MCP2551
2.0
2.1
ELECTRICAL
CHARACTERISTICS
Terms and Definitions
2.1.5
DIFFERENTIAL VOLTAGE, V
DIFF
(OF CAN BUS)
Differential voltage of the two-wire CAN bus, value
V
DIFF
= V
CANH
- V
CANL
.
A number of terms are defined in ISO-11898 that are
used to describe the electrical characteristics of a CAN
transceiver device. These terms and definitions are
summarized in this section.
2.1.6
INTERNAL CAPACITANCE, C
IN
(OF
A CAN NODE)
2.1.1
BUS VOLTAGE
Capacitance seen between CANL (or CANH) and
ground during the recessive state when the CAN node
is disconnected from the bus (see Figure 2-1).
V
CANL
and V
CANH
, denoting the voltages of the bus line
wires, CANL and CANH, relative to ground of each
individual CAN node.
2.1.7
INTERNAL RESISTANCE, R
IN
(OF A
CAN NODE)
2.1.2
COMMON MODE BUS VOLTAGE
RANGE
Resistance seen between CANL (or CANH) and
ground during the recessive state when the CAN node
is disconnected from the bus (see Figure 2-1).
Boundary voltage levels of V
CANL
and V
CANH
with
respect to ground, for which proper operation will occur,
if up to the maximum number of CAN nodes are
connected to the bus.
FIGURE 2-1:
PHYSICAL LAYER
DEFINITIONS
ECU
2.1.3
DIFFERENTIAL INTERNAL
CAPACITANCE, C
DIFF
(OF A CAN
NODE)
R
IN
CANL
R
IN
R
DIFF
C
IN
C
IN
GROUND
C
DIFF
CANH
Capacitance seen between CANL and CANH during
the recessive state when the CAN node is
disconnected from the bus (see Figure 2-1).
2.1.4
DIFFERENTIAL INTERNAL
RESISTANCE, R
DIFF
(OF A CAN
NODE)
Resistance seen between CANL and CANH during the
recessive state when the CAN node is disconnected
from the bus (see Figure 2-1).
DS21667C-page 6
Preliminary
錚?/div>
2002 Microchip Technology Inc.
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