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Revision 1.01

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AS1702, AS1703, AS1704, AS1705

Data Sheet

BTL Amplifier

7.1 BTL Amplifier

All devices are designed to drive loads differentially in a bridge-tied load (BTL) configuration.

Figure 4. Bridge Tied Load Configuration

The BTL configuration doubles the output voltage (illustrated in Figure 4) compared to a single-ended amplifier under

effective gain is given by:

the output voltage:

Since the BTL outputs are biased at mid-supply, there is no net DC voltage across the load. This eliminates the need

for the large, expensive, performance degrading DC-blocking capacitors required by single-ended amplifiers.

7.2 Power Dissipation and Heat Sinking

Normally, the devices dissipate a significant amount of power. The maximum power dissipation is given in Table 1 as

Continuous Power Dissipation, or it can be calculated by:

tor in °C/W as specified in Table 1. For example,

The increased power delivered by a BTL configuration results in an increase in internal power dissipation versus a sin-

+1

-1

(EQ 2)

2 2

(EQ 3)

(EQ 4)

(EQ 5)

L

(EQ 6)