- 您现在的位置：买卖IC网 > PDF目录43900 > L6730 (STMICROELECTRONICS) 20 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO20 PDF资料下载
参数资料
| 型号： | L6730 |
| 厂商： | STMICROELECTRONICS |
| 元件分类： | 稳压器 |
| 英文描述： | 20 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO20 |
| 封装： | HTSSOP-20 |
| 文件页数： | 25/52页 |
| 文件大小： | 1569K |
| 代理商： | L6730 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页当前第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页
L6730 - L6730B
Device description
Doc ID 11938 Rev 3
31/52
5.14.1
Fan power supply failure
In many applications the fan is driven by a DC motor that uses a DC/DC converter. Often
only the speed of the motor is controlled by varying the voltage applied to the input terminal
and there is no control on the torque because the current is not directly controlled. The
current has to be limited in case of overload or short-circuit, but without stopping the motor.
With the L6730B, the current can be limited without shutting down the system because
constant current protection is provided. In order to vary the motor speed, the output voltage
of the converter must be varied. Both L6730 and L6730B have a dedicated EAREF pin (see
Figure 4) which provides an external reference to the non-inverting input of the error-
amplifier.
In these applications the duty cycle depends on the motor’s speed and sometimes a 100%
duty cycle setting has to be used to attain the maximum speed. In these conditions, the
bootstrap capacitor can not be recharged and the system cannot work properly. Some PWM
controllers limit the maximum duty cycle to 80 or 90% in order to keep the bootstrap
capacitor charged, but this makes performance during the load transient worse. The
“bootstrap anti-discharging system” allows the L6730x to work at 100% without any
problem.
Figure 26.: 100% duty cycle operation on page 31 shows the following picture illustrates the
device behavior when the input voltage is 5 V and a 100% duty cycle is set by an external
reference.
5.14.2
No-sink at zero current operation
The L6730 can work in no-sink mode. If output current is zero the converter skip some
pulses and works with a lower switching frequency. Between two pulses can pass a
relatively long time (say 200-300 s) during which there’s no switching activity and the
current into the inductor is zero. In this condition the phase node is at the output voltage and
in some cases this is not enough to keep the bootstrap cap charged. For example, if Vout is
3.3 V the voltage across the bootstrap cap is only 1.7 V. The high-side MOSFET cannot be
Figure 26.
100% duty cycle operation
Vout=5V
Vin=5V
LGate
Fsw?6.3KHz
TOFF
≈200ns
≈
相关PDF资料 |
PDF描述 |
|---|---|
| L6730B | 20 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO20 |
| L6730TR | 20 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO20 |
| L6732CTR | 20 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16 |
| L6732 | SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16 |
| L6732TR | SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| L6730_09 | 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:Adjustable step-down controller with synchronous rectification |
| L6730B | 功能描述:DC/DC 开关控制器 Adjustable Step Down Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| L6730BTR | 功能描述:DC/DC 开关控制器 Adjustable Step Down Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| L6730C | 功能描述:IC REG CTRLR BUCK PWM VM 20TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:100% 电源电压:8.2 V ~ 30 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:0°C ~ 70°C 封装/外壳:8-DIP（0.300"，7.62mm） 包装:管件 产品目录页面:1316 (CN2011-ZH PDF) |
| L6730CQ | 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:Adjustable step-down controller with synchronous rectification |
发布紧急采购，3分钟左右您将得到回复。