Operation - Linear Technology DC1699A Demo Manual

DEMO MANUAL DC1699A

OPERATION

Current Sense Gain
The gain of the LT6108 current sense amplifier is set by
the ratio of R and R
OUT
means that the gain is set by the ratio of (R1 + R2 )/R7.
The gain error is primarily controlled by the precision of
the resistors used. The installed resistors are 1% tolerance
which will dominate the gain error. To reduce system gain
error, the resistors can be replaced with 0.1% resistors.
LED Indicator
The LED indicates the state of the comparator output.
When the LED is on, the comparator's output is low. When
the LED is off, the comparators output is high. When the
comparator output is latched low, the LT6108-1 must be
reset to unlatch the comparator output and turn off the LED.
Jumper Summary
Reset (JP1): The Reset jumper has two settings for manual
or auto mode. In manual mode, the user must press the
reset button to trigger the LTC6993 to send the 5μs pulse
that resets the latching comparators. In auto mode, the
LTC6991 will continuously reset the comparators every
10 seconds. The factory default setting is manual mode.
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resistors. In the demo circuit this
IN
Optional Settings
1. For supply voltages below 3.3V, remove R15 and install
R16 (0Ω jumper). When R16 is installed, the supply
voltage must stay between 2.7V to 6V to prevent dam-
aging the TimerBlox ® circuitry that is used to reset the
comparator output.
2. To power the LT6108 from a supply separate from the
load, remove R17 and connect the power supply to V
turret. The input cannot go more than 33V below V
3. There are a number of optional components (not
installed) that allow the DC1699 to be tailored to a
specific application:
To disconnect comparator input C
move R1 and R2 and install R14.
To add filtering to the amplifier output, install C6.
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IN OUT
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