SC414/SC424

12

Pin Descriptions

Pin #

Pin Name

Pin Function

1FB

Feedback input for switching regulator used to program the output voltage — connect to an external resis-

tor divider from VOUT to AGND.

2

V5V

Bias input for internal analog circuits and gate drives — connect to external 3V or 5V supply or bias connec-

tion to VLDO.

3, 26, PAD 1

AGND

Analog ground

4

VOUT

Switcher output voltage sense pin, and also the input to the internal switch-over between VOUT and VLDO.

5, 8-11

PAD 2

VIN

Input supply voltage

6

VLDO

5V LDO output

7

BST

Bootstrap pin — connect a capacitor from BST to LXBST to develop the floating supply for the high-side gate

drive.

12

LXBST

LX Boost — connect to the BST capacitor.

15,20, 21,

PAD 3

LX

Switching (phase) node

13, 14, 16-19

PGND

Power ground

22

PGOOD

Open-drain power good indicator — high impedance indicates power is good. An external pull-up

resistor is required.

23

ILIM

Current limit sense pin — used to program the current limit by connecting a resistor from ILIM to LXS.

24

LXS

LX sense — connects to RILIM resistor

25

EN/PSV

Enable/power save input for the switching regulator — connect to AGND to disable the switching regula-

tor. Float to operate in forced continuous mode (power save disabled). For SC414, connect to V5V to operate

with ultrasonic power save mode enabled. For SC424, connect to V5V to operate with power save mode

enabled with no minimum frequency.

27

TON

On-time programming input — set the on-time by connecting through a resistor to AGND

28

ENL

Enable input for the LDO — connect ENL to AGND to disable the LDO. Drive with logic to +3V for logic con-

trol, or program the VIN UVLO with a resistor divider between VIN, ENL, and AGND.