参数资料
型号: NCP1237BD65R2G
厂商: ON Semiconductor
文件页数: 16/41页
文件大小: 0K
描述: IC REG CTRLR FLYBACK PWM 7SOIC
标准包装: 1
PWM 型: 电流模式
输出数: 1
频率 - 最大: 70kHz
占空比: 85%
电源电压: 9.5 V ~ 28 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 125°C
封装/外壳: 8-SOIC(0.154",3.90mm 宽)7 引线
包装: 标准包装
其它名称: NCP1237BD65R2GOSDKR
NCP1237
? Normal operation : As long as the feedback voltage is
within the regulation range, the NCP1237 runs at a
fixed frequency (with jittering) in current ? mode
control, where the peak current (sensed on the CS pin)
is set by the voltage on the FB pin. A fixed ramp
?
needed for regulation is directly applied. V CC can be
maintained between V CC(on) and V CC(min) by the DSS.
Overload : The NCP1237 features a timer ? based
dual ? level overload detection, solely dependent on the
feedback information: as soon as the internal peak
?
?
compensation is applied internally to prevent
sub ? harmonic oscillations from occurring. The V CC
must be supplied by an external source (such as an
auxiliary winding), as the startup current source cannot
permanently supply the controller without overheating.
Light load operation : When the FB voltage decreases
below V FB(fold) , typically corresponding to a load of
20% (DCM design only) to 30% (CCM / DCM design)
of the maximum load, the switching frequency starts to
decrease down to f OSC(min) . By lowering the switching
losses, this feature helps to improve the efficiency in
light load conditions. The frequency jittering is disabled
in light load operation.
No load operation : When the FB voltage decreases
below V skip(in) , typically corresponding to a load of 1%
of the maximum load, the controller enters Skip mode.
By completely stopping the switching while the
feedback voltage is below V skip(out) , the losses are
further reduced, allowing to minimize the power
dissipation under extremely low load conditions. In
order to avoid audible noise, the peak current is
gradually increased during the t SSKIP duration while
exiting the skip mode (Soft ? Skip function). In case of
abrupt load increase during Soft ? Skip mode, the
soft ? skip portion is bypassed and the peak current
?
?
current setpoint goes above the V CS(tran) threshold, a
first internal timer starts to count, but the controller is
still able to regulate up to V ILIM . Once it reaches the
V ILIM clamp, the internal overload timer starts to count.
When either timer times out, the controller stops and
enters the protection mode, autorecovery for the B
version (the controller initiates a new start ? up after
t autorec elapses), or latched for the A version (the latch
is released if a brown ? out event occurs or V CC is reset).
Brown ? out : The NCP1237 features on its HV pin a
true AC line monitoring circuitry which includes a
minimum startup threshold, brown ? out protection, and
overvoltage protection. All of these circuits are
autorecovery and operate independently of any ripple
on the input voltage. They can even work with an
unfiltered, rectified AC input. All thresholds are fixed,
but they are designed to fit most of the standard ac ? dc
conversion applications.
Latch ? off : When the Latch input is pulled up (typically
by an overvoltage condition), or pulled low (typically
by an overtemperature condition, using the provided
current source with an NTC), the controller latches off.
The latch is released when a brown ? out condition
occurs, or when V CC decreases below V CC(reset) .
http://onsemi.com
16
相关PDF资料
PDF描述
NCP1238AD65R2G IC REG CTRLR FLYBACK PWM 7SOIC
NCP3011DTBR2G IC REG CTRLR BUCK PWM VM 14TSSOP
RPP50-483.3S CONV DC/DC 50W 36-75VIN 3.3VOUT
RPP40-2424DW CONV DC/DC 40W 9-36V +/-24VOUT
RPP40-2415DW-F CONV DC/DC 40W 9-36V +/-15VOUT
相关代理商/技术参数
参数描述
NCP1237PRINTGEVB 功能描述:电源管理IC开发工具 32W, 32V PRINTER ADAPTER RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
NCP1238 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Fixed Frequency Current Mode Controller for Flyback Converters
NCP1238AD65R2G 功能描述:电流型 PWM 控制器 DSS LATCH SOCP 65KHZ 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
NCP1238BD65R2G 功能描述:电流型 PWM 控制器 DSS AUTOR SOCP 65KHZ 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
NCP1239 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Low−Standby High Performance PWM Controller