參數(shù)資料
型號(hào)： IRU3004CF
廠商： International Rectifier
元件分類： 基準(zhǔn)電壓源/電流源
英文描述： 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC WITH DUAL LDO CONTROLLER
中文描述： 5位可編程同步降壓控制器IC具有雙LDO控制器
文件頁(yè)數(shù)： 12/17頁(yè)
文件大小： 104K
代理商： IRU3004CF
12
Rev. 1.7
07/16/02
IRU3004
www.irf.com
With the maximum heat sink temperature calculated in
the previous step, the heat-sink-to-air thermal resistance
(
θ
SA
) is calculated as follows:
Assuming T
A
= 35
8
C:
Next, a heat sink with lower
θ
SA
than the one calculated
in the previous step must be selected. One way is to
simply look at the graphs of the “Heat Sink Temp Rise
Above the Ambient” vs. the “Power Dissipation” given in
the heat sink manufacturers’ catalog and select a heat
sink that results in lower temperature rise than the one
calculated in previous step. The following heat sinks from
AAVID and Thermalloy meet this criteria.
Company
Thermalloy............................6078B
AAVID..................................577002
Part #
Following the same procedure for the Schottky diode
results in a heat sink with
θ
SA
=25
8
C/W. Although it is
possible to select a slightly smaller heat sink, for sim-
plicity, the same heat sink as the one for the high side
MOSFET is also selected for the synchronous MOSFET.
Switcher Current Limit Protection
The PWM controller uses the MOSFET R
DS(ON)
as the
sensing resistor to sense the MOSFET current and com-
pares to a programmed voltage which is set externally
via a resistor (Rcs) placed between the drain of the
MOSFET and the “CS+” terminal of the IC as shown in
the application circuit. For example, if the desired cur-
rent limit point is set to be 22A and from our previous
selection, the maximum MOSFET R
DS(ON)
=19m
, then
the current sense resistor, Rcs is calculated as:
Where:
I
B
= 200
μ
A is the internal current setting of the de-
vice
Switcher Timing Capacitor Selection
The switching frequency can be programmed using an
external timing capacitor. The value of Ct can be ap-
proximated using the equation below:
Where:
Ct = Timing Capacitor
Fsw = Switching Frequency
If Fsw = 200KHz:
LDO Power MOSFET Selection
The first step in selecting the power MOSFET for the
linear regulators is to select its maximum R
DS(ON)
based
on the input to output Dropout voltage and the maximum
load current.
For Vo = 1.5V, V
IN
= 3.3V and I
L
= 2A:
(V
- Vo)
I
L
Note that since the MOSFETs R
DS(ON)
increases with
temperature, this number must be divided by
≈
1.5, in
order to find the R
DS(on)
max at room temperature. The
Motorola MTP3055VL has a maximum of 0.18
R
DS(ON)
at room temperature, which meets our requirement.
To select the heat sink for the LDO MOSFET the first
step is to calculate the maximum power dissipation of
the device and then follow the same procedure as for the
switcher.
Where:
P
D
= Power Dissipation of the Linear Regulator
I
L
= Linear Regulator Load Current
For the 1.5V and 2A load:
Assuming T
J(max)
= 125
8
C then:
θ
SA
= T
8
C/W
P
D
3.82
83
T = Ts - T
A
= 118 - 35 = 83
8
C
Temperature Rise Above Ambient
Vcs = I
CL
×
R
DS
= 22
×
0.019 = 0.418V
0.418V
μ
A
B
Rcs = I
Vcs
Fsw
y
3.5
×
10
-5
Ct
Ct
y
200
×
10
3
3.5
×
10
-5
P
D
= (V
IN
- Vo)
×
I
L
P
D
= (3.3 - 1.5)
×
2 = 3.6W
Ts = T
J
- P
D
×
(
θ
JC
+
θ
CS
)
Ts = 125 - 3.6
×
(1.8 + 0.05) = 118
°
C
R
DS(max)
= = (3.3 - 1.5)
2
相關(guān)PDF資料
PDF描述
IRU3004CW 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC WITH DUAL LDO CONTROLLER
IRU3007 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK, NON-SYNCHRONOUS,ADJUSTABLE LDO AND 200mA ON-BOARD LDO
IRU3007CW 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK, NON-SYNCHRONOUS,ADJUSTABLE LDO AND 200mA ON-BOARD LDO
IRU3011 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC
IRU3011CW 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
IRU3004CW 功能描述:IC CTRL/REG SYNC BUCK 20-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,000 系列:- 應(yīng)用:電源，ICERA E400，E450 輸入電壓:4.1 V ~ 5.5 V 輸出數(shù):10 輸出電壓:可編程 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:42-WFBGA，WLCSP 供應(yīng)商設(shè)備封裝:42-WLP 包裝:帶卷 (TR)
IRU3004CWTR 功能描述:IC CTRL/REG SYNC BUCK 20-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,000 系列:- 應(yīng)用:電源，ICERA E400，E450 輸入電壓:4.1 V ~ 5.5 V 輸出數(shù):10 輸出電壓:可編程 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:42-WFBGA，WLCSP 供應(yīng)商設(shè)備封裝:42-WLP 包裝:帶卷 (TR)
IRU3005CW 制造商:未知廠家 制造商全稱:未知廠家 功能描述:
IRU3007 制造商:IRF 制造商全稱:International Rectifier 功能描述:5-BIT PROGRAMMABLE SYNCHRONOUS BUCK, NON-SYNCHRONOUS,ADJUSTABLE LDO AND 200mA ON-BOARD LDO
IRU3007CW 功能描述:IC CTRL/REG SYNC BUCK 28-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,000 系列:- 應(yīng)用:電源，ICERA E400，E450 輸入電壓:4.1 V ~ 5.5 V 輸出數(shù):10 輸出電壓:可編程 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:42-WFBGA，WLCSP 供應(yīng)商設(shè)備封裝:42-WLP 包裝:帶卷 (TR)
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*