参数资料
型号: TPA0122PWPG4
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: GREEN, PLASTIC, HTSSOP-24
文件页数: 19/33页
文件大小: 688K
代理商: TPA0122PWPG4
www.ti.com
CREST FACTOR AND THERMAL CONDITIONS
P
dB + 10 Log
P
W
P
ref
+ 10 Log
4 W
1 W
+ 6 dB
(9)
P
W + 10
PdB 10
P
ref
+ 63 mW (18-dB crest factor)
+ 125 mW (15-dB crest factor)
+ 250 mW (9-dB crest factor)
+ 500 mW (6-dB crest factor)
+ 1000 mW (3-dB crest factor)
+ 2000 mW (15-dB crest factor)
(10)
TPA0122
SLOS247C – JUNE 1999 – REVISED SEPTEMBER 2004
A final point to remember about Class-AB amplifiers (either SE or BTL) is how to manipulate the terms in the
efficiency equation to utmost advantage when possible. Note that in Equation 8, VDD is in the denominator. This
indicates that as VDD goes down, efficiency goes up.
Class-AB power amplifiers dissipate a significant amount of heat in the package under normal operating
conditions. A typical music CD requires 12-dB to 15-dB dynamic range, or headroom above the average power
output, to pass the loudest portions of the signal without distortion. In other words, music typically has a crest
factor between 12 dB and 15 dB. When determining the optimal ambient operating temperature, the internal
dissipated power at the average output power level must be used. From the TPA0122 data sheet, one can see
that when the TPA0122 is operating from a 5-V supply into a 3-
speaker that 4-W peaks are available.
Converting watts to dB:
Subtracting the headroom restriction to obtain the average listening level without distortion yields:
6 dB – 15 dB = –9 dB (15-dB crest factor)
6 dB – 12 dB = –6 dB (12-dB crest factor)
6 dB – 9 dB = –3 dB (9-dB crest factor)
6 dB – 6 dB = 0 dB (6-dB crest factor)
6 dB – 3 dB = 3 dB (3-dB crest factor)
Converting dB back into watts:
This is valuable information to consider when attempting to estimate the heat dissipation requirements for the
amplifier system. Comparing the absolute worst case, which is 2 W of continuous power output with a 3-dB crest
factor, against 12-dB and 15-dB applications drastically affects maximum ambient temperature ratings for the
system. Using the power dissipation curves for a 5-V, 3-
system, the internal dissipation in the TPA0122 and
maximum ambient temperatures is shown in Table 4.
Table 4. TPA0122 Power Rating, 5-V, 3-
Stereo
PEAK OUTPUT POWER
POWER DISSIPATION
MAXIMUM AMBIENT
AVERAGE OUTPUT POWER
(W)
(W/Channel)
TEMPERATURE(1)
4
2 W (3 dB)
1.7
-3
°C
4
1000 mW (6 dB)
1.6
6
°C
4
500 mW (9 dB)
1.4
24
°C
4
250 mW (12 dB)
1.1
51
°C
4
125 mW (15 dB)
0.8
78
°C
4
63 mW (18 dB)
0.6
85
°C(1)
(1)
Package limited to 85
°C ambient.
26
相关PDF资料
PDF描述
TPA0122PWPRG4 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO24
TPA0122PWP 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO24
TPA0122PWPR 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO24
TPA0132PWPRG4 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO24
TPA0142PWPR 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PDSO24
相关代理商/技术参数
参数描述
TPA0122PWPR 功能描述:音频放大器 2W Stereo APA With Int Gain Settings 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
TPA0122PWPRG4 功能描述:音频放大器 2W Stereo APA With Int Gain Settings 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
TPA0132 制造商:TI 制造商全称:Texas Instruments 功能描述:2-W STEREO AUDIO POWER AMPLIFIER WITH DC VOLUME CONTROL
TPA0132EVM 功能描述:音频 IC 开发工具 TPA0132 Eval Mod RoHS:否 制造商:Texas Instruments 产品:Evaluation Kits 类型:Audio Amplifiers 工具用于评估:TAS5614L 工作电源电压:12 V to 38 V
TPA0132PWP 功能描述:音频放大器 2W Stereo A 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