参数资料
型号: IR3840MTR1PBF
厂商: International Rectifier
文件页数: 11/32页
文件大小: 0K
描述: IC REG BUCK SYNC ADJ 12A 15QFN
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: 12A
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: IR3840MTR1PBFDKR
IR3840MPbF
Circuit Description
THEORY OF OPERATION
Introduction
The IR3840 uses a PWM voltage mode control
scheme with external compensation to provide
good noise immunity and maximum flexibility in
selecting inductor values and capacitor types.
The switching frequency is programmable from
250kHz to 1.5MHz and provides the capability of
optimizing the design in terms of size and
performance.
IR3840 provides precisely regulated output
voltage programmed via two external resistors
from 0.7V to 0.9*Vin.
The IR3840 operates with an external bias
supply from 4.5V to 5.5V, allowing an extended
operating input voltage range from 1.5V to 16V.
The device utilizes the on-resistance of the low
side MOSFET as current sense element, this
method enhances the converter’s efficiency and
reduces cost by eliminating the need for external
current sense resistor .
IR3840 includes two low R ds(on) MOSFETs using
IR’s HEXFET technology. These are specifically
designed for high efficiency applications.
Under-Voltage Lockout and POR
The under-voltage lockout circuit monitors the
input supply Vcc and the Enable input. It assures
that the MOSFET driver outputs remain in the off
state whenever either of these two signals drop
below the set thresholds. Normal operation
resumes once Vcc and Enable rise above their
thresholds.
The POR (Power On Ready) signal is generated
when all these signals reach the valid logic level
(see system block diagram). When the POR is
asserted the soft start sequence starts (see soft
start section).
Enable
The Enable features another level of flexibility for
start up. The Enable has precise threshold which
is internally monitored by Under-Voltage Lockout
(UVLO) circuit. Therefore, the IR3840 will turn on
only when the voltage at the Enable pin exceeds
this threshold, typically, 1.2V.
06/18/09
If the input to the Enable pin is derived from the
bus voltage by a suitably programmed resistive
divider, it can be ensured that the IR3840 does
not turn on until the bus voltage reaches the
desired level. Only after the bus voltage reaches
or exceeds this level will the voltage at Enable
pin exceed its threshold, thus enabling the
IR3840. Therefore, in addition to being a logic
input pin to enable the IR3840, the Enable
feature, with its precise threshold, also allows the
user to implement an Under-Voltage Lockout for
the bus voltage V in . This is desirable particularly
for high output voltage applications, where we
might want the IR3840 to be disabled at least
until V in exceeds the desired output voltage level.
Fig. 3a. Normal Start up, Device turns on
when the Bus voltage reaches 10.2V
Figure 3b. shows the recommended start-up
sequence for the non-sequenced operation of
IR3840, when Enable is used as a logic input.
Fig. 3b. Recommended startup sequence,
Non-Sequenced operation
11
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相关代理商/技术参数
参数描述
IR3840MTR1PBF 制造商:International Rectifier 功能描述:IC DC/DC SUPIRBUCK 12A 15QFN
IR3840MTRPBF 功能描述:直流/直流开关调节器 12A SupIRBuck Reg 250-1500kHz, 1.5-16V 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
IR3840WMPBF 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGHLY EFFICIENT INTEGRATED 12A SYNCHRONOUS BUCK REGULATOR
IR3840WMPBF_12 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGHLY EFFICIENT INTEGRATED 12A SYNCHRONOUS BUCK REGULATOR
IR3840WMTR1PBF 功能描述:直流/直流开关调节器 12A SupIRBuck Reg 250-1500kHz, 1.5-16V 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