Datasheet

ADP1870/ADP1871 Data Sheet
Rev. B | Page 16 of 44
CH1 1V
B
W
CH2 5A Ω
CH3 10V
B
W
CH4 2V
M1ms A CH1 1.56V
T 63.2%
1
2
3
4
OUTPUT VOLTAGE
INDUCTOR CURRENT
SW NODE
LOW SIDE
08730-057
Figure 58. Soft Start and RES Detect Waveform
2
CH2 5V
CH3 5V
MATH 2V 40ns
CH4 2V
M40ns A CH2 4.20V
T 29.0%
3
M
4
HIGH SIDE
HS MINUS
SW
SW NODE
LOW SIDE
T
A
= 25°C
08730-058
Figure 59. Output Drivers and SW Node Waveforms
2
CH2 5V
CH3 5V
MATH 2V 40ns
CH4 2V
M40ns A CH2 4.20V
T 29.0%
3
M
4
HIGH SIDE
HS MINUS
SW
SW NODE
LOW SIDE
16ns ( t
f ,DRVL
)
25ns ( t
r ,DRVH
)
22ns ( t
pdh DRVH
)
T
A
= 25°C
08730-059
Figure 60. Upper-Side Driver Rising and Lower-Side Falling Edge Waveforms
(C
IN
= 4.3 nF (Upper-/Lower-Side MOSFET),
Q
TOTAL
= 27 nC (V
GS
= 4.4 V (Q1), V
GS
= 5 V (Q3))
2
CH2 5V
CH3 5V
MATH 2V 20ns
CH4 2V
M20ns A CH2 4.20V
T 39.2%
3
M
4
HIGH SIDE
HS MINUS
SW
SW NODE
LOW SIDE
18ns ( t
r ,DRVL
)
24ns ( t
pdh ,DRVL
)
11ns ( t
f ,DRVH
)
T
A
= 25°C
08730-060
Figure 61. Upper-Side Driver Falling and Lower-Side Rising Edge Waveforms
(C
IN
= 4.3 nF (Upper-/Lower-Side MOSFET),
Q
TOTAL
= 27 nC (V
GS
= 4.4 V (Q1), V
GS
= 5 V (Q3))
570
550
530
510
490
470
450
430
–40 –20 120100806040200
TRANSCONDUCTANCE (µS)
TEMPERATURE (°C)
V
REG
= 5.5V
V
REG
= 3.6V
V
REG
= 2.7V
08730-061
Figure 62. Transconductance (G
m
) vs. Temperature
680
330
380
430
480
530
580
630
2.7 3.0 5.44.8 5.14.54.23.93.63.3
TRANSCONDUCTANCE (µS)
V
REG
(V)
+125°C
+25°C
–40°C
08730-062
Figure 63. Transconductance (G
m
) vs. V
REG