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LM5134

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SNVS808C – MAY 2012 – REVISED FEBRURARY 2016

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Copyright © 2012–2016, Texas Instruments Incorporated

Typical Application (continued)

8.2.1 Design Requirements

When selecting the proper gate driver device for an end application, some design considerations must first be

evaluated to make the most appropriate selection. Among these considerations are input-to-output configuration,

the input threshold type, bias supply voltage levels, peak source and sink currents, availability of independent

enable and disable functions, propagation delay, power dissipation, and package type.

Table 3. Design Parameters

PARAMETER

EXAMPLE VALUE

Input-to-output logic

Noninverting

Input threshold type

Logic level

10 V (minimum), 113 V (nominal), 15 V (peak)

Peak source and sink currents

Minimum 1.65-A source, minimum 1.65-A sink

Enable and disable function

Yes, required

Propagation delay

Maximum 40 ns or less

8.2.2 Detailed Design Procedure

8.2.2.1 Input-to-Output Logic

The design should specify which type of input-to-output configuration should be used. If turning on the power

MOSFET when the input signal is in high state is preferred, then the noninverting configuration must be selected.

If turning off the power MOSFET when the input signal is in high state is preferred, the inverting configuration

must be chosen. The LM5134 device can be configured in either an inverting or noninverting input-to-output

configuration, using the IN– or IN+ pins, respectively. To configure the device for use in inverting mode, tie the

IN+ pin to VDD and apply the input signal to the IN– pin. For the noninverting configuration, tie the IN– pin to

GND and apply the input signal to the IN+ pin.

8.2.2.2 Input Threshold Type

The type of controller used determines the input voltage threshold of the gate driver device. The LM5134B device

features a TTL and CMOS-compatible input threshold logic, with wide hysteresis. The threshold voltage levels

are low voltage and independent of the VDD supply voltage, which allows compatibility with both logic-level input

signals from microcontrollers, as well as higher-voltage input signals from analog controllers.

The LM5134A device features higher voltage thresholds for greater noise immunity, and controllers with higher

drive voltages.

See Electrical Characteristics for the actual input threshold voltage levels and hysteresis specifications for the

LM5134 device.

The bias supply voltage applied to the VDD pin of the device should never exceed the values listed in

Recommended Operating Conditions. However, different power switches demand different voltage levels to be

applied at the gate terminals for effective turnon and turnoff. With an operating range from 4 V to 12 V, the

LM5134 device can be used to drive a variety of power switches, such as Si MOSFETs (for example,

VGS = 4.5 V, 10 V, 12 V), BJTs, and wide-band gap power semiconductors (such as GaN, certain types of which

allow no higher than 6 V to be applied to the gate terminals).

8.2.2.4 Peak Source and Sink Currents

Generally, to minimize switching power losses, the switching speed of the power switch during turnon and turnoff

should be as fast as possible. However, very fast transitions on the Drain node voltage can lead to unwanted

emissions for EMI, and the turnon speed is often deliberately slowed down by placing a series resistor between

the Drive output and MOSFET gate to reduce these emissions.