SN

SP

SO

_

+

DC_CAL

DC_CAL

DC_CAL

S1

S2

S4

S3

S1

S2

S4

S3

5 kW

400 kW

100 W

_

+

REF

Vref /2

AVDD

AVDD

200 kW

100 kW

50 kW

5 kW

50 kW

100 kW

200 kW

400 kW

50 kW

50 kW

DRV8301

www.ti.com

SLOS719B – AUGUST 2011 – REVISED AUGUST 2013

Figure 4. Current Shunt Amplifier Simplified Block Diagram

BUCK CONVERTER

The buck converter in the DR8301 is the same as the TPS54160 buck converter. Although integrated in the

same device, buck converter is designed completely independent of rest of the gate driver circuitry. Since buck

will support external MCU or other external power need, the independency of buck operation is very critical for a

reliable system; this will give buck minimum impact from gate driver operations. Some examples are: when gate

driver shuts down due to any failure, buck will still operate unless the fault is coming from buck itself. The buck

keeps operating at much lower PVDD of 3.5V, this will assure the system to have a smooth power up and power

down sequence when gate driver is not able to operate due to a low PVDD.

The buck has an integrated high side n-channel MOSFET. To improve performance during line and load

transients the device implements a constant frequency, current mode control which reduces output capacitance

and simplifies external frequency compensation design.

The wide switching frequency of 300kHz to 2200kHz allows for efficiency and size optimization when selecting

the output filter components. The switching frequency is adjusted using a resistor to ground on the RT_CLK pin.

The device has an internal phase lock loop (PLL) on the RT_CLK pin that is used to synchronize the power

switch turn on to a falling edge of an external system clock.

The buck converter has a default start up voltage of approximately 2.5V. The EN_BUCK pin has an internal pull-

up current source that can be used to adjust the input voltage under voltage lockout (UVLO) threshold with two

external resistors. In addition, the pull up current provides a default condition. When the EN_BUCK pin is floating

the device will operate. The operating current is 116µA when not switching and under no load. When the device

is disabled, the supply current is 1.3µA.

Copyright © 2011–2013, Texas Instruments Incorporated

Submit Documentation Feedback

13

Product Folder Links: DRV8301