4 Pin Configuration and Functions

TPS546B26 RXX 37-Pin WQFN-FCRLF Package (Top
View)

Figure 4-1 RXX 37-Pin WQFN-FCRLF Package (Top View)

TPS546B26 RXX 37-Pin WQFN-FCRLF Package (Bottom
View)

Figure 4-2 RXX 37-Pin WQFN-FCRLF Package (Bottom View)

Table 4-1 Pin Functions

PIN		TYPE⁽¹⁾	DESCRIPTION
NAME	NO.	TYPE⁽¹⁾	DESCRIPTION
AGND	32	G	Analog ground pin, reference point for internal control circuitry.
BOOT	26	P	Supply rail for the high-side gate driver (boost terminal). Connect the bootstrap capacitor from this pin to PHASE pin. A high temperature (X7R) 0.1μF or greater value ceramic capacitor is recommended.
CNTL	27	I	CTRL pin, an active-high input pin that, when asserted high, causes the converter to begin the soft-start sequence for the output voltage rail.
GOSNS	31	I	Negative input of the differential remote sense circuit, connect to the ground sense point on the load side.
ISHARE	1	I/O	Do not connect (float)
MSEL1	36	I	Use a resitor to AGND to select options for the device. See Pin-Strapping.
MSEL2	6	I	Use a resistor to AGND to select configuration options for the device. See Pin-Strapping.
NC	37		Not connected. This pin is floating internally.
PG	2	O	Open-drain power-good indicator.
PGND	7, 8, 9, 10, 19	G	Power ground for the internal power stage.
PHASE	25	I/O	Return for high-side MOSFET driver. Shorted to SW internally. Connect the bootstrap capacitor from BOOT pin to PHASE pin.
PMB_ADDR/VORST#	29	I	The PMBus address, Primary or Secondary, Internal or External Feedback, Over-current Limit, Soft-start, and Fault Response can be set by tying an external resistor between this pin and AGND. See Pin-Strapping.
PMB_CLK	34	I	PMBus clock pin, open drain.
PMB_DATA	33	I/O	PMBus bi-directional data pin, open drain.
PVIN	20, 21, 22, 23, 24	P	Power input for both the power stage and the input of the internal VCC LDO.
SMB_ALERT_#	35	O	SMBALERT# as described in the SMBus specification. The pin is open-drain. The SMBALERT# indicator is used in conjunction with the Alert Response Address (ARA). During nominal operation, the SMBALERT# is held high.
SW	11–18	O	Output switching terminal of the power converter. Connect these pins to the output inductor.
TRIGGER	3	I/O	Do not connect (float)
VCC	4	P	Output of internal 4.5V LDO from PVIN and Supply for analog control circuitry. Bypass with a 10V rated X5R or better 2.2μF capacitor to AGND and connect to VDRV with a 1Ω resistor. Check layout guidelines for more details.
VDRV	5	—	5V supply for gate drivers. Bypass to PGND with a 10V rated X5R or better 2.2μF and connect to VCC with a 1Ω resistor. An external 5V bias can be connected to this pin to reduce power losses on the internal LDO or to allow operation with a lower PVIN voltage. Check layout guidelines for more details.
VOSNS	30	I	This pin is VOSNS and is the positive input of the differential remote sense circuit, connect to the Vout sense point on the load side.
VSEL/FB	28	I	When the device is configured to use the internal FB divider, this pin is VSEL. Use a resistor to AGND to select the output voltage. See Programming MSEL1 and Programming VSEL\FB. When the device is configured for an external resister divider, this pin is the feedback pin of the device. Connect this pin to the midpoint of a resistor divider to set the output voltage.

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