参数资料
型号: IR3856WMTR1PBF
厂商: International Rectifier
文件页数: 13/34页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 6A 17QFN
产品培训模块: SupIRBuck? Family and POL Design Tools Overview
标准包装: 1
系列: SupIRBuck™
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 0.7 V ~ 14.4 V
输入电压: 1.5 V ~ 16 V
PWM 型: 电压模式
频率 - 开关: 225kHz ~ 1.65MHz
电流 - 输出: 6A
同步整流器:
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 17-PowerVQFN
包装: 标准包装
供应商设备封装: 17-PQFN(4x5)
其它名称: IR3856WMTR1PBFDKR
PD-97506
IR3856WMPbF
Fig. 5. Pre-Bias startup pulses
Soft-Start
The IR3856W has a programmable soft-start to
control the output voltage rise and to limit the
Fig. 3c. Recommended startup sequence,
Sequenced operation
Pre-Bias Startup
IR3856W is able to start up into pre-charged
output, which prevents oscillation and
disturbances of the output voltage.
The output starts in asynchronous fashion and
keeps the synchronous MOSFET off until the first
current surge at the start-up. To ensure correct
start-up, the soft-start sequence initiates when
the Enable and Vcc rise above their UVLO
thresholds and generate the Power On Ready
(POR) signal. The internal current source
(typically 20uA) charges the external capacitor
C ss linearly from 0V to 3V. Figure 6 shows the
waveforms during the soft start.
The start up time can be estimated by:
gate signal for control MOSFET is generated.
Figure 4 shows a typical Pre-Bias condition at
start up.
T start =
( 1.4 - 0.7 ) * C SS
20 μ A
- - - - - - - - - - - - - - - - - - - - (1)
The synchronous MOSFET always starts with a
narrow pulse width and gradually increases its
duty cycle with a step of 25%, 50%, 75% and
100% until it reaches the steady state value. The
number of these startup pulses for the
synchronous MOSFET is internally programmed.
Figure 5 shows a series of 32, 16, 8 startup
pulses.
Fig. 4. Pre-Bias startup
Rev 9.0
During the soft start the OCP is enabled to
protect the device for any short circuit and over
current condition.
Fig. 6. Theoretical operation waveforms
during soft-start
13
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相关代理商/技术参数
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IR3856WMTRPBF 功能描述:直流/直流开关调节器 6A SupIRBuck Reg 750kHz, 1.5-16V in RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
IR3859MPBF 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGHLY EFFICIENT INTEGRATED 9A, SYNCHRONOUS BUCK REGULATOR
IR3859MTR1PBF 功能描述:直流/直流开关调节器 9A SupIRBuck Reg 250-1500kHz, 1.5-21V RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
IR3859MTR1PBF 制造商:International Rectifier 功能描述:IC DC-DC CONV 1.5 MHz QFN-17
IR3859MTRPBF 功能描述:直流/直流开关调节器 9A SupIRBuck Reg 250-1500kHz, 1.5-21V RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5