|
|
PDF ADP3025JRU-REEL Data sheet ( Hoja de datos )
| Número de pieza | ADP3025JRU-REEL | |
| Descripción | High Efficiency Dual Output Power Supply Controller | |
| Fabricantes | Analog Devices | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de ADP3025JRU-REEL (archivo pdf) en la parte inferior de esta página. Total 24 Páginas | ||
|
No Preview Available !
FEATURES
Wide input voltage range: 5.5 V to 25 V
High conversion efficiency > 96%
Integrated current sense—no external resistor required
Low shutdown current: 19 µA (typical)
Voltage mode PWM with input feed-forward for fast line
transient response
Dual synchronous buck controllers
Built-in gate drive boost circuit for driving external high-side
N-channel MOSFET
2 independently programmable output voltages:
Fixed 3.3 V or adjustable (800 mV to 6.0 V)
Fixed 5 V or adjustable (800 mV to 6.0 V)
Programmable PWM frequency
Integrated linear regulator controller
Extensive circuit protection functions
APPLICATIONS
Portable instruments
General-purpose dc-to-dc converters
High Efficiency Dual Output
Power Supply Controller
ADP3025
GENERAL DESCRIPTION
The ADP3025 is a highly efficient, dual synchronous buck
switching regulator controller optimized for converting a
battery or adapter input into the supply voltage required in
portable products and industrial systems. The oscillator
frequency can be programmed for 200 kHz or 300 kHz
operation, or can be synchronized to an external clock signal of
up to 350 kHz.
The ADP3025 provides accurate and reliable short-circuit
protection by using an internal current sense circuit that
reduces cost and increases overall efficiency. Other protection
features include programmable soft start, UVLO, and integrated
output undervoltage/overvoltage protection. The ADP3025
contains a linear regulator controller designed to drive an
external N-channel MOSFET. The linear regulator output is
adjustable and can be used to generate auxiliary supply voltages.
The ADP3025 is specified over the 0°C to 70°C commercial
temperature range and is available in a 38-lead TSSOP package.
VIN
5.5V TO 25V
5V
SIMPLIFIED FUNCTIONAL BLOCK DIAGRAM
Q3
L2
Q4
5V LINEAR
REGULATOR
800mV
REF
PFO
5V
SWITCHING
CONTROLLER
3.3V
SWITCHING
CONTROLLER
Q1
L1
Q2
3.3V
SS5
PWRGD
POWER-ON
RESET
LINEAR
CONTROLLER
ADP3025
SS3
Q5
2.5V
Figure 1.
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
1 page  
ABSOLUTE MAXIMUM RATINGS
Table 2. ADP3025 Stress Ratings
Parameter
Rating
VIN to AGND
AGND to PGND
–0.3 V to +27 V
±0.3 V
INTVCC
AGND – 0.3 V to +6 V
BST5, BST3 to PGND
–0.3 V to +32 V
BST5 to SW5
–0.3 V to +6 V
BST3 to SW3
CS5, CS3
SW3, SW5 to PGND
SD
–0.3 V to +6 V
AGND – 0.3 V to VIN
–2 V to VIN + 0.3 V
AGND – 0.3 V to +27 V
DRVL5/3 to PGND
DRVH5/3 to SW5/3
All Other Inputs and Outputs
θJA
Operating Ambient Temperature
Range
–0.3 V to INTVCC + 0.3 V
–0.3 V to INTVCC + 0.3 V
AGND – 0.3 V to
INTVCC + 0.3 V
98°C/W
0°C to 70°C
Junction Temperature Range
0°C to 150°C
Storage Temperature Range
–65°C to +150°C
Lead Temperature Range
(Soldering 10 sec)
300°C
ADP3025
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those listed in the operational sections
of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
this product features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
Rev. A | Page 5 of 24
5 Page 
THEORY OF OPERATION
The ADP3025 contains two synchronous step-down buck
controllers and a linear regulator controller. The buck control-
lers in the ADP3025 have the ability to provide either fixed
3.3 V and 5 V outputs or independently adjustable (800 mV to
6.0 V) outputs. Efficiency is improved by eliminating the
external current sense resistor, which is the main contributor to
loss during high current, low output voltage conditions.
INTERNAL 5 V SUPPLY (INTVCC)
An internal low dropout regulator (LDO) generates a 5 V
supply (INTVCC) that powers all the functional blocks within
the IC. The total current rating of this LDO is 50 mA. However,
this current is used for supplying gate drive power; current
should not be drawn from this pin for other purposes. Bypass
INTVCC to AGND with a 4.7 µF capacitor. A UVLO circuit is
also included in the regulator. When INTVCC < 4.05 V, the two
switching regulators and the linear regulator controller are shut
down. The UVLO hysteresis voltage is about 300 mV. The
internal LDO has a built-in foldback current limit so that it is
protected if a short circuit is applied to the 5 V output.
REFERENCE (REF)
The ADP3025 contains a precision 800 mV reference. Bypass
REF to AGND with a 22 nF ceramic capacitor. The reference is
intended for internal use only.
BOOSTED HIGH-SIDE GATE DRIVE SUPPLY (BST)
The gate drive voltage for the high-side N-channel MOSFET is
generated by a flying-capacitor boost circuit. The boost capaci-
tor connected between BST and SW is charged from the
INTVCC supply. Use only small-signal diodes for the boost
circuit.
SYNCHRONOUS RECTIFIER (DRVL)
Synchronous rectification is used to reduce conduction losses
and ensure proper startup of the boost gate driver circuit.
Antishoot-through protection has been included to prevent
Table 4. Operating Modes
SD SS5
Low
High
SS5 < 0.6 V
High
0.6 V < SS5 < 1.8 V
High 1.8 V < SS5
High
High
SS3
SS3 < 0.6 V
0.6 V < SS3 < 1.8 V
1.8 V < SS3
ADP3025
cross-conduction during switch transitions. The low-side driver
must be turned off before the high-side driver is turned on. For
typical N-channel MOSFETs, the dead time is approximately
50 ns. On the other edge, a dead time of approximately 50 ns is
achieved by an internal delay circuit. In discontinuous conduc-
tion mode (DCM), the synchronous rectifier is turned off when
the current flowing through the low-side MOSFET falls to zero.
In continuous conduction mode (CCM), the current flowing
through the low-side MOSFET never reaches zero, so the
synchronous rectifier is turned off by the next clock cycle.
OSCILLATOR FREQUENCY AND
SYNCHRONIZATION (SYNC)
The SYNC pin controls the oscillator frequency. When SYNC =
0 V, fOSC = 200 kHz; when SYNC = 5 V, fOSC = 300 kHz. 300 kHz
operation minimizes external component size and cost; 200 kHz
operation provides better efficiency and lower dropout. The
SYNC pin can also be used to synchronize the oscillator with an
external 5 V clock signal. A low-to-high transition on SYNC
initiates a new cycle. The synchronization range is 230 kHz to
350 kHz.
SHUTDOWN SD
Holding SD low puts the ADP3025 into ultralow current shut-
down mode. For automatic startup, SD can be tied to VIN via a
resistor.
SOFT START AND POWER-UP SEQUENCING (SS)
SS3 and SS5 are soft start pins for the two controllers. A 2 µA
pull-up current is used to charge an external soft start capacitor.
Power-up sequencing can easily be done by choosing different
capacitance. When SS3/SS5 < 0.6 V, the two switching regulators
are turned off. When 0.6 V < SS5/SS3 < 1.8 V, the regulators
start working in soft start mode. When SS3/SS5 > 1.8 V, the
regulators are in normal operating mode. The minimum soft
start time (~20 µs) is set by an internal capacitor. Table 4 shows
the ADP3025 operating modes.
Description
All Circuits Turned Off
5 V and 3.3 V Off; INTVCC = 5 V, REF = 800 mV
5 V in Soft Start
5 V in Normal Operation
3.3 V in Soft Start
3.3 V in Normal Operation
Rev. A | Page 11 of 24
11 Page | ||
| Páginas | Total 24 Páginas | |
| PDF Descargar | [ Datasheet ADP3025JRU-REEL.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| ADP3025JRU-REEL | High Efficiency Dual Output Power Supply Controller | Analog Devices |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |