User's Manual

Table Of Contents

GC864 Hardware User Guide

1vv0300733 Rev.12 – 2009-06-04

10.2.2. Output Lines Characteristics

TIP:

We suggest driving the load differentially from both output drivers, thus the output

swing will double and the need for the output coupling capacitor avoided. However if

particular OEM application needs also a Single Ended circuitry can be implemented,

but the output power will be reduced four times .

The OEM circuitry shall be designed to reduce the common mode noise typically

generated on the ground plane and to get the maximum power output from the

device (low resistance tracks).

WARNING:

The loads are directly connected to the amplifier outputs when in

Differential

configuration, through a capacitor when in

Single Ended

configuration. Using

Single Ended configuration, the unused output line must be left open . Not

respecting this constraint, the output stage will be damaged.

TIP :

Remember that there are slightly different electrical performances between the two

internal audio amplifiers:

• the

“Ear_MT”

lines

can directly drive a

Ω

load

at –12dBFS (**) in

Differential

configuration

• the “

Ear_HF”

lines can directly drive a

Ω

load

Differential

Single Ended

configurations

• There is no difference if the amplifiers drive an external amplifier

(**)

0dBFS

is the normalized overall Analog Gain for each Output channel equal to

3,7V

differential