SN65HVDA540-Q1, SN65HVDA541-Q1, SN65HVDA542-Q1

SN65HVDA540-5-Q1, SN65HVDA541-5-Q1, SN65HVDA542-5-Q1

SLLS804C – MARCH 2009 – REVISED JANUARY 2013

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Protection Features

TXD Dominant State Time Out

During normal mode, the only mode where the CAN driver is active, the TXD dominant time out circuit prevents

the transceiver from blocking network communication in event of a hardware or software failure where TXD is

disabled freeing the bus for communication between other network nodes. The CAN driver is re-activated when a

recessive signal is seen on TXD pin, thus clearing the dominant state time out. The CAN bus pins will be biased

to recessive level during a TXD dominant state time out.

APPLICATION NOTE: The maximum dominant TXD time allowed by the TXD Dominant state time out limits the

minimum possible data rate of the device. The CAN protocol allows a maximum of eleven successive dominant

bits (on TXD) for the worst case, where five successive dominant bits are followed immediately by an error

Thermal Shutdown

If the junction temperature of the device exceeds the thermal shut down threshold the device will turn off the

CAN driver circuits. This condition is cleared once the temperature drops below the thermal shut down

temperature of the device. The CAN bus pins will be biased to recessive level during a thermal shutdown.

Undervoltage Lockout / Unpowered Device

Both of the supply pins have undervoltage detection which place the device in forced standby mode to protect

tri-stated and the device does not pass any wake-up signals from the bus to the RXD pin. Since the device is

placed into forced standby mode the CAN bus pins have a common mode bias to ground protecting the CAN

network, see Figure 1 and Figure 2.

The device is designed to be an "ideal passive" load to the CAN bus if it is unpowered. The bus pins (CANH,

CANL) have extremely low leakage currents when the device is un-powered so they will not load down the bus

but rather be "no load". This is critical, especially if some nodes of the network will be unpowered while the rest

of the network remains in operation.

levels the device will typically need 300 µs to transition to normal operation.

Table 4. Undervoltage Protection

DEVICE

DEVICE STATE

BUS

RXD

Common mode

SN65HVDA540

Forced Standby Mode

HIGH (Recessive)

Common mode

Mirrors bus state via wake-up

SN65HVDA541

Bad

Good

Forced Standby Mode

Common mode

SN65HVDA542

Forced Standby Mode

HIGH (Recessive)

Common mode

SN65HVDA54x

Good

Bad

tri-state

Common mode

SN65HVDA54x-5

Bad

N/A

Forced Standby Mode

HIGH (Recessive) or tri-state

All Devices

Unpowered

Unpowered

No Load

High Z

(1)

See Figure 1 and Figure 2 for common mode bias information.

(2)

See Figure 3 and Figure 4 for operation of the low power wake up receiver and bus monitor for RXD Wake Up Request behavior and

Table 3 for the wake up receiver threshold levels.

(3)

to determine the digital I/O states or power the wake-up receiver.

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Product Folder Links: SN65HVDA540-Q1 SN65HVDA541-Q1 SN65HVDA540-5-Q1 SN65HVDA541-5-Q1

SN65HVDA542-5-Q1