8
LT3020/LT3020-1.2/
LT3020-1.5/LT3020-1.8
3020fc
UU
U
PI FU CTIO S
OUT (Pins 1, 2): These pins supply power to the load. Use
a minimum output capacitor of 2.2µF to prevent oscillations.
Applications with large load transients require larger out-
put capacitors to limit peak voltage transients. See the
Applications Information section for more information on
output capacitance and reverse output characteristics.
OUT (Pin 3, Fixed Voltage Device Only): This pin is the
sense point for the internal resistor divider. It should be
tied directly to the other OUT pins (1, 2) for best results.
ADJ (Pin 3, Adjustable Device Only): This pin is the
inverting terminal to the error amplifier. Its typical input
bias current of 20nA flows out of the pin (see curve of ADJ
Pin Bias Current vs Temperature in the Typical Perfor-
mance Characteristics). The ADJ pin reference voltage is
200mV (referred to GND).
GND (Pin 4): Ground.
SHDN (Pin 5): The SHDN pin puts the LT3020 into a low
power state. Pulling the SHDN pin low turns the output off.
Drive the SHDN pin with either logic or an open collector/
drain device with a pull-up resistor. The pull-up resistor
supplies the pull-up current to the open collector/drain
logic, normally several microamperes, and the SHDN pin
current, typically 2.3µA. If unused, connect the SHDN pin
to V
IN
. The LT3020 does not function if the SHDN pin is not
connected.
IN (Pins 7, 8): These pins supply power to the device. The
LT3020 requires a bypass capacitor at IN if it is more than
six inches away from the main input filter capacitor. The
output impedance of a battery rises with frequency, so
include a bypass capacitor in battery-powered circuits. A
bypass capacitor in the range of 2.2µF to 10µF suffices. The
LT3020 withstands reverse voltages on the IN pin with
respect to ground and the OUT pin. In the case of a reversed
input, which occurs if a battery is plugged in backwards,
the LT3020 acts as if a diode is in series with its input. No
reverse current flows into the LT3020 and no reverse volt-
age appears at the load. The device protects itself and the
load.
GND (Pin 9, DD8 Package Only): Ground. Solder Pin 9
(the exposed pad) to the PCB. Connect directly to Pin 4 for
best performance.
RMS Output Noise vs Load
Current (10Hz to 100kHz)
LOAD CURRENT (mA)
OUTPUT NOISE (µV
RMS
)
300
250
200
150
100
50
0
0.01 1 10 100
3020 G19
0.1
V
OUT
= 1.2V
C
OUT
= 2.2µF
No-Load Recovery Threshold
OUTPUT OVERSHOOT (%)
0
OUTPUT CURRENT SINK (mA)
18
16
12
14
10
8
6
4
2
0
3020 G20
15105
20
TYPICAL PERFOR A CE CHARACTERISTICS
UW
