L6725 - L6725A

Pin connections and functions

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Pin n°

Name

Function

5OCH

A resistor connected from this pin and the high-side MOSFET(s) drain sets the peak-

current-limit. The peak current is sensed through the high-side MOSFET(s). The

internal 100

equation:

6

PHASE

This pin is connected to the source of the high-side MOSFET(s) and provides the

return path for the high-side driver. This pin monitors the drop across both the upper

and lower MOSFET(s) for the current limit together with OCH and OCL.

7

HGATE

This pin is connected to the high-side MOSFET(s) gate.

8BOOT

Through this pin is supplied the high-side driver. Connect a capacitor from this pin to

9PGND

This pin has to be connected closely to the low-side MOSFET(s) source in order to

reduce the noise injection into the device.

10

LGATE

This pin is connected to the low-side MOSFET(s) gate.

11

5V internally regulated voltage. It is used to supply the internal drivers. Filter it to

ground with a 1uF ceramic cap.

12

Supply voltage pin. The operative supply voltage range is from 4.5V to 14V.

13

PGOOD

(L6725A)

N.C.

(L6725)

In L6725 this pin is N.C. With L6725A this pin is an open collector output and it is

pulled low if the output voltage is not

within the specified thresholds (90%-110%). If not used it may be left floating. Pull-up

14

SYNCH

(L6725A)

N.C.

(L6725)

In L6725 this pin is N.C. With L6725A it is a Master-Slave pin. Two or more devices

can be synchronized by simply

connecting the SYNCH pins together. The device operating with the highest FSW will

be the Master. The Slave devices will operate with 180° phase shift from the Master.

The best way to synchronize devices together is to set their FSW at the same value. If

it is not used the SYNCH pin can be left floating.

15

SGND

All the internal references are referred to this pin.

16

FB

the compensation network. This pin is also used to sense the output voltage in order

to manage the over voltage protection.

Table 4.

Pin functions

DSonHS

R

OCH

R

OCH

I

PEAK

I

⋅

=