参数资料
型号: TPA0212PWP
厂商: TEXAS INSTRUMENTS INC
元件分类: 音频控制
英文描述: 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO24
封装: POWERPAD, PLASTIC, HTSSOP-24
文件页数: 18/35页
文件大小: 662K
代理商: TPA0212PWP
www.ti.com
Efficiency of a BTL amplifier +
P
L
P
SUP
Where:
P
L +
V
Lrms
2
R
L
, and V
LRMS +
V
P
2
, therefore, P
L +
V
P
2
2 R
L
and PSUP + VDD IDDavg
and
I
DDavg +
1
p
0
V
P
R
L
sin(t) dt
+ *
1
p
V
P
R
L
[cos(t)]
p
0
+
2V
P
p
R
L
Therefore,
P
SUP +
2 V
DD VP
p
R
L
substituting PL and PSUP into the equation,
Efficiency of a BTL amplifier +
V
P
2
2 R
L
2 V
DD VP
p
R
L
+
p
V
P
4 V
DD
V
P +
2 P
L RL
Where:
(7)
PL = Power delivered to load
PSUP = Power drawn from power supply
VLRMS = RMS voltage on BTL load
RL = Load resistance
hBTL +
p
2 P
L RL
4 V
DD
Therefore,
VP = Peak voltage on BTL load
IDDavg = Average current drawn from the power supply
VDD = Power supply voltage
ηBTL = Efficiency of a BTL amplifier
(8)
TPA0212
SLOS284B – NOVEMBER 1999 – REVISED NOVEMBER 2004
Table 3 employs Equation 8 to calculate efficiencies for four different output power levels. Note that the efficiency
of the amplifier is quite low for lower power levels and rises sharply as power to the load is increased resulting in
a nearly flat internal power dissipation over the normal operating range. Note that the internal dissipation at full
output power is less than in the half power range. Calculating the efficiency for a specific system is the key to
proper power supply design. For a stereo 1-W audio system with 8-
loads and a 5-V supply, the maximum draw
on the power supply is almost 3.25 W.
Table 3. EFFICIENCY VS OUTPUT POWER IN 5-V, 8-
BTL SYSTEMS
OUTPUT POWER
EFFICIENCY
PEAK VOLTAGE
INTERNAL DISSIPATION
(W)
(%)
(V)
(W)
0.25
31.4
2.00
0.55
0.50
44.4
2.83
0.62
1.00
62.8
4.00
0.59
1.25
70.2
4.47(1)
0.53
(1)
High peak voltages cause the THD to increase.
25
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TPA0212PWP 制造商:Texas Instruments 功能描述:POWER AMP AUDIO CLASS AB HTSSOP24
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TPA0212PWPR 功能描述:音频放大器 Stereo Class-AB w/Ster Hdphn Drive RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel
TPA0212PWPRG4 功能描述:音频放大器 Stereo Class-AB w/Ster Hdphn Drive RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel
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