Datasheet

Data Sheet ADP160/ADP161/ADP162/ADP163
Rev. H | 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
V
OUT
(V)
EN VOLTAGE (V)
08628-035
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
EN VOLTAGE (V)
INPUT VOLTAGE (V)
08628-036
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 450040003500
3000
25002000
15001000
500
1.2V
2.5V
3.3V
EN VOLTAGE/V
OUT
(V)
TIME (µs)
EN
08628-037
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
1000800600
400200
1.2V
4.2V
EN VOLTAGE/V
OUT
(V)
TIME (µs)
EN
08628-038
C
OUT
= 1µF
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.