XR21V1410IL-0A-EB Datasheet, PDF (4/28 Pages) Exar Corporation – 1-CH FULL-SPEED USB UART

XR21V1410
1-CH FULL-SPEED USB UART
Pin Description
REV. 1.3.0
NAME
16-QFN
PIN #
TYPE
DESCRIPTION
USB Interface Signals
USBD+
15
USBD-
14
I/O _{USB port differential data plus. This pin has a 1.5 K Ohm internal pull-up.}
I/O _{USB port differential data minus.}
I²C Interface Signals
SDA
11
SCL
12
I/O OD
I/O OD
I²C-controller data input/output (open-drain). An optional external I²C
EEPROM can be used to store default configurations upon power-up
including the USB Vendor ID and Device ID. See Table 3. A pull-up
resistor (typically 4.7 to 10 KOhms) is required.
If an EEPROM is not used, this pin can be used with the SCL pin to
select the Remote Wake-up and Power modes. An external pull-up or
pull-down resistor is required. See Table 2
I²C-controller serial input clock. An optional external I²C EEPROM can
be used to store default configurations upon power-up including the USB
Vendor ID and Device ID. See Table 3. A pull-up resistor (typically 4.7
to 10 KOhms) is required.
If an EEPROM is not used, this pin can be used with the SDA pin to
select the Remote Wake-up and Power modes. An external pull-up or
pull-down resistor is required. See Table 2
Miscellaneous Signals
LOWPOWER
2
VCC
GND
16
1, 13
O _{Low power status output. The LOWPOWER pin will be asserted when-}
ever it is not safe to draw the amount of current from VBUS power
requested in the Device Max Power field of the Configuration Descriptor.
The LOWPOWER pin will behave differently for a low power device and a
high power device.
• Low-power device (<= 1 unit load or 100 mA i.e. bMaxPower <= 0x32):
LOWPOWER pin is asserted when the USB UART is in suspend mode.
• High-power deivce (bMaxPower > 0x32): LOWPOWER pin is
asserted when the USB UART is in suspend mode or when it is not yet
configured.
The LOWPOWER pin will be de-asserted whenever it is safe to draw the
amount of current requested in the Device Maximum Power field.
This pin is sampled momentarily at power-up or at any USB bus reset to
configure the polarity of the LOWPOWER output during suspend mode.
An external (10K) pull-up resistor will cause the LOWPOWER pin to be
asserted HIGH during suspend mode. An external (3.3K) pull-down resis-
tor will cause the LOWPOWER pin to be asserted LOW during suspend
mode.
Pwr _{+3.3V power supply. (Note that all device inputs are 5V tolerant.)}
Pwr _{Power supply common, ground.}
NOTE: Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
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