Datasheet LT1225 (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | Very High Speed Operational Amplifier |
| Pages / Page | 8 / 7 — APPLICATI. S I FOR ATIO. Compensation. AV = –5, CL = 1000pF. AV = 5, CL = … |
| File Format / Size | PDF / 231 Kb |
| Document Language | English |
APPLICATI. S I FOR ATIO. Compensation. AV = –5, CL = 1000pF. AV = 5, CL = 10,000pF. TYPICAL APPLICATI. Cable Driving
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Text Version of Document
LT1225
O U U W U APPLICATI S I FOR ATIO
domain and in the transient response. The photo of the
Compensation
small-signal response with 1000pF load shows 50% peak- The LT1225 has a typical gain-bandwidth product of ing. The large-signal response with a 10,000pF load shows 150MHz which allows it to have wide bandwidth in high the output slew rate being limited by the short-circuit gain configurations (i.e., in a gain of 10 it will have a current. bandwidth of about 15MHz). The amplifier is stable in a
AV = –5, CL = 1000pF AV = 5, CL = 10,000pF
noise gain of 5 so the ratio of the output signal to the inverting input must be 1/5 or less. Straightforward gain configurations of 5 or –4 are stable, but there are a few configurations that allow the amplifier to be stable for lower signal gains (the noise gain, however, remains 5 or more). One example is the summing amplifier shown in the typical applications section below. Each input signal has a gain of –RF/RIN to the output, but it is easily seen that LT1225 AI04 this configuration is equivalent to a gain of –4 as far as the The LT1225 can drive coaxial cable directly, but for best amplifier is concerned. Lag compensation can also be pulse fidelity the cable should be doubly terminated with used to give a low frequency gain less than 5 with a high a resistor in series with the output. frequency gain of 5 or greater. The example below has a DC gain of one, but an AC gain of 5. The break frequency of the RC combination across the amplifier inputs should be approximately a factor of 10 less than the gain band- width of the amplifier divided by the high frequency gain (in this case 1/10 of 150MHz/5 or 3MHz).
O U TYPICAL APPLICATI S Cable Driving Lag Compensation
R3 + IN V 75 CABLE Ω 75 Ω LT1225 VIN + OUT V – LT1225 V R4 OUT 500Ω R1 75Ω – 1k 100pF 2k R2 250Ω LT1225 TA03 AV = 1, f < 3MHz LT1225 TA04
Wein Bridge Oscillator Summing Amplifier
#327 430Ω LAMP RF – RIN VIN1 – LT1225 VOUT 1.5k RIN + >10VP-P LT1225 VOUT V 1MHz IN2 + 100pF 100pF RIN 1.5k VINn nR R F LT1225 TA05 IN = LT1225 TA06 4 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of circuits as described herein will not infringe on existing patent rights. 7
O U U W U APPLICATI S I FOR ATIO
domain and in the transient response. The photo of the
Compensation
small-signal response with 1000pF load shows 50% peak- The LT1225 has a typical gain-bandwidth product of ing. The large-signal response with a 10,000pF load shows 150MHz which allows it to have wide bandwidth in high the output slew rate being limited by the short-circuit gain configurations (i.e., in a gain of 10 it will have a current. bandwidth of about 15MHz). The amplifier is stable in a
AV = –5, CL = 1000pF AV = 5, CL = 10,000pF
noise gain of 5 so the ratio of the output signal to the inverting input must be 1/5 or less. Straightforward gain configurations of 5 or –4 are stable, but there are a few configurations that allow the amplifier to be stable for lower signal gains (the noise gain, however, remains 5 or more). One example is the summing amplifier shown in the typical applications section below. Each input signal has a gain of –RF/RIN to the output, but it is easily seen that LT1225 AI04 this configuration is equivalent to a gain of –4 as far as the The LT1225 can drive coaxial cable directly, but for best amplifier is concerned. Lag compensation can also be pulse fidelity the cable should be doubly terminated with used to give a low frequency gain less than 5 with a high a resistor in series with the output. frequency gain of 5 or greater. The example below has a DC gain of one, but an AC gain of 5. The break frequency of the RC combination across the amplifier inputs should be approximately a factor of 10 less than the gain band- width of the amplifier divided by the high frequency gain (in this case 1/10 of 150MHz/5 or 3MHz).
O U TYPICAL APPLICATI S Cable Driving Lag Compensation
R3 + IN V 75 CABLE Ω 75 Ω LT1225 VIN + OUT V – LT1225 V R4 OUT 500Ω R1 75Ω – 1k 100pF 2k R2 250Ω LT1225 TA03 AV = 1, f < 3MHz LT1225 TA04
Wein Bridge Oscillator Summing Amplifier
#327 430Ω LAMP RF – RIN VIN1 – LT1225 VOUT 1.5k RIN + >10VP-P LT1225 VOUT V 1MHz IN2 + 100pF 100pF RIN 1.5k VINn nR R F LT1225 TA05 IN = LT1225 TA06 4 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of circuits as described herein will not infringe on existing patent rights. 7
