XR21V1410IL-0C-EB Datasheet, PDF (4/30 Pages) Exar Corporation – 1-CH FULL-SPEED USB UART

XR21V1410
1-CH FULL-SPEED USB UART
REV. 1.4.0
NAME
16-QFN
PIN #
TYPE
DESCRIPTION
I²C Interface Signals
SDA
11
I/O _I2_{C-controller data input/output (open-drain). An optional external I}2_C
OD _{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 10k Ohms) 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
SCL
12
I/O _I2_{C-controller serial input clock. An optional external I}2_{C EEPROM can be}
OD _{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 10k Ohms)
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
O _{Low power status output. The LOWPOWER pin will be asserted whenever 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): LOW-
POWER pin is asserted when the USB UART is in suspend mode.
Power / Ground Signals
VCC
16
GND
1, 13
GND
Center
Pad
• 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 config-
ure the polarity of the LOWPOWER output during suspend mode. An external
(10K) pull-up resistor will cause the LOWPOWER pin to be asserted HIGH dur-
ing suspend mode. An external (3.3K) pull-down resistor will cause the LOW-
POWER pin to be asserted LOW during suspend mode.
Pwr _{+3.3V power supply.}
Pwr _{Power supply common, ground.}
Pwr _{The center pad on the back side of the QFN package is metallic and should be}
connected to GND on the PCB. The thermal pad size on the PCB should be
the approximate size of this center pad and should be solder mask defined.
The solder mask opening should be at least 0.0025" inwards from the edge of
the PCB thermal pad.
NOTE: Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
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