參數(shù)資料
型號(hào): L6569A
廠商: 意法半導(dǎo)體
英文描述: HIGH VOLTAGE HALF BRIDGE DRIVER WITH OSCILLATOR
中文描述: 高壓半橋驅(qū)動(dòng)器,振蕩器
文件頁數(shù): 5/13頁
文件大?。?/td> 110K
代理商: L6569A
5/13
L6569 L6569A
BootstrapFunction
The L6569 has an internal Bootstrap structure that enables the user to avoid the external diode needed, in sim-
ilar devices, to perform the charge of the bootstrap capacitor that, in turns, provide an appropriate driving to the
Upper External Mosfet.
The operation is achieved with an unique structure (patented) that uses a High Voltage Lateral DMOS driven
by an internal charge pump (see Block Diagram) and synchronized, with a 50 nsec delay, with the Low Side
Gate driver (LVG pin), actually working as a synchronous rectifier .
The charging pathfor the Bootstrap capacitor isclosed via the Lower External Mosfet that is driven ON (i.e. LVG
High) for a time interval:
T
C
= R
F
· C
F
· In2
1.1 · R
F
· C
F
starting from the time the Supply Voltage V
S
has reached the Turn On Voltage (V
SUVP
= 9 V typical value).
After time T
1
(seewaveform Diagram) the LDMOS that chargesthe Bootstrap Capacitor, is onwith a R
ON
=120
(typical value).
In the L6569A a different start up procedure isfollowed (see waveform Diagram). The Lower External Mosfet is
driveOFF until V
S
hasreached the TurnOn Threshold (V
SUVPp
), then againthe T
C
timeinterval starts asabove.
Being the LDMOS used to implement the bootstrap operation a ”bi-directional” switch the current flowing into
the BOOT pin (pin 8) can lead an undue stress to the LDMOS itself if a ZERO VOLTAGE SWITCHING opera-
tions is not ensured, and then an high voltage is applied to the BOOT pin. This condition can occur, for example,
when the load is removed and an high resistive value is placed in series with the gate of the external Power
Mos. To help the user to secure his design a SAFE OPERATING AREA for the Bootstrap LDMOS is provided
(fig. 7).
Let’s consider the steps that should be taken.
1) Calculate the Turn on delay ( td ) of your Lower Power MOS:
2) Calculate the Fall time ( tf ) of your Lower Power MOS:
where:
R
g
= External gate resistor
R
id
= 50
, typical equivalent output resistance of the driving buffer (when sourcing current)
V
TH
, C
iss
and Q
gd
are Power MOS parameters
V
S
= Low Voltage Supply.
3) Sketch the VBOOT waveform (using log-log scales) starting from the Drain Voltage of the Lower Power MOS
(remember to add the Vs, your LowVoltage Supply, value) on the Bootstrap LDMOS SOA . Onfig. 8 an example
is given where:
V
S
= Low Voltage Supply
V
HV
= High Voltage Supply Rail
The V
BOOT
voltage swing must fall below the curve identified by the actual operating frequency of your applica-
tion.
t
d
R
g
R
id
+
(
)
C
iss
V
S
1
----------
--------------------
ln
=
t
f
R
V
S
V
TH
--------+
Q
gd
=
相關(guān)PDF資料
PDF描述
L6569AD HIGH VOLTAGE HALF BRIDGE DRIVER WITH OSCILLATOR
L6569D HIGH VOLTAGE HALF BRIDGE DRIVER WITH OSCILLATOR
L6571A HIGH VOLTAGE HALF BRIDGE DRIVER WITH OSCILLATOR
L6571AD HIGH VOLTAGE HALF BRIDGE DRIVER WITH OSCILLATOR
L6571BD HIGH VOLTAGE HALF BRIDGE DRIVER WITH OSCILLATOR
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L6569A 制造商:STMicroelectronics 功能描述:IC HALF BRIDGE+OSC 6569 DIP8
L6569AD 功能描述:功率驅(qū)動(dòng)器IC Hi-Volt Half Bridge 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
L6569AD 制造商:STMicroelectronics 功能描述:HALF BRIDGE+OSC SMD 6569 SOIC8
L6569AD013TR 功能描述:功率驅(qū)動(dòng)器IC Hi-Volt Half Bridge 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
L6569D 功能描述:功率驅(qū)動(dòng)器IC Hi-Volt Half Bridge 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