参数资料
型号: FDMF6705B
厂商: Fairchild Semiconductor
文件页数: 16/19页
文件大小: 0K
描述: MOSFET DRMOS 40A 300KHZ 40PQFN
标准包装: 1
系列: XS™ DrMOS
类型: 高端/低端驱动器
输入类型: PWM
输出数: 1
电流 - 峰值输出: 40A
电源电压: 4.5 V ~ 5.5 V
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 40-PowerTFQFN
供应商设备封装: 40-PQFN(6x6)
包装: 标准包装
其它名称: FDMF6705BDKR
PCB Layout Guidelines
Figure 30 provides an example of a proper layout for
critical components. All of the high-current paths, such
as V IN , V SWH , V OUT , and GND copper, should be short
and wide for low inductance and resistance. This
technique achieves a more stable and evenly distributed
current flow, along with enhanced heat radiation and
system performance.
The following guidelines are recommendations for the
PCB designer:
1. Input ceramic bypass capacitors must be placed
close to the VIN and PGND pins. This helps reduce
the high-current power loop inductance and the input
current ripple induced by the power MOSFET
switching operation.
2. The V SWH copper trace serves two purposes. In
addition to being the high-frequency current path
from the DrMOS package to the output inductor, it
also serves as a heat sink for the low-side MOSFET
in the DrMOS package. The trace should be short
and wide enough to present a low-impedance path
for the high-frequency, high-current flow between the
DrMOS and inductor to minimize losses and
BOOT-to-VSWH loop size, including R BOOT and
C BOOT , should be as small as possible. The boot
resistor may be required when operating near the
maximum rated V IN . The boot resistor is effective at
controlling the high-side MOSFET turn-on slew rate
and VSHW overshoot. R BOOT can improve noise
operating margin in synchronous buck designs that
have noise issues due to ground bounce or high
positive and negative VSWH ringing. However,
inserting a boot resistance lowers the DrMOS
efficiency. Efficiency versus noise trade-offs must be
considered. R BOOT values from 0.5 to 3.0 Ω are
typically effective in reducing VSWH overshoot.
The VIN and PGND pins handle large current
transients with frequency components greater than
100 MHz. If possible, these pins should be
connected directly to the VIN and board GND
planes. The use of thermal relief traces in series with
these pins is discouraged since this adds
inductance to the power path. This added inductance
in series with either the VIN or PGND pin degrades
system noise immunity by increasing positive and
negative VSWH ringing.
temperature rise. Note that the VSWH node is a
high-voltage and high-frequency switching node with
high noise potential. Care should be taken to
minimize coupling to adjacent traces. Since this
copper trace also acts as a heat sink for the lower
FET, balance using the largest area possible to
improve DrMOS cooling while maintaining
acceptable noise emission.
8.
9.
CGND pad and PGND pins should be connected to
the GND plane copper with multiple vias for stable
grounding. Poor grounding can create a noise
transient offset voltage level between CGND and
PGND. This could lead to faulty operation of the
gate driver and MOSFETs.
Ringing at the BOOT pin is most effectively
MOSFETs are used in the output
4. PowerTrench
3. An output inductor should be located close to the
FDMF6705B to minimize the power loss due to the
VSWH copper trace. Care should also be taken so
the inductor dissipation does not heat the DrMOS.
?
stage. The power MOSFETs are effective at
minimizing ringing due to fast switching. In most
cases, no VSWH snubber is required. If a snubber is
used, it should be placed close to the VSWH and
PGND pins. The resistor and capacitor need to be of
proper size for the power dissipation.
5. VCIN, VDRV, and BOOT capacitors should be
placed as close as possible to the VCIN to CGND,
VDRV to CGND, and BOOT to PHASE pins to
ensure clean and stable power. Routing width and
length should be considered.
6. Include a trace from PHASE to VSWH to improve
noise margin. Keep the trace as short as possible.
7. The layout should include a place holder to insert a
small-value series boot resistor (R BOOT ) between the
boot capacitor (C BOOT ) and DrMOS BOOT pin. The
? 2011 Fairchild Semiconductor Corporation
FDMF6705B ? Rev. 1.0.3
16
controlled by close placement of the boot capacitor.
Do not add an additional BOOT to the PGND
capacitor. This may lead to excess current flow
through the BOOT diode.
10. The SMOD# and DISB# pins have weak internal
pull-up and pull-down current sources, respectively.
These pins should not have any noise filter
capacitors. Do not to float these pins unless
absolutely necessary.
11. Use multiple vias on each copper area to
interconnect top, inner, and bottom layers to help
distribute current flow and heat conduction. Vias
should be relatively large and of reasonably low
inductance. Critical high-frequency components,
such as R BOOT , C BOOT , the RC snubber, and bypass
capacitors should be located as close to the
respective DrMOS module pins as possible on the
top layer of the PCB. If this is not feasible, they
should be connected from the backside through a
network of low-inductance vias.
www.fairchildsemi.com
相关PDF资料
PDF描述
FDMF6705V MODULE DRMOS 40A 1000KHZ 40PQFN
FDMF6705 MODULE DRMOS HI PERF HF POWER66
FDMF6706B MODULE DRMOS 45A 40-PQFN
FDMF6706C MODULE DRMOS 40A 1000KHZ 40PQFN
FDMF6707B MODULE DRMOS 50A 300KHZ 40PQFN
相关代理商/技术参数
参数描述
FDMF6705V 功能描述:功率驱动器IC XS DrMOS; Hi-Freq Hi-Perf Module RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube
FDMF6706B 功能描述:功率驱动器IC Xtra-Small Hi-Perf Hi-Freq DrMOS Module RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube
FDMF6706C 功能描述:功率驱动器IC XS DrMOS; Hi-Freq Hi-Perf Module RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube
FDMF6707B 功能描述:功率驱动器IC XS DrMOS; Hi-Freq Hi-Perf Module RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube
FDMF6707C 功能描述:功率驱动器IC Xtra-Small Hi-Perf Hi-Freq DrMOS Module RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube