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参数资料
| 型号： | NCP1216AFORWEVB |
| 厂商： | ON Semiconductor |
| 文件页数： | 11/18页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL NCP1216A DC/DC CONV |
| 产品变化通告： | 1Q2012 Discontinuation 30/Mar/2012 |
| 设计资源： | NCP1216AFORWEVB Schematic NCP1216AFORWEVB Bill of Materials NCP1216AFORWEVB Test Procedure NCP1216AFORWEVB Gerber Zip |
| 标准包装： | 1 |
| 系列： | * |
| 其它名称： | NCP1216AFORWEVB-ND NCP1216AFORWEVBOS |
NCP1216, NCP1216A
the nominal switching frequency whose sweep is
synchronized with the V CC ripple. For instance, with a 2.2 V
peak ? to ? peak ripple, the NCP1216P065 frequency will
equal 65 kHz in the middle of the ripple and will increase as
V CC rises or decrease as V CC ramps down. Figure 20
portrays the behavior we have adopted:
To better understand how this skip cycle mode takes place,
a look at the operation mode versus the FB level
immediately gives the necessary insight:
FB
VCC OFF
V CC Ripple
65 kHz
68 kHz
Normal Current Mode Operation
4.2 V, F B Pin Open
3.2 V, Upper
Dynamic Range
1V
Skip Cycle Operation
I pMIN = 333 mV / R sense
62 kHz
VCC ON
Figure 20. V CC Ripple is Used to Introduce a
Frequency Jittering on the Internal Oscillator
Sawtooth
Skipping Cycle Mode
The NCP1216 automatically skips switching cycles when
the output power demand drops below a given level. This is
accomplished by monitoring the FB pin. In normal
operation, pin 2 imposes a peak current accordingly to the
load value. If the load demand decreases, the internal loop
asks for less peak current. When this setpoint reaches a
determined level, the IC prevents the current from
decreasing further down and starts to blank the output
pulses: the IC enters the so ? called skip cycle mode, also
named controlled burst operation. The power transfer now
depends upon the width of the pulse bunches (Figure 22).
Suppose we have the following component values:
L p , primary inductance = 350 m H
F sw , switching frequency = 65 kHz
I p skip = 600 mA (or 333 mV / R sense )
The theoretical power transfer is therefore:
Figure 21.
When FB is above the skip cycle threshold (1.0 V by
default), the peak current cannot exceed 1.0 V/R sense . When
the IC enters the skip cycle mode, the peak current cannot go
below V pin1 / 3.3. The user still has the flexibility to alter this
1.0 V by either shunting pin 1 to ground through a resistor
or raising it through a resistor up to the desired level.
Grounding pin 1 permanently invalidates the skip cycle
operation.
Power P1
Power
P2
Power
P3
1
2
Lp
Ip2
Fsw + 4 W.
(eq. 8)
Figure 22. Output Pulses at Various Power Levels
(X = 5 m s/div) P1 < P2 < P3
If this IC enters skip cycle mode with a bunch length of
10 ms over a recurrent period of 100 ms, then the total power
transfer is:
4
0.1 + 400 mW.
(eq. 9)
http://onsemi.com
11
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相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP1216AFORWGEVB | 功能描述:BOARD EVAL NCP1216A 35W RoHS:是 类别:编程器，开发系统 >> 评估板 - LED 驱动器 系列:* 标准包装:1 系列:PowerWise® 电流 - 输出 / 通道:20mA 输出及类型:1，非隔离 输出电压:17V 特点:可调光 输入电压:2.7 ~ 5.5 V 已供物品:板 已用 IC / 零件:LM3508 相关产品:LM3508TLX-ND - IC LED DRVR WHT BCKLGT 9USMDLM3508TLDKR-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLCT-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLTR-ND - IC LED DRVR WHT BCKLGT 9MICROSMD |
| NCP1216AP100 | 功能描述:开关变换器、稳压器与控制器 Current Mode PWM RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
| NCP1216AP100G | 功能描述:电流型 PWM 控制器 Current Mode PWM w/50% Duty Cycle Max 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 |
| NCP1216AP133 | 功能描述:电流型 PWM 控制器 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 |
| NCP1216AP133G | 功能描述:电流型 PWM 控制器 Current Mode PWM w/50% Duty Cycle Max 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 |
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