317B 查看數據表（PDF） - Linear Technology

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产品描述 (功能)

生产厂家

317B

Micropower, 600kHz PWM DC/DC Converters

Linear Technology 

LT1317/LT1317B

TYPICAL PERFOR A CE CHARACTERISTICS

Load Regulation (LT1317)

VOUT

50mV/DIV

DC COUPLED

OFFSET

ADDED

Load Regulation (LT1317)

VOUT

50mV/DIV

DC COUPLED

OFFSET

ADDED

Load Regulation (LT1317)

VOUT

50mV/DIV

DC COUPLED

OFFSET

ADDED

VIN = 1.5V

VOUT = 5V

ILOAD 25mA/DIV

1317 TPC19

VIN = 2V

VOUT = 5V

ILOAD 25mA/DIV

1317 TPC20

VIN = 2.5V

VOUT = 5V

ILOAD 50mA/DIV

1317 TPC21

Load Regulation (LT1317)

Load Regulation (LT1317)

Load Regulation (LT1317)

VOUT

50mV/DIV

DC COUPLED

OFFSET

ADDED

VOUT

50mV/DIV

DC COUPLED

OFFSET

ADDED

VIN = 1.5V

VOUT = 3.3V

ILOAD 25mA/DIV

1317 TPC22

Note: For load regulation pictures, double lines are due to

output capacitor ESR.

VIN = 2V

VOUT = 3.3V

ILOAD 50mA/DIV

VOUT

50mV/DIV

DC COUPLED

OFFSET

ADDED

1317 TPC23

VIN = 2.5V

VOUT = 3.3V

ILOAD 50mA/DIV

1317 TPC24

PIN FUNCTIONS

VC (Pin 1): Compensation Pin for Error Amplifier. Con-

nect a series RC network from this pin to ground. Typical

values for compensation are a 33k/3.3nF combination. A

100pF capacitor from the VC pin to ground is optional and

improves noise immunity. Minimize trace area at VC.

FB (Pin 2): Feedback Pin. Reference voltage is 1.24V.

Connect resistor divider tap here. Minimize trace area at

FB. Set VOUT according to: VOUT = 1.24V(1 + R1/R2).

SHDN (Pin 3): Shutdown. Pull this pin low for shutdown

mode (only the low-battery detector remains active).

Leave this pin floating or tie to a voltage between 1.4V and

6V to enable the device. SHDN pin is logic level and need

only meet the logic specification (1.4V for high, 0.4V for

low).

GND (Pin 4): Ground. Connect directly to local ground

plane.

SW (Pin 5): Switch Pin. Connect inductor/diode here.

Minimize trace area at this pin to keep EMI down.

VIN (Pin 6): Supply Pin. Must be bypassed close to the

pin.

LBI (Pin 7): Low-Battery Detector Input. 200mV refer-

ence. Voltage on LBI must stay between ground and

700mV. Low-battery detector remains active in shutdown

mode.

LBO (Pin 8): Low-Battery Detector Output. Open collec-

tor, can sink 10µA. A 1MΩ pull-up is recommended.

6

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