7/26

STLC1512

Thermal shutdown junction

130

150

175

Only the power amplifier is

shut down under overheat

condition

<1>

The quiescent current is the current flowing into pin PAOP/PAON when there is no signal.

<2>

This is the current drawn from the power supply that is connected to the center tap on the primary side of the transformer.

<3>

This is the current flowing into the pin PAIN or PAIP when there is no signal. The nature of the test set up makes this quantity

very difficult to measure. It is verified through simulation.

<4>

This will allow the distortion specs to be met while driving a 160W line impedance. This applies for a 550mA output current. The

worst case impedance for a nominal chip is 200 W.

<5>

This spec is meant as an aid in calculating the proper switching point. It applies for a 225mA output current.

<6>

This is a requirement on the input signal that allows the distortion spec to be met. It is not a testable parameter. The ran ge has

been arrived at from simulations.

<7>

The minimum sink current refers to peak signal current in normal operation. This is tested by placing a 80 W load as the lin e

impedance and ensuring that the amplifier still passes the distortion tests. The maximum sink current refers to the current tha t

will be delivered if tip and ring are shorted. A nominal chip can drive a 50W load while a worst case chip will drive 80W.

<8>

Slew Rate spec is to guarantee that there is no slewing limit on a maximum amplitude sine wave at 540kHz. A 100 mV step is

placed at the power amp input and the slew rate at the output of the amplifier is measured across the 100 Ohm load impedance.

<9>

Measured across the 100 Ohm line impedance. This noise spec can be converted to dB/Hz through the following formula,

The effect of the noise in the receive path can be obtained by subtracting the hybrid balance number.

<10> Two tone distortion is measured with two sine waves with each sine wave at an amplitude of 1/2 full scale (for signal gain of

20.1dB, the full scale signal at power amplifier input is 1.05 Vp). The two tone distortion requirement is measured from the rms

voltage of a single signal tone to the rms voltage of the distortion product. For the Two Tone A spec the tones are at f1=500KHz

and f2=300KHz giving Im2=200kHz and Im3=100kHz. For the Two tone B the tones are at f1= 500kHz and f2=450kHz so that

Im3=550kHz.

<11> A multi-tone sine wave is used for the DS (Down Stream) Multi-tone test. (The multi-tone signal will be 91 sine waves equally

spaced from 35x4.3125kHz to 125x4.3125kHz with a peak-to-rms voltage ratio of 5.3 and an rms voltage equal to 208mV. Each

tone will have a peak amplitude of 30.8mV) The multi-tone test measures the difference between the power of the test tones

and the maximum power of a single distortion product in the given bands.

<12> The thermal shut down can not be directly tested in production. It will be investigated at bench and a correlation will be done

hermal shutdown temperature.

Table 4. Power Amplifier Performance Specifications

N

dB

10

e

n

2

x1000

100

--------------------------

log

=