Datasheet LT3027 (Analog Devices) - 8
| Fabricante | Analog Devices |
| Descripción | Dual 100mA, Low Dropout, Low Noise, Micropower Regulator with Independent Inputs |
| Páginas / Página | 16 / 8 — PI FU CTIO S. ADJ1/ADJ2 (Pins 4/2):. SHDN1/SHDN2 (Pins 7/3):. BYP1/BYP2 … |
| Formato / tamaño de archivo | PDF / 341 Kb |
| Idioma del documento | Inglés |
PI FU CTIO S. ADJ1/ADJ2 (Pins 4/2):. SHDN1/SHDN2 (Pins 7/3):. BYP1/BYP2 (Pins 5/1):. IN1/IN2 (Pins 8/9):. OUT1/OUT2 (Pins 6/10):
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LT3027
U U U PI FU CTIO S ADJ1/ADJ2 (Pins 4/2):
Adjust Pin. These are the inputs to
SHDN1/SHDN2 (Pins 7/3):
Shutdown. The SHDN1/SHDN2 the error amplifiers. These pins are internally clamped to pins are used to put the corresponding channel of the ±7V. They have a bias current of 30nA which flows into the LT3027 regulator into a low power shutdown state. The pin (see curve of ADJ1/ADJ2 Pin Bias Current vs Tempera- output will be off when the pin is pulled low. The ture in the Typical Performance Characteristics section). SHDN1/SHDN2 pins can be driven either by 5V logic or The ADJ1 and ADJ2 pin voltage is 1.22V referenced to open-collector logic with pull-up resistors. The pull-up ground and the output voltage range is 1.22V to 20V. resistors are required to supply the pull-up current of the open-collector gates, normally several microamperes,
BYP1/BYP2 (Pins 5/1):
Bypass. The BYP1/BYP2 pins are and the SHDN1/SHDN2 pin current, typically 1µA. If used to bypass the reference of the LT3027 regulator to unused, the pin must be connected to VIN. The device will achieve low noise performance from the regulator. The not function if the SHDN1/SHDN2 pins are not connected. BYP1/BYP2 pins are clamped internally to ±0.6V (one VBE) from ground. A small capacitor from the correspond-
IN1/IN2 (Pins 8/9):
Inputs. Power is supplied to the device ing output to this pin will bypass the reference to lower the through the IN pins. A bypass capacitor is required on this output voltage noise. A maximum value of 0.01µF can be pin if the device is more than six inches away from the main used for reducing output voltage noise to a typical 20µVRMS input filter capacitor. In general, the output impedance of over a 10Hz to 100kHz bandwidth. If not used, this pin a battery rises with frequency, so it is advisable to include must be left unconnected. a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1µF to 10µF is sufficient. The
OUT1/OUT2 (Pins 6/10):
Output. The outputs supply LT3027 regulator is designed to withstand reverse volt- power to the loads. A minimum output capacitor of 1µF is ages on the IN pin with respect to ground and the OUT pin. required to prevent oscillations. Larger output capacitors In the case of a reverse input, which can happen if a battery will be required for applications with large transient loads is plugged in backwards, the device will act as if there is a to limit peak voltage transients. See the Applications diode in series with its input. There will be no reverse Information section for more information on output ca- current flow into the regulator and no reverse voltage will pacitance and reverse output characteristics. appear at the load. The device will protect both itself and the load.
Exposed Pad (Pin 11):
Ground. This pin must be soldered to the PCB and electrically connected to ground. 3027fa 8
U U U PI FU CTIO S ADJ1/ADJ2 (Pins 4/2):
Adjust Pin. These are the inputs to
SHDN1/SHDN2 (Pins 7/3):
Shutdown. The SHDN1/SHDN2 the error amplifiers. These pins are internally clamped to pins are used to put the corresponding channel of the ±7V. They have a bias current of 30nA which flows into the LT3027 regulator into a low power shutdown state. The pin (see curve of ADJ1/ADJ2 Pin Bias Current vs Tempera- output will be off when the pin is pulled low. The ture in the Typical Performance Characteristics section). SHDN1/SHDN2 pins can be driven either by 5V logic or The ADJ1 and ADJ2 pin voltage is 1.22V referenced to open-collector logic with pull-up resistors. The pull-up ground and the output voltage range is 1.22V to 20V. resistors are required to supply the pull-up current of the open-collector gates, normally several microamperes,
BYP1/BYP2 (Pins 5/1):
Bypass. The BYP1/BYP2 pins are and the SHDN1/SHDN2 pin current, typically 1µA. If used to bypass the reference of the LT3027 regulator to unused, the pin must be connected to VIN. The device will achieve low noise performance from the regulator. The not function if the SHDN1/SHDN2 pins are not connected. BYP1/BYP2 pins are clamped internally to ±0.6V (one VBE) from ground. A small capacitor from the correspond-
IN1/IN2 (Pins 8/9):
Inputs. Power is supplied to the device ing output to this pin will bypass the reference to lower the through the IN pins. A bypass capacitor is required on this output voltage noise. A maximum value of 0.01µF can be pin if the device is more than six inches away from the main used for reducing output voltage noise to a typical 20µVRMS input filter capacitor. In general, the output impedance of over a 10Hz to 100kHz bandwidth. If not used, this pin a battery rises with frequency, so it is advisable to include must be left unconnected. a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1µF to 10µF is sufficient. The
OUT1/OUT2 (Pins 6/10):
Output. The outputs supply LT3027 regulator is designed to withstand reverse volt- power to the loads. A minimum output capacitor of 1µF is ages on the IN pin with respect to ground and the OUT pin. required to prevent oscillations. Larger output capacitors In the case of a reverse input, which can happen if a battery will be required for applications with large transient loads is plugged in backwards, the device will act as if there is a to limit peak voltage transients. See the Applications diode in series with its input. There will be no reverse Information section for more information on output ca- current flow into the regulator and no reverse voltage will pacitance and reverse output characteristics. appear at the load. The device will protect both itself and the load.
Exposed Pad (Pin 11):
Ground. This pin must be soldered to the PCB and electrically connected to ground. 3027fa 8