4 Pin Configuration and Functions

Figure 4-1 DGX Package, 19-Pin VSSOP (Top View)

Table 4-1 Pin Functions

PIN		TYPE⁽¹⁾	DESCRIPTION
NAME	NO.	TYPE⁽¹⁾	DESCRIPTION
EN/UVLO	1	I	EN/UVLO input. A voltage on this pin above 1.24V enables normal operation. Forcing this pin below 0.3V shuts down the device reducing quiescent current to approximately 1.5µA (typical). Optionally connect to the input supply through a resistive divider to set the undervoltage lockout. When EN/UVLO is left floating an internal pull down of 100nA pulls EN/UVLO low and keeps the device in shutdown state.
OV	2	I	Adjustable overvoltage threshold input. Connect a resistor ladder from input supply, OV to GND. When the voltage at OVP exceeds the overvoltage cut-off threshold then the PD is pulled down to SRC turning OFF the external FET. When the voltage at OV goes below OV falling threshold then PU gets pulled up to BST, turning ON the external FET. OV must be connected to GND when not used. When OV is left floating an internal pull down of 100nA pulls OV low and keeps PU pulled up to BST.
INP	3	I	Input signal for external discharge FET control. CMOS compatible input reference to GND that sets the state of PD and PU pins. INP has an internal weak pull down of 100nA to GND to keep PD pulled to SRC when INP is left floating.
FLT_GD	4	O	Open drain fault output for gate drive UVLO. This pin asserts low when gate drive across PU to SRC is above 7.5V.
FLT	5	O	Open drain fault output. This pin asserts low during short circuit fault, input UVLO and during SCP comparator diagnosis. If FLT feature is not desired then connect it to GND.
GND	6	G	Connect GND to system ground.
CS_SEL	7	I	Current sense select input. Connect this pin to ground to activate high side current sense. Drive this pin to > 2V to activate low side current sensing. CS_SEL has an internal weak pull down of 100nA to GND.
ISCP	8	I	Short-circuit detection setting. A resistor across ISCP to GND sets the short circuit current comparator threshold. If short-circuit protection feature is not desired then connect CS+, CS–, and VS pins together and connect ISCP and TMR pins to GND.
TMR	9	I	Fault timer input. A capacitor across TMR pin to GND sets the delay time for short-circuit fault turn-off. Leave it open for fastest setting. If short-circuit protection feature is not desired then connect CS+, CS–, and VS pins together and connect ISCP and TMR pins to GND.
SCP_TEST	10	I	Internal short circuit comparator (SCP) diagnosis input. When SCP_TEST is driven low to high with INP pulled high, the internal SCP comparator operation is checked. FLT goes low and PD gets pulled to SRC if SCP comparator is functional. Connect SCP_TEST pin to GND if this feature is not desired. SCP_TEST has an internal weak pull down of 100nA to GND.
NC	11	—	No connect.
BST	12	O	High side bootstrapped supply. An external capacitor with a minimum value of > Q_g(tot) of the external FET must be connected between this pin and SRC.
SRC	13	O	Source connection of the external FET
PD	14	O	High current gate driver pull-down. This pin pulls down to SRC. For the fastest turn-off, tie this pin directly to the gate of the external high side MOSFET.
PU	15	O	High current gate driver pull-up. This pin pulls up to BST. Connect this pin to PD for maximum gate drive transition speed. A resistor can be connected between this pin and the gate of the external MOSFET to control the in-rush current during turn-on.
CS–	17	I	Current sense negative input.
CS+	18	I	Current sense positive input.
NC	19	—	No connect.
VS	20	Power	Supply pin of the controller.

(1) I = input, O = output, I/O = input and output, P = power, G = ground