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.

HT71D02/HT71D04

Power Line Data Transceiver

Rev. 1.00

7

June 30, 2010

LVD

9.0V

C1

VIN

CN

CP/TD

CX

CDLY

VO

TG

VSS/TS

+

Q1

CEB

Vref

VCC

VCC

VDD

Q3

Q4

Q2

MCU

VDD

VSS

I/O0

I/O1

104

R1

47uF

203

104

R2

R

270

+24V

0V

LDO

3.3V/5.0V

104

C2

Protection

Circuit