LT3083
9
3083fa
PIN FUNCTIONS
OUT (Pins 1-5,13/Pins 1-6,8,9,16,17/ Pin 3, Tab/Pin 3,
Tab): Output. The exposed pad of the DF package (Pin 13)
and the FE package (Pin 17) and the Tab of the DD-PAK
and TO-220 packages is an electrical connection to OUT.
Connect the exposed pad of the DF and FE packages and
the Tab of the DD-PAK package directly to OUT on the
PCB and the respective OUT pins for each package. There
must be a minimum load current of 1mA or the output
may not regulate.
SET (Pin 6/Pin 7/Pin 2/Pin 2): Set Point. This pin is the
non-inverting input to the error amplifier and the regula-
tion set point. A fixed current of 50μA flows out of this
pin through a single external resistor, which programs
the output voltage of the device. Output voltage range is
zero to the V
IN(MAX)
– V
DROPOUT
. Transient performance
can be improved by adding a small capacitor from the
SET pin to ground.
V
CONTROL
(Pins 7,8/Pins 10,11/Pin 4/Pin 4): Bias Sup-
ply. This is the supply pin for the control circuitry of the
device. Minimum input capacitance is 2.2µF (see Input
Capacitance and Stability in the Applications Information
section). The current flow into this pin is about 1.7% of
the output current. For the device to regulate, this voltage
must be more than 1.2V to 1.4V greater than the output
voltage (see dropout specifications in the Electrical Char-
acteristics section).
IN (Pins 9-12/Pins 12-15/Pin 5/Pin 5): Power Input. This
is the collector to the power device of the LT3083. The
output load current is supplied through this pin. Minimum
IN capacitance is 10µF (see Input Capacitance and Stabil-
ity in Applications Information section). For the device to
regulate, the voltage at this pin must be more than 0.1V
to 0.5V greater than the output voltage (see dropout
specifications in the Electrical Characteristics section).
NC (NA/NA/Pin 1/Pin 1): No Connection. No Connect pins
have no connection to internal circuitry and may be tied
to V
IN
, V
CONTROL
, V
OUT
, GND, or floated.
(DF/FE/Q/T Packages)
BLOCK DIAGRAM
–
+
V
CONTROL
IN
50µA
3083 BD
OUTSET
