- 您現在的位置：買賣IC網 > PDF目錄374019 > ADP3025JRU-REEL (ANALOG DEVICES INC) High Efficiency Dual Output Power Supply Controller PDF資料下載
參數資料
| 型號： | ADP3025JRU-REEL |
| 廠商： | ANALOG DEVICES INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | High Efficiency Dual Output Power Supply Controller |
| 中文描述： | DUAL SWITCHING CONTROLLER, 350 kHz SWITCHING FREQ-MAX, PDSO38 |
| 封裝： | MO-153BD-1, TSSOP-36 |
| 文件頁數： | 11/24頁 |
| 文件大小： | 609K |
| 代理商： | ADP3025JRU-REEL |
ADP3025
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.
Rev. A | Page 11 of 24
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
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, f
OSC
= 200 kHz; when SYNC = 5 V, f
OSC
= 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.
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
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
相關PDF資料 |
PDF描述 |
|---|---|
| ADP3025 | High Efficiency Dual Output Power Supply Controller |
| ADP3050AR-33 | Circular Connector Cable Assembly; Connector Type A:Circular Plug; Connector Type B:Stripped End Leads; Cable Length:10ft RoHS Compliant: Yes |
| ADP3050AR-5 | Circular Connector Cable Assembly; Connector Type A:Circular Receptacle; Connector Type B:Stripped End Leads; Cable Length:10ft RoHS Compliant: Yes |
| ADP3050 | 200 kHz, 1 A High-Voltage Step-Down Switching Regulator |
| ADP3050AR | 200 kHz, 1 A High-Voltage Step-Down Switching Regulator |
相關代理商/技術參數 |
參數描述 |
|---|---|
| ADP3025JRUZ-REEL | 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述: |
| ADP3026 | 制造商:AD 制造商全稱:Analog Devices 功能描述:High-Efficiency Notebook Computer Power Supply Controller |
| ADP3026ARU | 制造商:AD 制造商全稱:Analog Devices 功能描述:High-Efficiency Notebook Computer Power Supply Controller |
| ADP3026JRUZ-REEL | 制造商:Rochester Electronics LLC 功能描述:DUAL OUTPUT SYNCHRNOUS BUCK CONTROLLER - Tape and Reel 制造商:Analog Devices 功能描述: |
| ADP3031 | 制造商:AD 制造商全稱:Analog Devices 功能描述:2 MHz PWM Boost Switching Regulator |
發(fā)布緊急采購，3分鐘左右您將得到回復。