AP1086 Ver la hoja de datos (PDF) - Diodes Incorporated.
Número de pieza
componentes Descripción
Lista de partido
AP1086 Datasheet PDF : 8 Pages
| |||
Typical Application
AP1086
1.5A LOW DROPOUT POSITIVE ADJUSTABLE OR
FIXED-MODE REGULATOR
5V to 3.3V Fixed Mode Regulator
5V
C1
100uF
Vin
Vout
GND
Tab is Vout
3.3V/1.5A
C2
100uF
Adjustable Regulator
5V
C1
100uF
Vin
Vout
Adj
Tab is Vout
VOUT=Vref × (1+R2/R1)
R1
121 Ω
R2
121 Ω
2.5V/1.5A
C2
100uF
Note:
Vo
=
VREF
∗ (1+
R2 )
R1
Functional Description
Introduction
The AP1086 adjustable or fixed-mode Low Dropout (LDO) regulator is a 3 terminal device which can easily be programmed by internal
mask change to any voltages within the range of 1.25V to Vin-1.4V. The AP1086 only needs 1.4V differential between Vin and Vout to
maintain output regulation. In addition, the output voltage tolerances are also extremely tight and they include the transient response as
part of the specification. For example, Intel VRE specification calls for a total of +/- 100mV including initial tolerance, load regulation and 0
to 1.5A load step.
The AP1086 is specifically designed to meet the fast current transient needs as well as providing an accurate initial voltage, reducing the
overall system cost with the need for fewer output capacitors.
Load Regulation
Since the AP1086 is only a 3 terminal device, it is not possible to provide true remote sensing of the output voltage at the load. But it can
supply good load regulation by internal feedback bypass the external loss such as adjustable mode.
Stability
The AP1086 requires the use of an output capacitor as part of the frequency compensation in order to make the regulator stable. For
most applications a minimum of 10uF aluminum electrolytic capacitor insures both stability and good transient response.
Thermal Design
The AP1086 incorporates an internal thermal shutdown that protects the device when the junction temperature exceeds the maximum
allowable junction temperature. Although this device can operate with junction temperatures in the range of 150oC, it is recommended
that the selected heat sink be chosen such that during maximum continuous load operation the junction temperature is kept below the
temperature.
Layout Consideration
The output capacitors must be located as close to the Vout terminal of the device as possible. It is recommended to use a section of a
layer of the PC board as a plane to connect the Vout pin to the output capacitors to prevent any high frequency oscillation that may result
due to excessive trace inductance.
AP1086 Rev. 2
4 of 8
www.diodes.com
MARCH 2007
© Diodes Incorporated
Share Link: 