参数资料
型号: MC33025
厂商: Motorola, Inc.
英文描述: High Speed Double-Ended PWM Controller
中文描述: 高速双端PWM控制器
文件页数: 14/20页
文件大小: 516K
代理商: MC33025
MC34025 MC33025
14
MOTOROLA ANALOG IC DEVICE DATA
Vref
R2
R1
CSS
1
2
8
+
Figure 31. Buffered Maximum Clamp Level
In voltage mode operation, the maximum duty cycle can be clamped. By the
addition of a PNP transistor to buffer the clamp voltage, the Soft–Start current
is not affected by R1.
The new equation for Soft–Start is
t
Vclamp
0.6
9.0
μ
A
CSS
In current mode operation, this circuit will limit the maximum voltage allowed
at the ramp input to end a cycle.
Q
Q
T
Vin
To Current
Sense Input
RS
12
11
14
15
VC
Base Charge
Removal
0
+
IB
Figure 32. Bipolar Transistor Drive
The totem pole output can furnish negative base current for enhanced
transistor turn–off, with the addition of the capacitor in series with the base.
Q
Q
T
12
11
14
15
VC
Isolation
Boundary
Figure 33. Isolated MOSFET Drive
12
11
14
15
Q
Q
T
VC
VC
Figure 34. Direct Transformer Drive
The totem pole output can easily drive pulse transformers. A Schottky diode is recommended when driving inductive loads at high frequencies. The diode can reduce
the driver’s power dissipation due to excessive ringing, by preventing the output pin from being driven below ground.
Q
Q
T
Vin
To Current
Sense Input
RS
12
11
14
15
VC
Figure 35. MOSFET Parasitic Oscillations
A series gate resistor may be needed to damp high frequency parasitic
oscillation caused by a MOSFET’s input capacitance and any series wiring
inductance in the gate–source circuit. The series resistor will also decrease the
MOSFET’s switching speed. A Schottky diode can reduce the driver’s power
dissipation due to excessive ringing, by preventing the output pin from being
driven below ground. The Schottky diode also prevents substrate injection
when the output pin is driven below ground.
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相关代理商/技术参数
参数描述
MC33025DW 功能描述:电流型 PWM 控制器 Dual Output Voltage RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
MC33025DWG 功能描述:电流型 PWM 控制器 Dual Output Voltage or Current Mode PWM RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
MC33025DWR2 功能描述:电流型 PWM 控制器 Dual Output Voltage RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
MC33025DWR2G 功能描述:电流型 PWM 控制器 Dual Output Voltage or Current Mode PWM RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
MC33025P 功能描述:电流型 PWM 控制器 Dual Output Voltage RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14