Output voltage monitor and protections

L6706

36/47

Doc ID 15698 Rev 2

OCP during normal operation of the device. This value must take into consideration also the

transitions for details):

programmable through OCSET pin.

where

ΔIL is the inductor ripple current (peak-to-peak).

happen during the HS conduction time: as a consequence of OCP detection, the device will

or until the next clock cycle. This implies that the device limits the peak of the inductor

current.

maximum peak value to consider in the OC design.

The device works in constant-current, and the output voltage decreases as the load

increase, until the output voltage reaches the UVP threshold. When this threshold is

crossed, MOSFETs are turned off and the device stops working. Cycle the power supply or

the OUTEN pin to restart operation.

Figure 20.

Overcurrent protection connection

Note:

In order to avoid the OCP intervention during the DVID, the device automatically increases

the OCP threshold to 150% of the selected OCP threshold during every VID transition

Since the device reads the current information across inductor DCR, the process spread

and temperature variations of these sensing elements has to be considered. Also the

IOUT

OCP

IOUT

MAX

I

DVID

–

+

>

I

OCTH

V

OCSET

R

OCSET

----------------------

1.260 typ

()

R

OCSET

----------------------------

==

I

INFO

OCP

DCR

Rg

-------------

I

OUT

OCP

ΔIL

2

---------

+

⎝⎠

⎛⎞

⋅

=

OCSET

R

OCSET

V

()

DCR MAX

)

()

Rg

-----------------------------------

I

() ΔIL

2

---------

+

⎝⎠

⎛⎞

⋅

77

μA

+

-----------------------------------------------------------------------------------------------------------------------

=