100% Duty Cycle, Low-Noise,
Step-Down, PWM DC-DC Converter
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 2, TA = +25°C, unless otherwise noted.)
HEAVY-LOAD, PWM-MODE
SWITCHING WAVEFORMS
LIGHT-LOAD, PWM-MODE
SWITCHING WAVEFORMS
A
B
C
0mA
1µs/div
VIN = 5V, VOUT = 3.3V, LOAD = 500mA
A: LX, 5V/div
B: VOUT, 20mV/div, AC COUPLED
C: INDUCTOR CURRENT, 500mA/div
A
B
C
1µs/div
VIN = 5V, VOUT = 3.3V, LOAD = 0mA
A: LX, 5V/div
B: VOUT, 20mV/div, AC COUPLED
C: INDUCTOR CURRENT, 500mA/div
LIGHT-LOAD, PFM-MODE
SWITCHING WAVEFORMS
A
B
C
1µs/div
VIN = 5V, VOUT = 3.3V, LOAD = 0mA
A: LX, 5V/div
B: VOUT, 20mV/div, AC COUPLED
C: INDUCTOR CURRENT, 200mA/div
MEDIUM-LOAD, PFM-MODE
SWITCHING WAVEFORMS
A
B
C
10µs/div
VIN = 5V, VOUT = 3.3V, LOAD = 70mA
A: LX, 5V/div
B: VOUT, 20mV/div, AC COUPLED
C: INDUCTOR CURRENT, 200mA/div
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