Datasheet

Data Sheet ADP190/ADP191
Rev. E | Page 11 of 16
2
CH1 1V CH2 1V M4µs A CH1 2.34V
T 15.96µs
1
T
I
LOAD
= 100mA
C
LOAD
= 1µF
V
EN
= 3.6V
V
OUT
= 1.2V
V
OUT
= 1.8V
V
OUT
= 2.5V
V
EN
07874-017
Figure 23. ADP190 Typical Turn-On Delay Time with Varying Input Voltage
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
5000 100
200 300
400
TIME (µs)
INPUT VOLTAGE (V)
V
EN
= 1.8V
V
OUT
= 1.2V
V
OUT
= 1.8V
V
OUT
= 3.6V
07874-124
Figure 24. ADP191 Typical Turn-On Delay Time with Varying Input Voltage
The rise time is defined as the delta between the time from 10%
to 90% of VOUT reaching its final value. It is dependent on the
RC time constant where C = load capacitance (C
LOAD
) and R =
RDS
ON
||R
LOAD
. Because RDS
ON
is usually smaller than R
LOAD
, an
adequate approximation for RC is RDS
ON
× C
LOAD
. The ADP190/
ADP191 do not need any input or load capacitor, but capacitors
can be used to suppress noise on the board. If significant load
capacitance is connected, inrush current is a concern.
The ADP191 contains circuitry to limit the slew rate of the
switch turn to reduce the turn on inrush current. See Figure 25
and Figure 26 for a comparison of rise time and inrush current.
2
3
CH1 2V
CH3 2.00mA Ω
CH2 2V M10µs A CH1 2.32V
T
40.16µs
1
T
V
OUT
= 1.8V
I
LOAD
= 200mA
C
LOAD
= 1µF
V
EN
= 3.6V
V
EN
V
OUT
I
IN
07874-029
Figure 25. ADP190 Typical Rise Time and Inrush Current with C
LOAD
= 1 μF
2
3
CH1 2.00V CH2 100mA
CH3 2.00V
M20.0µs A CH1 1.24V
T 10.20%
1
V
EN
I
IN
V
OUT
T
07874-126
Figure 26. ADP191 Typical Rise Time and Inrush Current with C
LOAD
= 1 μF
2
3
CH1 2V
CH3 2.00mA Ω
CH2 2V M10µs A CH1 1.00V
T 39.8µs
1
V
OUT
= 1.8V
I
LOAD
= 200mA
C
LOAD
= 4.7µF
V
EN
= 3.6V
V
EN
V
OUT
I
IN
T
07874-019
Figure 27. ADP190 Typical Rise Time and Inrush Current with C
LOAD
= 4.7 µF