Datasheet

TLE6251D
Functional Description
Data Sheet 9 Rev. 1.0, 2012-07-27
4.3 Normal-operating Mode
In the normal-operating mode, the HS CAN transceiver TLE6251D sends the serial data stream on the TxD pin to
the CAN bus. The data on the CAN bus is displayed at the RxD pin simultaneously. In normal-operating mode, all
functions of the TLE6251D are active:
• The transmitter is active and drives data from the TxD to the CAN bus.
• The receiver is active and provides the data from the CAN bus to the RxD pin.
• The low-power receiver is disabled.
• The bus basing is set to
V
CC
/2.
• The undervoltage monitoring on the power supply
V
CC
and on the power supply V
IO
is active.
• The overtemperature protection is active.
To enter the normal-operating mode, set the STB pin to logical “low” (see Table 2 or Figure 4). The STB pin has
an internal pull-up resistor to the power-supply
V
IO
.
4.4 Stand-by Mode
Stand-by mode is an idle mode of the TLE6251D with optimized power consumption. In stand-by mode, the
TLE6251D can not send or receive any data. The normal mode receiver is switched off and only the low-power
receiver is active. An additional filter, implemented inside the low-power receiver ensures that only “dominant” and
“recessive” signals on the CAN bus, which are longer than the bus wake-up time
t
WU
are indicated at the RxD
output pin.
• The transmitter is disabled, and permanently “recessive”.
• The input TxD is disabled.
• The normal mode receiver is disabled.
• The low-power receiver is active.
• The RxD output is “high”, in case no wake-up signal on the CAN bus is detected (see Figure 5).
• The RxD output toggles according to the wake-up signal on the CAN bus (see Figure 5).
• The undervoltage monitoring on the power supply
V
CC
is disabled.
• The undervoltage monitoring on the power supply
V
IO
is active.
• The bus biasing is set to GND.
• The overtemperature protection is not active.
To enter the stand-by mode, set the pin STB to logical “high” (see Table 2 or Figure 4). The STB pin has an
internal pull-up resistor to the power-supply
V
IO
. In case the stand-by mode is not be used in the final application,
the STB pin needs to get connected to GND.
4.5 Power-down State
The power-down state means that the TLE6251D is not supplied. In the power-down state, the differential input
resistors of the receiver are switched off. The CANH and CANL bus interface of the TLE6251D acts as a high-
impedance input with a very small leakage current. The high-ohmic input does not influence the “recessive” level
of the CAN network and allows an optimized EME performance of the entire CAN network.