8

LT3020/LT3020-1.2/

LT3020-1.5/LT3020-1.8

3020fc

PI FU CTIO S

OUT (Pins 1, 2): These pins supply power to the load. Use

a minimum output capacitor of 2.2

µFtopreventoscillations.

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 2.3

µA. If unused, connect the SHDN pin

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 2.2

µFto10µFsuffices.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)

300

250

200

150

100

50

0

0.01

1

10

100

3020 G19

0.1

No-Load Recovery Threshold

OUTPUT OVERSHOOT (%)

0

18

16

12

14

10

8

6

4

2

0

3020 G20

15

10

5

20

TYPICAL PERFOR A CE CHARACTERISTICS