Electronic Components Datasheet Search |
|
EL2386C Datasheet(PDF) 10 Page - Elantec Semiconductor |
|
EL2386C Datasheet(HTML) 10 Page - Elantec Semiconductor |
10 / 16 page EL2386C 250 MHz Triple Current Feedback Amp wDisable Applications Information Contd Capacitance at the Inverting Input Any manufacturer’s high-speed voltage- or cur- rent-feedback amplifier can be affected by stray capacitance at the inverting input For inverting gains this parasitic capacitance has little effect because the inverting input is a virtual ground but for non-inverting gains this capacitance (in conjunction with the feedback and gain resistors) creates a pole in the feedback path of the amplifi- er This pole if low enough in frequency has the same destabilizing effect as a zero in the forward open-loop response The use of large value feed- back and gain resistors further exacerbates the problem by further lowering the pole frequency The experienced user with a large amount of PC board layout experience may find in rare cases that the EL2386C has less bandwidth than ex- pected In this case the inverting input may have less parasitic capacitance than expected The re- duction of feedback resistor values (or the addi- tion of a very small amount of external capaci- tance at the inverting input e g 05 pF) will increase bandwidth as desired Please see the curves for Frequency Response for Various RF and RG and Frequency Response for Various CIN- Feedback Resistor Values The EL2386C has been designed and specified at gains of a1 and a2 with RF e 750X This value of feedback resistor gives 250 MHz of b3dB bandwidth at AV ea1 with about 25 dB of peaking and 180 MHz of b3 dB bandwidth at AV ea2 with about 01 dB of peaking Since the EL2386C is a current-feedback amplifier it is also possible to change the value of RF to get more bandwidth As seen in the curve of Fre- quency Response For Various RF and RG band- width and peaking can be easily modified by varying the value of the feedback resistor Because the EL2386C is a current-feedback am- plifier its gain-bandwidth product is not a con- stant for different closed-loop gains This feature actually allows the EL2386C to maintain about the same b3 dB bandwidth regardless of closed- loop gain However as closed-loop gain is in- creased bandwidth decreases slightly while sta- bility increases Since the loop stability is im- proving with higher closed-loop gains it becomes possible to reduce the value of RF below the spec- ified 750 X and still retain stability resulting in only a slight loss of bandwidth with increased closed-loop gain Supply Voltage Range and Single- Supply Operation The EL2386C has been designed to operate with supply voltages having a span of greater than 3V and less than 12V In practical terms this means that the EL2386C will operate on dual supplies ranging from g15V to g6V With a single-sup- ply the EL2386C will operate from a3V to a 12V As supply voltages continue to decrease it be- comes necessary to provide input and output voltage ranges that can get as close as possible to the supply voltages The EL2386C has an input voltage range that extends to within 1V of either supply So for example on a single a5V supply the EL2386C has an input range which spans from 1V to 4V The output range of the EL2386C is also quite large extending to within 1V of the supply rail On a g5V supply the output is therefore capable of swinging from b4V to a4V Single-supply output range is even larger because of the increased negative swing due to the exter- nal pull-down resistor to ground On a single a 5V supply output voltage range is about 03V to 4V Video Performance For good video performance an amplifier is re- quired to maintain the same output impedance and the same frequency response as DC levels are changed at the output This is especially difficult when driving a standard video load of 150 X be- cause of the change in output current with DC level Until the EL2386C good Differential Gain could only be achieved by running high idle cur- rents through the output transistors (to reduce variations in output impedance) These currents were typically comparable to the entire 3 mA supply current of each EL2386C amplifier Spe- 10 |
Similar Part No. - EL2386C |
|
Similar Description - EL2386C |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |