.
Port B[0:7] – Bi-directional 8-bit I/O port with 2 mA drive strength and a
programmable pull-up resistor. PB[0,1,4:7] have dual functions as shown below:
Port Pin
PB0
PB1
PB4
PB5
PB6
PB7
Alternate Function
T0, Timer/Counter0 External Input
T1, Timer/Counter1 External Input
SSN, SPI Slave Port Select or SCL, I2C Serial Bus Clock
MOSI, SPI Slave Port Select Input
MISO, SPI Master Data In, Slave Data Out
SCK, SPI Master Clock Out, Slave Clock In
2603G–USB–04/06