參數(shù)資料
型號(hào)： IRU3073CQ
廠商： International Rectifier
英文描述： SYNCHRONOUS PWM CONTROLLER WITH OVER-CURRENT PROTECTION / LDO CONTROLLER
中文描述： 同步PWM控制器，帶有過(guò)電流保護(hù)/ LDO控制器
文件頁(yè)數(shù)： 9/21頁(yè)
文件大?。?/td> 236K
代理商： IRU3073CQ
IRU3073
9
Rev. 1.0
09/17/03
www.irf.com
If
i = 25%(I
O
), then the output inductor will be:
L = 3.125
μ
H
The Coilcraft DO5022HC series provides a range of in-
ductors in different values, low profile suitable for large
currents. 3.3
μ
H is a good choice for this application.
This will result to a ripple approximately 23% of output
current.
Output Capacitor Selection
The criteria to select the output capacitor is normally
based on the value of the Effective Series Resistance
(ESR). In general, the output capacitor must have low
enough ESR to meet output ripple and load transient
requirements, yet have high enough ESR to satisfy sta-
bility requirements. The ESR of the output capacitor is
calculated by the following relationship:
V
I
O
The Sanyo TPC series, Poscap capacitor is a good choice.
The 6TPC330M, 330
μ
F, 6.3V has an ESR 40m
. Se-
lecting two of these capacitors in parallel, results to an
ESR of
20m
which achieves our low ESR goal.
The capacitor value must be high enough to absorb the
inductor's ripple current. The larger the value of capaci-
tor, the lower will be the output ripple voltage.
Power MOSFET Selection
The IRU3073 uses two N-Channel MOSFETs. The se-
lections criteria to meet power transfer requirements is
based on maximum drain-source voltage (V
DSS
), gate-
source drive voltage (V
GS
), maximum output current, On-
resistance R
DS(ON)
and thermal management.
The MOSFET must have a maximum operating voltage
(V
DSS
) exceeding the maximum input voltage (V
IN
).
The gate drive requirement is almost the same for both
MOSFETs. Logic-level transistor can be used and cau-
tion should be taken with devices at very low V
GS
to pre-
vent undesired turn-on of the complementary MOSFET,
which results a shoot-through current.
The total power dissipation for MOSFETs includes con-
duction and switching losses. For the Buck converter,
the average inductor current is equal to the DC load cur-
rent. The conduction loss is defined as:
The R
DS(ON)
temperature dependency should be consid-
ered for the worst case operation. This is typically given
in the MOSFET data sheet. Ensure that the conduction
losses and switching losses do not exceed the package
ratings or violate the overall thermal budget.
Choose IRF7832 for both control MOSFET and synchro-
nous MOSFET. This device provides low on-resistance
in a compact SOIC 8-Pin package.
The MOSFETs have the following data:
IRF7832
V
DSS
= 30V
I
D
= 16A @ 70
8
C
R
DS(ON)
= 4m
The total conduction losses will be:
P
CON(TOTAL)
= P
CON(UPPER)
+ P
CON(LOWER)
P
CON(TOTAL)
= 0.38W
The switching loss is more difficult to calculate, even
though the switching transition is well understood. The
reason is the effect of the parasitic components and
switching times during the switching procedures such
as turn-on / turnoff delays and rise and fall times. The
control MOSFET contributes to the majority of the switch-
ing losses in synchronous Buck converter. The synchro-
nous MOSFET turns on under zero voltage conditions,
therefore, the turn on losses for synchronous MOSFET
can be neglected. With a linear approximation, the total
switching loss can be expressed as:
V
2
T
The switching time waveform is shown in Figure 9.
2
2
P
COND
(Upper Switch) = I
LOAD
×
R
DS(ON)
×
D
×
P
COND
(Lower Switch) = I
LOAD
×
R
DS(ON)
×
(1 - D)
×
= R
DS(ON)
Temperature Dependency
Where:
V
O
= Output Voltage Ripple
i = Inductor Ripple Current
V
O
= 50mV and
I
23% of 8A = 1.89A
This results to: ESR=26.5m
ESR
≤
---(10)
Where:
V
DS(OFF)
= Drain to Source Voltage at off time
t
r
= Rise Time
t
f
= Fall Time
T = Switching Period
I
LOAD
= Load Current
P
SW
=
I
LOAD
---(12)
×
t
r
+
t
f
×
相關(guān)PDF資料
PDF描述
IRU3138CS SYNCHRONOUS PWM CONTROLLER FOR TERMINATION POWER SUPPLY APPLICATIONS
IRU3138 SYNCHRONOUS PWM CONTROLLER FOR TERMINATION POWER SUPPLY APPLICATIONS
IRUD360CW40 ULTRAFAST SOFT RECOVERY DIODE
IRUH33PA13A1M Ultra Low Dropout Positive Adjustable Linear Regulator +3.3Vin at 3.0A
IRUH33PA13A1MK Ultra Low Dropout Positive Adjustable Linear Regulator +3.3Vin at 3.0A
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
IRU3073CQTR 功能描述:IC REG DL BCK/LINEAR 16-QSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?降壓（降壓）同步（2），線性（LDO）（1） 功能:任何功能 輸出數(shù):3 頻率 - 開關(guān):300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅(qū)動(dòng)器:無(wú) 帶監(jiān)控器:無(wú) 帶序列發(fā)生器:是 電源電壓:4.5 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類型:* 封裝/外殼:28-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:* 包裝:帶卷 (TR) 其它名稱:ISL6402IVZ-TTR
IRU3137 制造商:IRF 制造商全稱:International Rectifier 功能描述:8-PIN SYNCHRONOUS PWM CONTROLLER
IRU3137CS 制造商:IRF 制造商全稱:International Rectifier 功能描述:8-PIN SYNCHRONOUS PWM CONTROLLER
IRU3137CSTR 功能描述:IC REG CTRLR BUCK PWM VM 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 包裝:帶卷 (TR)
IRU3137CSTRPBF 功能描述:IC REG CTRLR BUCK PWM VM 8-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 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

*
*
*