ADP1879 Analog Devices, ADP1879 Datasheet - Page 15

• Manufacturer Part Number: ADP1879
• Description: Synchronous Buck Controller with Constant On-Time and Valley Current Mode with Power Saving Mode
• Manufacturer: Analog Devices

Data Sheet
Figure 52. Negative Step During Heavy Load Transient Behavior—Forced PWM
Figure 53. Output Short-Circuit Behavior Leading to Hiccup Mode
2
1
3
4
1
2
4
3
1
2
3
4
CH1 10A Ω
CH3 20V
CH1 2V
CH3 10V
CH1 5V
CH3 10V
INDUCTOR CURRENT
at Light Load, 12 A (See Figure 95 Application Circuit)
Figure 54. Magnified Waveform During Hiccup Mode
OUTPUT VOLTAGE
SW NODE
SW NODE
LOW SIDE
B
B
W
W
LOW
SIDE
CH2 200mV
CH4 5V
CH2 5A Ω
CH4 5V
CH2 10A Ω
CH4 5V
B
W
M10µs
M4ms
M10µs
T
T
T
12A NEGATIVE STEP
OUTPUT VOLTAGE
23.8%
49.4%
36.2%
INDUCTOR CURRENT
OUTPUT VOLTAGE
LOW SIDE
SW NODE
A CH1
A CH1
A CH2
920mV
5.60A
8.20A
Rev. 0 | Page 15 of 40
Figure 57. Output Voltage Ripple Waveform During PSM Operation
1
2
4
3
1
2
4
3
1
2
3
4
Figure 55. Start-Up Behavior at Heavy Load, 12 A, 300 kHz
CH1 2V
CH3 10V
CH1 2V
CH3 10V
CH1 50mV
CH3 10V
Figure 56. Power-Down Waveform During Heavy Load
OUTPUT VOLTAGE
LOW SIDE
SW NODE
B
B
B
W
W
W
(See Figure 95 Application Circuit)
B
W
CH2 5A Ω
CH4 5V
CH2 5A Ω
CH4 5V
CH2 5A Ω
CH4 5V
INDUCTOR CURRENT
at Light Load, 2 A
OUTPUT VOLTAGE
LOW SIDE
SW NODE
OUTPUT VOLTAGE
INDUCTOR CURRENT
LOW SIDE
SW NODE
M2ms
M4ms
M2µs
ADP1878/ADP1879
T
T
T
32.8%
41.6%
35.8%
INDUCTOR CURRENT
A CH1
A CH1
A CH2
720mV
720mV
3.90A