3/23

L6997

8

VFB

PWM comparator feedback input. Short this pin to INT pin when using the integrator function, or

to VSENSE pin without integrator.

9

OSC

Connect this pin to the input voltage through a voltage divider in order to provide the feed-

forward function. It cannot be left floating.

10

SS

Soft start pin. A 5

µA constant current charges an external capacitor which value sets the soft-

start time.

11

ILIM

An external resistor connected between this pin and GND sets the current limit threshold.

12

SHDN

Shutdown. When connected to GND the device and the drivers are OFF. It cannot be left floating.

13

OVP

Open drain output. During the over voltage condition it is pulled up by an external resistor.

14

PGOOD

Open drain output. During the soft start and in case of output voltage fault it is low. It is pulled up

by external resistor.

15

PGND

Low Side driver ground.

16

LGATE

Low Side driver output.

17

Low Side driver supply.

18

PHASE

Return path of the High Side driver.

19

HGATE

High side MOSFETS driver output.

20

BOOT

Bootstrap capacitor pin. High Side driver is supplied through this pin.

ELECTRICAL CHARACTERISTICS

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

SUPPLY SECTION

Vin

Input voltage range

Vout=Vref Fsw=110Khz Iout=1A

1

28

V

3

5.5

V

Turn-onvoltage

2.86

2.97

V

Turn-off voltage

2.75

2.9

V

Hysteresis

90

mV

Quiescent Current Drivers

VFB > VREF

7

20

µA

IqVcc

Device Quiescent current

VFB > VREF

400

600

µA

SHUTDOWN SECTION

SHDN

Device On

1.2

V

Device Off

0.6

V

Drivers shutdown current

SHDN to GND

5

µA

Devices shutdown current

SHDN to GND

1

15

µA

SOFT START SECTION

Soft Start current

4

6

µA

Active Soft start and voltage

300

400

500

mV

CURRENT LIMIT AND ZERO CURRENT COMPARATOR

ILIM input bias current

4.6

5

5.4

µA

Zero Crossing Comparator offset

Phase-gnd

-2

2

mV

Current limit factor

1.6

1.8

2

µA

PIN FUNCTION (continued)

N°

Name

Description