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參數(shù)資料
| 型號： | RT8020DPQW |
| 廠商： | Richtek Technology Corporation |
| 元件分類： | DC/DC變換器 |
| 英文描述： | Dual High-Efficiency PWM Step-Down DC-DC Converter |
| 中文描述： | 雙高效率的PWM降壓型DC - DC轉換器 |
| 文件頁數(shù)： | 12/14頁 |
| 文件大?。?/td> | 229K |
| 代理商： | RT8020DPQW |
RT8020
12
DS8020-03 August 2007
www.richtek.com
Checking Transient Response
The regulator loop response can be checked by looking
at the load transient response. Switching regulators take
several cycles to respond to a step in load current. When
a load step occurs, V
OUT
immediately shifts by an amount
equal to
I
LOAD
(ESR), where ESR is the effective series
resistance of C
OUT
.
I
LOAD
also begins to charge or
discharge C
OUT
generating a feedback error signal used
by the regulator to return V
OUT
to its steady-state value.
During this recovery time, V
OUT
can be monitored for
overshoot or ringing that would indicate a stability problem.
Layout Considerations
Follow the PCB layout guidelines for optimal performance
of RT8020.
}
For the main current paths, keep their traces short and
wide.
}
Put the input capacitor as close as possible to the device
pins (VIN and GND).
}
LX node is with high frequency voltage swing and should
be kept small area. Keep analog components away from
LX node to prevent stray capacitive noise pick-up.
}
Connect feedback network behind the output capacitors.
Keep the loop area small. Place the feedback
components near the RT8020.
}
Connect all analog grounds to a command node and
then connect the command node to the power ground
behind the output capacitors.
and the synchronous switch. Thus, the series resistance
looking into the LX pin is a function of both top and bottom
MOSFET R
DS(ON)
and the duty cycle (DC) is shown as
follows :
R
SW
= R
DS(ON)TOP
x DC + R
DS(ON)BOT
x (1
DC)
The R
DS(ON)
for both the top and bottom MOSFETs can be
obtained from the Typical Performance Characteristics
curves. Thus, to obtain I
2
R losses, simply add R
SW
to R
L
and multiply the result by the square of the average output
current. Other losses including C
IN
and C
OUT
ESR
dissipative losses and inductor core losses generally
account for less than 2% of the total loss.
Thermal Considerations
The maximum power dissipation depends on the thermal
resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference between
junction to ambient. The maximum power dissipation can
be calculated by following formula :
P
D(MAX)
= ( T
J(MAX)
T
A
) /
θ
JA
Where T
J(MAX)
is the maximum junction temperature, T
A
is
the ambient temperature and the
θ
JA
is the junction to
ambient thermal resistance. For recommended operating
conditions specification of RT8020 DC/DC converter,
where T
J(MAX)
is the maximum junction temperature of
the die and T
A
is the ambient temperature. The junction
to ambient thermal resistance
θ
JA
is layout dependent.
For WDFN-12L 3x3 packages, the thermal resistance
θ
JA
is 60
°
C/W on the standard JEDEC 51-7 four-layers
thermal test board. The maximum power dissipation at
T
A
= 25
°
C can be calculated by following formula :
P
D(MAX)
= (125
°
C
25
°
C) / (60
°
C/W) = 1.667W for
WDFN-12L 3x3 packages
The maximum power dissipation depends on operating
ambient temperature for fixed T
J(MAX)
and thermal
resistance
θ
JA
. For RT8020 packages, the Figure 4 of de-
rating curves allows the designer to see the effect of rising
ambient temperature on the maximum power allowed.
Figure 4. De-rating Curves for RT8020 Package
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
0
25
50
75
100
125
Ambient Temperature (
°
C)
M
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| RT8020E | 制造商:RICHTEK 制造商全稱:Richtek Technology Corporation 功能描述:Dual High-Efficiency PWM Step-Down DC/DC Converter |
| RT8020GQW | 功能描述:IC REG BUCK SYNC ADJ 1A 12WDFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關穩(wěn)壓器 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝: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: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 供應商設備封裝:8-PDIP |
| RT8020PQW | 制造商:Richtek 功能描述:Dual output DC/DC Converter |
| RT8023 | 制造商:RICHTEK 制造商全稱:Richtek Technology Corporation 功能描述:1.2MHz 1.5A Synchronous Step-Down Converter with Two LDOs |
| RT8023GQW | 功能描述:IC REG TRPL BCK/LINEAR 24WQFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標準包裝:2,500 系列:- 拓撲:降壓（降壓）同步（3），線性（LDO）（2） 功能:任何功能 輸出數(shù):5 頻率 - 開關: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 驅動器:無 帶監(jiān)控器:無 帶序列發(fā)生器:是 電源電壓:5.6 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類型:* 封裝/外殼:* 供應商設備封裝:* 包裝:* |
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