Datasheet

LM3102

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SNVS515G –SEPTEMBER 2007–REVISED JANUARY 2012

PIN DESCRIPTIONS

Pin Ball Name Description Application Information

1,9,10,12,19,2 N/C No Connection These pins must be left unconnected.

2, 3 A2, A3, B2, SW Switching Node Internally connected to the source of the main

B3, C2, C3, MOSFET and the drain of the Synchronous

D2, D3, D4 MOSFET. Connect to the inductor.

4, 5 A4, B4 VIN Input supply voltage Supply pin to the device. Nominal input range is

4.5V to 42V.

6 C4 BST Connection for bootstrap capacitor Connect a 33 nF capacitor from the SW pin to this

pin. An internal diode charges the capacitor during

the main MOSFET off-time.

7 E3, E4, F1, AGND Analog Ground Ground for all internal circuitry other than the

F2, F3, G3 PGND pin.

8 G2 SS Soft-start An 8 µA internal current source charges an

external capacitor to provide the soft- start function.

11 GND Ground Must be connected to the AGND pin for normal

operation. The GND and AGND pins are not

internally connected.

13 G1 FB Feedback Internally connected to the regulation and over-

voltage comparators. The regulation setting is 0.8V

at this pin. Connect to feedback resistors.

14 G4 EN Enable Connect a voltage higher than 1.26V to enable the

regulator. Leaving this input open circuit will enable

the device at internal UVLO level.

15 F4 RON On-time Control An external resistor from the VIN pin to this pin

sets the main MOSFET on-time.

16 E1, E2 VCC Start-up regulator Output Nominally regulated to 6V. Connect a capacitor of

not less than 680 nF between the VCC and AGND

pins for stable operation.

17, 18 A1, B1, C1, PGND Power Ground Synchronous MOSFET source connection. Tie to a

D1 ground plane.

EP EP Exposed Pad Thermal connection pad. Connect to the ground

plane.

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

Product Folder Links: LM3102