參數(shù)資料
型號(hào)： ISL6441IRZ-T
廠商： INTERSIL CORP
元件分類(lèi)： 穩(wěn)壓器
英文描述： 16-Bit Bus Termination Networks With Bus Hold Function 20-SOIC -40 to 85
中文描述： DUAL SWITCHING CONTROLLER, 1550 kHz SWITCHING FREQ-MAX, PQCC28
封裝： 5 X 5 MM, ROHS COMPLIANT, PLASTIC, MO-220, QFN-28
文件頁(yè)數(shù)： 15/18頁(yè)
文件大?。?/td> 382K
代理商： ISL6441IRZ-T
15
FN9197.1
October 4, 2005
Base-Drive Noise Reduction
The high-impedance base driver is susceptible to system
noise, especially when the linear regulator is lightly loaded.
Capacitively coupled switching noise or inductively coupled
EMI onto the base drive causes fluctuations in the base
current, which appear as noise on the linear regulator’s
output. Keep the base drive traces away from the step-down
converter, and as short as possible, to minimize noise
coupling. A resistor in series with the gate drivers reduces
the switching noise generated by PWM. Additionally, a
bypass capacitor may be placed across the base-to-emitter
resistor. This bypass capacitor, in addition to the transistor’s
input capacitor, could bring in second pole that will de-
stabilize the linear regulator. Therefore, the stability
requirements determine the maximum base-to-emitter
capacitance.
Layout Guidelines
Careful attention to layout requirements is necessary for
successful implementation of an ISL6441 based DC/DC
converter. The ISL6441 switches at a very high frequency
and therefore the switching times are very short. At these
switching frequencies, even the shortest trace has
significant impedance. Also the peak gate drive current rises
significantly in extremely short time. Transition speed of the
current from one device to another causes voltage spikes
across the interconnecting impedances and parasitic circuit
elements. These voltage spikes can degrade efficiency,
generate EMI, increase device over voltage stress and
ringing. Careful component selection and proper PC board
layout minimizes the magnitude of these voltage spikes.
There are two sets of critical components in a DC/DC
converter using the ISL6441; the switching power
components and the small signal components. The
switching power components are the most critical from a
layout point of view because they switch a large amount of
energy so they tend to generate a large amount of noise.
The critical small signal components are those connected to
sensitive nodes or those supplying critical bias currents. A
multi-layer printed circuit board is recommended.
Layout Considerations
1. The Input capacitors, Upper FET, Lower FET, Inductor
and Output capacitor, should be placed first. Isolate these
power components on the topside of the board with their
ground terminals adjacent to one another. Place the input
high frequency decoupling ceramic capacitor very close
to the MOSFETs.
2. Use separate ground planes for power ground and small
signal ground. Connect the SGND and PGND together
close of the IC. Do not connect them together anywhere
else.
3. The loop formed by Input capacitor, the top FET and the
bottom FET must be kept as small as possible.
4. Insure the current paths from the input capacitor to the
MOSFET; to the output inductor and output capacitor are
as short as possible with maximum allowable trace
widths.
5. Place The PWM controller IC close to lower FET. The
LGATE connection should be short and wide. The IC can
be best placed over a quiet ground area. Avoid switching
ground loop current in this area.
6. Place Vcc_5V bypass capacitor very close to Vcc_5V pin
of the IC and connect its ground to the PGND plane.
7. Place the gate drive components BOOT diode and BOOT
capacitors together near controller IC.
8. The output capacitors should be placed as close to the
load as possible. Use short wide copper regions to
connect output capacitors to load to avoid inductance and
resistances.
9. Use copper filled polygons or wide but short trace to
connect junction of upper FET, lower FET and output
inductor. Also keep the PHASE node connection to the IC
short. Do not unnecessarily oversize the copper islands
for PHASE node. Since the phase nodes are subjected to
very high dv/dt voltages, the stray capacitor formed
between these islands and the surrounding circuitry will
tend to couple switching noise.
10. Route all high speed switching nodes away from the
control circuitry.
11. Create a separate small analog ground plane near the IC.
Connect SGND pin to this plane. All small signal
grounding paths including feedback resistors, current
limit setting resistors and SYNC/SDx pull down resistors
should be connected to this SGND plane.
12. Ensure the feedback connection to output capacitor is
short and direct.
Component Selection Guidelines
MOSFET Considerations
The logic level MOSFETs are chosen for optimum efficiency
given the potentially wide input voltage range and output
power requirements. Two N-Channel MOSFETs are used in
each of the synchronous-rectified buck converters for the
PWM1 and PWM2 outputs. These MOSFETs should be
0.79
0.8
0.82
0.83
0.85
0
40
60
FEEDBACK VOLTAGE (V)
E
20
50
30
10
C
0.81
0.84
FIGURE 21. LINEAR CONTROLLER GAIN
ISL6441
相關(guān)PDF資料
PDF描述
ISL6441IR-T 1.4MHz Dual, 180 Degree Out-of-Phase, Step-Down PWM and Single Linear Controller
ISL6443IR 16-Bit Bus Termination Networks With Bus Hold Function 20-SO -40 to 85
ISL6443IR-T 300kHz Dual, 180 Degree Out-of-Phase, Step-Down PWM and Single Linear Controller
ISL6443IR-TK 300kHz Dual, 180 Degree Out-of-Phase, Step-Down PWM and Single Linear Controller
ISL6443IRZ 300kHz Dual, 180 Degree Out-of-Phase, Step-Down PWM and Single Linear Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ISL6441IRZ-TK 功能描述:IC CTRLR PWM 1.4MHZ DUAL 28-QFN RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 電源管理 - 專(zhuān)用 系列:- 應(yīng)用說(shuō)明:Ultrasound Imaging Systems Application Note 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:37 系列:- 應(yīng)用:醫(yī)療用超聲波成像，聲納 電流 - 電源:- 電源電壓:2.37 V ~ 6 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:56-WFQFN 裸露焊盤(pán) 供應(yīng)商設(shè)備封裝:56-TQFN-EP（8x8） 包裝:管件
ISL6442EVAL1Z 功能描述:EVAL BOARD FOR ISL6442 RoHS:是 類(lèi)別:編程器，開(kāi)發(fā)系統(tǒng) >> 評(píng)估板 - DC/DC 與 AC/DC（離線）SMPS 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:True Shutdown™ 主要目的:DC/DC，步升 輸出及類(lèi)型:1，非隔離 功率 - 輸出:- 輸出電壓:- 電流 - 輸出:1A 輸入電壓:2.5 V ~ 5.5 V 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):升壓 頻率 - 開(kāi)關(guān):3MHz 板類(lèi)型:完全填充 已供物品:板 已用 IC / 零件:MAX8969
ISL6442IA 功能描述:IC REG TRPL BCK/LINEAR 24QSOP RoHS:否 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?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(kāi)關(guān):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(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 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(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
ISL6442IA-TK 功能描述:IC REG TRPL BCK/LINEAR 24QSOP RoHS:否 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?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(kāi)關(guān):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(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 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(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
ISL6442IAZ 功能描述:IC REG TRPL BCK/LINEAR 24QSOP RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?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(kāi)關(guān):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(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 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(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*