- 您现在的位置：买卖IC网 > PDF目录68993 > FA5515P (FUJI ELECTRIC CO LTD) 1.5 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDIP8 PDF资料下载
参数资料
| 型号： | FA5515P |
| 厂商： | FUJI ELECTRIC CO LTD |
| 元件分类： | 稳压器 |
| 英文描述： | 1.5 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDIP8 |
| 封装： | DIP-8 |
| 文件页数： | 2/22页 |
| 文件大小： | 260K |
| 代理商： | FA5515P |
FA551X
10
Fig. 8
Soft start timing chart
Fig. 7
Soft start circuit
Fig. 6
CS pin waveform
Fig. 5
CS pin circuit
3. CS pin circuit
As shown in Figure 5, capacitor Cs is connected to the CS pin.
The CS pin voltage varies depending on the charging voltage of
this capacitor Cs.
When the power is turned on, the constant current source
(5.2A) begins to charge capacitor. Accordingly, the CS pin
voltage rises as shown in Figure 6. The CS pin voltage is
connected to the PWM comparator, which is characterized to
make output based on the lowest of input voltages. The device
enters soft-start mode while the CS pin voltage is between 1.0V
and VTHCSM (FA5510/14: 1.92V, FA5511/15: 2.4V).
During normal operation, the CS pin is clamped at 4.0V by
internal zener diode. If the output voltage drops due to an
overload and the FB voltage rises to 3.5V or more, the clamp
voltage 4.0V is canceled and the CS pin voltage rises to 9.5V.
The CS pin is also connected to latch comparator C2. If the CS
pin voltage rises to 8.5V or more, comparator C2 toggles to turn
off the 5V REF circuit, thereby shutting the output down.
Since the CS pin is also connected to comparator C1, the 5V
REF circuit can be turned off to shut the output down by
dropping the CS pin voltage below 0.68V. In this way,
comparator C1 can be used for output on-off control.
As explained above, the CS pin can be used for soft-start,
overload output shutdown, and output on-off control by varying
the voltage. Further details on the above three major functions
of the CS pin are given below.
3.1 Soft start function
Figure 7 shows the soft start circuit. Figure 8 is a soft-start
operation timing chart. The CS pin is connected to capacitor
Cs. When the power is turned on, the constant current source
(5.2A) begins to charge the capacitor. As shown in the timing
chart, the CS pin voltage rises slowly in accordance with the
capacitor Cs charging current. The CS pin is also connected to
the IC internal PWM comparator, which has such
characteristics that the voltage is determined to output on the
basis of the lowest of input voltages. The comparator output
pulse slowly widens to cause a soft start as shown in the timing
chart.
The soft start period can be approximately estimated by the
period tS, from the time the IC is activated to the time the output
pulse width widens to 30%. The period tS is given by the
following equation:
PWM
Output
circuit
UVLO
REF
RT
CS
FB
VCC
OSC
5V VCC
ENB
5V REF
4V
0.8/0.68V
8.5/7.9V
5.2
A
DMAX
Cs
C3
3.5V
8
6
1
2
7
C1
C2
9.5
8.5
4.0
VTHCSM
1.0
0.68/0.8
0
CS
pin
voltage
Vcs
[V]
OFF mode
Soft start
Momentary
overload or
overvoltage
Overload or
overvoltage
Shutdown
Time t
OUT pin output
CS pin voltage
DT voltage
Oscillator output
FB pin voltage
6
8
2
1
VCC
CS
Cs
FB
RT
OSC
PWM
DMAX
5.2
A
Output
circuit
..................................................... (3)
Cs: Soft start capacitor [F]
tS [ms]
310
CS [ms]
相关PDF资料 |
PDF描述 |
|---|---|
| FA5514N | 1.5 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO8 |
| FA5515N | 1.5 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO8 |
| FA5510N | 1.5 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO8 |
| FA5511P | 1.5 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDIP8 |
| FA5514P | 1.5 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDIP8 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| FA5515P-D1 | 制造商:Fuji Electric 功能描述: |
| FA551X | 制造商:未知厂家 制造商全称:未知厂家 功能描述:CMOS IC For Switching Power Supply Control |
| FA5526 | 制造商:FUJI 制造商全称:Fuji Electric 功能描述:Fuji Switching Power Control IC |
| FA5527 | 制造商:FUJI 制造商全称:Fuji Electric 功能描述:Fuji Switching Power Control IC |
| FA5527P-A2 | 制造商:Fuji Electric 功能描述: |
发布紧急采购，3分钟左右您将得到回复。