XR16M752_09 Datasheet, PDF (8/54 Pages) Exar Corporation – HIGH PERFORMANCE DUART WITH 64-BYTE FIFO

XR16M752/XR68M752
HIGH PERFORMANCE DUART WITH 64-BYTE FIFO
Pin Description
REV. 1.1.1
NAME
32-QFN
PIN #
48-TQFP 49-STBGA
TYPE
PIN #
PIN #
DESCRIPTION
RESET
24
36
B7
(RESET#)
EN485#
-
-
A6
ENIR#
-
-
F7
VCC
26
42
B5
GND
13
17
G3
GND Center Pad
-
-
NC
9
12, 25, 37
A1
I When 16/68# pin is HIGH for Intel bus interface, this input
becomes RESET (active high). When 16/68# pin is LOW
for Motorola bus interface, this input becomes RESET#
(active low).
A 40 ns minimum active pulse on this pin will reset the
internal registers and all outputs of channel A and B. The
UART transmitter output will be held HIGH, the receiver
input will be ignored and outputs are reset during reset
period (see Table 16).
I _{Auto RS-485 half-duplex direction output enable for}
channel A and B (active low, internal pull-up resistor).
Connect this pin to VCC or leave unconnected for normal
RTS# A/B function. Connect to GND for auto RS-485
half-duplex direction output via the RTS# A/B pins. The
Auto RS-485 half-duplex direction output control feature
can be disabled via DLD[6] after power-up. SEE ”AUTO
RS485 HALF-DUPLEX CONTROL” ON PAGE 18.
I _{IR mode enable for channel A and B (active low, internal}
pull-up resistor). Connect this pin to VCC or leave uncon-
nected for normal TX and RX. Connect to GND for both
channel A and B to power up in the IR mode. The IR
mode can be disabled via DLD[7] after power-up. SEE
”INFRARED MODE” ON PAGE 20.
Pwr _{1.62V to 3.63V power supply.}
Pwr _{Power supply common, ground.}
Pwr _{The center pad on the backside 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 approxi-
mate 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.
No Connection.
Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
8