Philips TDA5051A

1999 May 31 4

Philips Semiconductors Product speciﬁcation

Home automation modem TDA5051A

PINNING

SYMBOL PIN DESCRIPTION

DATAIN 1 digital data input (active LOW)

DATAOUT 2 digital data output (active LOW)

VDDD 3 digital supply voltage

CLKOUT 4 clock output

DGND 5 digital ground

SCANTEST 6 test input (LOW in application)

OSC1 7 oscillator input

OSC2 8 oscillator output

APGND 9 analog ground for power ampliﬁer

TXOUT 10 analog signal output

VDDAP 11 analog supply voltage for power

ampliﬁer

AGND 12 analog ground

VDDA 13 analog supply voltage

RXIN 14 analog signal input

PD 15 power-down input (active HIGH)

TEST1 16 test input (HIGH in application) Fig.2 Pin configuration.

handbook, halfpage

TDA5051AT

MGK833

DATAIN

DATAOUT

VDDD

CLKOUT

DGND

SCANTEST

OSC1

OSC2 APGND

TXOUT

VDDAP

AGND

VDDA

RXIN

TEST1

FUNCTIONAL DESCRIPTION

Both transmission and reception stages are controlled

either by the master clock of the microcontroller or by the

on-chip reference oscillator connected to a crystal. This

ensures the accuracy of the transmission carrier and the

exact trimming of the digital filter, thus making the

performance totally independent of application

disturbances such as component spread, temperature,

supply drift and so on.

The interface with the power network is made by means of

an LC network (see Fig.18). The device includes a power

output stage that feeds a 120 dBµV(RMS) signal on a

typical 30 Ωload.

To reduce power consumption, the IC is disabled by a

power-down input (pin PD): in this mode, the on-chip

oscillator remains active and the clock continues to be

supplied at pin CLKOUT. For low-power operation in

reception mode, this pin can be dynamically controlled by

the microcontroller, see Section “Power-down mode”.

When the circuit is connected to an external clock

generator (see Fig.6), the clock signal must be applied at

pin OSC1 (pin 7); OSC2 (pin8) must be left open-circuit.

Fig.7 shows the use of the on-chip clock circuit.

All logic inputs and outputs are compatible with

TTL/CMOS levels, providing an easy connection to a

standard microcontroller I/O port.

The digital part of the IC is fully scan-testable. Two digital

inputs, SCANTEST and TEST1, are used for production

test: these pins must be left open-circuit in functional mode

(correct levels are internally defined by pull-up or

pull-down resistors).

Transmission mode

To provide strict stability with respect to environmental

conditions, the carrier frequency is generated by scanning

the ROM memory under the control of the microcontroller

clock or the reference frequency provided by the on-chip

oscillator. High frequency clocking rejects the aliasing

components to such an extent that they are filtered by the

coupling LC network and do not cause any significant

disturbance. The data modulation is applied through

pin DATAIN and smoothly applied by specific digital circuits

to the carrier (shaping). Harmonic components are limited

in this process, thus avoiding unacceptable disturbance of

the transmission channel (according to CISPR16 and

EN50065-1 recommendations). A −55dB Total Harmonic

Distortion (TDH) is reached when the typical LC coupling

network (or an equivalent filter) is used.