- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384525 > ISL6431ACB (INTERSIL CORP) Advanced Pulse Width Modulation (PWM) Controller for Broadband Applications PDF資料下載
參數(shù)資料
| 型號： | ISL6431ACB |
| 廠商： | INTERSIL CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Advanced Pulse Width Modulation (PWM) Controller for Broadband Applications |
| 中文描述： | SWITCHING CONTROLLER, 340 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封裝： | PLASTIC, MS-012AA, SOIC-8 |
| 文件頁數(shù)： | 5/10頁 |
| 文件大?。?/td> | 215K |
| 代理商： | ISL6431ACB |
5
The overcurrent function will trip at a peak inductor current
(I
PEAK)
determined by:
where I
OCSET
is the internal OCSET current source (20
μ
A
typical). The OC trip point varies mainly due to the
MOSFET’s r
DS(ON)
variations. To avoid overcurrent tripping
in the normal operating load range, find the R
OCSET
resistor
from the equation above with:
1. The maximum r
DS(ON)
at the highest junction
temperature.
2. The minimum I
OCSET
from the specification table.
3. Determine I
PEAK
for
where
I is the output inductor ripple current.
For an equation for the ripple current see the section under
component guidelines titled ‘Output Inductor Selection’.
,
Soft Start
The POR function initiates the soft start sequence after the
overcurrent set point has been sampled. Soft start clamps the
error amplifier output (COMP pin) and reference input (non-
inverting terminal of the error amp) to the internally generated
Soft Start voltage. Figure 2 shows a typical start up interval
where the COMP/OCSET pin has been released from a
grounded (system shutdown) state. Initially, the COMP/OCSET
is used to sample the overcurrent setpoint by disabling the error
amplifier and drawing 20
μ
A through R
OCSET
. Once the
overcurrent level has been sampled, the soft start function is
initiated. The clamp on the error amplifier (COMP/OCSET pin)
initially controls the converter’s output voltage during soft start.
The oscillator’s triangular waveform is compared to the ramping
error amplifier voltage. This generates PHASE pulses of
increasing width that charge the output capacitor(s). When the
internally generated Soft Start voltage exceeds the feedback
(FB pin) voltage, the output voltage is in regulation. This
method provides a rapid and controlled output voltage rise. The
entire startup sequence typically take about 11ms.
Current Sinking
The ISL6431A incorporates a MOSFET shoot-through
protection method which allows a converter to sink current
as well as source current. Care should be exercised when
designing a converter with the ISL6431A when it is known
that the converter may sink current.
When the converter is sinking current, it is behaving as a
boost converter that is regulating it’s input voltage. This
means that the converter is boosting current into the V
CC
rail, which supplies the bias voltage to the ISL6431A. If there
is nowhere for this current to go, such as to other distributed
loads on the V
CC
rail, through a voltage limiting protection
device, or other methods, the capacitance on the V
CC
bus
will absorb the current. This situation will allow voltage level
of the V
CC
rail to increase. If the voltage level of the rail is
boosted to a level that exceeds the maximum voltage rating
of the ISL6431A, then the IC will experience an irreversible
failure and the converter will no longer be operational.
Ensuring that there is a path for the current to follow other
than the capacitance on the rail will prevent this failure
mode.
Application Guidelines
Layout Considerations
As in any high frequency switching converter, layout is very
important. Switching current from one power device to another
can generate voltage transients across the impedances of the
interconnecting bond wires and circuit traces. These
interconnecting impedances should be minimized by using
wide, short printed circuit traces. The critical components
should be located as close together as possible, using ground
plane construction or single point grounding.
FIGURE 1. OVERCURRENT OPERATION
TIME (5ms/DIV.)
OUTPUT INDUCTOR
CURRENT
5A/DIV.
I
PEAK
I
x R
DS ON
)
---------------r
=
I
PEAK
I
OUT MAX
)
I
2
(
----------
)
+
>
FIGURE 2. SOFT START INTERVAL
V
OUT
500mV/DIV.
COMP/OCSET
1V/DIV.
TIME (2ms/DIV.)
ISL6431A
相關PDF資料 |
PDF描述 |
|---|---|
| ISL6520A | Adjustable Precision Shunt Regulator 3-SOT-23 -40 to 125 |
| ISL6525CBZ | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| ISL6525 | Adjustable Precision Shunt Regulator 5-SOT-23 -40 to 125 |
| ISL6525CB | Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller |
| ISL6526ACRZ | Single Synchronous Buck Pulse-Width Modulation (PWM) Controller |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| ISL6431CB | 功能描述:電壓模式 PWM 控制器 For Home Gateways RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
| ISL6431CB-T | 功能描述:IC REG CTRLR BUCK PWM VM 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 包裝:帶卷 (TR) |
| ISL6431IB | 制造商:Intersil Corporation 功能描述: |
| ISL6432CB | 制造商:Intersil Corporation 功能描述: |
| ISL6432CB-T | 功能描述:IC REG QD BCK/LINEAR 16-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標準包裝:2,500 系列:- 拓撲:降壓（降壓）同步（3），線性（LDO）（2） 功能:任何功能 輸出數(shù):5 頻率 - 開關:300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅(qū)動器:無 帶監(jiān)控器:無 帶序列發(fā)生器:是 電源電壓:5.6 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類型:* 封裝/外殼:* 供應商設備封裝:* 包裝:* |
發(fā)布緊急采購，3分鐘左右您將得到回復。