Os motores de busca de Datasheet de Componentes eletrônicos |
|
AD743KN Folha de dados(PDF) 10 Page - Analog Devices |
|
AD743KN Folha de dados(HTML) 10 Page - Analog Devices |
10 / 12 page AD743 REV. C –10– AN INPUT-IMPEDANCE-COMPENSATED, SALLEN-KEY FILTER The simple high pass filter of Figure 35 has an important source of error which is often overlooked. Even 5 pF of input capacitance in amplifier “A” will contribute an additional 1% of passband amplitude error, as well as distortion, proportional to the C/V characteristics of the input junction capacitance. The addition of the network designated “Z” will balance the source impedance–as seen by “A”–and thus eliminate these errors. Figure 35. An Input Impedance Compensated Sallen-Key Filter TWO HIGH PERFORMANCE ACCELEROMETER AMPLIFIERS Two of the most popular charge-out transducers are hydrophones and accelerometers. Precision accelerometers are typically calibrated for a charge output (pC/g).* Figures 36a and 36b show two ways in which to configure the AD743 as a low noise charge amplifier for use with a wide variety of piezoelectric accelerometers. The input sensitivity of these circuits will be determined by the value of capacitor C1 and is equal to: ∆V OUT = ∆Q OUT C1 The ratio of capacitor C1 to the internal capacitance (CT) of the transducer determines the noise gain of this circuit (1 + CT/C1). The amplifiers voltage noise will appear at its output amplified by this amount. The low frequency bandwidth of these circuits will be dependent on the value of resistor R1. If a “T” network is used, the effective value is: R1 (1 + R2/R3). Figure 36a. A Basic Accelerometer Circuit *pC = Picocoulombs g = Earth's Gravitational Constant Figure 36b. An Accelerometer Circuit Employing a DC Servo Amplifier A dc servo-loop (Figure 36b) can be used to assure a dc output which is <10 mV, without the need for a large compensating resistor when dealing with bias currents as large as 100 nA. For optimal low frequency performance, the time constant of the servo loop (R4C2 = R5C3) should be: Time Constant ≥ 10 R11+ R2 R3 C1 A LOW NOISE HYDROPHONE AMPLIFIER Hydrophones are usually calibrated in the voltage-out mode. The circuits of Figures 37a and 37b can be used to amplify the output of a typical hydrophone. Figure 37a shows a typical dc coupled circuit. The optional resistor and capacitor serve to counteract the dc offset caused by bias currents flowing through resistor R1. Figure 37b, a variation of the original circuit, has a low frequency cutoff determined by an RC time constant equal to: Time Constant = 1 2 π× C C × 100 Ω Figure 37a. A Basic Hydrophone Amplifier |
Nº de peça semelhante - AD743KN |
|
Descrição semelhante - AD743KN |
|
|
Ligação URL |
Privacy Policy |
ALLDATASHEETPT.COM |
ALLDATASHEET é útil para você? [ DONATE ] |
Sobre Alldatasheet | Publicidade | Contato conosco | Privacy Policy | roca de Link | Lista de Fabricantes 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 |