- 您現在的位置：買賣IC網 > PDF目錄384734 > MIC2169MM (Micrel Semiconductor,Inc.) 500 KHZ PWM SYNCHRONOUS BUCK CONTROL IC PDF資料下載
參數資料
| 型號： | MIC2169MM |
| 廠商： | Micrel Semiconductor,Inc. |
| 英文描述： | 500 KHZ PWM SYNCHRONOUS BUCK CONTROL IC |
| 中文描述： | 500千赫的PWM同步降壓控制IC |
| 文件頁數： | 9/14頁 |
| 文件大?。?/td> | 160K |
| 代理商： | MIC2169MM |
November 2003
9
M9999-111803
MIC2169
Micrel
The peak-to-peak inductor current (AC ripple current) is:
I
V
(V max
V max
V
L
)
f
PP
OUT
OUT
S
=
×
×
×
)
)
The peak inductor current is equal to the average output
current plus one half of the peak-to-peak inductor ripple
current.
I
I
max
(
0.5 I
PK
OUT
PP
=
+
)
The RMS inductor current is used to calculate the I
2
×
R
losses in the inductor.
I
I
max
(
1
1
3
I
(
I
max
INDUCTOR(rms)
OUT
P
OUT
2
=
×
+
)
)
Maximizing efficiency requires the proper selection of core
material and minimizing the winding resistance. The high
frequency operation of the MIC2169 requires the use of ferrite
materials for all but the most cost sensitive applications.
Lower cost iron powder cores may be used but the increase
in core loss will reduce the efficiency of the power supply. This
is especially noticeable at low output power. The winding
resistance decreases efficiency at the higher output current
levels. The winding resistance must be minimized although
this usually comes at the expense of a larger inductor. The
power dissipated in the inductor is equal to the sum of the core
and copper losses. At higher output loads, the core losses are
usually insignificant and can be ignored. At lower output
currents, the core losses can be a significant contributor.
Core loss information is usually available from the magnetics
vendor. Copper loss in the inductor is calculated by the
equation below:
P
I
R
INDUCTORCu
INDUCTOR(rms)
WINDING
2
=
×
The resistance of the copper wire, R
WINDING
, increases with
temperature. The value of the winding resistance used should
be at the operating temperature.
R
R
1 0.0042 (T
(
T
)
WINDING(hot)
WINDING(20 C)
HOT
20 C
=
×
)
where:
T
HOT
= temperature of the wire under operating load
T
20
°
C
= ambient temperature
R
WINDING(20
°
C)
is room temperature winding resistance (usu-
ally specified by the manufacturer)
Output Capacitor Selection
The output capacitor values are usually determined capaci-
tors ESR (equivalent series resistance). Voltage and RMS
current capability are two other important factors selecting
the output capacitor. Recommended capacitors tantalum,
low-ESR aluminum electrolytics, and POSCAPS. The output
capacitor
’
s ESR is usually the main cause of output ripple.
The output capacitor ESR also affects the overall voltage
feedback loop from stability point of view. See
“
Feedback
Loop Compensation
”
section for more information. The
maximum value of ESR is calculated:
R
V
I
ESR
OUT
PP
≤
where:
V
OUT
= peak-to-peak output voltage ripple
I
PP
= peak-to-peak inductor ripple current
The total output ripple is a combination of the ESR output
capacitance. The total ripple is calculated below:
V
I
(1 D)
×
C
f
I
R
OUT
PP
OUT
S
2
PP
ESR
2
=
×
+
×
(
)
where:
D = duty cycle
C
OUT
= output capacitance value
f
S
= switching frequency
The voltage rating of capacitor should be twice the voltage for
a tantalum and 20% greater for an aluminum electrolytic.
The output capacitor RMS current is calculated below:
I
I
12
C
PP
OUT(rms)
=
The power dissipated in the output capacitor is:
P
I
R
DISS(C
C
ESR(C
)
OUT
OUT(rms)2
OUT
)
=
×
Input Capacitor Selection
The input capacitor should be selected for ripple current
rating and voltage rating. Tantalum input capacitors may fail
when subjected to high inrush currents, caused by turning the
input supply on. Tantalum input capacitor voltage rating
should be at least 2 times the maximum input voltage to
maximize reliability. Aluminum electrolytic, OS-CON, and
multilayer polymer film capacitors can handle the higher
inrush currents without voltage derating. The input voltage
ripple will primarily depend on the input capacitor
’
s ESR. The
peak input current is equal to the peak inductor current, so:
V
I
R
IN
INDUCTOR(peak)
ESR(C )
=
×
The input capacitor must be rated for the input current ripple.
The RMS value of input capacitor current is determined at the
maximum output current. Assuming the peak-to-peak induc-
tor ripple current is low:
I
I
max
(
D (1 D)
C (rms)
OUT
≈
×
)
The power dissipated in the input capacitor is:
P
I
R
DISS(C )
C (rms)
ESR(C )
2
=
×
相關PDF資料 |
PDF描述 |
|---|---|
| MIC2169 | 500 KHZ PWM SYNCHRONOUS BUCK CONTROL IC |
| MIC2171BT | Isolated Flyback Switching Regulator with 9V Output |
| MIC2171BU | Isolated Flyback Switching Regulator with 9V Output |
| MIC2171 | Isolated Flyback Switching Regulator with 9V Output |
| MIC2185 | Low Voltage Synchronous Boost PWM Control IC |
相關代理商/技術參數 |
參數描述 |
|---|---|
| MIC2169YMM | 功能描述:直流/直流開關調節(jié)器 Replaced by MIC2169AYMM (Lead Free) RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| MIC2169YMM TR | 功能描述:直流/直流開關調節(jié)器 Replaced by MIC2169AYMM TR (Lead Free) RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| MIC2171 | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:100kHz 2.5A Switching Regulator Preliminary Information |
| MIC2171_07 | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:100kHz 2.5A Switching Regulator |
| MIC2171BT | 功能描述:IC REG MULTI CONFIG 2.5A TO220-5 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關穩(wěn)壓器 系列:- 標準包裝:20 系列:SIMPLE SWITCHER® 類型:降壓（降壓） 輸出類型:固定 輸出數:1 輸出電壓:12V 輸入電壓:4 V ~ 60 V PWM 型:電壓模式 頻率 - 開關:52kHz 電流 - 輸出:1A 同步整流器:無 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:16-DIP（0.300"，7.62mm） 包裝:管件 供應商設備封裝:16-DIP 其它名稱:*LM2575HVN-12LM2575HVN-12 |
發(fā)布緊急采購，3分鐘左右您將得到回復。