Datasheet

VREF

Gate

Voltage

Boost

Narrow Pulse at

each Turn On

Anti Shoot -

Through

Circuitry

Input Signal

NMOS

, Pull Up

OUTL

OUTH

UCC27611

www.ti.com

SLUSBA5B –DECEMBER 2012

Enable Function

As mentioned earlier, an enable and disable function can be easily implemented in UCC27611 using the unused

input pin. When IN+ is pulled down to GND or IN- is pulled down to VDD, the output is disabled. Thus IN+ pin

can be used like an enable pin that is based on active high logic, while IN- can be used like an enable pin that is

based on active low logic.

Output Stage

The output stage of the UCC27611 device is illustrated in Figure 14. OUTH and OUTL are externally connected

and pinned out as OUTH and OUTL pins. The UCC27611 device features a unique architecture on the output

stage which delivers the highest peak source current when it is most needed during the Miller plateau region of

the power switch turn-on transition (when the power switch drain and collector voltage experiences dV and dt).

The device output stage features a hybrid pull-up structure using a parallel arrangement of N-channel and P-

channel MOSFET devices. By turning on the N-channel MOSFET during a narrow instant when the output

changes state from low to high, the gate-driver device is able to deliver a brief boost in the peak-sourcing current

enabling fast turn on.

Figure 14. UCC27611 Gate Driver Output Structure

The R

parameter (see ELECTRICAL CHARACTERISTICS) is a DC measurement and it is representative of

the on-resistance of the P-channel device only, since the N-channel device is turned on only during output

change of state from low to high. Thus the effective resistance of the hybrid pull-up stage is much lower than

what is represented by ROH parameter. The pull-down structure is composed of a N-channel MOSFET only. The

parameter (see ELECTRICAL CHARACTERISTICS), which is also a DC measurement, is representative of

true impedance of the pull-down stage in the device.

The UCC27611 is capable of delivering 4-A source, 6-A sink (asymmetrical drive) at VDD = 12 V. Strong sink

capability in asymmetrical drive results in a very low pull-down impedance in the driver output stage which boosts

immunity against parasitic, Miller turn on (C x dV/dt turn on) effect, especially where low gate-charge MOSFETs

or emerging wide band-gap GaN power switches are used.

Product Folder Links: UCC27611