5 Pin Configuration and Functions

Figure 5-1 DDA Package8-Pin SO PowerPAD™ Integrated Circuit Package Top View

Table 5-1 Pin Functions

PIN		I/O⁽¹⁾	DESCRIPTION
NO.	NAME	I/O⁽¹⁾	DESCRIPTION
1	GND	G	Ground connection for internal circuits
2	VIN	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.
3	EN/UVLO	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.
4	RON	I	On-time programming pin. A resistor between this pin and GND sets the buck switch on-time.
5	FB	I	Feedback input of voltage regulation comparator
6	PGOOD	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.
7	BST	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.
8	SW	P	Switching node that is internally connected to the source of the high-side NMOS buck switch and the drain of the low-side NMOS synchronous rectifier. Connect to the switching node of the power inductor.
—	EP	—	Exposed pad of the package. No internal electrical connection. Solder 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