Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.COM

X  

LM4870M Datasheet(PDF) 6 Page - National Semiconductor (TI)

[Old version datasheet] Texas Instruments acquired National semiconductor.
Part # LM4870M
Description  1.1W Audio Power Amplifier with Shutdown Mode
Download  8 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  NSC [National Semiconductor (TI)]
Direct Link  http://www.national.com
Logo NSC - National Semiconductor (TI)

LM4870M Datasheet(HTML) 6 Page - National Semiconductor (TI)

  LM4870M Datasheet HTML 1Page - National Semiconductor (TI) LM4870M Datasheet HTML 2Page - National Semiconductor (TI) LM4870M Datasheet HTML 3Page - National Semiconductor (TI) LM4870M Datasheet HTML 4Page - National Semiconductor (TI) LM4870M Datasheet HTML 5Page - National Semiconductor (TI) LM4870M Datasheet HTML 6Page - National Semiconductor (TI) LM4870M Datasheet HTML 7Page - National Semiconductor (TI) LM4870M Datasheet HTML 8Page - National Semiconductor (TI)  
Zoom Inzoom in Zoom Outzoom out
 6 / 8 page
background image
Application Information (Continued)
ceeded momentarily, due to the discharging time constant of
the bias-pin voltage. This time constant is established by the
two 50k resistors (in parallel) with the series bypass capaci-
tor value.
When a set of headphones are plugged into the system, the
contact pin of the headphone jack is disconnected from the
signal pin, interrupting the voltage divider set up by resistors
R1 and R2. Resistor R1 then pulls up the HP-IN1 pin, en-
abling the headphone function and disabling the LM4870
amplifier. The headphone amplifier then drives the head-
phones, whose impedance is in parallel with resistor R2.
Since the typical impedance of headphones are 32
Ω, resis-
tor R2 has negligible effect on the output drive capability.
Also shown in
Figure 3 are the electrical connections for the
headphone jack and plug. A 3-wire plug consists of a Tip,
Ring, and Sleave, where the Tip and Ring are signal carrying
conductors and the Sleave is the common ground return.
One control pin contact for each headphone jack is sufficient
to indicate to control inputs that the user has inserted a plug
into a jack and that another mode of operation is desired.
For a system implementation where the headphone amplifier
is designed using a split supply, the output coupling cap, C
C
and resistor R2 of
Figure 3, can be eliminated. The function-
ality described earlier remains the same, however.
In addition, the HP-SENSE pin, although it may be con-
nected to the SHUTDOWN pin as shown in
Figure 2, may
still be used as a control flag. It is capable of driving the input
to another logic gate or approximately 2 mA without serious
loading.
AUDIO POWER AMPLIFIER DESIGN
Design a 500 mW/8
Ω Audio Amplifier
Given:
Power Output:
1.0Wrms
Load Impedance:
8
Input Level:
1 Vrms(max)
Input Impedance:
20 k
Bandwidth:
100 Hz-20 kHz ±0.25 dB
A designer must first determine the needed supply rail to ob-
tain the specified output power. The Output Power vs Supply
Voltage graphs in the Typical Performance Characteris-
tics section show how much power the LM4870 will output
given different supply voltage. According to the graph, 4.6V
DS100094-7
FIGURE 2. HP-SENSE Pin to
SHUTDOWN Pin Connection
DS100094-8
FIGURE 3. Typical Headphone Control Input Circuitry
www.national.com
6


Similar Part No. - LM4870M

ManufacturerPart #DatasheetDescription
logo
National Semiconductor ...
LM4871 NSC-LM4871 Datasheet
243Kb / 8P
   1.1W Audio Power Amplifier with Shutdown Mode
LM4871 NSC-LM4871 Datasheet
469Kb / 16P
   3W Audio Power Amplifier with Shutdown Mode
logo
Texas Instruments
LM4871 TI1-LM4871 Datasheet
1Mb / 23P
[Old version datasheet]   3W Audio Power Amplifier with Shutdown Mode
LM4871LD TI1-LM4871LD Datasheet
1Mb / 23P
[Old version datasheet]   3W Audio Power Amplifier with Shutdown Mode
LM4871LD/NOPB TI1-LM4871LD/NOPB Datasheet
1Mb / 23P
[Old version datasheet]   3W Audio Power Amplifier with Shutdown Mode
More results

Similar Description - LM4870M

ManufacturerPart #DatasheetDescription
logo
National Semiconductor ...
LM4861 NSC-LM4861 Datasheet
218Kb / 8P
   1.1W Audio Power Amplifier with Shutdown Mode
LM4871 NSC-LM4871 Datasheet
243Kb / 8P
   1.1W Audio Power Amplifier with Shutdown Mode
logo
Texas Instruments
LM4861MX TI-LM4861MX Datasheet
892Kb / 20P
[Old version datasheet]   1.1W Audio Power Amplifier with Shutdown Mode
logo
Unisonic Technologies
PA4871 UTC-PA4871 Datasheet
231Kb / 6P
   1.1W AUDIO POWER AMPLIFIER WITH SHUTDOWN MODE
logo
National Semiconductor ...
LM4861 NSC-LM4861_03 Datasheet
276Kb / 12P
   1.1W Audio Power Amplifier with Shutdown Mode
logo
Unisonic Technologies
PA4871 UTC-PA4871_17 Datasheet
236Kb / 7P
   1.1W AUDIO POWER AMPLIFIER WITH SHUTDOWN MODE
PA4871 UTC-PA4871_15 Datasheet
277Kb / 6P
   1.1W AUDIO POWER AMPLIFIER WITH SHUTDOWN MODE
logo
Texas Instruments
LM4861MX TI1-LM4861MX Datasheet
919Kb / 20P
[Old version datasheet]   LM4861 1.1W Audio Power Amplifier with Shutdown Mode
logo
Integrated Silicon Solu...
IS31AP4991A ISSI-IS31AP4991A Datasheet
373Kb / 11P
   1.1W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
IS31AP4991A-GRLS2-TR ISSI-IS31AP4991A-GRLS2-TR Datasheet
373Kb / 11P
   1.1W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
More results


Html Pages

1 2 3 4 5 6 7 8


Datasheet Download

Go To PDF Page


Link URL




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

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   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
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com