参数资料
型号: TS4990EIKJT
厂商: STMICROELECTRONICS
元件分类: 音频/视频放大
英文描述: 1.2 W, 1 CHANNEL, AUDIO AMPLIFIER, PBGA9
封装: ROHS COMPLIANT, FCP-9
文件页数: 13/32页
文件大小: 797K
代理商: TS4990EIKJT
Application information
TS4990
20/31
and the maximum value is obtained when:
and its value is:
Note:
This maximum value is only dependent on power supply voltage and load values.
The efficiency is the ratio between the output power and the power supply:
The maximum theoretical value is reached when VPEAK = VCC, so:
4.5
Decoupling of the circuit
Two capacitors are needed to correctly bypass the TS4990: a power supply bypass
capacitor Cs and a bias voltage bypass capacitor Cb.
Cs has particular influence on the THD+N in the high frequency region (above 7kHz) and an
indirect influence on power supply disturbances. With a value for Cs of 1F, you can expect
THD+N levels similar to those shown in the datasheet.
In the high frequency region, if Cs is lower than 1F, it increases THD+N and disturbances
on the power supply rail are less filtered.
On the other hand, if Cs is higher than 1F, those disturbances on the power supply rail are
more filtered.
Cb has an influence on THD+N at lower frequencies, but its function is critical to the final
result of PSRR (with input grounded and in the lower frequency region).
If Cb is lower than 1F, THD+N increases at lower frequencies and PSRR worsens.
If Cb is higher than 1F, the benefit on THD+N at lower frequencies is small, but the benefit
to PSRR is substantial.
Note that Cin has a non-negligible effect on PSRR at lower frequencies. The lower the value
of Cin, the higher the PSRR.
4.6
Wake-up time (tWU)
When the standby is released to put the device ON, the bypass capacitor Cb is not charged
immediately. Because Cb is directly linked to the bias of the amplifier, the bias will not work
properly until the Cb voltage is correct. The time to reach this voltage is called wake-up time
or tWU and specified in the electrical characteristics tables with Cb =1F.
If Cb has a value other than 1F, refer to the graph in Figure 60 on page 19 to establish the
wake-up time.
δP
diss
δP
out
------------------ = 0
P
diss
max
2V
CC
2
π
2
R
L
---------------
(W)
=
η=
P
out
P
supply
------------------- =
πV
PEAK
4V
CC
-----------------------
π
4
----- = 78.5%
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TS4990EKIJT 1.2 W, 1 CHANNEL, AUDIO AMPLIFIER, PBGA9
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相关代理商/技术参数
参数描述
TS4990EKIJT 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:1.2 W audio power amplifier with active low standby mode
TS4990ID 功能描述:音频放大器 1.2W audio Pwr amp 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
TS4990IDT 功能描述:音频放大器 1.2W audio Pwr amp 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
TS4990IJT 制造商:ST 功能描述:1W AUDIO POWER AMPLIFIER WITH ACTIVE LOW STANDBY MODE
TS4990IQT 功能描述:音频放大器 1.2W audio pow. amp. 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