- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385772 > RT8010B (Richtek Technology Corporation) 1.5MHz, 800mA, High Efficiency PWM Step-Down DC/DC Converter PDF資料下載
參數(shù)資料
| 型號： | RT8010B |
| 廠商： | Richtek Technology Corporation |
| 英文描述： | 1.5MHz, 800mA, High Efficiency PWM Step-Down DC/DC Converter |
| 中文描述： | 1.5MHz的，800mA電流，高效率的PWM降壓型DC / DC轉(zhuǎn)換器 |
| 文件頁數(shù)： | 8/12頁 |
| 文件大?。?/td> | 265K |
| 代理商： | RT8010B |
RT8010B
8
DS8010B-00 July 2007
www.richtek.com
Preliminary
+
≤
OUT
L
OUT
8fC
1
ESR
Δ
I
Δ
V
Applications Information
The basic RT8010B application circuit is shown in Typical
Application Circuit. External component selection is
determined by the maximum load current and begins with
the selection of the inductor value and operating frequency
followed by C
IN
and C
OUT
.
Inductor Selection
For a given input and output voltage, the inductor value
and operating frequency determine the ripple current. The
ripple current
Δ
I
L
increases with higher V
IN
and decreases
with higher inductance.
Having a lower ripple current reduces the ESR losses in
the output capacitors and the output voltage ripple. Highest
efficiency operation is achieved at low frequency with small
ripple current. This, however, requires a large inductor.
A reasonable starting point for selecting the ripple current
is
Δ
I
L
= 0.4(I
MAX
). The largest ripple current occurs at the
highest V
IN
. To guarantee that the ripple current stays
below a specified maximum, the inductor value should be
chosen according to the following equation :
Inductor Core Selection
Once the value for L is known, the type of inductor must
be selected. High efficiency converters generally can not
afford the core loss found in low cost powdered iron cores,
forcing the use of more expensive ferrite or mollypermalloy
cores. Actual core loss is independent of core size for a
fixed inductor value but it is very dependent on the
inductance selected. As the inductance increases, core
losses decrease. Unfortunately, increased inductance
requires more turns of wire and therefore copper losses
will increase.
Ferrite designs have very low core losses and are preferred
at high switching frequencies, so design goals can
concentrate on copper loss reduction and saturation
prevention. Ferrite core material saturates
“
hard
”
, which
means that inductance collapses abruptly when the peak
1
×
×
=
IN
OUT
V
OUT
V
L
V
L
f
Δ
I
1
×
Δ
×
=
IN(MAX)
V
OUT
V
L(MAX)
OUT
I
f
V
L
design current is exceeded. This results in an abrupt
increase in inductor ripple current and consequent output
voltage ripple. Do not allow the core to saturate!
Different core materials and shapes will change the size/
current and price/current relationship of an inductor.
Toroid or shielded pot cores in ferrite or permalloy materials
are small and do not radiate energy but generally cost
more than powdered iron core inductors with similar
characteristics. The choice of which style inductor to use
mainly depends on the price vs size requirements and
any radiated field/EMI requirements.
C
IN
and C
OUT
Selection
The input capacitance, C
IN
, is needed to filter the
trapezoidal current at the source of the top MOSFET. To
prevent large ripple voltage, a low ESR input capacitor
sized for the maximum RMS current should be used. RMS
current is given by :
1
V
V
V
V
I
I
OUT
IN
IN
OUT
OUT(MAX)
RMS
=
This formula has a maximum at V
IN
= 2V
OUT
, where
I
RMS
= I
OUT
/2. This simple worst-case condition is
commonly used for design because even significant
deviations do not offer much relief or choose a capacitor
rated at a higher temperature than required. Several
capacitors may also be paralleled to meet size or height
requirements in the design.
The selection of C
OUT
is determined by the effective series
resistance (ESR) that is required to minimize voltage ripple
and load step transients, as well as the amount of bulk
capacitance that is necessary to ensure that the control
loop is stable. Loop stability can be checked by viewing
the load transient response as described in a later section.
The output ripple,
Δ
V
OUT
, is determined by :
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| RT8010BGQW | 1.5MHz, 800mA, High Efficiency PWM Step-Down DC/DC Converter |
| RT8011 | 2A, 4MHz, Synchronous Step-Down Regulator |
| RT8011AGF | 2A, 4MHz, Synchronous Step-Down Regulator |
| RT8011AGQW | 2A, 4MHz, Synchronous Step-Down Regulator |
| RT8011APF | 2A, 4MHz, Synchronous Step-Down Regulator |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| RT8010BGQW | 功能描述:IC REG BUCK SYNC ADJ 0.8A 8WDFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 類型:升壓（升壓） 輸出類型:可調(diào)式 輸出數(shù):1 輸出電壓:5 V ~ 25 V 輸入電壓:2.3 V ~ 5.5 V PWM 型:電流模式 頻率 - 開關(guān):600kHz，1.2MHz 電流 - 輸出:1A 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP，8-MSOP（0.118"，3.00mm 寬） 包裝:管件 供應(yīng)商設(shè)備封裝:8-MSOP |
| RT8010GQW | 功能描述:IC REG BUCK SYNC ADJ 1A 6WDFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 類型:升壓（升壓） 輸出類型:可調(diào)式 輸出數(shù):1 輸出電壓:5 V ~ 25 V 輸入電壓:2.3 V ~ 5.5 V PWM 型:電流模式 頻率 - 開關(guān):600kHz，1.2MHz 電流 - 輸出:1A 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP，8-MSOP（0.118"，3.00mm 寬） 包裝:管件 供應(yīng)商設(shè)備封裝:8-MSOP |
| RT8011 | 制造商:RICHTEK 制造商全稱:Richtek Technology Corporation 功能描述:2A, 4MHz, Synchronous Step-Down Regulator |
| RT8011AGF | 制造商:RICHTEK 制造商全稱:Richtek Technology Corporation 功能描述:2A, 4MHz, Synchronous Step-Down Regulator |
| RT8011AGQW | 功能描述:IC REG BUCK SYNC ADJ 2A 8WDFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:50 系列:- 類型:升壓（升壓） 輸出類型:兩者兼有 輸出數(shù):1 輸出電壓:5V，2 V ~ 16.5 V 輸入電壓:2 V ~ 16.5 V PWM 型:- 頻率 - 開關(guān):45kHz 電流 - 輸出:50mA 同步整流器:無 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:8-DIP（0.300"，7.62mm） 包裝:管件 供應(yīng)商設(shè)備封裝:8-PDIP |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。