参数资料
型号: IR3811MTRPBF
厂商: International Rectifier
文件页数: 8/21页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 7A 15QFN
产品培训模块: SupIRBuck™ Integrated Point-of-Load Regulators
SupIRBuck? Family and POL Design Tools Overview
产品变化通告: (EP) Parts Discontinuation 25/May/2012
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: 0.6 V ~ 12 V
输入电压: 2.5 V ~ 21 V
PWM 型: 电压模式
频率 - 开关: 600kHz
电流 - 输出: 7A
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: 15-PowerVQFN
包装: 标准包装
供应商设备封装: PQFN(5x6)
产品目录页面: 1384 (CN2011-ZH PDF)
其它名称: IR3811MTRPBFDKR
PD-60334
IR3811MPbF
Circuit Description
THEORY OF OPERATION
The IR3811 is a voltage mode PWM
synchronous regulator and operates with a fixed
600kHz switching frequency, allowing the use of
small external components.
The output voltage is set by feedback pin (Fb)
and the internal reference voltage (0.6V). These
are two inputs to error amplifier. The error signal
between these two inputs is amplified and it is
compared to a fixed frequency linear sawtooth
ramp.
A trailing edge modulation is used for generating
fixed frequency pulses (PWM) which drives the
internal N-channel MOSFETs.
The internal oscillator circuit uses on-chip
circuitry, eliminating the need for external
Pre-Bias Startup
The IR3811 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
gate signal for control MOSFET is generated.
Figure 4 shows a typical Pre-Bias condition at
start up.
Depending on system configuration, a specific
number of output capacitors may be required to
prevent discharging the output voltage.
components.
The IR3811 operates with single input voltage
from 4.5V to 14V allowing an extended operating
input voltage range.
The over-current protection is performed by
sensing current through the R DS(on) of low side
MOSFET. This method enhances the converter’s
efficiency and reduces cost by eliminating a
current sense resistor. The current limit is
V
Pre-Bias Voltage
Vo
Time
programmable by using an external resistor.
Fig. 4: Pre-Bias start up
Under-Voltage Lockout
The under-voltage lockout circuit monitors the
two input supplies (Vcc and Vc) and assures that
the MOSFET driver outputs remain in the off
state whenever the supply voltage drops below
set thresholds. Lockout occurs if Vcc or Vc fall
below 4.3V and 3.3V respectively. Normal
operation resumes once Vcc and Vc rise above
the set values.
Thermal Shutdown
Temperature sensing is provided inside the
IR3811. The trip threshold is typically set to
140 o C. When trip threshold is exceeded, thermal
shutdown turns off both MOSFETs. Thermal
shutdown is not latched and automatic restart is
initiated when the sensed temperature drops
within the operating range. There is a 20 o C
hysteresis in the thermal shutdown threshold.
10/04/08
Shutdown
The output can be shutdown by pulling the soft-
start pin below 0.3V. This can easily be done by
using an external small signal transistor. During
shutdown both MOSFET drivers will be turned
off. Normal operation will resume by cycling soft
start pin.
External Reference and Tracking
IR3811 is able to operate as a stand alone
regulator by connecting the Vref to Vp. In this
case the reference voltage is 0.6V. For tracking
application Vref pin can be left floating and the
Vp pin will be connected to master voltage which
IR3811 will track. In this case the Vp voltage is
the IC’s reference voltage.
8
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相关代理商/技术参数
参数描述
IR3812MPBF 制造商:International Rectifier 功能描述:
IR3812MPBF_08 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGHLY INTEGRATED 4A WIDE-INPUT VOLTAGE, SYNCHRONOUS BUCK REGULATOR
IR3812MTR1PBF 功能描述:直流/直流开关调节器 4A SupIRBuck Reg 600kHz, 2.5-21V 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
IR3812MTRPBF 功能描述:直流/直流开关调节器 4A SupIRBuck Reg 600kHz, 2.5-21V 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
IR3820AMPBF 制造商:International Rectifier 功能描述:Conv DC-DC Single Step Down 2.5V to 21V 15-Pin Power QFN EP