参数资料
型号: CS2841BEBN8
厂商: ON Semiconductor
文件页数: 6/10页
文件大小: 0K
描述: IC REG CTRLR BST FLYBK PWM 8-DIP
产品变化通告: LTB Notification 03/Jan/2008
标准包装: 50
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: 8-DIP(0.300",7.62mm)
包装: 管件
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
ESM18DRYS CONN EDGECARD 36POS DIP .156 SLD
GBB55DHLN CONN EDGECARD 110PS .050 DIP SLD
ESM25DRST CONN EDGECARD 50POS DIP .156 SLD
ESM22DRES CONN EDGECARD 44POS .156 EYELET
ASM10DRAN CONN EDGECARD 20POS .156 R/A
相关代理商/技术参数
参数描述
CS2841BEBN8G 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
CS2841BED14 功能描述:电流型 PWM 控制器 1A 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
CS2841BED14G 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
CS2841BEDR14 功能描述:电流型 PWM 控制器 1A 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
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