Data Sheet

ADP160/ADP161/ADP162/ADP163

Rev. G | Page 15 of 24

To guarantee the performance of the ADP16x, it is imperative

that the effects of dc bias, temperature, and tolerances on the

behavior of the capacitors are evaluated for each.

ENABLE FEATURE

The ADP16x use the EN pin to enable and disable the VOUT

pin under normal operating conditions. As shown in Figure 37,

when a rising voltage on EN crosses the active threshold, VOUT

turns on. When a falling voltage on EN crosses the inactive

threshold, VOUT turns off.

4.5

3.5

2.5

4.0

3.0

2.0

1.5

0.5

1.0

0

0.5

0.7

0.9

1.1

1.3

1.5

EN VOLTAGE (V)

Figure 37. Typical EN Pin Operation

As shown in Figure 37, the EN pin has hysteresis built in. This

prevents on/off oscillations that can occur due to noise on the

EN pin as it passes through the threshold points.

The EN pin active/inactive thresholds are derived from the VIN

voltage. Therefore, these thresholds vary with changing input

voltage. Figure 38 shows typical EN active/inactive thresholds

when the input voltage varies from 2.2 V to 5.5 V.

1.1

1.0

0.9

0.8

0.7

0.6

0.5

2.0

2.5

3.0

3.5

EN RISE

EN FALL

4.0

4.5

5.0

INPUT VOLTAGE (V)

Figure 38. Typical EN Pin Thresholds vs. Input Voltage

The start-up behavior of the ADP16x is shown in Figure 39.

The shutdown behavior of the ADP160/ADP161 is shown in

Figure 40.

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

0

4500

4000

3500

3000

2500

2000

1500

1000

500

1.2V

2.5V

3.3V

TIME (µs)

EN

Figure 39. Typical Start-Up Behavior (ADP16x)

4.5

3.5

4.0

3.0

2.5

2.0

1.5

1.0

0.5

0

0

1000

800

600

400

200

1.2V

4.2V

TIME (µs)

EN

Figure 40. Typical Shutdown Behavior, No Load (ADP160/ADP161)

CURRENT LIMIT AND THERMAL OVERLOAD

PROTECTION

The ADP16x are protected against damage due to excessive

power dissipation by current and thermal overload protection

circuits. The ADP16x are designed to current limit when the

output load reaches 320 mA (typical). When the output load

exceeds 320 mA, the output voltage is reduced to maintain a

constant current limit.

Thermal overload protection is included, which limits the junction

temperature to a maximum of 150°C (typical). Under extreme

conditions (that is, high ambient temperature and power dissipation),

when the junction temperature starts to rise above 150°C, the

output is turned off, reducing the output current to zero. When

the junction temperature drops below 135°C, the output is turned

on again and the output current is restored to its nominal value.