5 Pin Configuration and Functions

Figure 5-1 8-Pin SO PowerPADDDA Package(Top View)

Table 5-1 Pin Functions

Pin		Type⁽¹⁾	Description
Name	NO.	Type⁽¹⁾	Description
GND	1	G	Ground connection for internal circuits
VIN	2	P/I	Regulator supply input pin to high-side power MOSFET and internal bias regulator. Connect directly to the input supply of the buck converter with short, low impedance paths.
EN/UVLO	3	I	Precision enable and undervoltage lockout (UVLO) programming pin. If the EN/UVLO voltage is below 1.1 V, the converter is in shutdown mode with all functions disabled. If the UVLO voltage is greater than 1.1 V and below 1.5 V, the converter is in standby mode with the internal VCC regulator operational and no switching. If the EN/UVLO voltage is above 1.5 V, the start-up sequence begins.
RON	4	I	On-time programming pin. A resistor between this pin and GND sets the buck switch on time.
FB	5	I	Feedback input of voltage regulation comparator
PGOOD	6	O	Power-good indicator. This pin is an open-drain output pin. Connect to a source voltage through an external pullup resistor between 10 kΩ to 100 kΩ.
BST	7	P/I	Bootstrap gate-drive supply. Required to connect a high-quality 2.2-nF, 50-V X7R ceramic capacitor between BST and SW to bias the internal high-side gate driver.
SW	8	P	Switching node that is internally connected to the source of the high-side NMOS buck switch. Connect to the switching node of the power inductor and schottky diode.
EP	—	—	Exposed pad of the package. No internal electrical connection. Connect the EP to the GND pin and connect to a large copper plane to reduce thermal resistance.

(1) G = Ground, I = Input, O = Output, P = Power