參數(shù)資料
型號: LM5109SD
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: MOSFETs
英文描述: 100V / 1A Peak Half Bridge Gate Driver
中文描述: 1 A HALF BRDG BASED MOSFET DRIVER, DSO8
封裝: 4 X 4 MM, LLP-8
文件頁數(shù): 7/9頁
文件大?。?/td> 657K
代理商: LM5109SD
Timing Diagram
Layout Considerations
The optimum performance of high and low side gate drivers
cannot be achieved without taking due considerations during
circuit board layout. Following points are emphasized.
1.
A low ESR / ESL capacitor must be connected close to
the IC, and between V
DD
and V
SS
pins and between HB
and HS pins to support high peak currents being drawn
from VDD during turn-on of the external MOSFET.
2.
To prevent large voltage transients at the drain of the top
MOSFET, a low ESR electrolytic capacitor must be con-
nected between MOSFET drain and ground (V
SS
).
3.
In order to avoid large negative transients on the switch
node (HS) pin, the parasitic inductances in the source of
top MOSFET and in the drain of the bottom MOSFET
(synchronous rectifier) must be minimized.
4.
Grounding Considerations:
a) The first priority in designing grounding connections
is to confine the high peak currents from charging and
discharging the MOSFET gate in a minimal physical
area. This will decrease the loop inductance and mini-
mize noise issues on the gate terminal of the MOSFET.
The MOSFETs should be placed as close as possible to
the gate driver.
b) The second high current path includes the boot-
strap capacitor, the bootstrap diode, the local ground
referenced bypass capacitor and low side MOSFET
body diode. The bootstrap capacitor is recharged on the
cycle-by-cycle basis through the bootstrap diode from
the ground referenced V
bypass capacitor. The re-
charging occurs in a short time interval and involves high
peak current. Minimizing this loop length and area on the
circuit board is important to ensure reliable operation.
HS Transient Voltages Below
Ground
The HS node will always be clamped by the body diode of
the lower external FET. In some situations, board resis-
tances and inductances can cause the HS node to tran-
siently swing several volts below ground. The HS node can
swing below ground provided:
1.
HS must always be at a lower potential than HO. Pulling
HO more than -0.3V below HS can activate parasitic
transistors resulting in excessive current to flow from the
HB supply possibly resulting in damage to the IC. The
same relationship is true with LO and VSS. If necessary,
a Schottky diode can be placed externally between HO
and HS or LO and GND to protect the IC from this type
of transient. The diode must be placed as close to the IC
pins as possible in order to be effective.
2.
HB to HS operating voltage should be 15V or less .
Hence, if the HS pin transient voltage is -5V, VDD should
be ideally limited to 10V to keep HB to HS below 15V.
3.
A low ESR bypass capacitor between HB to HS as well
as VDD to VSS is essential for proper operation. The
capacitor should be located at the leads of the IC to
minimize series inductance. The peak currents from LO
and HO can be quite large. Any series inductances with
the bypass capacitor will cause voltage ringing at the
leads of the IC which must be avoided for reliable
operation.
20150518
FIGURE 3.
L
www.national.com
7
相關(guān)PDF資料
PDF描述
LM5109SDX 100V / 1A Peak Half Bridge Gate Driver
LM5109MA 100V / 1A Peak Half Bridge Gate Driver
LM5109MAX 100V / 1A Peak Half Bridge Gate Driver
LM5109 100V / 1A Peak Half Bridge Gate Driver
LM5110-2M Dual 5A Compound Gate Driver with Negative Output Voltage Capability
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM5109SD/NOPB 功能描述:功率驅(qū)動(dòng)器IC RoHS:否 制造商:Micrel 產(chǎn)品:MOSFET Gate Drivers 類型:Low Cost High or Low Side MOSFET Driver 上升時(shí)間: 下降時(shí)間: 電源電壓-最大:30 V 電源電壓-最小:2.75 V 電源電流: 最大功率耗散: 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Tube
LM5109SDX 制造商:NSC 制造商全稱:National Semiconductor 功能描述:100V / 1A Peak Half Bridge Gate Driver
LM510W 制造商:BEAVERSWOOD 功能描述:MARKER MAG WHITE 50X100MM PK100
LM511 制造商:SEOUL 制造商全稱:Seoul Semiconductor 功能描述:RED OVAL LAMP LED
LM5110 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Dual 5A Compound Gate Driver with Negative Output Voltage Capability