XR19L402
5
REV. 1.0.3
TWO CHANNEL INTEGRATED UART AND RS-485 TRANSCEIVER
NOTE: Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain. For CMOS/TTL Voltage levels, ’LOW’
indicates a voltage in the range 0V to VIL and ’HIGH’ indicates a voltage in the range VIH to VCC.
FIGURE 3. RECOMMENDED 3.3V OR 5V POWER SUPPLY CONNECTIONS
R_EN
VCC33
VCC50
GND
1 uF
3.3V
GND
0.1 uF
R_EN
VCC33
VCC50
GND
1 uF
3.3V Power Supply
5V Power Supply
5V
RXBSEL
44
I
When RXBSEL is HIGH, RXB is the receive data input.
When RXBSEL is LOW, RXB+ and RXB- are the receive data inputs.
VCC33
22
Pwr 3.3V power supply. When VCC33 is used, R_EN pin should be connected to GND.
A 0.1 uF capacitor to GND is recommended on this power supply pin. If VCC33 is not used
as the power supply pin, VCC33 should be left unconnected. See
CMOS/TTL input pins, except XTAL1, are 5V tolerant.
VCC50
39
Pwr 5.0V power supply. When VCC50 is used, R_EN pin should be connected to VCC.
A 1uF capacitor to GND is recommended on the VCC50 power supply pin. The 1uF capac-
itor is recommended whether VCC33 or VCC50 is used as the power supply pin. See
Figure 3 below. All CMOS/TTL input pins, except XTAL1, are 5V tolerant.
GND
24, 37
Pwr Power supply common, ground.
-
PAD
Pwr The center pad on the backside of the 64-QFN package is metallic and is not electrically
connected to anything inside the device. It must be soldered on to the PCB and may be
optionally 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.
NC
26, 29, 32,
35
-
No Connect. Note that in Motorola mode, the IOR# pin also becomes an NC pin.
Pin Descriptions
NAME
48-QFN
PIN#
TYPE
DESCRIPTION