Electronic Components Datasheet Search |
|
MIC914 Datasheet(PDF) 10 Page - Micrel Semiconductor |
|
MIC914 Datasheet(HTML) 10 Page - Micrel Semiconductor |
10 / 12 page MIC914 Micrel MIC914 10 June 2000 Applications Information The MIC914 is a high-speed, voltage-feedback operational amplifier featuring very low supply current and excellent stability. This device is unity gain stable with R L ≤ 200Ω and capable of driving high capacitance loads. Stability Considerations The MIC914 is unity gain stable and it is capable of driving unlimited capacitance loads, but some design considerations are required to ensure stability. The output needs to be loaded with 200 Ω resistance or less and/or have suffi- cient load capacitance to achieve stability (refer to the “Load Capacitance vs. Phase Margin” graph). For applications requiring a little less speed, Micrel offers the MIC911, a more heavily compensated version of the MIC914 which provides extremely stable operation for all load resis- tance and capacitance. For stability considerations at different supply voltages, please refer to the graph elsewhere in the datasheet entitled "Gain Bandwidth and Phase Margin vs. Supply Voltage". Driving High Capacitance The MIC914 is stable when driving high capacitance (see “Typical Characteristics: Gain Bandwidth and Phase Margin vs. Load Capacitance”) making it ideal for driving long coaxial cables or other high-capacitance loads. Phase margin remains constant as load capacitance is increased. Most high-speed op amps are only able to drive limited capacitance. Note: increasing load capacitance does reduce the speed of the device (see “Typical Characteris- tics: Gain Bandwidth and Phase Margin vs. Load”). In applications where the load capaci- tance reduces the speed of the op amp to an unacceptable level, the effect of the load capaci- tance can be reduced by adding a small resistor (<100 Ω) in series with the output. Feedback Resistor Selection Conventional op amp gain configurations and resistor selec- tion apply, the MIC914 is NOT a current feedback device. Also, for minimum peaking, the feedback resistor should have low parasitic capacitance, usually 470 Ω is ideal. To use the part as a follower, the output should be connected to input via a short wire. Layout Considerations All high speed devices require careful PCB layout. The following guidelines should be observed: Capacitance, par- ticularly on the two inputs pins will degrade performance; avoid large copper traces to the inputs. Keep the output signal away from the inputs and use a ground plane. It is important to ensure adequate supply bypassing capaci- tors are located close to the device. Power Supply Bypassing Regular supply bypassing techniques are recommended. A 10 µF capacitor in parallel with a 0.1µF capacitor on both the positive and negative supplies are ideal. For best perfor- mance all bypassing capacitors should be located as close to the op amp as possible and all capacitors should be low ESL (equivalent series inductance), ESR (equivalent series resis- tance). Surface-mount ceramic capacitors are ideal. Thermal Considerations The SOT-23-5 package, like all small packages, has a high thermal resistance. It is important to ensure the IC does not exceed the maximum operating junction (die) temperature of 85 °C. The part can be operated up to the absolute maximum temperature rating of 125 °C, but between 85°C and 125°C performance will degrade, in particular CMRR will reduce. An MIC914 with no load, dissipates power equal to the quiescent supply current * supply voltage PV V I DV V S (no load) =− () +− When a load is added, the additional power is dissipated in the output stage of the op amp. The power dissipated in the device is a function of supply voltage, output voltage and output current. PV V I DV OUT OUT (output stage) =− () + Total Power Dissipation P P DD t =+ (no load) (outpu stage) Ensure the total power dissipated in the device is no greater than the thermal capacity of the package. The SOT23-5 package has a thermal resistance of 260 °C/W. Max Allowable Power Dissipation TT JA . = − (max) (max) 260W |
Similar Part No. - MIC914 |
|
Similar Description - MIC914 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |