Wide 4.5V to 28V Input, Dual-Output

Synchronous Buck Controller

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9

Pin Description

PIN

NAME

FUNCTION

1

FB1

Feedback Input for Regulator 1. Connect FB1 to a resistive divider between Output 1 and SGND to adjust

the output voltage between 0.6V and (0.85 x input voltage (V)). See the Setting the Output Voltage section.

2

EN1

Active-High Enable Input for Regulator 1. When the voltage at EN1 exceeds 1.2V (typ), the controller begins

regulating OUT1. When the voltage falls below 1.05V (typ), the regulator is turned off. The EN1 input can be

3

EN2

Active-High Enable Input for Regulator 2. When the voltage at EN2 exceeds 1.2V (typ), the controller begins

regulating OUT2. When the voltage falls below 1.05V (typ), the regulator is turned off. The EN2 input can be

4

PGOOD1

Power-Good Output (Open Drain) for Channel 1. To obtain a logic signal, pull up PGOOD1 with an external

resistor connected to a positive voltage below 28V.

5

DL1

reaches the UVLO rising threshold voltage.

6

PGND1

Low-Side Gate-Driver Supply Return (Regulator 1). Connect to the source of the low-side MOSFET of

Regulator 1.

7

LX1

External Inductor Connection for Regulator 1. Connect LX1 to the switched side of the inductor. LX1 serves

as the lower supply rail for the DH1 high-side gate driver and as sensing input of the synchronous

8

BST1

Boost Flying-Capacitor Connection for Regulator 1. Connect a ceramic capacitor with a minimum value of

100nF between BST1 and LX1.

9

DH1

reaches the UVLO rising threshold voltage.

10

DH2

reaches the UVLO rising threshold voltage.

11

BST2

Boost Flying-Capacitor Connection for Regulator 2. Connect a ceramic capacitor with a minimum value of

100nF between BST2 and LX2.

12

LX2

External Inductor Connection for Regulator 2. Connect LX2 to the switched side of the inductor. LX2 serves

as the lower supply rail for the DH2 high-side gate driver and as sensing input of the synchronous