Data Sheet

ADP198

Rev. D | Page 11 of 16

THEORY OF OPERATION

GND

EN

VIN

SEL0

SEL1

VOUT

ADP198

SLEW

RATE CONTROL

LEVEL SHIFT

REVERSE

POLARITY

PROTECTION

Figure 22. Functional Block Diagram

The ADP198 is a high-side PMOS load switch that is designed

for supply operation between 1.65 V and 6.5 V. The PMOS load

supports 1 A of continuous load current. The ADP198 features

low quiescent current at 2.5 μA typical using a 2.8 V supply.

The enable input incorporates a nominal 4 MΩ pull-down

resistor. SEL0 and SEL1 program the start-up time of the load

switch to reduce inrush current when the switch is turned on.

The reverse current protection circuitry prevents current from

flowing backwards through the ADP198 when the output voltage

is greater than the input voltage. A comparator senses the differ-

ence between the input and output voltages. When the difference

between the input voltage and output voltage exceeds 75 mV,

the body of the PFET is switched to VOUT and turned off or

opened. In other words, the gate is connected to VOUT.

The packaging is a space-saving 1 mm × 1 mm, 4-ball WLCSP.

The ADP198 is also available in a 2 mm × 2 mm × 0.55 mm,

0.5 mm pitch LFCSP.