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Info about LTC1910 (and how it works with LTC6101)
A generic gate driver accepts low power input and converts it to a higher current gate driving
MOSFET. In our circuit, we are using the gate driver in conjunction with an operational amplifier as
a smart switch that can monitor the current reading. The LT1910 controls the N-channel MOSFET,
SUB85N06-5*, that drives the controlled load, while also maintaining a minimum operating voltage.
The LTC6101 supplies the current output in proportion to the sense resistor which accounts for the
voltage drop. It’s important to note that this sense resistor is also responsible for overload detection
to avoid op amp burn out. The time it remains turned off can be adjusted using an external timer.
Compared to older popular op amps, LTC6100, the LTC6101 can withstand up to 70V and can be
infinitely gain configurable. The LTC1910 also fits these parameters able to withstand up to 60V
with a current of 40mA along most pins. Linear technologies recommend only using these
components on a copper board as to reduce additional resistance caused by solder. Overall the
circuit configuration is responsible for flowing current through certain devices, while the gate driver
uses a sense resistor to control minimum operating voltage.
Additional Details on 1910:
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Capacitor on pin 2 determines the duration of deactivation upon current overload. T. For
example, CT = 0.33µF yields a 50ms restart period but example model recommends 1 uF.
Pin 3 monitors pin 2 and indicates overcurrent conditions and returns LOW. When the
voltage on the pin 2 exceeds 3.3V, pin 3 is turned on again to act as an indicator. This can be
useful in testing or debugging if the operational amplifier is not working.
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Pin 4 used with CMOS logic, and when it is not used, the internal 75kΩ resistor pulls the pin
below 1 V to output a LOW on pin 5. May have to use voltage regulator to maintain above 2
V for functionality.
Pin 5 is the MOSFET gate. It is not LOW when Pin 4 is greater than 2 V, or when pin 2 falls
below 2.9V.
Pin 6 is the sense pin which connects to the input of the supply- referenced comparator with
a 65mV nominal offset. Device outputs LOW when the offset exceeds 65mV. Rs can be at
max 10kΩ, but since we don’t want to burn out the LTC6101, the resistance will be kept
minimal to fit the equation VO=49.9*Rs*IL.
Pin 8 operates both a current provider and a kelvin connection. We are only going to use it
for its current-sense operation.
Recommend talking about a load, as I am unsure what exactly we need, maybe a small valued
resistor below 1Ω for high current (I=V/R), or anything else.
*The SUB85N06-5 is a 60V operating N channel MOSFET