- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377776 > LTC3738CUHF (LINEAR TECHNOLOGY CORP) 3-Phase Buck Controller for Intel VRM9/VRM10 with Active Voltage Positioning PDF資料下載
參數(shù)資料
| 型號： | LTC3738CUHF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 3-Phase Buck Controller for Intel VRM9/VRM10 with Active Voltage Positioning |
| 中文描述： | 5 A SWITCHING CONTROLLER, 630 kHz SWITCHING FREQ-MAX, PQCC38 |
| 封裝： | 7 X 5 MM, PLASTIC, M0-220WHKD, QFN-38 |
| 文件頁數(shù)： | 14/32頁 |
| 文件大?。?/td> | 316K |
| 代理商： | LTC3738CUHF |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁當(dāng)前第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁
14
LTC3738
3738f
APPLICATIOU
The basic application circuit is shown on the first page of
this data sheet. External component selection is driven by
the load requirement, and normally begins with the selec-
tion of an inductance value based upon the desired
operating frequency, inductor current and output voltage
ripple requirements. Once the inductors and operating
frequency have been chosen, the current sensing resis-
tors can be calculated. Next, the power MOSFETs and
Schottky diodes are selected. Finally, C
IN
and C
OUT
are
selected according to the required voltage ripple require-
ments. The circuit shown on the first page of this data
sheet can be configured for operation up to a MOSFET
supply voltage of 28V (limited by the external MOSFETs).
W
U
U
Operating Frequency
The IC uses a constant frequency architecture with the
frequency determined by an internal capacitor. This ca-
pacitor is charged by a fixed current plus an additional
current which is proportional to the voltage applied to the
PLLFLTR pin. Refer to the Phase-Locked Loop and Fre-
quency Synchronization and Setup sections for additional
information.
A graph for the voltage applied to the PLLFLTR pin versus
frequency is given in Figure 2. As the operating frequency
is increased the gate charge losses will be higher, reducing
efficiency (see Efficiency Considerations). The maximum
switching frequency is approximately 530kHz.
Inductor Value Calculation and Output Ripple Current
The operating frequency and inductor selection are inter-
related in that higher operating frequencies allow the use
of smaller inductor and capacitor values. So why would
anyone ever choose to operate at lower frequencies with
larger components The answer is efficiency. A higher
frequency generally results in lower efficiency because of
MOSFET gate charge and transition losses. In addition to
this basic tradeoff, the effect of inductor value on ripple
current and low current operation must also be consid-
ered. The PolyPhase approach reduces both input and
output ripple currents while optimizing individual output
stages to run at a lower fundamental frequency, enhancing
efficiency.
The inductor value has a direct effect on ripple current. The
inductor ripple current
I
L
per individual section, N,
decreases with higher inductance or frequency and in-
creases with higher V
IN
or V
OUT
:
I
V
fL
V
V
L
OUT
OUT
IN
=
1
where f is the individual output stage operating frequency.
In a PolyPhase converter, the net ripple current seen by the
output capacitor is much smaller than the individual
inductor ripple currents due to the ripple cancellation. The
details on how to calculate the net output ripple current
can be found in Application Note 77.
Figure 3 shows the net ripple current seen by the output
capacitors for the different phase configurations. The
output ripple current is plotted for a fixed output voltage as
the duty factor is varied between 10% and 90% on the
x-axis. The output ripple current is normalized against the
inductor ripple current at zero duty factor. The graph can
be used in place of tedious calculations. As shown in
Figure 3, the zero output ripple current is obtained when:
V
V
k
N
where k
N
OUT
IN
=
=
, ,..., –
1
Figure 2. Operating Frequency vs V
PLLFLTR
PLLFLTR PIN VOLTAGE (V)
550
450
350
250
150
0
0.5
1.0
1.5
2.0
2.5
O
3738 F02
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC3770 | Synchronous Controller with Margining, Tracking and PLL |
| LTC3770EG | Synchronous Controller with Margining, Tracking and PLL |
| LTC3770EUH | Synchronous Controller with Margining, Tracking and PLL |
| LTC3776 | 16-Bit Buffer/Driver With 3-State Outputs 48-TVSOP -40 to 85 |
| LTC3776EUF | Dual 2-Phase, No RSENSE Synchronous Controller for DDR/QDR Memory Termination |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC3738CUHF#PBF | 功能描述:IC CTRLR SW REG 3PH STPDWN 38QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:43 系列:- 應(yīng)用:控制器，Intel VR11 輸入電壓:5 V ~ 12 V 輸出數(shù):1 輸出電壓:0.5 V ~ 1.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:48-QFN（7x7） 包裝:管件 |
| LTC3738CUHF#TR | 功能描述:IC CTRLR SW REG 3PH STPDWN 38QFN RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:43 系列:- 應(yīng)用:控制器，Intel VR11 輸入電壓:5 V ~ 12 V 輸出數(shù):1 輸出電壓:0.5 V ~ 1.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:48-QFN（7x7） 包裝:管件 |
| LTC3738CUHF#TRPBF | 功能描述:IC CTRLR SW REG 3PH STPDWN 38QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標(biāo)準(zhǔn)包裝:43 系列:- 應(yīng)用:控制器，Intel VR11 輸入電壓:5 V ~ 12 V 輸出數(shù):1 輸出電壓:0.5 V ~ 1.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:48-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:48-QFN（7x7） 包裝:管件 |
| LTC-3743KG | 制造商:Lite-On Semiconductor Corporation 功能描述: |
| LTC3765EMSE#PBF | 功能描述:IC CTLR GATE DRIVER 16-MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源控制器，監(jiān)視器 系列:Direct Flux Limit™ 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 應(yīng)用:多相控制器 輸入電壓:- 電源電壓:9 V ~ 14 V 電流 - 電源:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP（5x5） 包裝:帶卷 (TR) |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。