Texas Instruments UCC2891 manual Overall Efficiency Output Current

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Power Up/Down Test Procedures

7 Power Up/Down Test Procedures

OVERALL EFFICIENCY

vs

OUTPUT CURRENT

	93
		VIN = 48 V
	91
	89
%					VIN = 72 V
-
Efficiency			VIN = 36 V
	87
Percent	85
	83
	81					VOUT = 3.3 V
						fS = 300 kHz
	79
	2	6	10	14	18	22	26
			IOUT - Output Current - A

Figure 3.

POWER LOSS

vs

OUTPUT CURRENT

	12
		VOUT = 3.3 V
		fS = 300 kHz
	10
- W
- Power Loss	8
	6
LOSS		VIN = 72 V
P
	4					VIN = 48 V
				VIN = 36 V
	2
	2	6	10	14	18	22	26	30
			IOUT - Output Current - A

GAIN AND PHASE

			vs
			FREQUENCY
	60				180
			Phase
	40				120
	20				60
dB		Gain				- °
Gain -	0				0	Phase
	-20				-60
		VIN = 36 V
	-40	IOUT = 10 A			-120
		gM = -8 dB
		ΦM = 50°
	-60				-180
	10	100	1 k	10 k	100 k
			f - Frequency - Hz

Figure 5.

Figure 4.

10 Using the UCC2891 Active Clamp Current Mode PWM Controller SLUU178A –November 2003 –Revised December 2006

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