Electronic Components Datasheet Search |
|
THAT4311 Datasheet(PDF) 8 Page - List of Unclassifed Manufacturers |
|
THAT4311 Datasheet(HTML) 8 Page - List of Unclassifed Manufacturers |
8 / 12 page The log-domain filter cutoff frequency is usually placed well below the frequency range of interest. For an audio-band detector, a typical value would be 5Hz, or a 32ms time constant (t). The filter’s time constant is determined by an external capacitor at- tached to the CT pin, and an internal current source (ITIME) connected to CT. The current source is pro- grammed via the IT pin: current in IT is mirrored to ITIME with a gain of approximately one. The resulting time constant t is approximately equal to (0.026 ´ CT) / IT. Note that, as a result of the mathe- matics of rms detection, the attack and release time constants are fixed in their relationship to each other. The DC output of the detector is scaled with the same constant of proportionality as the VCA gain control: 6.1mV/dB. The detector’s zero dB reference (Iin0, the input current which causes zero volts out- put), is determined by IT as follows: Iin0=IT. The detector output stage is capable of sinking or sour- cing l00mA. Differences between the 4311’s RMS-Level Detec- tor circuitry and that of the THAT 2252 RMS Detec- tor are as follows: 1. The rectifier in the 4311 RMS Detector is inter- nally balanced by design, and cannot be balanced via an external control. The 4311 will typically balance positive and negative halves of the input signal within ±1.5%, but in extreme cases the mismatch may reach +20%. However, a 20% mismatch will not sig- nificantly increase ripple-induced distortion in dy- namics processors over that caused by signal ripple alone. 2. The time constant of the 4311’s RMS detector is determined by the combination of an external ca- pacitor (connected to the CT pin) and an internal, programmable current source. The current source is equal to IT. Normally, a resistor is not connected di- rectly to the CT pin on the 4311. 3. The zero dB reference point, or level match, is not adjustable via an external current source. How- ever, as in the 2252, the level match is affected by the timing current, which, in this case, is drawn from the IT pin and mirrored internally to CT. 4. The input stage of the 4311 RMS detector uses integrated P-channel FETs rather than a bias-current corrected bipolar differential amplifier. Input bias currents are therefore negligible, improving perfor- mance at low signal levels. The Opamps - in Brief The three opamps in the 4311 are intended for general purpose applications. All are 5MHz opamps with slew rates of approximately 2V/ms. All use bipo- lar PNP input stages. However, the design of each is optimized for its expected use. Therefore, to get the THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com Page 8 Low-voltage, Analog Engine® Dynamics Processor Preliminary Information IN 17 12 OUT VCA EC+ SYM EC- OA3 Vref U1A THAT 4311 Iset 2 TC 5 IN 1 OUT 4 RMS U1B THAT 4311 3 7 OA2 Vref 6 U1C THAT 4311 18 19 20 OA1 U1D THAT 4311 Cap 8 Vee 10 Vref 9 Vcc 11 Vref U1E THAT 4311 Vref R1 20k R2 20k R3 51R R4 51k C1 47u C2 47p C5 10u C8 22u C7 100n R5 50k +5 +5 Signal In Signal Out Control Port Drive N/C N/C N/C N/C N/C N/C N/C N/C N/C 15 14 13 16 + ++ Fig 18. Circuit showing gain control at EC+ |
Similar Part No. - THAT4311 |
|
Similar Description - THAT4311 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |