Datasheet LT1229, LT1230 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | Dual and Quad 100MHz Current Feedback Amplifiers |
| Pages / Page | 16 / 10 — APPLICATI. S I FOR ATIO. Large-Signal Response, AV = 2, RF = RG = 750. … |
| File Format / Size | PDF / 247 Kb |
| Document Language | English |
APPLICATI. S I FOR ATIO. Large-Signal Response, AV = 2, RF = RG = 750. Maximum Supply Voltage for 75
Model Line for this Datasheet
Text Version of Document
LT1229/LT1230
O U U W U APPLICATI S I FOR ATIO
Assumptions:
Large-Signal Response, AV = 2, RF = RG = 750
Ω 1. The maximum ambient is 70°C for the commercial parts (C suffix) and 125°C for the full temperature parts (M suffix). 2. The load is a double-terminated video cable, 150Ω. 3. The maximum output voltage is 2V (peak or DC). 4. The thermal resistance of each package: J8 is 100°C/W J is 80°/W N8 is 100°C/W N is 70°/W LT1229 • TA07 S8 is 150°C/W S is 110°/W Larger feedback resistors will reduce the slew rate as will
Maximum Supply Voltage for 75
Ω
Cable Driving Applications at
lower supply voltages, similar to the way the bandwidth is
Maximum Ambient Temperature
reduced.
PART PACKAGE MAX POWER AT TA MAX SUPPLY Large-Signal Response, A
LT1229MJ8 Ceramic DIP 0.500W at 125°C V
V = 10, RF = 1k, RG = 110
Ω S < ±10.1 LT1229CJ8 Ceramic DIP 1.050W at 70°C VS < ±18.0 LT1229CN8 Plastic DIP 0.800W at 70°C VS < ±15.6 LT1229CS8 Plastic SO8 0.533W at 70°C VS < ±10.6 LT1230MJ Ceramic DIP 0.625W at 125°C VS < ±6.6 LT1230CJ Ceramic DIP 1.313W at 70°C VS < ±13.0 LT1230CN Plastic DIP 1.143W at 70°C VS < ±11.4 LT1230CS Plastic SO14 0.727W at 70°C VS < ±7.6
Slew Rate
The slew rate of a current feedback amplifier is not independent of the amplifier gain the way it is in a tradi- tional op amp. This is because the input stage and the LT1229 • TA08 output stage both have slew rate limitations. The input
Settling Time
stage of the LT1229/LT1230 amplifiers slew at about The characteristic curves show that the LT1229/LT1230 100V/µs before they become nonlinear. Faster input sig- amplifiers settle to within 10mV of final value in 40ns to nals will turn on the normally reverse-biased emitters on 55ns for any output step up to 10V. The curve of settling the input transistors and enhance the slew rate signifi- to 1mV of final value shows that there is a slower thermal cantly. This enhanced slew rate can be as much as contribution up to 20µs. The thermal settling component 2500V/µs. comes from the output and the input stage. The output The output slew rate is set by the value of the feedback contributes just under 1mV per volt of output change and resistors and the internal capacitance. At a gain of ten with the input contributes 300µV per volt of input change. a 1k feedback resistor and ±15V supplies, the output slew Fortunately, the input thermal tends to cancel the output rate is typically 700V/µs and – 1000V/µs. There thermal. For this reason the noninverting gain of two is no input stage enhancement because of the high gain. configurations settles faster than the inverting gain of one. 10
O U U W U APPLICATI S I FOR ATIO
Assumptions:
Large-Signal Response, AV = 2, RF = RG = 750
Ω 1. The maximum ambient is 70°C for the commercial parts (C suffix) and 125°C for the full temperature parts (M suffix). 2. The load is a double-terminated video cable, 150Ω. 3. The maximum output voltage is 2V (peak or DC). 4. The thermal resistance of each package: J8 is 100°C/W J is 80°/W N8 is 100°C/W N is 70°/W LT1229 • TA07 S8 is 150°C/W S is 110°/W Larger feedback resistors will reduce the slew rate as will
Maximum Supply Voltage for 75
Ω
Cable Driving Applications at
lower supply voltages, similar to the way the bandwidth is
Maximum Ambient Temperature
reduced.
PART PACKAGE MAX POWER AT TA MAX SUPPLY Large-Signal Response, A
LT1229MJ8 Ceramic DIP 0.500W at 125°C V
V = 10, RF = 1k, RG = 110
Ω S < ±10.1 LT1229CJ8 Ceramic DIP 1.050W at 70°C VS < ±18.0 LT1229CN8 Plastic DIP 0.800W at 70°C VS < ±15.6 LT1229CS8 Plastic SO8 0.533W at 70°C VS < ±10.6 LT1230MJ Ceramic DIP 0.625W at 125°C VS < ±6.6 LT1230CJ Ceramic DIP 1.313W at 70°C VS < ±13.0 LT1230CN Plastic DIP 1.143W at 70°C VS < ±11.4 LT1230CS Plastic SO14 0.727W at 70°C VS < ±7.6
Slew Rate
The slew rate of a current feedback amplifier is not independent of the amplifier gain the way it is in a tradi- tional op amp. This is because the input stage and the LT1229 • TA08 output stage both have slew rate limitations. The input
Settling Time
stage of the LT1229/LT1230 amplifiers slew at about The characteristic curves show that the LT1229/LT1230 100V/µs before they become nonlinear. Faster input sig- amplifiers settle to within 10mV of final value in 40ns to nals will turn on the normally reverse-biased emitters on 55ns for any output step up to 10V. The curve of settling the input transistors and enhance the slew rate signifi- to 1mV of final value shows that there is a slower thermal cantly. This enhanced slew rate can be as much as contribution up to 20µs. The thermal settling component 2500V/µs. comes from the output and the input stage. The output The output slew rate is set by the value of the feedback contributes just under 1mV per volt of output change and resistors and the internal capacitance. At a gain of ten with the input contributes 300µV per volt of input change. a 1k feedback resistor and ±15V supplies, the output slew Fortunately, the input thermal tends to cancel the output rate is typically 700V/µs and – 1000V/µs. There thermal. For this reason the noninverting gain of two is no input stage enhancement because of the high gain. configurations settles faster than the inverting gain of one. 10
