參數(shù)資料
型號： IR3628MPBF
廠商： International Rectifier
英文描述： HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER
中文描述： 高頻同步PWM降壓控制器
文件頁數(shù)： 21/22頁
文件大小： 581K
代理商： IR3628MPBF
IR3628MPbF
08/10/2007
Circuit Description
THEORY OF OPEARTION
Introduction
The
IR3628
is
a
voltage
mode
PWM
synchronous controller 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 external
reference voltage (0.6V). These are two inputs to
error amplifier. The error signal between these
two inputs is compared to a fixed frequency
linear sawtooth ramp and generates fixed
frequency pulses of variable duty-cycle (D) which
drivers N-channel external MOSFETs.
The timing of the IC is controlled by an internal
oscillator circuit that uses on-chip capacitor to set
the switching frequency.
The IR3628 operates with single input voltage
from 4.5V to 12V allowing an extended operating
input voltage range.
The current limit is programmable and uses on-
resistance of the low-side MOSFET, eliminating
the need for external current sense resistor
.
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 Vc or Vcc fall
below 3.3V and 4.2V respectively. Normal
operation resumes once Vc and Vcc rise above
the set values.
Thermal Shutdown
Temperature sensing is provided inside IR3628.
The trip threshold is typically set to 145oC. 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 20oC hysteresis in
the thermal shutdown threshold.
Minimum Pulse Width
The time required of turning on and off the high
side MOSFET is defined as “Minimum Pulse
Width”. To ensure that a reliable operation is
achieved the following condition needs to be met:
Shutdown
The output can be shutdown by pulling the soft-
start pin below 0.3V. This can be easily 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.
Error Amplifier
The IR3628 is a voltage mode controller. The
error amplifier is of transconductance type. The
amplifier is capable of operating with Type III
compensation control scheme using low ESR
output capacitance.
Pre-Bias Startup
IR3628 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.
Depends on system configuration, specific
amount of output capacitors may be required to
prevent discharging the output voltage.
Fig. 4: Pre-Bias start up
Vo
Time
Volt
Pre-Bias Voltage
(Output Voltage before startup)
External Reference and Tracking
IR3628 is able to operate as a stand alone
converter by connecting the Vref to Vp. In this
case the reference voltage is 0.6V. For tracking
application the Vref can be left floating and the
Vp pin will be connected to master voltage which
IR3628 will track. In this case the Vp voltage is
the IC’s reference voltage.
8
s
in
out
on
F
V
T
*
(max)
(min) <
相關PDF資料
PDF描述
IR3628MTRPBF HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER
IR3629AMPBF HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629AMTRPBF HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629A HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629 HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
相關代理商/技術參數(shù)
參數(shù)描述
IR3628MTRPBF 功能描述:電壓模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
IR3629 制造商:IRF 制造商全稱:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629A 制造商:IRF 制造商全稱:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629AMPBF 制造商:IRF 制造商全稱:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT
IR3629AMTRPBF 功能描述:電壓模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
發(fā)布緊急采購，3分鐘左右您將得到回復。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*