参数资料
型号: CS2841BEDR14
厂商: ON Semiconductor
文件页数: 6/10页
文件大小: 0K
描述: IC REG CTRLR BST FLYBK CM 14SOIC
产品变化通告: Product Obsolescence 11/Feb/2009
标准包装: 2,500
PWM 型: 电流模式
输出数: 1
频率 - 最大: 52kHz
占空比: 95%
电源电压: 7.8 V ~ 25 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 14-SOIC(0.154",3.90mm 宽)
包装: 带卷 (TR)
CS2841B
CIRCUIT DESCRIPTION
Undervoltage Lockout
During Undervoltage Lockout (Figure 5), the output
driver is biased to a high impedance state. The output should
be shunted to ground with a resistor to prevent output
leakage current from activating the power switch.
When the power supply sees a sudden large output current
increase, the control voltage will increase allowing the duty
cycle to momentarily increase. Since the duty cycle tends to
exceed the maximum allowed to prevent transformer
saturation in some power supplies, the internal oscillator
waveform provides the maximum duty cycle clamp as
programmed by the selection of OSC components.
V CC
ON/OFF Command
to Reset of IC
V REF
V ON = 8.0 V
V OFF = 7.4 V
OSC
R T
C T
GND
I CC
< 15 mA
< 1.0 mA
7.4 V
8.0 V
V CC
Timing Parameters
V upper
V lower
Figure 5. Typical Undervoltage Characteristics
Sawtooth Mode
t c
t d
PWM Waveform
To generate the PWM waveform, the control voltage from
the error amplifier is compared to a current sense signal
representing the peak output inductor current (Figure 6). An
increase in V CC causes the inductor current slope to
increase, thus reducing the duty cycle. This is an inherent
feed-forward characteristic of current mode control, since
the control voltage does not have to change during changes
of input supply voltage.
Large R T ( ≈ 10 k W )
Triangular Mode
Small R T ( ≈ 700 k W )
V OSC
Internal Clock
V OSC
OSC
OSC
RESET
EA Output
Switch
Current
Internal Clock
Figure 7. Oscillator Timing Network and
Parameters
V CC
Setting the Oscillator
I O
V O
Figure 6. Timing Diagram for Key CS2841B
Parameters
Oscillator timing capacitor, C T , is charged by V REF
through R T and discharged by an internal current source.
During the discharge time, the internal clock signal blanks
out the output to the Low state, thus providing a user selected
maximum duty cycle clamp. Charge and discharge times are
determined by the general formulas:
http://onsemi.com
6
相关PDF资料
PDF描述
GCC12DRST-S273 CONN EDGECARD 24POS DIP .100 SLD
DS1817R-5+T&R IC ECONRST 3.3V ACT HI 5%SOT23-3
CS2841BED14G IC REG CTRLR BST FLYBK CM 14SOIC
CS2841BED14 IC REG CTRLR BST FLYBK CM 14SOIC
RBM18DTAI-S189 CONN EDGECARD 36POS R/A .156 SLD
相关代理商/技术参数
参数描述
CS2841BEDR14G 功能描述:电流型 PWM 控制器 1A Current Mode PWM Control Automotive 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
CS2841BEN8 制造商:CHERRY 制造商全称:CHERRY 功能描述:Automotive Current Mode PWM Control Circuit
CS2842 制造商:未知厂家 制造商全称:未知厂家 功能描述:
CS28423AGD14 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC
CS28423AGD8 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC