UG-179 Datasheet, PDF (5/12 Pages) Analog Devices – Automatic PFM/PWM mode switching

Evaluation Board User Guide
TYPICAL PERFORMANCE CHARACTERISTICS
100
90
80
70
60
50
INDUCTOR: LPS6225-472MLC
DIODE: B230A
40
0
0.2
0.4
0.6
V_OUT = 5.0V
V_OUT = 3.3V
V_OUT = 2.5V
0.8
1.0
1.2
I_OUT (A)
Figure 2. Efficiency Curve, VIN = 12 V, fSW = 1.4 MHz
100
INDUCTOR: LPS6225-103MLC
DIODE: B230A
90
80
70
60
V_OUT = 5.0V
50
V_OUT = 3.3V
V_OUT = 2.5V
V_OUT = 1.8V
V_OUT = 1.2V
40
0
0.2
0.4
0.6
0.8
1.0
1.2
I_OUT (A)
Figure 3. Efficiency Curve, VIN = 12 V, fSW = 700 kHz
0.20
f_SW = 1.4MHz
0.15
f_SW = 700kHz
0.10
0.05
0
–0.05
–0.10
–0.15
–0.20
5
8
11
14
17
20
V_IN (V)
Figure 4. Line Regulation, VOUT = 3.3 V, IOUT = 500 mA
UG-179
0.20
f_SW = 1.4MHz
0.15
f_SW = 700kHz
0.10
0.05
0
–0.05
–0.10
–0.15
–0.20
0
0.2
0.4
0.6
0.8
1.0
1.2
I_OUT (A)
Figure 5. Load Regulation, VOUT = 3.3 V, VIN = 12 V
V_OUT
1
IL
SW
4
2
CH1 5mV ^BW CH2 5V ^BW M400ns
CH4 500mA Ω ^BW
A CH2 7.4V
Figure 6. Steady State at Heavy Load, fSW = 1.4 MHz, IOUT = 1 A
V_OUT
1
IL
4
SW
2
CH1 20mV
BW _{CH2 5V}
BW _M10µs
CH4 200mA Ω ^BW
A CH2 8V
Figure 7. Steady State at Light Load, fSW = 1.4 MHz, IOUT = 40 mA
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