MP6922—DUAL FAST TURN-OFF INTELLIGENT CONTROLLER

MP6922 Rev. 1.23

www.MonolithicPower.com

7

9/19/2012

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2012 MPS. All Rights Reserved.

BLOCK DIAGRAM

EN

PGND

RCP

LL

Figure 1—Functional Block Diagram

OPERATION

The MP6922 supports operation in DCM, CCM

and CrCM condition. Operating in either a DCM

or CrCM condition, the control circuitry controls

the gate in forward mode and will turn the gate

off when the MOSFET current is fairly low. In

CCM operation, the control circuitry turns off the

gate when very fast transients occur.

Blanking

The control circuitry contains blanking function.

When it pulls the MOSFET on/off, it makes sure

that the on/off state at least lasts for some time.

The turn on blanking time is ~1us, which

determines the minimum on-time. During the turn

on blanking period, the turn off threshold is not

totally blanked, but changed to ~+50mV (instead

of 0mV). This assures that the part can always

be turned off even during the turn on blanking

period. (Albeit slower, so it is not recommended

CCM condition in LLC converter, otherwise shoot

through may occur)

VD Clamp

Voltage JFET is used at the input. To avoid

excessive currents when Vg goes below -0.7V, a

and the drain of the external MOSFET.

Under-Voltage Lockout (UVLO)

into sleep mode and Vg is pulled down by a

10k

Ω resistor.

Enable pin

If EN is pulled low, the part is in sleep mode.

Thermal shutdown

If the junction temperature of the IC exceeds