 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LT1684 Datasheet(PDF) 10 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LT1684 Datasheet(HTML) 10 Page - Linear Technology |
|
|
10 / 16 page  10 LT1684 The component selections for the active tracking supply lowpass MFB filter configuration follow the relations: C2 = mC1 m ≤ 1 / [4Q2(1+|HO|)] R2 = 1± [1–4mQ2(1+|HO|)]1/2 2 ωnC1mQ R1 = R2 / |HO| R3 =1 ωn2C12R2m Example: Conditions: Output ring tone peak voltage = 100V Ring frequency = 20Hz Input duty cycle range = 10% to 90% Filter Q = 0.707 Set: fn = ωn / 2π = 100Hz Choose: C1 = 1.0µF (a convenient value) Then: m ≤ [4(0.7)2(1+100)]–1 ≈ .005 C2 = mC1 C2 = 4700pF (sets m = 0.0047) R2 = 1± [1– 4(0.0047)(0.707)2(101)]1/2 (4 π100)(1e–6)(.0047)(0.707) R2 = 300k R1 = 300k/100 R1 = 3.0k R3 = [(2π100)2(1e–6)2(300k)(0.0047)]–1 R3 = 2k This filter configuration yields a DC Gain of 100, a corner frequency of just under 100Hz with gain reduction of only 0.1% at 20Hz, and a 10kHz carrier rejection of greater than 40dB at the output. Active Tracking Supply Components Given the previous discussion, implementation of an active tracking supply system may seem almost trivial. Active Tracking Supply Lowpass Multiple Feedback Filter Transfer Characteristic (AV vs fn) However, bootstrapping an amplifier system about its own output creates a complex myriad of inherent stability and response issues. Attempting such a configuration with generic “jelly-bean” components is not recommended for the faint of heart or type-A personalities. The LT1684, however, makes for a simplistic approach to active track- ing component selection. The high voltage MOSFET transistors used in the circuit must have an operating VDS specified at greater than the corresponding high voltage supply rail plus the opposite maximum excursion of the output signal. For example, if a system is designed with a 240V supply (+ 120V, –120V) and outputs a ring signal that has a 100V peak amplitude, the MOSFET VDS ratings must be greater than 240/2 + 100 = 220V. Active Filter Tuned Oscillator— No PWM Input Required A simple yet effective method of producing a high quality sine wave is to place a high-Q bandpass filter and a hard limited gain element in a positive feedback loop. This circuit will oscillate at the bandpass frequency, producing a sine wave at the filter output. The product of the funda- mental component of the limiter and the filter gain at the bandpass frequency determines the output amplitude. This type of circuit is commonly referred to as an active filter tuned oscillator. HERTZ (Hz) 1 10 100 1K 10K 100K 1684 F02 –50 0 50 APPLICATIO S I FOR ATIO |
Similar Part No. - LT1684 |
|
Similar Description - LT1684 |
|
|
|
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
