Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

TPA721 Datasheet(PDF) 15 Page - Texas Instruments

Part No. TPA721
Description  700-mW MONO LOW-VOLTAGE AUDIO POWER AMPLIFIER
Download  24 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  TI [Texas Instruments]
Homepage  http://www.ti.com
Logo 

TPA721 Datasheet(HTML) 15 Page - Texas Instruments

Zoom Inzoom in Zoom Outzoom out
 15 / 24 page
background image
www.ti.com
APPLICATION SCHEMATICS
Audio
Input
Bias
Control
VDD
700 mW
6
5
7
VO+
VDD
1
2
4
BYPASS
IN–
VDD/2
CI
CS
1
µF
CB
2.2
µF
SHUTDOWN
VO– 8
GND
From System Control
3
IN+
RI
10 k
RF
50 k
+
+
COMPONENT SELECTION
Gain-Setting Resistors, RF and RI
BTL gain + * 2
R
F
R
I
(5)
Effective impedance +
R
F
R
I
R
F )
R
I
(6)
TPA721
SLOS231E – NOVEMBER 1998 – REVISED JUNE 2004
Figure 26 is a schematic diagram of a typical handheld audio application circuit, configured for a gain of –10 V/V.
Figure 26. TPA721 Application Circuit
The following sections discuss the selection of the components used in Figure 26.
The gain for each audio input of the TPA721 is set by resistors RF and RI according to Equation 5 for BTL mode.
BTL mode operation brings about the factor 2 in the gain equation due to the inverting amplifier mirroring the
voltage swing across the load. Given that the TPA721 is a MOS amplifier, the input impedance is high;
consequently, input leakage currents are not generally a concern, although noise in the circuit increases as the
value of RF increases. In addition, a certain range of RF values is required for proper startup operation of the
amplifier. Taken together, it is recommended that the effective impedance seen by the inverting node of the
amplifier be set between 5 k
Ω and 20 kΩ. The effective impedance is calculated in Equation 6.
As an example, consider an input resistance of 10 k
Ω and a feedback resistor of 50 kΩ. The BTL gain of the
amplifier would be –10 V/V, and the effective impedance at the inverting terminal would be 8.3 k
Ω, which is well
within the recommended range.
For high-performance applications, metal film resistors are recommended because they tend to have lower noise
levels than carbon resistors. For values of RF above 50 kΩ, the amplifier tends to become unstable due to a pole
formed from RF and the inherent input capacitance of the MOS input structure. For this reason, a small
compensation capacitor of approximately 5 pF should be placed in parallel with RF when RF is greater than
50 k
Ω. This, in effect, creates a low-pass filter network with the cutoff frequency defined in Equation 7.
15


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24 


Datasheet Download




Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn