Single/Dual, 16ns, High Sink/Source

Current Gate Drivers

10

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Detailed Description

The MAX15024 single gate driver’s internal source and

sink transistor outputs are brought out of the IC to inde-

pendent outputs allowing control of the external

MOSFET’s rise and fall time. The MAX15024 single

gate driver is capable of sinking an 8A peak current

and sourcing a 4A peak current. The MAX15025 dual

gate drivers are capable of sinking a 4A peak current

and sourcing a 2A peak current.

An integrated adjustable low-dropout linear voltage

regulator (LDO) provides gate drive amplitude control

and optimization. The single gate-driver propagation

delay time is minimized and matched between the

inverting and noninverting inputs. The dual gate-driver

propagation delay is matched between channels.

The MAX15024 has a dual input (IN+ and IN-), allows

the use of an inverting or noninverting input, and is

offered in TTL or CMOS-logic standards. The

MAX15025 is offered with configurations of inverting

and noninverting inputs with TTL or CMOS standards

(see the

Selector Guide).

LDO Voltage Regulator Feedback Control

The MAX15024/MAX15025 include an internal LDO

designed to deliver a stable reference voltage for use

as a supply voltage for the internal MOSFET gate dri-

vers. Connect the LDO feedback FB/SET to GND to set

channel transistor is ON and the internal p-channel tran-

sistor is OFF, holding the output at GND independent of

the state of the inputs so that the external MOSFETs

remain OFF in the UVLO condition. The UVLO threshold is

3.5V (typ) with 200mV (typ) hysteresis to avoid chattering.

When the device is operated at very low temperatures

and below the UVLO threshold, the driver output could

go high impedance. In this case, it is recommended

adding a 10k

Ω resistor to PGND to discharge the gate

of the external MOSFET (see Figures 4 and 5).

Input Control

The MAX15024 features inverting and noninverting

input terminals. These inputs provide for flexibility of

an inverting input. Connect IN- to GND when using IN+

as a noninverting input.

Shoot-Through Protection

The MAX15024/MAX15025 provide protection that

avoids any cross-conduction between the internal p-

channel and n-channel devices. It also eliminates shoot-

through, thus reducing the quiescent supply current.

Exposed Pad (EP)

The MAX15024/MAX15025 include an exposed pad

allowing greater heat dissipation from the internal die to

the outside environment. Solder the exposed pad care-

fully to GND or thermal pad to enhance the thermal

performance.

Applications Information

Supply Bypassing, Device Grounding,

and Placement

Ample supply bypassing and device grounding are

extremely important because when large external

capacitive loads are driven, the peak current at the

ground shifts are forms of negative feedback for invert-

ers and, if excessive, can cause multiple switching

when the inverting input is used and the input slew rate

is low. The device driving the input should be refer-

enced to the MAX15024/MAX15025 GND. Ground

shifts due to insufficient device grounding can disturb

other circuits sharing the same AC ground return path.

paths can cause oscillations due to the very high di/dt

that results when the MAX15024/MAX15025 are

switched with any capacitive load. A 0.1µF or larger

value ceramic capacitor is recommended for bypass-

pins as possible. When driving very large loads

(> 10nF) at minimum rise time, 10µF or more of parallel

storage capacitance is recommended. A ground plane

is highly recommended to minimize ground return resis-

tance and series inductance. Care should be taken to

place the MAX15024/MAX15025 as close as possible to

the external MOSFET being driven to further minimize

board inductance and AC path resistance.