Datasheet LT1567 (Analog Devices) - 9
| Hersteller | Analog Devices |
| Beschreibung | 1.4nV/√Hz 180MHz Filter Building Block |
| Seiten / Seite | 16 / 9 — APPLICATIO S I FOR ATIO. Differential Output Feature. Signal Ground. Gain … |
| Dateiformat / Größe | PDF / 208 Kb |
| Dokumentensprache | Englisch |
APPLICATIO S I FOR ATIO. Differential Output Feature. Signal Ground. Gain vs Frequency
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LT1567
U U W U APPLICATIO S I FOR ATIO
The simple-to-use spreadsheet requires the user to de- input) and they share a single reference node on the chip. fine the desired corner (or center) frequency, the pass- Two pins permit access to this node: DC BIAS and band gain and a capacitor value for a choice of second or BYPASS. For a clean reference over a wide bandwidth, the third order Chebyshev or Butterworth lowpass or second normal procedure is to connect DC BIAS to a DC potential order bandpass filters. or ground and BYPASS to a decoupling capacitor that returns to a ground plane. The spreadsheet outputs the required external standard component values and provides a circuit diagram.
Differential Output Feature Signal Ground
The multiple feedback filter section of Figure 1 inherently includes two outputs of opposite signal polarity: a DC Both operational amplifiers within the LT1567 are de- inverting output from the OA (Pin 1) and a DC noninverting signed for inverting operation (constant common mode V – OUT 1 6 C2 R3 LT1567 600Ω C1 600Ω R1 2 – VIN DESIGN EQUATIONS FOR fCENTER ≤ 1MHz fCENTER IS THE FILTER’S CENTER FREQUENCY R2 – + MAXIMUM fCENTER = 5MHz/GAIN 7 0.1µF V + OUT GN IS GAIN AT fCENTER = R3/R1, R2 = R3, C1 = C2 3 + √GN + 1 fCENTER fCENTER = –3dB BANDWIDTH = 7pF 2 • π • R2 • C1 √GN + 1 5 150Ω √GN + 1 √GN + 1 C1 ≤ R3 = 2500 • f V+ V– C 2π • C1 • fCENTER 8 0.1µF 4 0.1µF V+ V– 1567 F02a
Gain vs Frequency
25 20 15 10 5 GAIN (dB) 0 –5 –10 –15 50k 500k 5M FREQUENCY (Hz) 1567 F02b GAIN IS MEASURED TO EITHER OUTPUT ALONE. IF OUTPUT USED DIFFERENTIALLY, V + – OUT – VOUT = 2× VIN
Figure 2. 2nd Order Bandpass Filter and Gain Response for fC = 500kHz, Gain = 10 (C1 = C2 = 1000pF, R2 = R3 = 1.05k, R1 = 105
Ω
)
1567fa 9
U U W U APPLICATIO S I FOR ATIO
The simple-to-use spreadsheet requires the user to de- input) and they share a single reference node on the chip. fine the desired corner (or center) frequency, the pass- Two pins permit access to this node: DC BIAS and band gain and a capacitor value for a choice of second or BYPASS. For a clean reference over a wide bandwidth, the third order Chebyshev or Butterworth lowpass or second normal procedure is to connect DC BIAS to a DC potential order bandpass filters. or ground and BYPASS to a decoupling capacitor that returns to a ground plane. The spreadsheet outputs the required external standard component values and provides a circuit diagram.
Differential Output Feature Signal Ground
The multiple feedback filter section of Figure 1 inherently includes two outputs of opposite signal polarity: a DC Both operational amplifiers within the LT1567 are de- inverting output from the OA (Pin 1) and a DC noninverting signed for inverting operation (constant common mode V – OUT 1 6 C2 R3 LT1567 600Ω C1 600Ω R1 2 – VIN DESIGN EQUATIONS FOR fCENTER ≤ 1MHz fCENTER IS THE FILTER’S CENTER FREQUENCY R2 – + MAXIMUM fCENTER = 5MHz/GAIN 7 0.1µF V + OUT GN IS GAIN AT fCENTER = R3/R1, R2 = R3, C1 = C2 3 + √GN + 1 fCENTER fCENTER = –3dB BANDWIDTH = 7pF 2 • π • R2 • C1 √GN + 1 5 150Ω √GN + 1 √GN + 1 C1 ≤ R3 = 2500 • f V+ V– C 2π • C1 • fCENTER 8 0.1µF 4 0.1µF V+ V– 1567 F02a
Gain vs Frequency
25 20 15 10 5 GAIN (dB) 0 –5 –10 –15 50k 500k 5M FREQUENCY (Hz) 1567 F02b GAIN IS MEASURED TO EITHER OUTPUT ALONE. IF OUTPUT USED DIFFERENTIALLY, V + – OUT – VOUT = 2× VIN
Figure 2. 2nd Order Bandpass Filter and Gain Response for fC = 500kHz, Gain = 10 (C1 = C2 = 1000pF, R2 = R3 = 1.05k, R1 = 105
Ω
)
1567fa 9