4
FN7360.5
November 5, 2007
V
EN_HI
EN Input High Level 2.6 V
V
EN_LO
EN Input Low Level 1V
I
EN
Enable Pull-up Current V
EN
= 0 -4 -2.5 µA
TM, S
EL_HI
Input High Level 2.6 V
TM, S
EL_LO
Input Low Level 1V
DC Electrical Specifications V
DD
= V
IN
= 3.3V, T
A
= T
J
= +25°C, C
OSC
= 390pF, Unless Otherwise Specified
PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT
Pin Descriptions
PIN NUMBER PIN NAME PIN FUNCTION
1 COMP Error amplifier output; place loop compensation components here
2 VREF Bandgap reference bypass capacitor; typically 0.01µF to 0.047µF to SGND
3 FB Voltage feedback input; connected to external resistor divider between V
OUT
and SGND for adjustable
output; also used for speed-up capacitor connection
4 VO Output sense for fixed output; also used for speed-up capacitor connection
5 VTJ Junction temperature monitor output, connected to a 0.01µF - 0.047µF to SGND
6 TM Stress test enable; allows ±5% output movement; needs a pull-down resistor (1k - 100k); connect to
SGND if function is not used
7 SEL Positive or negative voltage margining set pin; needs a pull-down resistor (1k - 100k); connect to SGND
if function is not used
8, 9, 10, 11, 12, 13 LX Inductor drive pin; high current output whose average voltage equals the regulator output voltage
14, 15 NC Not used
16, 17, 18 PGND Ground return of the regulator; connected to the source of the low-side synchronous NMOS Power FET
19, 20, 21 VIN Power supply input of the regulator; connected to the drain of the high-side PMOS Power FET
22 VDD Control circuit positive supply; connected to V
IN
through an internal 20Ω resistor
23 PG Power-good window comparator output; logic 1 when regulator output is within ±10% of target output
voltage
24 EN Chip enable, active high; a 2µA internal pull-up current enables the device if the pin is left open; a
capacitor can be added at this pin to delay the start of a converter
25 STP Auxilliary supply tracking positive input; tied to regulator output to synchronize start-up with a second
supply; leave open for standalone operation; 2µA internal pull-up current
26 STN Auxiliary supply tracking negative input; connect to output of a second supply to synchronize start-up;
leave open for standalone operation; 2µA internal pull-up current
27 COSC Oscillator timing capacitor (see performance curves)
28 SGND Control circuit negative supply or signal ground
EL7554
