 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LM3916 Datasheet(PDF) 10 Page - National Semiconductor (TI) |
|
|
||||||||||||||||||||||||||||||
LM3916 Datasheet(HTML) 10 Page - National Semiconductor (TI) |
|
|
10 / 27 page  Application Hints (Continued) For precision full-wave averaging use the circuit in Figure 5. Using 1% resistors for R1 through R4, gain for positive and negative signal differs by only 0.5 dB worst case. Substitut- ing 5% resistors increases this to 2 dB worst case. (A 2 dB gain difference means that the display may have a ±1dBer- ror when the input is a nonsymmetrical transient). The aver- aging time constant is R5 •C2. A simple modification results in the precision full-wave detector of Figure 6. Since the filter capacitor is not buffered, this circuit can drive only high im- pedance loads such as the input of an LM3916. AUDIO METER STANDARDS VU Meter The audio level meter most frequently encountered is the VU meter. Its characteristics are defined as the ANSI specifica- tion C165. The LM3916’s outputs correspond to the meter indications specified with the omission of the −2 VU indica- tion. The VU scale divisions differ slightly from a linear scale in order to obtain whole numbers in dB. Some of the most important specifications for an AC meter are its dynamic characteristics. These define how the meter responds to transients and how fast the reading decays. The VU meter is a relatively slow full-wave averaging type, speci- fied to reach 99% deflection in 300 ms and overshoot by 1 to 1.5%. In engineering terms this means a slightly under- damped second order response with a resonant frequency of 2.1 Hz andaQof 0.62. Figure 7 depicts a simple rectifier/ filter circuit that meets these criteria. DS007971-11 D1, D2: 1N914 or 1N4148 Average Peak R2 1k 100k R3 100k 1k R1 = R2 for AV = 1 R1 = R2/10 for AV = 10 C1 = 10/R1 FIGURE 4. Precision Half-Wave Rectifier DS007971-12 D1, D2: 1N914 or 1N4148 FIGURE 5. Precision Full-Wave Average Detector DS007971-13 D1, D2, D3, D4: 1N914 OR 1N4148 Attack and decay time to DIN PPM spec. Response down 1 dB for 10 ms tone burst. Decays 20 dB in 1.5s. FIGURE 6. Precision Full-Wave Peak Detector www.national.com 10 |
Similar Part No. - LM3916 |
|
Similar Description - LM3916 |
|
|
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 |
| 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
