Functional Description

These devices provide a way to transmit and receive data on the common power lines of an

interconnected array of microcontroller based subsystems. By having one of these devices inside each

subsystem, the shared power and data cabling can be reduced to a simple two line type, offering major

installation cost reductions.

Shared Power Line

All microcontroller based subsystems are connected together via the same two line power connection.

The ground line is hardwired to each subsystem while the positive power line is connected to the VIN

pin on each of the HT71D0x devices. An internal Low Dropout Voltage Regulator within the

HT71D0x devices, converts this input power supply voltage to a fixed voltage level which is supplied

to the subsystem microcontroller and other circuit components. In this way when the power line

voltage is changed due to the transmission or reception of data the subsystem circuits still continue to

receive a regulated power supply.

HT71D02/HT71D04

Power Line Data Transceiver

Rev. 1.00

5

June 30, 2010

P o s i t i v e P o w e r S y p p l y L i n e

M a s t e r

C o n t r o l l e r

G r o u n d L i n e

H T 7 1 D 0 x

M C U

H T 7 1 D 0 x

M C U

H T 7 1 D 0 x

M C U

S u b s y s t e m

# 1

S u b s y s t e m

# 2

S u b s y s t e m

# n

System Block Diagram