FEATURES
n Current Sense Amplifier
– Fast Step Response: 500ns
– Low Offset Voltage: 125µV Maximum
– Low Gain Error: 0.2% Maximum
n Internal 400mV Precision Reference
n Internal Latching Comparators with Reset
– Fast Response Time: 500ns
– Total Threshold Error: ±1.25% Maximum
– Two Comparator Polarity Options
n Wide Supply Range: 2.7V to 60V
n Supply Current: 550µA
n Low Shutdown Current: 5µA Maximum
n Specified for –40°C to 125°C Temperature Range
n Available in 10-Lead MSOP Package
APPLICATIONS
n Overcurrent, Undercurrent and Fault Detection
n Current Shunt Measurement
n Battery Monitoring
n Motor Control
n Automotive Monitoring and Control
n Remote Sensing
n Industrial Control
LT6109-1/LT6109-2
High Side Current Sense
Amplifier with Reference
and Comparators
DESCRIPTION
The LT®6109 is a complete high side current sense device
that incorporates a precision current sense amplifier, an
integrated voltage reference and two comparators. Two
versions of the LT6109 are available. The LT6109-1 has
the comparators connected in opposing polarity and the
LT6109-2 has the comparators connected in the same polar-
ity. In addition, the current sense amplifier and comparator
inputs and outputs are directly accessible. The amplifier
gain and comparator trip points are configured by external
resistors. The open-drain comparator outputs allows for
easy interface to other system components.
The overall propagation delay of the LT6109 is typically
only 1.4µs, allowing for quick reaction to overcurrent
and undercurrent conditions. The 1MHz bandwidth al-
lows the LT6109 to be used for error detection in critical
applications such as motor control. The high threshold
accuracy of the comparators, combined with the ability to
latch both comparators, ensures the LT6109 can capture
high speed events.
The LT6109 is fully specified for operation from –40°C to
125°C, making it suitable for industrial and automotive ap-
plications. The LT6109 is available in a small 10-lead MSOP.
L, LT, LTC, LTM, TimerBlox, Linear Technology and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
TYPICAL APPLICATION
Circuit Fault Protection with Latching Load Disconnect and Early Warning Indication
12V
6.2V*
1k
10k
1k
2N2700
0.1Ω
3.3V
1.62k 100k
100Ω
SENSEHI SENSELO
V+ OUTA
LT6109-2
RESET EN/RST
100mA WARNING OUTC2
250mA DISCONNECT OUTC1 V–
INC2
INC1
IRF9640
TO LOAD
0.1µF
VOUT
6.04k
2.37k
1.6k
*CMH25234B
610912 TA01a
Response to Overcurrent Event
VLOAD
10V/DIV
0V
ILOAD
200mA/DIV
0mA
VOUTC1
5V/DIV 0V
VOUTC2
5V/DIV 0V
250mA DISCONNECT
100mA WARNING
5µs/DIV
610912 TA01b
610912fa
1
Free Datasheet http://www.Datasheet4U.com
