Si8540 High-side DC Current Sensor

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Si8540 Current Sensor Amplifier Block Diagram

The Si8540 is a complete, uni-directional, high voltage high-side current sense amplifier for use in portable PCs, cellular infrastructure equipment, high-end routers, smart battery packs, automotive applications and other power management applications that require current monitoring and current control loops. The Si8540 is designed to be an extremely cost-effective, value-added current sense amplifier that has low power requirements, can sense a wide range of currents with different resistor values and comes in an extremely compact 5-pin SOT-23 or 8-pin SOIC package.

The Si8540 measures the voltage drop across a sense resistor in the high voltage side of a line. Large values of current can be measured by using a small resistor value and keeping the series voltage drop low across the sense resistor. The Si8540 operates from a single supply +5 to +36 V and has a current output that can be converted to a ground referenced voltage with a resistor ROUT. The amplification factor of the current sense can be adjusted with a choice of external resistor ratios.

 

Features

  • +5 to +36 V supply operation
  • 0.2% full scale accuracy
  • 90 μA max supply current
  • 9 μA shutdown current
  • -40 to +85 ºC
 

Applications

  • Battery chargers
  • DC motor control
  • Smart battery packs
  • Backup systems
  • Current control applications
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Data Sheet (1)

Document NameDescriptionVersionLast Updated
Si8540.pdf
Si8540 Data Sheet1.15/18/2010

User Guides (2)

Document NameDescriptionVersionLast Updated
Open-Loop_POL-EVB.pdf
Open-Loop POL-EVB User's Guide0.39/20/2010
Si85xx-TB_UG.pdf
Si85xx Target Board User's Guide0.48/5/2010

Application Notes (2)

Document NameDescriptionVersionLast Updated
AN398.pdf
AN398: Using Si85xx Current Sensors in Switch-Mode Power Supplies0.121/14/2010
AN520.pdf
AN520: CMOS Advanced Galvanic Isolators for Medical Electronics0.16/17/2010

White Papers (2)

Document NameDescriptionVersionLast Updated
Evaluating-AC-Current-Sensor-Options-for-Power-Delivery-Systems.pdf
Evaluating AC Current Sensor Options for Power Delivery Systems
ISOdriver White Paper.pdf
ISOdriver White Paper4/19/2010

PCN (2)

Document NameDescriptionVersionLast Updated
1102181.pdf
Si8540 Assembly Supplier Change IDS to UNISEMM Std
1005251.pdf
Si8540 MSL2A Improvement and Datasheet rev1.1 Std
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Product Matrix


Part Number Available DocumentsPin 7 FunctionPackageFull Scale CurrentDev KitTemperature RangeInitial AccuracyOutput ModeIsolation Rating
Si8540Data Sheet
-5-pin SOT or 8-pin SOIC0.1 to 10 A-40 to 85 °C0.2%Current-
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