Electronic Components Datasheet Search |
|
EL2003C Datasheet(PDF) 10 Page - Elantec Semiconductor |
|
EL2003C Datasheet(HTML) 10 Page - Elantec Semiconductor |
10 / 17 page 10 EL2003C, EL2033C 100MHz Video Line Driver Driving Cables There are at least three ways to use the EL2003C and EL2033C to drive cables, as shown in the adjacent fig- ure. The most obvious is to directly connect the cable to the output of the buffer. This results in a gain determined by the output resistance of the EL2003C or EL2033C and the characteristic impedance of the cable, assuming it is properly terminated. For RG-58 into 50 Ω the gain is about -1dB, exclusive of cable losses. For optimum response and minimum reflections it is important for the cable to be properly terminated. Double termination of a cable is the cleanest way to drive it since reflections are absorbed on both ends of the cable. The cable source resistor is equal to the character- istic impedance of the cable less the output resistance of the EL2003C and EL2033C. The gain is -6dB exclusive of the cable attenuation. Back matching is the last and most interesting way to drive a cable. The cable source resistor is again the char- acteristic impedance less the output resistance of the EL2003C and EL2033C; the termination resistance is now much greater than the cable impedance. The gain is 0dB and DC levels waste no power. An additional EL2003C or EL2033C make a good receiver at the terminating end. Because an unterminated cable looks like a resonant circuit, the receiving EL2003C or EL2033C should have an isolating resistor in series with its input to prevent oscillations when the cable is not connected to the driver. Of course if the cable is always connected to the back match, no resistor is necessary. WARNING: ONE END OF A CABLE MUST BE PROPERLY TERMINATED. If neither end is termi- nated in the cable characteristic impedance, the cable will have standing waves that appear as resonances in the frequency response. The resonant frequencies are a function of the cable length and even relatively short cables can cause problems at frequencies as low as 1MHz. Longer cables should be terminated on both ends. Op Amp Booster The EL2003C or EL2033C can boost the output drive of almost any monolithic op amp. Because the phase shift in the EL2003C and EL2033C is low at the op amp's unity gain frequency, no additional compensation is required. By following an op amp with an EL2003C or EL2033C, the buffered op amp can drive cables and other low impedance loads directly. Even decompen- sated high speed op amps can take advantage of the EL2003C’s or EL2033C’s 100mA drive. Driving capacitive loads with any closed loop amplifier creates special problems. The open loop output imped- ance works into the load capacitance to generate phase lag which can make the loop unstable. The output Direct Drive Double Matched Back Matched Op Amp Booster |
Similar Part No. - EL2003C |
|
Similar Description - EL2003C |
|
|
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 |