TJA1021T/20.118 NXP Semiconductors, TJA1021T/20.118 Datasheet - Page 6

• Manufacturer Part Number: TJA1021T/20.118
• Manufacturer: NXP Semiconductors

Specifications of TJA1021T/20.118

• Operating Supply Voltage (min): 5.5V
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / Rohs Status: Compliant

NXP Semiconductors
[5]
TJA1021_5
Product data sheet
Power-on mode is entered after switching on V
7.2 Sleep mode
7.3 Standby mode
7.4 Normal mode
This mode is the most power-saving mode of the TJA1021. Despite its extreme low
current consumption, the TJA1021 can still be woken up remotely via pin LIN, or woken up
locally via pin WAKE_N, or activated directly via pin SLP_N. Filters at the inputs of the
receiver (LIN), of pin WAKE_N and of pin SLP_N prevent unwanted wake-up events due
to automotive transients or EMI. All wake-up events have to be maintained for a certain
time period (t
Sleep mode is initiated by a falling edge on pin SLP_N in Normal mode. To enter Sleep
mode successfully (INH becomes floating), the sleep command (pin SLP_N = LOW) must
be maintained for at least t
In Sleep mode the internal slave termination between pins LIN and V
minimize the power dissipation in the event that pin LIN is short-circuited to ground. Only a
weak pull-up between pins LIN and V
Sleep mode can be activated independently from the actual level on pin LIN, pin TXD or
pin WAKE_N. So it is guaranteed that the lowest power consumption is achievable even in
case of a continuous dominant level on pin LIN or a continuous LOW on pin WAKE_N.
When V
Sleep mode.
Standby mode is entered automatically whenever a local or remote wake-up occurs while
the TJA1021 is in Sleep mode. These wake-up events activate pin INH and enable the
slave termination resistor at the pin LIN. As a result of the HIGH condition on pin INH the
voltage regulator and the microcontroller can be activated.
Standby mode is signalled by a LOW-level on pin RXD which can be used as an interrupt
for the microcontroller.
In Standby mode (pin SLP_N is still LOW), the condition of pin TXD (weak pull-down or
strong pull-down) indicates the wake-up source: weak pull-down for a remote wake-up
request and strong pull-down for a local wake-up request.
Setting pin SLP_N HIGH during Standby mode results in the following events:
In Normal mode the TJA1021 is able to transmit and receive data via the LIN bus line. The
receiver detects the data stream at the LIN bus input pin and transfers it via pin RXD to the
microcontroller (see
the bus. The receiver has a supply-voltage related threshold with hysteresis and an
•
•
•
An immediate reset of the wake-up source flag; thus releasing the possible strong
pull-down at pin TXD before the actual mode change (after t
A change into Normal mode if the HIGH level on pin SLP_N has been maintained for
a certain time period (t
An immediate reset of the wake-up request signal on pin RXD
BAT
drops below the power-on-reset threshold V
wake(dom)LIN
BAT
Figure
.
Rev. 05 — 22 October 2009
, t
wake(dom)WAKE_N
gotosleep
gotonorm
1): HIGH at a recessive level and LOW at a dominant level on
.
)
BAT
is present.
and t
gotonorm
).
th(POR)L
LIN 2.1/SAE J2602 transceiver
, the TJA1021 enters
gotonorm
BAT
© NXP B.V. 2009. All rights reserved.
TJA1021
) is performed
is disabled to
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