TH3122KDF MELEXIS [Melexis Microelectronic Systems], TH3122KDF Datasheet - Page 6

• Manufacturer Part Number: TH3122KDF
• Description: K-Bus Transceiver with integrated Voltage Regulator
• Manufacturer: MELEXIS [Melexis Microelectronic Systems]

Application Hints
Operating during Disturbances
The absence of V
shift either alone or in any combination, do not influence
or disturb the communication between other bus nodes.
Undervoltage
The reset unit secures the correct behavior of the driver
during undervoltage. The inputs have pull-up or pull-
down characteristics and have therefore defined voltage
levels.
With 4.5V
within the correct parameters .
If V
bus. The receive mode is also active.
If V
SENSE and SO output the correct signal if V
The specificated values of the input voltages on SO can’t
guaranteed.
There should be used an LC-Filter to minimize the influence of EMI on the BUS lines.
Application Circuitry
3901003122
Rev 004
BUS
CC
optional
RES1
V
< V
Bat
10
RES1
V
CC
the bus driver is tristate.
V
CC
battery reverse diode
 4 .5V the TxD signal is transmitted to the
33uH
S
5.25V the bus connection operates
,V
100p
100u
CC
or GND connection or ground
47n
82p
K-Bus Transceiver with integrated Voltage Regulator
Figure 8 - Application Circuit
CC
> V
RES
VS
EN
VTR
GND
GND
BUS
SI
SO
.
Page 6
TH3122
SEN/STA
Regulator Circuitry
The choice and dimension of the capacitor on VCC is
determined by application point of view. Important
parameters are the current difference on load changes
and the maximum short time voltage drop.
The VCC pin must be connected to a min. 2
capacitor for stable operating of the regulator in the
whole operating range.
Short Circuit Proof
All in- and outputs are short circuit proof to battery and
ground. A thermal shut down circuit prevents VCC and
BUS from any damage.
Baud Rate
The TH3122 has a maximum Baud rate of 9600 Baud
(C
BUS
SENSE
RESET
< 25nF, R
GND
GND
VCC
RxD
TxD
PU
> 400 )
.
6.8u
TH3122
Control Unit
Reset
RxD
+5V
TxD
Port X.1
C
Dec/04
F