XR68C681J-F Exar Corporation, XR68C681J-F Datasheet - Page 30

• Manufacturer Part Number: XR68C681J-F
• Description: IC UART CMOS DUAL 44PLCC
• Manufacturer: Exar Corporation
• Type: CMOS Dual Channel UARTr

Specifications of XR68C681J-F

• Number Of Channels: 2, DUART
• Package / Case: 44-LCC (J-Lead)
• Features: *
• Fifo's: 1 Byte, 3 Byte
• Voltage - Supply: 5V
• Mounting Type: Surface Mount
• Data Rate: 1 Mbps
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Supply Current: 15 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 5 V
• Propagation Delay Time Ns: 400 ns
• No. Of Channels: 2
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: PLCC
• No. Of Pins: 44
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 1016-1324-5



Note: if the user programs either nibble of the Clock
Select Register (CSRn[7:4] or CSRn[3:0]) with values
ranging from 0
a source for timing. However, these standard bit rates
(presented in Table 9) apply only if the X1/CLK pin is
driven with a 3.6864 MHz signal. If a signal with a different
frequency (fo) is applied to the X1/CLK pin, then the
DUART channel is running at the following baud rate:
Actual Baud Rate =
provided that fo is between 2.0 MHz and 4.0 MHz.
1X vs 16X Clock Signals
XR68C681
16
Table
Register
to C
Table 6
16
, then the user is using the BRG as
Baud Rate Value • fo
Table 10. Command Register Control Over the Extend Bit
MHz
Contents
Resulting Action
(Note: the b suffix denotes a binary expression. x = don’t care
value).
Table 10
Figure 10
Table 1