Datasheet LT3493 (Analog Devices) - 6
| Fabricante | Analog Devices |
| Descripción | 1.2A, 750kHz Step-Down Switching Regulator in 2mm × 3mm DFN |
| Páginas / Página | 20 / 6 — PIN FUNCTIONS. FB (Pin 1):. VIN (Pin 5):. SHDN (Pin 6):. GND (Pin 2):. … |
| Formato / tamaño de archivo | PDF / 607 Kb |
| Idioma del documento | Inglés |
PIN FUNCTIONS. FB (Pin 1):. VIN (Pin 5):. SHDN (Pin 6):. GND (Pin 2):. BOOST (Pin 3):. Exposed Pad (Pin 7):. SW (Pin 4):. BLOCK DIAGRAM
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LT3493
PIN FUNCTIONS FB (Pin 1):
The LT3493 regulates its feedback pin to
VIN (Pin 5):
The VIN pin supplies current to the LT3493’s 780mV. Connect the feedback resistor divider tap to this internal regulator and to the internal power switch. This pin. Set the output voltage according to VOUT = 0.78V • pin must be locally bypassed. (1 + R1/R2). A good value for R2 is 10k.
SHDN (Pin 6):
The SHDN pin is used to put the LT3493 in
GND (Pin 2):
Tie the GND pin to a local ground plane shutdown mode. Tie to ground to shut down the LT3493. below the LT3493 and the circuit components. Return the Tie to 2.3V or more for normal operation. If the shutdown feedback divider to this pin. feature is not used, tie this pin to the VIN pin. SHDN also
BOOST (Pin 3):
The BOOST pin is used to provide a drive provides a soft-start function; see the Applications Infor- voltage, higher than the input voltage, to the internal bipolar mation section. NPN power switch.
Exposed Pad (Pin 7):
The Exposed Pad must be soldered
SW (Pin 4):
The SW pin is the output of the internal power to the PCB and electrically connected to ground. Use a switch. Connect this pin to the inductor, catch diode and large ground plane and thermal vias to optimize thermal boost capacitor. performance.
BLOCK DIAGRAM
VIN V 5 IN C2 INT REG AND UVLO D2 3 BOOST ON OFF 3 SLOPE R R3 COMP Q SHDN 6 C3 S Q DRIVER Q1 C4 L1 OSC SW 4 VOUT C1 D1 FREQUENCY FOLDBACK VC gm 780mV GND FB 2 1 R2 R1 3493 BD 3493fb 6
PIN FUNCTIONS FB (Pin 1):
The LT3493 regulates its feedback pin to
VIN (Pin 5):
The VIN pin supplies current to the LT3493’s 780mV. Connect the feedback resistor divider tap to this internal regulator and to the internal power switch. This pin. Set the output voltage according to VOUT = 0.78V • pin must be locally bypassed. (1 + R1/R2). A good value for R2 is 10k.
SHDN (Pin 6):
The SHDN pin is used to put the LT3493 in
GND (Pin 2):
Tie the GND pin to a local ground plane shutdown mode. Tie to ground to shut down the LT3493. below the LT3493 and the circuit components. Return the Tie to 2.3V or more for normal operation. If the shutdown feedback divider to this pin. feature is not used, tie this pin to the VIN pin. SHDN also
BOOST (Pin 3):
The BOOST pin is used to provide a drive provides a soft-start function; see the Applications Infor- voltage, higher than the input voltage, to the internal bipolar mation section. NPN power switch.
Exposed Pad (Pin 7):
The Exposed Pad must be soldered
SW (Pin 4):
The SW pin is the output of the internal power to the PCB and electrically connected to ground. Use a switch. Connect this pin to the inductor, catch diode and large ground plane and thermal vias to optimize thermal boost capacitor. performance.
BLOCK DIAGRAM
VIN V 5 IN C2 INT REG AND UVLO D2 3 BOOST ON OFF 3 SLOPE R R3 COMP Q SHDN 6 C3 S Q DRIVER Q1 C4 L1 OSC SW 4 VOUT C1 D1 FREQUENCY FOLDBACK VC gm 780mV GND FB 2 1 R2 R1 3493 BD 3493fb 6