Datasheet LT1994 (Analog Devices) - 18
| Manufacturer | Analog Devices |
| Description | Low Noise, Low Distortion Fully Differential Input/Output Amplifier/Driver |
| Pages / Page | 20 / 18 — TYPICAL APPLICATIONS. A Single-Ended to Differential Voltage Conversion … |
| File Format / Size | PDF / 232 Kb |
| Document Language | English |
TYPICAL APPLICATIONS. A Single-Ended to Differential Voltage Conversion with Source Impedance Matching and Level Shifting
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LT1994
TYPICAL APPLICATIONS
3. Calculate R3, R2 and R1 using the standard 5% C2 Example: The specifi ed –3dB frequency is 1MHz Gain = 1 value, the specifi ed f3dB and the specifi ed passband 1. Using f gain (Gn) 3dB = 1000kHz, C2abs = 400pF 2. Nearest standard 5% value to 400pF is 390pF and C21 MHz 1 f ≤ M 1 Hz and Gain ≤ 8 8 . or Gain = C22 = 390pF and C11 = 3900pF dB 3 ≤ f dB 3 3. Using f3dB = 1000kHz, C2 = 390pF and Gain = 1, R1 = 549Ω, R2 = 549Ω and R3 = 15.4Ω (nearest 1% R1, R2 and R3 equations (C2 in pF and f3dB in kHz) values). R11 = R21 = 549Ω, R21 = R22 = 549Ω and 1.121– 1.131– 0.127 • Gn • 108 ( )) R31 = R32 = 15.4Ω. R3 = No ( te ) 1 Note 1: The equations for R1, R2, R3 are ideal and do Gn ( +1 •C2• f ) 3d dB not account for the fi nite gain bandwidth product (GBW) . 1 266 • 1015 of the LT1994 (70MHz). The maximum gain is set by R2 = R3•C22 • f 2 the C1/C2 ratio (which for convenience is set equal to dB 3 ten). R2 R1= Note 2: The calculated value of a capacitor is chosen Gn to produce input resistors less than 600Ω. If a higher value input resistance is required then multiply all resis- tor values and divide all capacitor values by the same number.
A Single-Ended to Differential Voltage Conversion with Source Impedance Matching and Level Shifting
RS 50Ω 50Ω 374Ω 402Ω V+ VIN 0.1μF V 54.9Ω 3 1 4 – + – V VOUT + 2 VOCM + 0.25V VOUT V LT1994 OCM VOCM 0.1μF 8 – V V V IN + – V + OCM – 0.25V OUT OUT 1 5 6 0 t 0 t 7 402Ω 402Ω 1994 TA05 –1 1994fb 18
TYPICAL APPLICATIONS
3. Calculate R3, R2 and R1 using the standard 5% C2 Example: The specifi ed –3dB frequency is 1MHz Gain = 1 value, the specifi ed f3dB and the specifi ed passband 1. Using f gain (Gn) 3dB = 1000kHz, C2abs = 400pF 2. Nearest standard 5% value to 400pF is 390pF and C21 MHz 1 f ≤ M 1 Hz and Gain ≤ 8 8 . or Gain = C22 = 390pF and C11 = 3900pF dB 3 ≤ f dB 3 3. Using f3dB = 1000kHz, C2 = 390pF and Gain = 1, R1 = 549Ω, R2 = 549Ω and R3 = 15.4Ω (nearest 1% R1, R2 and R3 equations (C2 in pF and f3dB in kHz) values). R11 = R21 = 549Ω, R21 = R22 = 549Ω and 1.121– 1.131– 0.127 • Gn • 108 ( )) R31 = R32 = 15.4Ω. R3 = No ( te ) 1 Note 1: The equations for R1, R2, R3 are ideal and do Gn ( +1 •C2• f ) 3d dB not account for the fi nite gain bandwidth product (GBW) . 1 266 • 1015 of the LT1994 (70MHz). The maximum gain is set by R2 = R3•C22 • f 2 the C1/C2 ratio (which for convenience is set equal to dB 3 ten). R2 R1= Note 2: The calculated value of a capacitor is chosen Gn to produce input resistors less than 600Ω. If a higher value input resistance is required then multiply all resis- tor values and divide all capacitor values by the same number.
A Single-Ended to Differential Voltage Conversion with Source Impedance Matching and Level Shifting
RS 50Ω 50Ω 374Ω 402Ω V+ VIN 0.1μF V 54.9Ω 3 1 4 – + – V VOUT + 2 VOCM + 0.25V VOUT V LT1994 OCM VOCM 0.1μF 8 – V V V IN + – V + OCM – 0.25V OUT OUT 1 5 6 0 t 0 t 7 402Ω 402Ω 1994 TA05 –1 1994fb 18