参数资料
| 型号： | ISL6441IR-TK |
| 厂商： | Intersil |
| 文件页数： | 15/18页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM DUAL 1.4MHZ 28-QFN |
| 标准包装： | 1,000 |
| 应用： | 电源 |
| 电流 - 电源： | 2mA |
| 电源电压： | 5.6 V ~ 24 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-VFQFN 裸露焊盘 |
| 供应商设备封装： | 28-QFN 裸露焊盘（5x5） |
| 包装： | 带卷 (TR) |
ISL6441
60
50
40
30
20
10
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.
0
0.79
0.80
0.81 0.82 0.83
FEEDBACK VOLTAGE (V)
0.84
0.85
3. The loop formed by Input capacitor, the top FET and the
bottom FET must be kept as small as possible.
FIGURE 21. LINEAR CONTROLLER GAIN
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
destabilize 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.
15
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
selected based upon r DS(ON) , gate supply requirements,
and thermal management considerations.
FN9197.3
May 26, 2009
相关PDF资料 |
PDF描述 |
|---|---|
| ISL6443AIVZ | IC CTRLR SGL/STP DWN PWM 28TSSOP |
| ISL6443IR-TK | IC CTRLR PWM DUAL 300KHZ 28-QFN |
| ISL6444CA-T | IC CONTROLLER DDR 28-QSOP |
| ISL6445IAZ | IC REG CTRLR BUCK PWM CM 24-QSOP |
| ISL6455AIRZS2698 | IC REG TRPL SYNC DUAL LDO 24-QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6441IRZ | 功能描述:IC CTRLR SGL/STEP DOWN PWM 28QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 应用:热电冷却器 电流 - 电源:- 电源电压:3 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:28-SOIC（0.173"，4.40mm 宽）裸露焊盘 供应商设备封装:28-TSSOP 裸露焊盘 包装:管件 产品目录页面:1410 (CN2011-ZH PDF) |
| ISL6441IRZS2695 | 制造商:Intersil Corporation 功能描述: |
| ISL6441IRZ-T | 功能描述:IC CTRLR PWM DUAL 1.4MHZ 28-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 应用说明:Ultrasound Imaging Systems Application Note 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:37 系列:- 应用:医疗用超声波成像，声纳 电流 - 电源:- 电源电压:2.37 V ~ 6 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:56-WFQFN 裸露焊盘 供应商设备封装:56-TQFN-EP（8x8） 包装:管件 |
| ISL6441IRZ-TK | 功能描述:IC CTRLR PWM 1.4MHZ DUAL 28-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 应用说明:Ultrasound Imaging Systems Application Note 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:37 系列:- 应用:医疗用超声波成像，声纳 电流 - 电源:- 电源电压:2.37 V ~ 6 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:56-WFQFN 裸露焊盘 供应商设备封装:56-TQFN-EP（8x8） 包装:管件 |
| ISL6442EVAL1Z | 功能描述:EVAL BOARD FOR ISL6442 RoHS:是 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC，步升 输出及类型:1，非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
发布紧急采购，3分钟左右您将得到回复。