AP7173-SPG-13 Diodes Inc, AP7173-SPG-13 Datasheet - Page 10

• Manufacturer Part Number: AP7173-SPG-13
• Description: IC REG LDO ADJ 1.5A 8SOIC
• Manufacturer: Diodes Inc

Specifications of AP7173-SPG-13

• Regulator Topology: Positive Adjustable
• Voltage - Output: 0.8 ~ 3.3 V
• Voltage - Input: 1 ~ 5.5 V
• Voltage - Dropout (typical): 0.165V @ 1.5A
• Number Of Regulators: 1
• Current - Output: 1.5A (Max)
• Current - Limit (min): 2A
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width) Exposed Pad, 8-eSOIC. 8-HSOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AP7173-SPG-13; AP7173-SPG-13DITR

Application Notes
BIAS VOLTAGE V
The AP7173 is a low V
an NMOS pass FET. The VCC pin must be connected to a
DC bias supply V
the gate drive of the pass FET to function properly and to
obtain low dropout. The V
higher than the V
27 illustrates the typical application circuit for the AP7173.
ADJUSTABLE OUTPUT VOLTAGE
With an external voltage divider, the AP7173 can provide
output voltage from 0.8V to 3.3V. R1 and R2 can be
calculated for any output voltage using the following
equation, where V
reference
combinations for commonly used output voltages. For
maximum voltage accuracy, R2 should be ≤ 5kΩ.
INPUT V
It is important to keep the IN and VCC pins clear of large
ripples, glitches and other noises by connecting capacitors
to the IN and VCC pins. The required capacitance on these
pins is strongly dependent on source and wiring
impedance of the supplies.
To provide good decoupling for the input power supply V
it is recommended that a ceramic capacitor with
capacitance of at least 1μF is connected between the IN
and GND pins at a location as close to them as possible.
High quality, low ESR capacitors should be used for better
performance.
It is critical to provide good decoupling to the VCC pin for
the AP7173’s internal control circuitry to function properly.
The minimum recommended capacitance for the V
1μF when the V
and V
recommended minimum capacitance for V
Again good quality, low ESR capacitors should be used for
optimum performance.
OUTPUT CAPACITOR
The output capacitor affects the stability and transient
response of the LDO. The AP7173 is designed to be stable
for all types of output capacitors ≥ 2.2μF, single or multiple
in parallel.
AP7173
Document number: DS31369 Rev. 9 - 2
Figure 27. Typical Application Circuit for AP7173
VCC
IN
voltage.
AND BIAS V
are connected to the same supply, the
VCC
V
IN
VCC
OUT
and V
and in the range of 2.7V-5.5V. Figure
VCC
REF
= V
for the internal control circuitry and
Refer
IN
=0.8 is the AP7173’s internal
REF
IN
, low dropout regulator that uses
VCC
are separate supplies. If the V
VCC
x (1 + R1/R2)
to
CAPACITORS
needs to be equal to or
Table
1
VCC
for
is 4.7μF.
resistor
VCC
www.diodes.com
1.5A LOW DROPOUT LINEAR REGULATOR WITH
IN
is
IN
,
10 of 15
Using high quality, low ESR capacitors and placing them
DROPOUT VOLTAGE
The very low dropout makes the AP7173 well suited for
high-current, low V
specified low-dropout performance for such applications,
the VCC pin should be connected to a separate supply of
at least 3.25V higher than V
application circuit where V
For applications where low dropout is not required or a
separate V
can be tied together. In this situation, a voltage difference
of at least 1.7V between the V
maintained for the V
the pass FET. Therefore, the V
more below V
PROGRAMMABLE SOFT-START
The AP7173 features a voltage-controlled soft-start that is
programmable with an external capacitor (C
AP7173 achieves a monotonic soft-start by tracking the
voltage ramp of the external soft-start capacitor until the
ramp voltage reaches the internal reference voltage.
close to the OUT and GND pins can improve perfomance.
Figure. 29 Typical Application Circuit for AP7173
Figure. 28 Typical Application Circuit for AP7173
VCC
Without an Auxiliary VCC Rail
Using Separate VCC and IN Rails
PROGRAMMABLE SOFT-START
IN
supply is not available, the IN and VCC pins
, as shown in Figure 29.
IN
/low V
VCC
to provide enough gate drive to
VCC
OUT
is 5V and V
applications. To achieve the
OUT
VCC
OUT
. Figure 28 shows an
and V
needs to be 1.7V or
OUT
AP7173
© Diodes Incorporated
OUT
is 1.2V.
has to be
April 2011
SS
). The