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参数资料
| 型号： | APW7077 |
| 厂商： | Anpec Electronics Corporation |
| 元件分类： | DC/DC变换器 |
| 英文描述： | PWM Step-Up DC-DC Converter |
| 中文描述： | PWM升压型DC - DC转换器 |
| 文件页数： | 16/21页 |
| 文件大小： | 444K |
| 代理商： | APW7077 |
Copyright
ANPEC Electronics Corp.
Rev. A.4 - S ep, 2005
APW 7077/ A
www.anpec.com.tw
16
Ground Plane
One point grounding should be used for the output
power return ground, the input power return ground,
and the device switch ground to reduce noise. The
input ground and output ground traces must be thick
enough for current to flow through and for reducing
ground bounce.
Power Signal Traces
Low resistance conducting paths should be used for
the power carrying traces to reduce power loss so as
to improve efficiency (short and thick traces for con-
necting the inductor L can also reduce stray
inductance). Trace connections made to the inductor
and schottky diode should be minimized to reduce
power dissipation and increase overall efficiency.
Output Capacitor
The output capacitor should be placed close to the
output terminals to obtain better smoothing effect on
the output ripple.
The output capacitor, C
OUT
, should also be placed close
to the IC. Any copper trace connections for the C
OUT
capacitor can increase the series resistance, which
directly effects output voltage ripple and efficiency.
Lay out Considerations
Switching Noise Decoupling Capacitor
On APW7077 fixed voltage application, a 0.1
μ
F ce-
ramic capacitor should be placed close to the V
OUT
pin
and GND pin of the chip to filter the switching spikes
in the output voltage monitored by the V
OUT
pin.
Feedback Network
On APW7077A application, the feedback networks
should be connected directly to a dedicated analog
ground plane and this ground plane must connect to
the GND pin. If no analog ground plane is available
then this ground must tie directly to the GND pin. The
feedback network, resistors R1 and R2, should be kept
close to the FB pin, and away from the inductor, to
minimize copper trace connections that can inject noise
into the system.
Input Capacitor
In APW7077A high output voltage application circuit,
the input voltage(V
IN
) is tied to chip supply pin(V
DD
).
The input capacitor C
IN
in V
IN
must be placed close to
the IC. This will reduce copper trace resistance which
effects input voltage ripple of the IC. For additional
input voltage filtering, a 1
μ
F capacitor can be placed
in parallel with C
IN
, close to the V
DD
pin, to shunt any
high frequency noise to ground.
the controller’s EXT pin must be able to supply the
necessary driving current. Rb can be calculated by
the following equation:
Since the pulse current flows through the transistor,
the exact Rb value should be finely tuned by the
experiment. Generally, a small Rb value can increase
the output current capability, but the efficiency will
decrease due to more energy is used to drive the
transistor. Moreover, a speed–up capacitor, Cb, should
be connected in parallel with Rb to reduce switching
loss and improve efficiency. Cb can be calculated by
the equation below:
It is due to the variation in the characteristics of the
transistor used. The calculated value should be used
as the initial test value and the optimized value should
be obtained by the experiment.
Ex ternal Component S election ( Cont.)
External Switch Transistor (Cont.)
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| APW7077ARBI-TR | PWM Step-Up DC-DC Converter |
| APW7077ARBI-TRL | PWM Step-Up DC-DC Converter |
| APW7077ARBI-TU | PWM Step-Up DC-DC Converter |
| APW7077ARBI-TUL | PWM Step-Up DC-DC Converter |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| APW7077ARBI-TR | 制造商:ANPEC 制造商全称:Anpec Electronics Coropration 功能描述:PWM Step-Up DC-DC Converter |
| APW7077ARBI-TRL | 制造商:ANPEC 制造商全称:Anpec Electronics Coropration 功能描述:PWM Step-Up DC-DC Converter |
| APW7077ARBI-TU | 制造商:ANPEC 制造商全称:Anpec Electronics Coropration 功能描述:PWM Step-Up DC-DC Converter |
| APW7077ARBI-TUL | 制造商:ANPEC 制造商全称:Anpec Electronics Coropration 功能描述:PWM Step-Up DC-DC Converter |
| APW7077AZBI-TR | 制造商:ANPEC 制造商全称:Anpec Electronics Coropration 功能描述:PWM Step-Up DC-DC Converter |
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