SC415

7

Pin Descriptions

Pin #

Pin Name

Pin Function

1

LX1

Switching (phase) node for VOUT1

2

BST1

Boost capacitor connection for VOUT1 high-side gate drive

3

VDD1

5V supply input for VOUT1 analog circuits and gate drive outputs. Under-voltage lockout for the 5V supply is

sensed on VDD1 only.

4

DL1

Gate drive output for the VOUT1 low-side external MOSFET

5

EN1

Enable input for VOUT1. Ground to disable the VOUT1 switcher. Leave open to enable VOUT1 switcher with

power-save disabled. Connect to VDD1 to enable VOUT1 in power-save mode.

6

SS1

Soft-start input for VOUT1. For independent start-up, connect a capacitor to RTN.

7

VOUT1

Connect to the output capacitor of VOUT1. Used for DH1 On-Time generation, and for VOUT1 regulation when

FB1 is connected to VDD1 or RTN.

8

FB1

Feedback input for VOUT1. Connect to an external resistor divider to adjust VOUT1, or connect to RTN or VDD1

to select internal feedback resistors via the VOUT1 pin.

9

RTN

Analog return (ground) for both VOUT1 and VOUT2

10

TON

On-time adjust input. Connect a resistor from VIN to TON to program the on-time. The on-time one-shot for

VOUT1 is internally set at 20% greater than for VOUT2, to prevent frequency interaction between the two con-

verters.

11

FB2

Feedback input for VOUT2. Connect to an external resistor divider to adjust VOUT2, or connect to RTN or VDD2

to select internal feedback resistors via the VOUT2 pin.

12

VOUT2

Connect to the output capacitor of VOUT2. Used for side 2 On-Time generation, and for VOUT2 regulation when

FB2 is connected to VDD2 or RTN.

13

SS2

Soft-start input for VOUT1. For independent start-up, connect a capacitor to RTN.

14

EN2

Enable input for VOUT2. Ground to disable the VOUT2 switcher. Leave open to enable VOUT2 switcher with

power-save disabled. Connect to VDD2 to enable VOUT2 in power-save mode.

15

DL2

Gate drive output for the VOUT2 low-side external MOSFET

16

VDD2

5V supply input for VOUT2 analog circuits and gate drive outputs. VDD2 must connect to the same supply as

VDD1.

17

BST2

Boost capacitor connection for VOUT2 high-side gate drive

18

LX2

Switching (phase) node for VOUT2

19

DH2

Gate drive output for the VOUT2 high-side external MOSFET

20

ILIM2

Current limit input for VOUT2. Connect through a resistor to the drain of the VOUT2 low-side MOSFET.

21

PGD2

Open-drain Power Good output for VOUT2

22

PGD1

Open-drain Power Good output for VOUT1

23

ILIM1

Current limit input for VOUT1. Connect through a resistor to the drain of the VOUT1 low-side MOSFET.

24

DH1

Gate drive output for the VOUT1 high-side external MOSFET

T

PAD

Power ground for VOUT1 and VOUT2 gate drivers, and thermal pad for heatsinking