Ultra Precision Zero Drift Current Sensor – Range Up To 12A
This LTC6102-based Ultra Precision Zero Drift High-Side Current-Sense Amplifier measures load current by amplifying the voltage drop across an on-board resistor. It offers precise, proportional unipolar output (200mV/A nominal), operates on 4V to 60V supplies, and eliminates ground-loop errors.
This is an Ultra Precision Zero Drift High-Side Current-Sense Amplifier module, featuring the LTC6102 chip and it is designed to amplify the voltage drop across an on-board current-sense resistor, providing a precise unipolar output voltage proportional to the load current. The circuit incorporates a scaling resistor, R4, which programs the gain of the circuit to 33.3V/V. Notably, the LTC6102 enables current measurements on supplies ranging from 4V to 60V.
A key advantage of this design is its ability to eliminate ground-loop errors. Since the output voltage is developed as a controlled current through a load resistance, ground-loop errors can be effectively eliminated by simply locating the load resistors at the destination point, such as subsequent signal processing stages (e.g., A/D conversion). This feature ensures accurate and reliable current measurements, making the module suitable for a wide range of applications.
The LTC6102 operates by amplifying the voltage drop on a sense resistor R1 placed in series with the power source of a load to be monitored. The sense inputs of the amplifier differentially measure the sense-resistor drop to control an internal variable current source that allows translation of the input information to a level referenced to V– (ground in this circuit). The circuit gain is established by the ratio of the output resistor R4 to the input resistor and is essentially as accurate as the resistors used. The sense resistor installed is 6mΩ and the resistor ratio sets the gain to 33.3V/V, so the nominal output scaling is 200mV per Ampere of load current. Other scaling can be produced by resistor R4 replacement.
Features
- Power Input 4V to 60V DC
- Load Current 12A Maximum
- Output 0.2V/A (2.4V, when Load 12A)
- Output Voltage that Corresponds to the Load Current-Out = 0.2×IOUT
- High Current Screw Terminals for Supply Input and Output
- Header Connector for Output (Voltage Monitor)
- PCB Dimensions 40.01 x 16.83 mm
Connections
- CN1 Power Input: Pin 1 = 4V To 60V Input 0 To 12A, Pin 2 = GND
- CN2 Output (Load): Pin 1 = 4V To 60V, 0 To 12A
- CN3 Voltage Monitor: Pin 1 Current Sense Feedback Output 0.2V/1A, Pin 2 = GND
Schematic
Parts List
| NO. | QNTY. | REF. | DESC. | MANUFACTURER | SUPPLIER | SUPPLIER PART NO |
|---|---|---|---|---|---|---|
| 1 | 2 | CN1,CN2 | 2 PIN SCREW TERMINAL PITCH 7.62MM | AMPHENOL | DIGIKEY | 609-3954-ND |
| 2 | 1 | CN3 | 2 PIN MALE HEADER PITCH 2.54MM | WURTH | DIGIKEY | 732-5315-ND |
| 3 | 1 | C1 | 100nF/25V CERAMIC SMD SIZE 0603 | YAGEO/MURATA | DIGIKEY | |
| 4 | 1 | R1 | 0.006E/3W 1% SMD SIZE 2512 OR 4527 | BOURNS INC | DIGIKEY | 118-CRE2512-FZ-R006E-3CT-ND |
| 5 | 1 | R2 | 150E 5% SMD SIZE 0805 | YAGEO/MURATA | DIGIKEY | |
| 6 | 1 | R3 | 0E SMD SIZE 0805 | YAGEO/MURATA | DIGIKEY | |
| 7 | 1 | R4 | 4.99K 1% SMD SIZE 0805 | YAGEO/MURATA | DIGIKEY | |
| 8 | 1 | U1 | LTC6102 | ANALOG DEVICE | DIGIKEY | LTC6102IMS8#TRPBFCT-ND |
Connections
