Electronic Components Datasheet Search |
|
LTC6101HVAHMS8 Datasheet(PDF) 9 Page - Linear Technology |
|
LTC6101HVAHMS8 Datasheet(HTML) 9 Page - Linear Technology |
9 / 20 page LTC6101/LTC6101HV 9 6101fa Figure 2. Kelvin Input Connection Preserves Accuracy Despite Large Load Current APPLICATIO S I FOR ATIO LTC6101 ROUT VOUT 6101 F02 3 5 4 2 1 RIN V+ LOAD RSENSE Useful Gain Configurations Gain RIN ROUT VSENSE at VOUT = 5V IOUT at VOUT = 5V 20 499 10k 250mV 500 µA 50 200 10k 100mV 500 µA 100 100 10k 50mV 500 µA Selection of External Current Sense Resistor The external sense resistor, RSENSE, has a significant effect on the function of a current sensing system and must be chosen with care. First, the power dissipation in the resistor should be considered. The system load current will cause both heat and voltage loss in RSENSE. As a result, the sense resistor should be as small as possible while still providing the input dynamic range required by the measurement. Note that input dynamic range is the difference between the maximum input signal and the minimum accurately repro- duced signal, and is limited primarily by input DC offset of the internal amplifier of the LTC6101. In addition, RSENSE must be small enough that VSENSE does not exceed the maximum input voltage specified by the LTC6101, even under peak load conditions. As an example, an application may require that the maximum sense voltage be 100mV. If this application is expected to draw 2A at peak load, RSENSE should be no more than 50mΩ. Once the maximum RSENSE value is determined, the mini- mum sense resistor value will be set by the resolution or dynamic range required. The minimum signal that can be accurately represented by this sense amp is limited by the input offset. As an example, the LTC6101B has a typical input offset of 150 µV. If the minimum current is 20mA, a sense resistor of 7.5m Ω will set VSENSE to 150µV. This is the same value as the input offset. A larger sense resistor will reduce the error due to offset by increasing the sense voltage for a given load current. Choosing a 50m Ω RSENSE will maximize the dynamic range and provide a system that has 100mV across the sense resistor at peak load (2A), while input offset causes an error equivalent to only 3mA of load current. Peak dissipation is 200mW. If a 5m Ω sense resistor is employed, then the effective current error is 30mA, while the peak sense voltage is reduced to 10mV at 2A, dissipat- ing only 20mW. The low offset and corresponding large dynamic range of the LTC6101 make it more flexible than other solutions in this respect. The 150 µV typical offset gives 60dB of dynamic range for a sense voltage that is limited to 150mV max, and over 70dB of dynamic range if the rated input maximum of 500mV is allowed. Sense Resistor Connection Kelvin connection of the IN– and IN+ inputs to the sense resistor should be used in all but the lowest power appli- cations. Solder connections and PC board interconnec- tions that carry high current can cause significant error in measurement due to their relatively large resistances. One 10mm x 10mm square trace of one-ounce copper is approximately 0.5m Ω. A 1mV error can be caused by as little as 2A flowing through this small interconnect. This will cause a 1% error in a 100mV signal. A 10A load current in the same interconnect will cause a 5% error for the same 100mV signal. By isolating the sense traces from the high- current paths, this error can be reduced by orders of magnitude. A sense resistor with integrated Kelvin sense terminals will give the best results. Figure 2 illustrates the recommended method. |
Similar Part No. - LTC6101HVAHMS8 |
|
Similar Description - LTC6101HVAHMS8 |
|
|
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 |