ADP1875 Analog Devices, ADP1875 Datasheet - Page 14

• Manufacturer Part Number: ADP1875
• Description: Synchronous Buck Controller with Constant On-Time, Valley Current Mode, and Power Saving Mode
• Manufacturer: Analog Devices

ADP1874/ADP1875
Figure 41. Internal Boost Rectifier Drop vs. VREG (Low Input Voltage)
1280
1200
1120
1040
800
720
640
560
480
400
320
240
160
960
880
800
720
640
560
480
400
320
240
160
720
640
560
480
400
320
240
160
80
80
80
300
2.7
2.7
Figure 42. Internal Boost Rectifier Drop vs. VREG
Figure 40. Internal Rectifier Drop vs. Frequency
400
3.1
3.1
VREG = 2.7V
VREG = 3.6V
VREG = 5.5V
V
V
V
300kHz
1MHz
IN
IN
IN
= 5.5V
= 13V
= 16.5V
500
3.5
3.5
Over V
FREQUENCY (kHz)
600
3.9
3.9
VREG (V)
VREG (V)
IN
Variation
1MHz
300kHz
+125°C
+25°C
–40°C
+125°C
+25°C
–40°C
700
4.3
4.3
800
4.7
4.7
900
T
5.1
5.1
A
= 25°C
1000
5.5
5.5
Rev. 0 | Page 14 of 44
Figure 44. Power Saving Mode (PSM) Operational Waveform, 100 mA
Figure 43. Lower-Side MOSFET Body Diode Conduction Time vs. VREG
1
2
3
4
1
2
3
4
80
72
64
56
48
40
32
24
16
8
CH1 50mV
CH3 10V
CH1 50mV
CH3 10V
2.7
Figure 45. PSM Waveform at Light Load, 500 mA
3.1
B
B
W
W
B
B
W
W
3.5
CH2 5A Ω
CH4 5V
CH2 5A Ω
CH4 5V
3.9
VREG (V)
M400ns
M4.0µs
T
T
35.8%
35.8%
4.3
300kHz
1MHz
OUTPUT VOLTAGE
INDUCTOR CURRENT
SW NODE
LOW SIDE
OUTPUT VOLTAGE
INDUCTOR CURRENT
SW NODE
LOW SIDE
4.7
A CH2
A CH2
5.1
+125°C
+25°C
–40°C
3.90A
3.90A
5.5