HT71D02 Datasheet, PDF (7/11 Pages) Holtek Semiconductor Inc – Power Line Data Transceiver

HT71D02/HT71D04
Power Line Data Transceiver
Application Considerations
It is envisaged that the devices will be used together with microcontroller based subsystems which will
be required to provide two I/O pins for data transmission and reception. The MCU pin connected to the
TG pin must be setup as an output while the MCU pin connected to the CX pin must be setup as an
input.
The power supply impedence will play an important role in applications using these devices and must
be well defined for reliable data transmission and reception.
The external components connected to the CP/TD pin must be chosen carefully to ensure that an
adequate pulse duration on pin CX is generated.
The usual decoupling precautions must be taken to ensure reliable operation.
Application Circuits
The following application circuit shows the device used in conjunction with a microcontroller.
+24V
0V
R
270
47uF
VIN
104
VCC
LDO
3.3V/5.0V
R1
CEB
VDD
VO
Q1
VCC
RPU1 CDLY
VDD
104
VSS
R2
104
CN
CP/TD
VSS/TS
LVD
9.0V
C1
+
Protection
Circuit
Q4
Q2
Q3
VDD
RPU2
C2
Vref
203
VO
CX
RX
Note: RX = 80kX
MCU
I/O0
TG
I/O1
Rev. 1.00
7
June 30, 2010