Texas Instruments TPS40051 manual Test Results / Performance Data, Efficiency and Power Loss

SLUU161 – April, 2003

6 Test Results / Performance Data

6.1Efficiency and Power Loss

Figure 3 shows the efficiency as the load is varied from 1 A to over 15 A. The typical efficiency remains over 90% as the load ranges from 3 A to 12 A.

				EFFICIENCY
					vs
	94				LOAD
	92
	90
%	88
–
Efficiency	86
	84
	82
	80
	78
	0	2	4	6	8	10	12	14	16
			IOUT – Output Current – A

Figure 3

			POWER DISSIPATION
					vs
					LOAD
	7
	6
– W	5
Dissipation
	4
– Power	3
	2
DISS
P	1
	0
	0	2	4	6	8	10	12	14	16
				IOUT – Output Current – A

Figure 4

6.2Closed Loop Performance

OVERALL GAIN AND PHASE

vs

OSCILLATOR FREQUENCY

	50	Phase		160
	40			140
	30			120
			Gain	100	°
Gain – dB	20				–
					Phase
	10			80
	0			60
	–10			40
	–20			20
	–30	1 k	10 k	0
	100			100 k

fOSC – Oscillator Frequency – kHz

Figure 5.

TPS40051-Based Design Converts 12-V Bus to 1.8 V at 15 A (SLUP195) 11