Texas Instruments TPS40090EVM-002 manual Compensation Components, R11

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SLUU195 − June 2004

4.8Compensation Components

The TPS40090 uses peak current mode control. Type II network is used here, which is implemented to provide one zero and two poles. The first pole is placed at the origin to improve DC regulation.

The ESR zero of the power stage is:

	fESRZ	+		1		+ 354 kHz
			2p	RC COUT

The zero is placed near 3.96 kHz to produce a reasonable time constant.

fZ +	1
	2p R11 C11

The second pole is placed at ESR zero (354 kHz).

	fP1 +	1
	fP1 +	2p R11	C11 C12
			C11 C12
			C11)C12

The resulting values selected for this design are:

•R11 = 40.2 kΩ

•C11 = 1000 pF

•C12 = 10 pF

(12)

(13)

(14)

TPS40090 Multi-Phase Buck Converter and TPS2834 Drivers Steps-Down from 12-V to 1.5-V at 100 A

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Contents User’s Guide EVM Important Notice Dynamic Warnings and Restrictions Introduction Schematic FeaturesTransen Frequency of Operation Component SelectionInput Capacitor Selection Inductance ValuePH, D + if N PH v 1, DI OUTD, DI OUT N PH, D Output Ripple Cancellation and Capacitor SelectionIripple + L VoutCurrent Sensing Mosfet SelectionOUT Overcurrent Limit ProtectionR11 Compensation ComponentsConnections for the Test Test SetupTotal Power Loss Output Current Efficiency and Power LossTest Results and Performance Data Overall Efficiency Output CurrentClosed-Loop Performance Gain and Phase Oscillator FrequencyOutput Ripple and Noise Transient Response Transient ResponseJ11 Short Circuit Start up with Pre-Biased OutputLayout Considerations Top Side Component Assembly EVM Assembly Drawing and PCB LayoutTop Side Copper Internal 2 Power Plane Bottom Layer Copper QTY List of MaterialsLoad Transient Circuit Products Applications Important Notice