参数资料
型号: NCP1396BDR2G
厂商: ON Semiconductor
文件页数: 22/25页
文件大小: 0K
描述: IC REG CTRLR ISO PWM VM 16-SOIC
产品变化通告: Package Pin Removal 11/Feb/2008
标准包装: 1
PWM 型: 电压模式
输出数: 1
频率 - 最大: 575kHz
占空比: 52%
电源电压: 10.5 V ~ 20 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: 16-SOIC(0.154",3.90mm 宽)15 引线
包装: 标准包装
其它名称: NCP1396BDR2GOSDKR
NCP1396A, NCP1396B
reaches the VtimerON level (4 V typical), then all pulses
are stopped. If the fault input signal is still present, then the
controller permanently stays off and the voltage on the
timer capacitor does not move (Itimer is on and the voltage
is clamped to 5 V). If the fault input signal is removed
(because pulses are off for instance), Itimer turns off and
the capacitor slowly discharges to ground via a resistor
installed in parallel with it. As a result, the designer can
easily determine the time during which the power supply
stays locked by playing on Rtimer. Now, when the timer
capacitor voltage reaches 1 V typical (VtimerOFF), the
comparator instructs the internal logic to issues pulses as on
a clean soft-- start sequence (soft-- start is activated). Please
note that the discharge resistor can not be lower than 4 V
/ Itimer otherwise the voltage on Ctimer will not reach the
turn-- off voltage of 4 V.
In both cases, when the fault is validated, both outputs
Mlower and Mupper are internally pulled down to ground.
On Figure 46 example, a voltage proportional to primary
current, once averaged, gives an image of the input power
in case Vin is kept constant via a PFC circuit. If the output
loading increases above a certain level, the voltage on this
pin will pass the 1 V threshold and start the timer. If the
overload stays there, after a few tens of milli-- seconds,
switching pulses will disappear and a protective
auto-- recovery cycle will take place. Adjusting the resistor
R in parallel with the timer capacitor will give the
flexibility to adjust the fault burst mode.
SMPS Stops
4V
Fault is Gone
SMPS Re--starts
1V
Reset at Re--start
Figure 48. A resistor can easily program the capacitor discharge time
V CC
FB
Fast Fault
Figure 49. Skip cycle can be implemented via two
resistors on the FB pin to the Fast fault input
Fast Input
The fast input is not affected by a delayed action. As soon
as its voltage exceeds 1 V typical, all pulses are off and
maintained off as long as the fault is present. When the pin
is released, pulses come back and the soft-- start is activated.
Thanks to the low activation level of 1 V, this pin can
observe the feedback pin via a resistive divided and thus
implement skip cycle operation. The resonant converter
can be designed to lose regulation in light load conditions,
forcing the FB level to increase. When it reaches the
programmed level, it triggers the fast fault input and stops
pulses. Then Vout slowly drops, the loop reacts by
decreasing the feedback level which, in turn, unlocks the
pulses, Vout goes up again and so on: we are in skip cycle
mode.
Startup Behavior
When the V CC voltage grows-- up, the internal current
consumption is kept to Istrup, allowing to crank-- up the
converter via a resistor connected to the bulk capacitor.
When V CC reaches the V CC(on) level, output Mlower goes
high first and then output Mupper. This sequence will
always be the same whatever triggers the pulse delivery:
fault, OFF to ON etc ? Pulsing the output Mlower high first
gives an immediate charge of the bootstrap capacitor.
Then, the rest of pulses follow, delivered at the highest
switching value, set by the resistor on pin 2. The soft-- start
capacitor ensures a smooth frequency decrease to either the
programmed minimum value (in case of fault) or to a value
corresponding to the operating point if the feedback loop
closes first. Figure 50 shows typical signals evolution at
power on.
http://onsemi.com
22
相关PDF资料
PDF描述
NCP1397ADR2G IC REG CTRLR ISO PWM 16-SOIC
NCP1417DMR2 IC REG BST SYNC ADJ 0.2A 8MICRO
NCP1421DMR2 IC REG BST SYNC ADJ 0.6A 8MICRO
NCP1450ASN50T1G IC REG CTRLR BST PWM VM 5TSOP
NCP1521BMUTBG IC REG BUCK SYNC ADJ 0.6A 6UDFN
相关代理商/技术参数
参数描述
NCP1396BPG 功能描述:电压模式 PWM 控制器 RESONANT MODE CNTRLR W/ H/L SIDES DRIVERS RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
NCP1396D 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:High Performance Resonant Mode Controller featuring High--Voltage Drivers
NCP1397A 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:High Performance Resonant Mode Controller with Integrated High-Voltage Drivers
NCP1397ADR2G 功能描述:电流型 PWM 控制器 NCP1397A 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
NCP1397B 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:High Performance Resonant Mode Controller with Integrated High-Voltage Drivers