XR17D154IV Exar Corporation, XR17D154IV Datasheet - Page 8

• Manufacturer Part Number: XR17D154IV
• Description: Universal QUART W/ PCI Bus Interface.
• Manufacturer: Exar Corporation

Specifications of XR17D154IV

• Features: *
• Number Of Channels: 4, QUART
• Fifo's: 64 Byte
• Protocol: RS485
• Voltage - Supply: 3.3V, 5V
• With Auto Flow Control: Yes
• With Irda Encoder/decoder: Yes
• With False Start Bit Detection: Yes
• With Modem Control: Yes
• Mounting Type: Surface Mount
• Package / Case: 144-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS Compliant

XR17D154
UNIVERSAL (3.3V AND 5V) PCI BUS QUAD UART
The XR17D154 is designed to operate with VCC (voltage to the UART Core Logic) greater than or equal to
VIO. See Table 1 below for valid combintions of VCC and VIO that can be used with the device..
For a universal add-in card, it is usually unknown whether it will be plugged into a 3.3V or 5V PCI slot, therefore
VCC must be 5V to guarantee proper functionality in any PCI slot as shown in
system, the designer can choose to use a 3.3V or 5V power supply for the UART core voltage. Of course, the
core voltage can be 3.3V only when the VIO is 3.3V. In
XR17D154 in an embedded system.
F
1.0 APPLICATION EXAMPLES
IGURE
3. T
YPICAL
(3.3V or 5V)
(up to 33.34MHz)
A
VIO
PPLICATION FOR A
T
ABLE
CLK
1: V
ALID
VCC
5.0V
5.0V
3.3V
3.3V
C
Interface
OMBINATIONS OF
U
Local
PCI
Bus
NIVERSAL
5.0V
3.3V
5.0V
3.3V
VIO
A
DD
M ax Crystal Frequency = 24M Hz
8
-
M ax External Clock = 50M Hz
IN
VCC
Figure
UART Core Logic
C
UART Channel 0
UART Channel 1
UART Channel 2
UART Channel 3
ARD
AND
Invalid
Valid
Valid
Valid
4, examples 1-3 show valid applications of the
VIO S
UPPLY
V
OLTAGES
Figure
VCC = 5V
3. In an embedded
xr
REV. 1.2.2