- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄372219 > SPX1587AU-3.3 3A Low Dropout Voltage Regulator Adjustable & Fixed Output, Fast Response PDF資料下載
參數(shù)資料
| 型號： | SPX1587AU-3.3 |
| 元件分類： | 基準電壓源/電流源 |
| 英文描述： | 3A Low Dropout Voltage Regulator Adjustable & Fixed Output, Fast Response |
| 中文描述： | 第3A低壓差線性穩(wěn)壓器可調(diào)節(jié) |
| 文件頁數(shù)： | 3/7頁 |
| 文件大小： | 187K |
| 代理商： | SPX1587AU-3.3 |
Rev. 10/30/00
SPX1587
APPLICATION HINTS
The SPX1587 incorporates protection against over-current
faults, reversed load insertion, over temperature operation, and
positive and negative transient voltage. However, the use of
an output capacitor is required in order to improve the stability
and the performances.
Stability
The output capacitor is part of the regulator’s frequency
compensation system. Either a 22
μ
F aluminum electrolytic
capacitor or a 10
μ
F solid tantalum capacitor between the
output terminal and ground guarantees stable operation for all
operating conditions.
However, in order to minimize overshoot and undershoot, and
therefore optimize the design, please refer to the section
‘Ripple Rejection’.
Ripple Rejection
Ripple rejection can be improved by adding a capacitor
between the ADJ pin and ground as shown in figure 6. When
ADJ pin bypassing is used, the value of the output capacitor
required increases to its maximum (22
μ
F for an aluminum
electrolytic capacitor, or 10
μ
F for a solid tantalum capacitor).
If the ADJ pin is not bypass, the value of the output capacitor
can be lowered to 10
μ
F for an electrolytic aluminum capacitor
or 4.7
μ
F for a solid tantalum capacitor.
However the value of the ADJ-bypass capacitor should be
chosen with respect to the following equation:
C = 1 / (6.28 * F
R
* R
1
)
Where C
= value of the capacitor in Farads (select an
equal or larger standard value),
F
R
= ripple frequency in Hz,
R
1
= value of resistor R
1
in Ohms.
If an ADJ-bypass capacitor is use, the amplitude of the output
ripple will be independent of the output voltage. If an ADJ-
bypass capacitor is not used, the output ripple will be
proportional to the ratio of the output voltage to the reference
voltage:
M = V
OUT
/ V
REF
Where M = multiplier for the ripple seen when the ADJ pin
is optimally bypassed.
V
REF
= Reference Voltage
Reducing parasitic resistance and inductance
One solution to minimize parasitic resistance and inductance is
to connect in parallel capacitors. This arrangement will
improve the transient response of the power supply if your
system requires rapidly changing current load condition.
Thermal Consideration
Although the SPX1587 offers some limiting circuitry for
overload conditions, it is necessary not to exceed the
maximum junction temperature, and therefore to be careful
about thermal resistance. The heat flow will follow the lowest
resistance path, which is the Junction-to-case thermal
resistance. In order to insure the best thermal flow of the
component, a proper mounting is required. Note that the case
of the device is electrically connected to the output. In case
the case has to be electrically isolated, a thermally conductive
spacer can be used. However do not forget to consider its
contribution to thermal resistance.
Assuming:
V
IN
= 10V, V
OUT
= 5V, I
OUT
= 1.5A, T
A
= 50
°
C/W,
θ
Heatsink Case
= 6
°
C/W,
θ
Heatsink Case
= 0.5
°
C/W,
θ
JC
= 3
°
C/W
Power dissipation under this condition
P
D
= (V
IN
– V
OUT
) * I
OUT
= 7.5W
Junction Temperature
T
J
= T
A
+ P
D
* (
θ
Case - HS
+
θ
HS
+
θ
JC
)
For the Control Sections
T
J
= 50 + 7.5*(0.5 +6=3) = 121.25
°
C
121.25
°
C < T
J (max)
for the Control & Power Sections.
In both case reliable operation is insured by adequate junction
temperature.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| SPX1587AU-5.0 | 3A Low Dropout Voltage Regulator Adjustable & Fixed Output, Fast Response |
| SPX1587T-1.5 | 3A Low Dropout Voltage Regulator Adjustable & Fixed Output, Fast Response |
| SPX1587T-1.8 | 3A Low Dropout Voltage Regulator |
| SPX1587U-1.8 | 3A Low Dropout Voltage Regulator |
| SPX2701AT3-5.0 | 700mA Low Dropout Voltage Regulators With Shutdown |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SPX1587AU-5.0 | 制造商:Exar Corporation 功能描述:Voltage Regulator |
| SPX1587AU-5-0 | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:3A Low Dropout Voltage Regulator |
| SPX1587AU-L | 功能描述:低壓差穩(wěn)壓器 - LDO 3A LOW DROPOUT RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓（最大值）:307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20 |
| SPX1587AU-L-3-3 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: |
| SPX1587R | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:3A Low Dropout Voltage Regulator Adjustable & Fixed Output, Fast Response |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。