Datasheet

+ f

G (high)

) Q

G (low)

TPS40192, TPS40193

SLUS719E –MARCH 2007–REVISED MAY 2013

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5-V Regulator

These devices have an on board 5-V regulator that allows the parts to operate from a single voltage feed. No

separate 5-V feed to the part is required. This regulator needs to have a minimum of 1-μF of capacitance on the

BP5 pin for stability. A ceramic capacitor is suggested for this purpose.

This regulator can also be used to supply power to nearby circuitry, eliminating the need for a separate LDO in

some cases. If this pin is used for external loads, be aware that this is the power supply for the internals of the

TPS40192/3. While efforts have been made to reduce sensitivity, any noise induced on this line has an adverse

effect on the overall performance of the internal circuitry and shows up as increased pulse jitter, or skewed

reference voltage. Also, when the device is disabled by pulling the EN pin low, this regulator is turned off and will

not be available to supply power.

The amount of power available from this pin varies with the size of the power MOSFETs that the drivers must

operate. Larger MOSFETs require more gate drive current and reduce the amount of power available on this pin

for other tasks. The total current that can be drwan from this pin by both the gate drive and external loads cannot

exceed 50mA. The device uses up to 4mA from the regulator and the total gate drive current can be found from

Equation 5.

For regulator stability, a 1-μF capacitor is required to be connected from BP5 to GND. In some applications using

higher gate charge MOSFETs, a larger capacitor is required for noise suppression. For a total gate charge of

both the high and low side MOSFETs greater than 20 nC, a 2.2-μF or larger capacitor is recommended.

where

• I

is the required gate drive current

• f

is the switching frequency (600 kHz for TPS40192, and 300 kHz for TPS40193)

• Q

G(high)

is the gate charge requirement for the high-side FET when V

=5 V

• Q

G(low)

is the gate charge requirement for the low-side FET when V

=5 V (5)

Product Folder Links: TPS40192 TPS40193