TPS2816, TPS2817, TPS2818, TPS2819, TPS2828, TPS2829,

SINGLECHANNEL HIGHSPEED MOSFET DRIVER

SLVS160C – FEBRUARY 1997 – REVISED OCTOBER 2002

14

www.ti.com

APPLICATION INFORMATION

MOSFETs are voltage-driven devices that require very little steady-state drive current. However, the large input

capacitance (200 pF to 3000 pF or greater) of these devices requires large current surges to reduce the turn-on

and turn-off times. The TPS2816 series of high-speed drivers can supply up to 2 A to a MOSFET, greatly

reducing the switching times. The fast rise times and fall times and short propagation delays allow for operation

in today’s high-frequency switching converters.

In addition, MOSFETs have a limited gate-bias voltage range, usually less than 20 V. The TPS2816 series of

drivers extends this operating range by incorporating an on-board series regulator with an input range up to 40 V.

This regulator can be used to power the drivers, the PWM chip, and other circuitry, providing the power

dissipation rating is not exceeded.

When using these devices, care should be exercised in the proper placement of the driver, the switching

MOSFET, and the bypass capacitor. Because of the large input capacitance of the MOSFET, the driver should

be placed close to the gate to eliminate the possibility of oscillations caused by trace inductance ringing with

the gate capacitance of the MOSFET. When the driver output path is longer than approximately 2 inches, a

resistor in the range of 10

Ω should be placed in series with the gate drive as close as possible to the MOSFET.

A ceramic bypass capacitor is also recommended to provide a source for the high-speed current transients that

the MOSFET requires. This capacitor should be placed between VCC and GND of the driver (see Figures 20

and 21).

Regulator

0.1

µF

1

2

3

5

4

Input

TPS2816

VCC

Load

Figure 20. VCC < 14 V

Regulator

4.7

µF

1

2

3

5

4

Input

TPS2816

VDD

Load

0.1

µF

+

Figure 21. VCC > 14 V