参数资料
| 型号： | NCP1337DR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 12/15页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR FLYBK ISO PWM 7SOIC |
| 标准包装： | 1 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 130kHz |
| 电源电压： | 11 V ~ 20 V |
| 降压： | 无 |
| 升压： | 无 |
| 回扫： | 是 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 是 |
| 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： | NCP1337DR2GOSDKR |
NCP1337
The input information is the current injected in FB pin by
the feedback loop. The range of current is from 40 m A for
overload detection to 220 m A corresponding to V CSrippleIN .
In transients, currents from 0 to more than 400 m A may also
appear: the circuitry is able to sustain them.
To regulate the FB pin voltage, the operational amplifier
needs to have a high gain and a wide bandwidth. But the
feedback information used internally needs to be filtered,
because we don’t want the controller to be sensitive to the
switching noise. For this purpose, a 20 kHz filter is added
after the shunt regulator, and any reading of the feedback
signal (for ripple mode, fault detection, or setpoint
elaboration) is done after.
Soft Burst Mode (Protection Mode)
The NCP1337 features a fault timer to detect an overload
completely independently of the V CC voltage. As soon as
the feedback loop asks for the maximum power, a fault is
detected, and an internal timer is started. When the fault
disappears the timer is reset, but if the timer reaches 80 ms,
the protection mode is activated.
Once this protection is toggled, output pulses are stopped
and DSS is deactivated (HV current source turn ? on
threshold changes from VCC MIN to VCC LATCH ). V CC
slowly decreases (the current consumption is ICC3), and
the HV current source is switched ON when V CC reaches
VCC LATCH . As a result V CC increases until VCC ON , but the
controller does not start as the output is still forced low.
V CC decreases again down to VCC LATCH , and a new
start ? up cycle occurs. On the second attempt, the output is
released, and NCP1337 effectively starts, with the
soft ? start activated. Figure 4 illustrates this behavior.
Safety Features
The NCP1337 includes several safety features to help the
power supply designer to build a rugged design:
? OVP (Overvoltage on V CC ): Activated when voltage
on pin V CC is higher than 18.6 V
? Brown ? Out (Undervoltage lockout on bulk voltage):
Activated when voltage on pin BO is below 500 mV
? Disable (Comparator activated by an external signal):
Activated when the voltage on BO pin is higher than
3.0 V but below 5.0 V
? TSD (Temperature shutdown): Typically activated
when the die temperature is above 150 ° C, released at
120 ° C
All these events have the same consequence for the
controller: the DRV pulses are stopped. When the condition
disappears, the controller restarts with the soft ? start
activated. However, as the fault timer is still active, it can
time out while the switching is stopped. As a result the
controller will go into protection mode, and won’t restart
instantaneously.
? Permanent Latch (Comparator activated by an external
signal): Activated when the voltage on BO pin is
above 5.0 V
When this comparator is activated, the DRV pulses are
stopped, and the DSS is deactivated (only the start ? up
current source is turned on each time V CC reaches
VCC LATCH , maintaining V CC between 5.0 V and 12 V):
the controller stays in this position until the V CC voltage is
decreased below 4.0 V, i.e., when the power supply is
unplugged from the mains (in normal operation, as soon as
a voltage is present on the HV pin, V CC is always kept
above 5.0 V).
Soft ? Skip Mode
The soft ripple mode is a skip mode with a large
hysteresis on the skip comparator in order to ensure a
noise ? free and high ? efficiency operation in low ? load
conditions (standby). When internal setpoint is reaching
V CSrippleIN = 100 mV (corresponding to 20% of the
maximum setpoint), the output pulses are stopped. Then
FB loop asks for more power and internal setpoint is
increasing: when it reaches V CSrippleOUT = 130 mV
(corresponding to 25% of the maximum setpoint), the
output starts switching again. Soft ? Skip is activated in each
activity following a stop period. See Figure 5 for detailed
timing diagram.
HV Current Source
NCP1337 features a DSS, to allow operation without any
auxiliary voltage. But to protect the die in case of
short ? circuit on V CC pin, the current delivered by the HV
current source is lowered when V CC voltage is below 1.5 V.
In the case the current consumed on the DRV pin is
higher than the DSS capability (high Qg MOSFET or
failure), the HV current source is switched ON when V CC
reaches VCC MIN , but the voltage on V CC pin keep on
decreasing. If there is no UVLO threshold to stop the DRV
pulses, the gate voltage will become too low and the risk is
high to destroy the MOSFET. NCP1337 features an
additional comparator, which threshold is 9.0 V: when V CC
reaches this level whereas the HV current source is ON,
DRV pulses are stopped and the protection mode is
activated.
The maximum dV/dt that can be applied to the V CC pin
is 9.0 V/ms. The supply capacitor is selected to ensure the
maximum dV/dt is not exceeded.
Brown ? Out
The brown ? out protection comparator has a fixed
reference of 500 mV. When the comparator is activated
(i.e., when the input voltage V IN is above the starting level),
a 10 m A internal current source is activated and creates an
offset across the bottom resistor of the external resistor
divider. It gives the minimum hysteresis of the brown ? out
protection. By adding a series resistor between the divider
and the BO pin, it is possible to adjust (increase) the
hysteresis.
The BO pin also features two additional comparators: the
first one (that toggles at 3.0 V) stops the DRV pulses,
whereas the second one (that toggles at 5.0 V) permanently
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相关PDF资料 |
PDF描述 |
|---|---|
| NCP1338DR2G | IC REG CTRLR FLYBK ISO PWM 7SOIC |
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| NCP1378PG | IC REG CTRLR FLYBACK PWM 7-PDIP |
| NCP1379DR2G | IC CTLR QUASI CURRENT MODE 8SOIC |
| NCP1380DDR2G | IC REG CTRLR FLYBK ISO PWM 8SOIC |
相关代理商/技术参数 |
参数描述 |
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| NCP1337PG | 功能描述:电流型 PWM 控制器 PWM CONTROLLER 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 |
| NCP1338 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:PWM Current-Mode Controller for Free Running Quasi-Resonant Operation |
| NCP1338DR2G | 功能描述:电流型 PWM 控制器 PWM CNTRL SOIC 8 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 |
| NCP1338PG | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:PWM Current-Mode Controller for Free Running Quasi-Resonant Operation |
| NCP1351 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Power Factor Controllers |
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