APL158115FC-TRL ANPEC [Anpec Electronics Coropration], APL158115FC-TRL Datasheet - Page 8

• Manufacturer Part Number: APL158115FC-TRL
• Description: DUAL INPUT LOW DROPOUT REGULATOR
• Manufacturer: ANPEC [Anpec Electronics Coropration]

APL1581
General
The APL1581 (adjustable or fixed) regulator is a 5 ter-
minal device designed specifically to provide extremely
low dropout voltages comparable to the PNP type with-
out the disadvantage of the extra power dissipation
due to the base current associated with PNP regulators.
This is done by bringing out the control pin of the regu-
lator that provides the base current to the power NPN
and connecting it to a voltage that is greater than the
voltage present at the VIN pin. This flexibility makes
APL1581 ideal for applications where dual inputs are
available, such as a computer motherboard with an
ATX power supply that provides 5V and 3.3V to the
board.
APL1581 is equipped with a 1.25V reference, preci-
sion and fast voltage regulations, on-chip current and
thermal limits, and remote sensing capability to re-
duce system total cost.
Application Information
Copyright
Rev. B.5 - Mar., 2008
Typical Characteristics
80
70
60
50
40
30
20
10
V
0
IN-
Control Pin Current vs. Output Current
0
V
OUT
0.5
ANPEC Electronics Corp.
=1.0V
1
Output Current (A)
1.5
T
J
=75°C
2
2.5
T
J
=25°C
3
T
J
=0°C
T
3.5
J
T
=-50°C
J
=125°C
4
4.5
5
8
APL1581 is available in SOP-8P, TO-252-5,
TO-263-5, and TO-220-5 packages to meet different
power dissipation applications.
Output Voltage Setting
See Figure 1 Adjustable APL1581 develops a 1.25V
reference voltage between the VSENSE pin and the
ADJ pin. Placing a resistor between these two termi-
nals causes a constant current to flow through R1 and
down through R2 to set the overall output voltage. In
general, R1 is chosen so that this current is the speci-
fied minimum load current of 10mA.The current out of
the ADJ pin is small, typically 50 A and itadds to the
current from R1. Because IADJ is very small, it needs
to be considered only when very precise output volt-
age setting is required. For best regulation, the top of
the resistor divider should be connected directly to
the SENSE pin. The adjustable APL1581 can be pro-
V
70
60
50
40
30
20
10
0
IN-
Control Pin Current vs. Output Current
0
V
OUT
0.5
=4.25V
1
1.5
T
Output Current (A)
J
=75°C
2
T
2.5
J
=25°C
T
3
J
=0°C
T
www.anpec.com.tw
3.5
J
=-50°C
T
J
=125°C
4
4.5
5