TS4984FC Datasheet, PDF (18/30 Pages) STMicroelectronics – 1.2W Stereo Audio Power Amplifier with Active Low Standby Mode

Application Information
4 Application Information
TS4984FC
The TS4984 integrates two monolithic power amplifiers with a BTL (Bridge Tied Load) output
type (explained in more detail in Section 4.1). For this discussion, only the left-channel amplifier
will be referred to.
Referring to the schematic in Figure 62, we assign the following variables and values:
V_in = Vin1-
V_out1 = VOUT1+
V_out2 = VOUT1-
R_in = Rin1
R_feed = Rfeed1
C_feed = Cfeed1
Figure 62. Typical application schematic - left channel
Cfeed = Cfeed1
Rfeed = Rfeed1
VCC
Cs
1u
IN1
2
GND ¹
Cin = Cin1
Vin- = VIN1-
-
Rin = Rin1
Vin+ = VIN1+ ₊
STDBY
Bias
BYPASS
Cb
1u
TS4984
-
AV = -1
+
Vout1 = VOUT1+
RL
Vout2 = VOUT1-
4.1 BTL configuration principle
BTL (Bridge Tied Load) means that each end of the load is connected to two single-ended
output amplifiers. Thus, we have:
Single-ended output 1 = V_out1 = V_out (V),
Single-ended output 2 = V_out2 = -V_out (V), V_out1 - V_out2 = 2V_out (V)
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