參數(shù)資料
型號(hào): MAX9789BETJ+
廠商: Maxim Integrated Products
文件頁(yè)數(shù): 8/28頁(yè)
文件大小: 0K
描述: IC AMP AUDIO 2W STER AB 32TQFN
產(chǎn)品培訓(xùn)模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標(biāo)準(zhǔn)包裝: 60
系列: DirectDrive®
類(lèi)型: AB 類(lèi)
輸出類(lèi)型: 2-通道(立體聲)帶立體聲耳機(jī)
在某負(fù)載時(shí)最大輸出功率 x 通道數(shù)量: 2W x 2 @ 4 歐姆; 100mW x 2 @ 16 歐姆
電源電壓: 4.5 V ~ 5.5 V
特點(diǎn): 消除爆音,靜音,短路保護(hù)和熱保護(hù),關(guān)機(jī)
安裝類(lèi)型: 表面貼裝
供應(yīng)商設(shè)備封裝: 32-TQFN-EP(5x5)
封裝/外殼: 32-WFQFN 裸露焊盤(pán)
包裝: 管件
MAX9789/MAX9790
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
16
______________________________________________________________________________________
The voltage coefficient of the capacitor, the change
in capacitance due to a change in the voltage
across the capacitor, distorts the audio signal. At
frequencies around the -3dB point, this effect is
maximized and the voltage coefficient appears as
frequency-dependent distortion. Figure 3 shows the
THD+N introduced by two different capacitor
dielectrics. Note that around the -3dB point, THD+N
increases dramatically.
The combination of low-frequency attenuation and fre-
quency-dependent distortion compromises audio
reproduction. DirectDrive improves low-frequency
reproduction in portable audio equipment that empha-
sizes low-frequency effects, such as multimedia lap-
tops, MP3, CD, and DVD players (See Table 2).
Charge Pump
The MAX9789/MAX9790 feature a low-noise charge
pump. The 550kHz switching frequency is well beyond
the audio range, and does not interfere with the audio
signals. The switch drivers feature a controlled switching
speed that minimizes noise generated by switching
transients. Limiting the switching speed of the charge
pump minimizes the di/dt noise caused by the parasitic
bond wire and trace inductance.
BIAS
The MAX9789/MAX9790 feature an internally generat-
ed, power-supply independent, common-mode bias
voltage of 1.8V referenced to GND. BIAS provides both
click-and-pop suppression and sets the DC bias level
for the amplifiers. The BIAS pin should be bypassed to
GND with a 1F capacitor. No external load should be
applied to BIAS. Any load lowers the BIAS voltage,
affecting the overall performance of the device.
Headphone and Speaker Amplifier Gain
The MAX9789/MAX9790 feature programmable speak-
er amplifier gain, set by the logic voltages applied to
pins GAIN1 and GAIN2. Table 3 shows the logic com-
binations that can be applied to pins GAIN1 and GAIN2
and their affects on the speaker amplifier gain. The
headphone amplifier gain is fixed at 3.5dB.
0
-30
1
10
100
1k
10k
100k
LOW-FREQUENCY ROLLOFF
(RL = 16
Ω)
-24
-27
-12
-15
-18
-21
-6
-9
-3
FREQUENCY (Hz)
ATTENUATION
(dB)
DirectDrive
330
μF
220
μF
100
μF
33
μF
Figure 2. Low-Frequency Attenuation of Common DC-Blocking
Capacitor Values
ADDITIONAL THD+N DUE TO
DC-BLOCKING CAPACITORS
FREQUENCY (Hz)
THD+N
(%)
10k
1k
100
0.001
0.01
0.1
1
10
0.0001
10
100k
TANTALUM
COUT = 100
μF
RL = 16
Ω
ALUM/ELEC
Figure 3. Distortion Contributed by DC-Blocking Capacitors
MAX9789/MAX9790
GAIN1
GAIN2
SPEAKER MODE
GAIN (dB)
HEADPHONE
MODE GAIN (dB)
0
6
3.5
0
1
10
3.5
1
0
15.6
3.5
1
21.6
3.5
Table 3. MAX9789/MAX9790
Programmable Gain Settings
f-3dB (Hz)
COUT (F)
RL = 16
Ω
RL = 32
Ω
22
452
226
33
301
151
100
99
50
220
45
23
330*
30
15
470
21
11
Table 2. Low-Frequency Rolloff
*Vista requirement for 32Ω load.
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參數(shù)描述
MAX9789BETJ+ 功能描述:音頻放大器 Windows Vista Class AB Speaker Amp RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類(lèi)型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX9789BETJ+T 功能描述:音頻放大器 Windows Vista Class AB Speaker Amp RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類(lèi)型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX9789CETJ+ 功能描述:音頻放大器 Windows Vista Class AB Speaker Amp RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類(lèi)型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX9789CETJ+T 功能描述:音頻放大器 Windows Vista Class AB Speaker Amp RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類(lèi)型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX978EEE 功能描述:校驗(yàn)器 IC Quad High Speed Comparator RoHS:否 制造商:STMicroelectronics 產(chǎn)品: 比較器類(lèi)型: 通道數(shù)量: 輸出類(lèi)型:Push-Pull 電源電壓-最大:5.5 V 電源電壓-最小:1.1 V 補(bǔ)償電壓(最大值):6 mV 電源電流(最大值):1350 nA 響應(yīng)時(shí)間: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SC-70-5 封裝:Reel