Datasheet

TMS320LF2406
or
TMS320LF2407
IOPF6
1
2
3
4
8
7
6
5
D
GND
V
CC
R
CANH
CANL
V
ref
R
S
1
1 Mbps
Driver Output
NRZ Data
SN65HVD230
SN65HVD231
SN65HVD232
SLOS346K –MARCH 2001– REVISED FEBRUARY 2011 www.ti.com
OPERATING MODES
R
S
(pin 8) of the SN65HVD230 and SN65HVD231 provides for three different modes of operation: high-speed
mode, slope-control mode, and low-power mode.
High-Speed
The high-speed mode can be selected by applying a logic low to R
S
(pin 8). The high-speed mode of operation is
commonly employed in industrial applications. High-speed allows the output to switch as fast as possible with no
internal limitation on the output rise and fall slopes. The only limitations of the high-speed operation are cable
length and radiated emission concerns, each of which is addressed by the slope control mode of operation.
If the low-power standby mode is to be employed in the circuit, direct connection to a DSP output pin can be
used to switch between a logic-low level (< 1 V) for high speed operation, and the logic-high level (> 0.75 V
CC
)
for standby. Figure 30 shows a typical DSP connection, and Figure 31 shows the HVD230 driver output signal in
high-speed mode on the CAN bus.
Figure 30. R
S
(Pin 8) Connection to a TMS320LF2406/07 for High Speed/Standby Operation
Figure 31. Typical High Speed SN65HVD230 Output Waveform Into a 60-Ω Load
Slope Control
Electromagnetic compatibility is essential in many applications using unshielded bus cable to reduce system
cost. To reduce the electromagnetic interference generated by fast rise times and resulting harmonics, the rise
and fall slopes of the SN65HVD230 and SN65HVD231 driver outputs can be adjusted by connecting a resistor
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Product Folder Link(s): SN65HVD230 SN65HVD231 SN65HVD232