- 您现在的位置：买卖IC网 > PDF目录176103 > ISL6208CB-T (INTERSIL CORP) High Voltage Synchronous Rectified Buck MOSFET Driver PDF资料下载
参数资料
| 型号： | ISL6208CB-T |
| 厂商： | INTERSIL CORP |
| 元件分类： | MOSFETs |
| 英文描述： | High Voltage Synchronous Rectified Buck MOSFET Driver |
| 中文描述： | 4 A HALF BRDG BASED MOSFET DRIVER, PDSO8 |
| 封装： | PLASTIC, MS-012AA, SOIC-8 |
| 文件页数： | 10/11页 |
| 文件大小： | 1692K |
| 代理商： | ISL6208CB-T |
8
FN9115.3
August 7, 2008
Diode Emulation
Diode emulation allows for higher converter efficiency under
light load situations. With diode emulation active, the
ISL6208 will detect the zero current crossing of the output
inductor and turn off LGATE. This ensures that
discontinuous conduction mode (DCM) is achieved. Diode
emulation is asynchronous to the PWM signal. Therefore,
the ISL6208 will respond to the FCCM input immediately
after it changes state. Refer to“Typical Performance
Waveforms” on page 7. NOTE: Intersil does not recommend
Diode Emulation use with rDS(ON) current sensing
topologies. The turn-OFF of the low side MOSFET can
cause gross current measurement inaccuracies.
Three-State PWM Input
A unique feature of the ISL6208 and other Intersil drivers is
the addition of a shutdown window to the PWM input. If the
PWM signal enters and remains within the shutdown window
for a set holdoff time, the output drivers are disabled and
both MOSFET gates are pulled and held low. The shutdown
state is removed when the PWM signal moves outside the
shutdown window. Otherwise, the PWM rising and falling
thresholds outlined in the Electrical Specifications Table on
page 3 determine when the lower and upper gates are
enabled.
Adaptive Shoot-Through Protection
Both drivers incorporate adaptive shoot-through protection
to prevent upper and lower MOSFETs from conducting
simultaneously and shorting the input supply. This is
accomplished by ensuring the falling gate has turned off one
MOSFET before the other is allowed to turn on.
During turn-off of the lower MOSFET, the LGATE voltage is
monitored until it reaches a 1V threshold, at which time the
UGATE is released to rise. Adaptive shoot-through circuitry
monitors the upper MOSFET gate-to-source voltage during
UGATE turn-off. Once the upper MOSFET gate-to-source
voltage has dropped below a threshold of 1V, the LGATE is
allowed to rise.
Internal Bootstrap Diode
This driver features an internal bootstrap Schottky diode.
Simply adding an external capacitor across the BOOT and
PHASE pins completes the bootstrap circuit.
The bootstrap capacitor must have a maximum voltage rating
above the maximum battery voltage plus 5V. The bootstrap
capacitor can be chosen from Equation 1:
where QGATE is the amount of gate charge required to fully
charge the gate of the upper MOSFET. The
ΔV
BOOT term is
defined as the allowable droop in the rail of the upper drive.
As an example, suppose an upper MOSFET has a gate
charge, QGATE, of 25nC at 5V and also assume the droop in
the drive voltage over a PWM cycle is 200mV. One will find
that a bootstrap capacitance of at least 0.125F is required.
The next larger standard value capacitance is 0.15F. A
good quality ceramic capacitor is recommended.
Power Dissipation
Package power dissipation is mainly a function of the
switching frequency and total gate charge of the selected
MOSFETs. Calculating the power dissipation in the driver for
a desired application is critical to ensuring safe operation.
Exceeding the maximum allowable power dissipation level
will push the IC beyond the maximum recommended
operating junction temperature of +125°C. The maximum
allowable IC power dissipation for the SO-8 package is
approximately 800mW. When designing the driver into an
application, it is recommended that the following calculation
be performed to ensure safe operation at the desired
frequency for the selected MOSFETs. The power dissipated
by the driver is approximated as shown in Equation 2:
C
BOOT
Q
GATE
ΔV
BOOT
------------------------
≥
(EQ. 1)
FIGURE 8. BOOTSTRAP CAPACITANCE vs BOOT RIPPLE
VOLTAGE
20nC
ΔVBOOT_CAP (V)
C
B
OOT_
C
AP
(F)
2.0
1.6
1.4
1.0
0.8
0.6
0.4
0.2
0.0
0.3
0.0
0.1
0.2
0.4
0.5
0.6
0.9
0.7
0.8
1.0
QGATE = 100nC
1.2
1.8
50
nC
Pf
sw 1.5 VUQU
V
LQL
+
() I
VCCVCC
+
=
(EQ. 2)
ISL6208
相关PDF资料 |
PDF描述 |
|---|---|
| ISL6208CBZ | High Voltage Synchronous Rectified Buck MOSFET Driver |
| ISL6208CBZ-T | High Voltage Synchronous Rectified Buck MOSFET Driver |
| ISL6227CA | Dual Mobile-Friendly PWM Controller with DDR Option |
| ISL6227CA-T | Dual Mobile-Friendly PWM Controller with DDR Option |
| ISL6227CAZ | Dual Mobile-Friendly PWM Controller with DDR Option |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6208CBZ | 功能描述:功率驱动器IC VER OF ISL6208CB IBM FAB 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 |
| ISL6208CBZ-T | 功能描述:功率驱动器IC VER OF ISL6208CB-T - IBM FAB 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 |
| ISL6208CHRZ-T | 制造商:Intersil Corporation 功能描述:LEAD-FREE VERSION OF ISL6208CR - COST IMPROVEMENT - JAZZ FAB - Tape and Reel 制造商:Intersil Corporation 功能描述:IC MOSFET DRVR SYNC BUCK 8DFN |
| ISL6208CIRZ-T | 制造商:Intersil Corporation 功能描述:LEAD-FREE VERSION OF ISL6208CR - COST IMPROVEMENT - JAZZ FAB - Tape and Reel 制造商:Intersil Corporation 功能描述:IC MOSFET DRVR SYNC BUCK 8DFN |
| ISL6208CR | 功能描述:IC MOSFET DRVR SYNC BUCK 8-QFN RoHS:否 类别:集成电路 (IC) >> PMIC - MOSFET，电桥驱动器 - 外部开关 系列:- 标准包装:50 系列:- 配置:低端 输入类型:非反相 延迟时间:40ns 电流 - 峰:9A 配置数:1 输出数:1 高端电压 - 最大（自引导启动）:- 电源电压:4.5 V ~ 35 V 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:TO-263-6，D²Pak（5 引线+接片），TO-263BA 供应商设备封装:TO-263 包装:管件 |
发布紧急采购，3分钟左右您将得到回复。