LT8300
pin FuncTions
EN/UVLO (Pin 1): Enable/Undervoltage Lockout. The
EN/UVLO pin is used to enable the LT8300. Pull the pin
below 0.3V to shut down the LT8300. This pin has an ac-
mary SW pin. The ratio of the R resistor to the internal
FB
trimmed 12.23k resistor, times the internal bandgap
reference, determines the output voltage (plus the effect
of any non-unity transformer turns ratio). Minimize trace
area at this pin.
curate 1.223V threshold and can be used to program a V
IN
undervoltage lockout (UVLO) threshold using a resistor
divider from V to ground. A 2.5µA current hysteresis
IN
SW (Pin 4): Drain of the 150V Internal DMOS Power
Switch. Minimize trace area at this pin to reduce EMI and
voltage spikes.
allowstheprogrammingofV UVLOhysteresis. Ifneither
IN
function is used, tie this pin directly to V .
IN
GND (Pin 2): Ground. Tie this pin directly to local ground
plane.
V
(Pin 5): Input Supply. The V pin supplies current
IN
IN
to internal circuitry and serves as a reference voltage for
R
(Pin 3): Input Pin for External Feedback Resistor.
the feedback circuitry connected to the R pin. Locally
FB
FB
Connect a resistor from this pin to the transformer pri-
bypass this pin to ground with a capacitor.
8300f
6