Datasheet LT3062 (Analog Devices) - 10

LT3062 Series
pin FuncTions REF/BYP (Pin 1):
Reference/ Bypass. Connecting a single The LT3062 withstands reverse voltages on the IN pin capacitor from this pin to GND bypasses the LT3062’s with respect to the GND and OUT pins. In a reversed input reference noise and soft-starts the reference. A 10nF by- situation, such as the battery plugged in backwards, the pass capacitor typically reduces output voltage noise to LT3062 behaves as if a large value resistor is in series with 30μVRMS in a 10Hz to 100kHz bandwidth. Soft-start time its input. Limited reverse current flows into the LT3062 is directly proportional to the REF/BYP capacitor value. and no reverse voltage appears at the load. The device If the LT3062 is placed in shutdown, REF/BYP is actively protects itself and the load. pulled low by an internal device to reset soft-start. If low
SHDN (Pin 7):
Shutdown. Pulling the SHDN pin low puts noise or soft-start performance is not required, this pin the LT3062 into a low power state and turns the output must be left floating (unconnected). Do not drive this pin off. Drive the SHDN pin with either logic or an open collec- with any active circuitry. tor/drain with a pull-up resistor. The resistor supplies the
ADJ (Pin 2):
Adjust. This pin is the error amplifier’s invert- pull-up current to the open collector/drain logic, normally ing terminal. Its typical bias current of 15nA flows out of several microamperes, and the SHDN pin current, typi- the pin (see curve of ADJ Pin Bias Current vs Temperature cally less than 3µA. If unused, connect the SHDN pin to in the Typical performance Characteristics section). The VIN. The LT3062 does not function if the SHDN pin is not ADJ pin voltage is 600mV referenced to GND. connected. The SHDN pin cannot be driven below GND
OUT (Pins 3, 4):
Output. These pins supply power to the unless tied to the IN pin. If the SHDN pin is driven below load. A minimum output capacitor of 3.3µF is required GND while IN is powered, the output will turn on. SHDN to prevent oscillations. Large load transient applications pin logic cannot be referenced to a negative rail. require larger output capacitors to limit peak voltage
GND (Pin 8, Exposed Pad Pin 9):
Ground. Connect the transients. See the Applications Information section for bottom of the external resistor divider that sets the output more information on transient response and reverse output voltage directly to GND for optimum regulation. Tie the characteristics. The output voltage range is 600mV to 40V. exposed pad Pin 9 directly to Pin 8 and the PCB ground.
IN (Pins 5, 6):
Input. These pins supply power to the This exposed pad provides enhanced thermal performance device. The LT3062 requires a bypass capacitor at IN if with its connection to the PCB ground. See the Applica- the device is located more than six inches from the main tions Information section for thermal considerations and input filter capacitor. In general, the output impedance of calculating junction temperature. a battery rises with frequency, so it is advisable to include a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1µF to 10µF suffices. See Input Capacitance and Stability in the Application Information section for more information. 3062fa 10 For more information www.linear.com/LT3062