- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377541 > IRU3011 (International Rectifier) 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC PDF資料下載
參數(shù)資料
| 型號(hào)： | IRU3011 |
| 廠商： | International Rectifier |
| 英文描述： | 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC |
| 中文描述： | 5位可編程同步降壓控制器IC |
| 文件頁數(shù)： | 8/13頁 |
| 文件大?。?/td> | 77K |
| 代理商： | IRU3011 |
8
Rev. 1.6
08/20/02
IRU3011
www.irf.com
APPLICATION INFORMATION
An example of how to calculate the components for the
application circuit is given below.
Assuming, two sets of output conditions that this regu-
lator must meet,
a) Vo=2.8V, Io=14.2A,
Vo=185mV,
Io=14.2A
b) Vo=2V, Io=14.2A,
Vo=140mV,
Io=14.2A
the regulator design will be done such that it meets the
worst case requirement of each condition.
Output Capacitor Selection
The first step is to select the output capacitor. This is
done primarily by selecting the maximum ESR value
that meets the transient voltage budget of the total
Vo
specification. Assuming that the regulators DC initial
accuracy plus the output ripple is 2% of the output volt-
age, then the maximum ESR of the output capacitor is
calculated as:
The Sanyo MVGX series is a good choice to achieve
both the price and performance goals. The 6MV1500GX,
1500
μ
F, 6.3V has an ESR of less than 36m
typical.
Selecting 6 of these capacitors in parallel has an ESR
of
≈
6m
which achieves our low ESR goal.
Other type of electrolytic capacitors from other manu-
facturers to consider are the Panasonic FA series or the
Nichicon PL series.
Reducing the Output Capacitors Using Voltage Level
Shifting Technique
The trace resistance or an external resistor from the output
of the switching regulator to the Slot 1 can be used to
the circuit advantage and possibly reduce the number of
output capacitors, by level shifting the DC regulation point
when transitioning from light load to full load and vice
versa. To accomplish this, the output of the regulator is
typically set about half the DC drop that results from
light load to full load. For example, if the total resistance
from the output capacitors to the Slot 1 and back to the
Gnd pin of the device is 5m
and if the total
I, the
change from light load to full load is 14A, then the output
voltage measured at the top of the resistor divider which
is also connected to the output capacitors in this case,
must be set at half of the 70mV or 35mV higher than the
DAC voltage setting.
This intentional voltage level shifting during the load tran-
sient eases the requirement for the output capacitor ESR
at the cost of load regulation. One can show that the
new ESR requirement eases up by half the total trace
resistance. For example, if the ESR requirement of the
output capacitors without voltage level shifting must be
7m
then after level shifting the new ESR will only need
to be 8.5m
if the trace resistance is 5m
(7 + 5/2=9.5).
However, one must be careful that the combined “volt-
age level shifting” and the transient response is still within
the maximum tolerance of the Intel specification. To in-
sure this, the maximum trace resistance must be less
than:
Rs
≤
2
×
(Vspec - 0.02
×
Vo -
Vo) /
I
Where :
Rs = Total maximum trace resistance allowed
Vspec = Intel total voltage spec
Vo = Output voltage
Vo = Output ripple voltage
I = load current step
For example, assuming:
Vspec =
±
140mV =
±
0.1V for 2V output
Vo = 2V
Vo = assume 10mV = 0.01V
I = 14.2A
Then the Rs is calculated to be:
However, if a resistor of this value is used, the maximum
power dissipated in the trace (or if an external resistor is
being used) must also be considered. For example if
Rs=12.6m
, the power dissipated is:
Io
2
×
Rs = 14.2
2
×
12.6 = 2.54W
This is a lot of power to be dissipated in a system. So, if
the Rs=5m
, then the power dissipated is about 1W
which is much more acceptable. If level shifting is not
implemented, then the maximum output capacitor ESR
was shown previously to be 7m
which translated to
≈
6
of the 1500
μ
F, 6MV1500GX type Sanyo capacitors. With
Rs=5m
, the maximum ESR becomes 9.5m
which is
equivalent to
≈
4 caps. Another important consideration
is that if a trace is being used to implement the resistor,
the power dissipated by the trace increases the case
temperature of the output capacitors which could seri-
ously effect the life time of the output capacitors.
ESR
≤
100
14.2
Rs
≤
2
×
(0.140 - 0.02
×
2 - 0.01) / 14.2 = 12.6m
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| IRU3011CW | 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC |
| IRU3018 | 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS LDO CONTROLLER AND 200mA LDO ON-BOARD |
| IRU3018CW | 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS LDO CONTROLLER AND 200mA LDO ON-BOARD |
| IRU3021M | 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS TRIPLE LDO CONTROLLER |
| IRU3021MCW | 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS TRIPLE LDO CONTROLLER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| IRU3011CW | 功能描述:IC CTRL SYNC BUCK 5BIT 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) |
| IRU3011CWPBF | 制造商:International Rectifier 功能描述:DC DC Cntrlr Single-OUT Sync Buck 20-Pin SOIC W |
| IRU3011CWTR | 功能描述:IC CTRL SYNC BUCK 5BIT 20SOIC(W) 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) |
| IRU3012CWTR | 功能描述:IC REG BUCK SYNC 20SOIC(W) RoHS:否 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:20 系列:SIMPLE SWITCHER® 類型:降壓（降壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:12V 輸入電壓:4 V ~ 60 V PWM 型:電壓模式 頻率 - 開關(guān):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(yīng)商設(shè)備封裝:16-DIP 其它名稱:*LM2575HVN-12LM2575HVN-12 |
| IRU3013 | 制造商:IRF 制造商全稱:International Rectifier 功能描述:VRM 8.5 COMPATIBLE 5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER IC WITH TRIPLE LDO CONTROLLER |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。