SI9243A Datasheet, PDF (4/5 Pages) Vishay Siliconix – Single-Ended Bus Transceiver

Si9243AEY
Vishay Siliconix
PIN CONFIGURATION
RX_K
RX_L
V_DD
TX
Narrow Body
SO Package
1
8
2
7
3
6
4
5
L
V_BAT
K
GND
Top View
ORDERING INFORMATION
Part Number
Temperature Range
Si9243AEY
–40 to 125_C
PIN DESCRIPTION
Pin Number Symbol
Description
1
RX_K
K Receiver, Output
2
RX_L
L Receiver, Output
3
V_DD
Positive Power Supply
4
TX
Transmit, Input
5
GND
Ground Connection
6
K
K Transmit/Receive, Bidirectional
7
V_BAT
Battery Power Supply
8
L
L Transmit, Input
FUNCTIONAL DESCRIPTION
The Si9243AEY can be either in transmit or receive mode and
it contains over temperature, and short circuit V_BAT fault
detection circuits.
The voltage on the K and L pins are internally compared to
V_BAT/2. If the voltage on the K or L pin is less than V_BAT/2 then
RX_K or RX_L output will be “low.” If the voltage on the K or L pin
is greater than V_BAT/2 then RX_K or RX_L output will be “high.
In order to be in transmit mode, TX must be set “low.” The TX
signal is then internally inverted and turns the MOSFET on,
causing the K pin to be “low.” In transmit mode, the processor
monitors the RX_K and TX. When the two mirror each other
there is no fault. In the event of over temperature, or short
circuit to V_BAT, the Si9243AEY will turn off the K output to
protect the IC. The K pin will stay in high impedance and RX_K
will follow the K pin. The fault will be reset when TX is toggled
high. RX_K, RX_L and TX pins have internal pull up resistor to
V_DD while K and L pins have internal pull down resistors. When
any one of the TX, V_BAT or GND pins is open the K output is off.
When the TX pin is set “high” the Si9243AEY is in receive
mode and the internal MOSFET is turned off. RX_L and RX_K
outputs will follow L and K inputs respectively.
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Document Number: 70788
S-02936—Rev. D, 22-Jan-01