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参数资料
| 型号： | IR3628MPBF |
| 厂商： | International Rectifier |
| 文件页数： | 8/22页 |
| 文件大小： | 0K |
| 描述： | IC CTLR PWM BUCK SYNC 12-MLPD |
| 标准包装： | 122 |
| 应用： | 控制器，DDR |
| 输入电压： | 4.5 V ~ 14 V |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 9.94 V |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 12-VFDFN 裸露焊盘 |
| 供应商设备封装： | 12-MLPD |
| 包装： | 管件 |
IR3628MP b F
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
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.
below 3.3V and 4.2V respectively. Normal
operation resumes once Vc and Vcc rise above
Volt
Vo
the set values.
Pre-Bias Voltage
T on (min) <
Thermal Shutdown
Temperature sensing is provided inside IR3628.
The trip threshold is typically set to 145 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.
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:
V out
V in (max) * F s
08/10/2007
(Output Voltage before startup)
Time
Fig. 4: Pre-Bias start up
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
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相关代理商/技术参数 |
参数描述 |
|---|---|
| IR3628MTRPBF | 功能描述:电压模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| IR3629 | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629A | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629AMPBF | 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER WITH POWER GOOD OUTPUT |
| IR3629AMTRPBF | 功能描述:电压模式 PWM 控制器 HI FREQ SYNC PWM 600kHz 5 or 12V 0.6 RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
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