Electronic Components Datasheet Search
 ALLDATASHEET.COM Part #DescriptionMarking X

## INA138 Datasheet(PDF) 5 Page - Burr-Brown (TI)

 [Old version datasheet] Texas Instruments acquired Burr-Brown Corporation.
 Part # INA138 Description High-Side Measurement CURRENT SHUNT MONITOR Download 15 Pages Scroll/Zoom 100% Manufacturer BURR-BROWN [Burr-Brown (TI)] Direct Link http://www.burr-brown.com Logo

## INA138 Datasheet(HTML) 5 Page - Burr-Brown (TI)

 5 / 15 pageINA138, INA1685SBOS122Cwww.ti.comTYPICAL CHARACTERISTICS (Cont.)At TA = +25°C, V+ = 5V, VIN+ = 12V, and RL = 125kΩ, unless otherwise noted.STEP RESPONSE10µs/div200mVG = 1100mV100mVG = 10mV50mV/divSTEP RESPONSE10µs/divG = 250VG = 100V1V/div500mV/divOPERATIONFigure 1 illustrates the basic circuit diagram for both theINA138 and INA168. Load current IS is drawn from supply VSthrough shunt resistor RS. The voltage drop in shunt resistorVS is forced across RG1 by the internal op amp, causingcurrent to flow into the collector of Q1. External resistor RLconverts the output current to a voltage, VOUT, at the OUT pin.The transfer function for the INA138 is:IO = gm (VIN+ – VIN– )(1)where gm = 200µA/V.In the circuit of Figure 1, the input voltage, (VIN+ – VIN– ), isequal to IS • RS and the output voltage, VOUT, is equal toIO • RL. The transconductance, gm, of the INA138 is200µA/V. The complete transfer function for the currentmeasurement amplifier in this application is:VOUT = (IS) (RS) (200µA/V) (RL)(2)The maximum differential input voltage for accurate mea-surements is 0.5V, which produces a 100µA output current.A differential input voltage of up to 2V will not cause damage.Differential measurements (pins 3 and 4) must be unipolarwith a more-positive voltage applied to pin 3. If a more-negative voltage is applied to pin 3, the output current, IO, willbe zero, but it will not cause damage.BASIC CONNECTIONFigure 1 shows the basic connection of the INA138. Theinput pins, VIN+ and VIN– , should be connected as closely aspossible to the shunt resistor to minimize any resistance inseries with the shunt resistance. The output resistor, RL, isshown connected between pin 1 and ground. Best accuracyis achieved with the output voltage measured directly acrossRL. This is especially important in high-current systemswhere load current could flow in the ground connections,affecting the measurement accuracy.No power-supply bypass capacitors are required for stabilityof the INA138. However, applications with noisy or high-impedance power supplies may require decoupling capaci-tors to reject power-supply noise. Connect bypass capacitorsclose to the device pins.POWER SUPPLIESThe input circuitry of the INA138 can accurately measurebeyond its power-supply voltage, V+. For example, the V+power supply can be 5V, whereas the load power supplyvoltage is up to +36V (or +60V with the INA168). The outputvoltage range of the OUT terminal, however, is limited by thelesser of the two voltages (see “Output Voltage Range” section).SELECTING RS AND RLThe value chosen for the shunt resistor, RS, depends on theapplication and is a compromise between small-signal accu-racy and maximum permissible voltage loss in the measure-ment line. High values of RS provide better accuracy at lowercurrents by minimizing the effects of offset, while low values ofRS minimize voltage loss in the supply line. For most applica-tions, best performance is attained with an RS value thatprovides a full-scale shunt voltage range of 50mV to 100mV.Maximum input voltage for accurate measurements is 500mV.RL is chosen to provide the desired full-scale output voltage.The output impedance of the INA138 OUT terminal is veryhigh which permits using values of RL up to 500kΩ withexcellent accuracy. The input impedance of any additionalcircuitry at the output should be much higher than the valueof RL to avoid degrading accuracy.

## Similar Part No. - INA138_11

 Manufacturer Part # Datasheet Description Texas Instruments INA138 1Mb / 27P [Old version datasheet]   High-Side Measurement Current Shunt Monitor INA138 1Mb / 27P [Old version datasheet]   INA1x8 High-Side Measurement Current Shunt Monitor
More results

## Similar Description - INA138_11

 Manufacturer Part # Datasheet Description Texas Instruments INA139 200Kb / 11P [Old version datasheet]   High-Side Measurement CURRENT SHUNT MONITOR INA139-Q1 1Mb / 16P [Old version datasheet]   HIGH-SIDE MEASUREMENT CURRENT SHUNT MONITOR INA139NA 408Kb / 15P [Old version datasheet]   High-Side Measurement CURRENT SHUNT MONITOR INA138NA250G4 422Kb / 15P [Old version datasheet]   High-Side Measurement CURRENT SHUNT MONITOR INA138-Q1 1Mb / 19P [Old version datasheet]   HIGH-SIDE MEASUREMENT CURRENT SHUNT MONITOR INA139 950Kb / 25P [Old version datasheet]   High-Side Measurement Current Shunt Monitor Burr-Brown (TI) INA138 69Kb / 7P High-Side Measurement CURRENT SHUNT MONITOR Texas Instruments INA138 1Mb / 27P [Old version datasheet]   High-Side Measurement Current Shunt Monitor INA169-Q1 157Kb / 12P [Old version datasheet]   HIGH SIDE MEASUREMENT CURRENT SHUNT MONITOR INA138-Q1 1Mb / 22P [Old version datasheet]   HIGH-SIDE MEASUREMENT CURRENT SHUNT MONITOR
More results