Datasheet LT6118 (Analog Devices) - 9

LT6118
pin FuncTions OUTA (Pin 6):
Current Output of the Sense Amplifier. This
SENSEHI (Pin 8):
Sense Amplifier Input. The internal pin will source a current that is equal to the sense voltage sense amplifier will drive SENSEHI to the same potential divided by the external gain setting resistor, RIN. as SENSELO. A resistor (typically RIN) tied from supply
V+ (Pin 7):
Positive Supply Pin. The V+ pin can be con- to SENSEHI sets the output current, IOUT = VSENSE/RIN, nected directly to either side of the sense resistor, R where VSENSE is the voltage developed across RSENSE. SENSE. When V+ is tied to the load end of the sense resistor, the
Exposed Pad (Pin 9, DCB Package Only):
V–. The exposed SENSEHI pin can go up to 0.2V above V+. Supply current pad may be left open or connected to device V–. Connect- is drawn through this pin. ing the exposed pad to a V– plane will improve thermal management in high voltage applications. The exposed pad should not be used as the primary connection for V–.
block DiagraM
7 V+ 100Ω 3k SENSEHI 34V 8 – 6V SENSELO 3k 1 + OUTA 6 V– V– V+ V– 100nA LE 2 V+ – INC 5 OUTC OVERCURRENT FLAG 3 + 400mV REFERENCE V– V– 4 6118 F01
Figure 1. Block Diagram applicaTions inForMaTion
The LT6118 high side current sense amplifier provides The LT6118 comparator has a threshold set with a built-in accurate monitoring of currents through an external sense 400mV precision reference and has 10mV of hysteresis. resistor. The input sense voltage is level-shifted from the The open-drain output can be easily used to level shift to sensed power supply to a ground referenced output and digital supplies. is amplified by a user-selected gain to the output. The output voltage is directly proportional to the current flow-
Amplifier Theory of Operation
ing through the sense resistor. An internal sense amplifier loop forces SENSEHI to have the same potential as SENSELO as shown in Figure 2. 6118f For more information www.linear.com/LT6118 9 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Typical Application Related Parts