Data Sheet ADP1190A
THEORY OF OPERATION
The ADP1190A is a high-side load switch integrated with four
signal switches. The load switch and signal switches are turned
on by a low signal on the
EN
pin. When the device is disabled,
the T1 to T4 pins are actively pulled down with a nominal
resistance of 215 Ω. There is a 5 ms debounce counter on
EN
for use with a mechanical
EN
switch. That is, hold
EN
low for
5 ms before the device is enabled. If
EN
transitions high before
this timeout, the counter is reset and starts a new 5 ms count.
The signal paths are N-channel MOSFETs with 3 Ω on resistance.
Break-before-make logic control ensures that the active pull-down
is off before the signal path is enabled.
The ADP1190A also has an internal charge pump that provides
a regulated voltage at the gates of the N-channel MOSFETs,
resulting in a more stable signal switch on resistance over
different input voltages and temperature.
Figure 21. Block Diagram with ESD Protection Devices
S1
S2
S3
S4
IN
5ms
DEBOUNCE
LOAD
SWITCH
ADP1
190A
CHARGE
PUMP
EN
T1
T2
T3
T4
OUT
GND
ON
OFF
1
1539-021
Rev. 0 | Page 9 of 12
