- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄16612 > DC1561A (Linear Technology)EVAL BOARD FOR LTC4278 PDF資料下載
參數(shù)資料
| 型號： | DC1561A |
| 廠商： | Linear Technology |
| 文件頁數(shù)： | 18/42頁 |
| 文件大小： | 0K |
| 描述： | EVAL BOARD FOR LTC4278 |
| 設(shè)計資源： | DC1561A Design Files |
| 標(biāo)準(zhǔn)包裝： | 1 |
| 主要目的： | 電源管理，以太網(wǎng)供電（POE） |
| 嵌入式： | 否 |
| 已用 IC / 零件： | LTC4278 |
| 已供物品： | 板 |
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頁第14頁第15頁第16頁第17頁當(dāng)前第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頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁
LTC4278
25
4278fc
Assuming relatively fixed power supply efficiency, Eff,
power balance gives:
POUT = Eff PIN
VOUT IOUT = Eff VIN IIN
Average primary-side current is expressed in terms of
output current as follows:
IIN =K1IOUT
where:
K1=
VOUT
VIN Eff
So, the effective change in VOUT target is:
ΔVOUT =K1
RSENSE
RCMP
R1NSF ΔIOUT
thus:
ΔVOUT
ΔIOUT
=K1
RSENSE
RCMP
R1NSF
where:
K1 = dimensionless variable related to VIN, VOUT and
efficiency, as previously explained
RSENSE = external sense resistor
Nominal output impedance cancellation is obtained by
equating this expression with RS(OUT):
K1
RSENSE
RCMP
R1NSF =
ESR
+RDS(ON)
1– DC
Solving for RCMP gives:
RCMP =K1
RSENSE 1–DC
(
)
ESR
+RDS(ON)
R1NSF
Thepracticalaspectsofapplyingthisequationtodetermine
an appropriate value for the RCMP resistor are discussed
subsequently in the Applications Information section.
Transformer Design
Transformer design/specification is the most critical part
of a successful application of the LTC4278. The following
sections provide basic information about designing the
transformer and potential tradeoffs. If you need help, the
LTC Applications group is available to assist in the choice
and/or design of the transformer.
Turns Ratios
The design of the transformer starts with determining
duty cycle (DC). DC impacts the current and voltage stress
on the power switches, input and output capacitor RMS
currents and transformer utilization (size vs power). The
ideal turns ratio is:
NIIDEAL=
VOUT
VIN
1– DC
DC
Avoid extreme duty cycles, as they generally increase cur-
rent stresses. A reasonable target for duty cycle is 50%
at nominal input voltage.
For instance, if we wanted a 48V to 5V converter at 50%
DC then:
NIIDEAL=
5
48
1– 0.5
0.5
=
1
9.6
In general, better performance is obtained with a lower
turns ratio. A DC of 45.5% yields a 1:8 ratio.
APPLICATIONS INFORMATION
MP
RCMPF
50k
VIN
VFLBK
R2 LOAD
COMP I
R1
FB
VFB
Q1 Q2
RCMP
CCMP
RSENSE
SENSE+
4278 F11
Q3
–
+
A1
16
22
21
20
Figure 11. Load Compensation Diagram
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| VE-B32-EW | CONVERTER MOD DC/DC 15V 100W |
| H3AAH-6406M | IDC CABLE - HSC64H/AE64M/HSC64H |
| L-07C43NKV6T | CER INDUCTOR 43NH 0402 |
| EBC22DREI-S13 | CONN EDGECARD 44POS .100 EXTEND |
| ECO-S1EA562BA | CAP ALUM 5600UF 25V 20% SNAP |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DC1561B | 功能描述:EVAL BOARD FOR LTC4278 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估演示板和套件 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:數(shù)字電位器 嵌入式:- 已用 IC / 零件:AD5258 主要屬性:- 次要屬性:- 已供物品:板 相關(guān)產(chǎn)品:AD5258BRMZ1-ND - IC POT DGTL I2C1K 64P 10MSOPAD5258BRMZ10-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ100-ND - IC POT DGTL I2C 100K 64P 10MSOPAD5258BRMZ50-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ1-R7-ND - IC POT DGTL I2C 1K 64P 10MSOPAD5258BRMZ10-R7-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ50-R7-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ100-R7-ND - IC POT DGTL I2C 100K 64P 10MSOP |
| DC1561W | 制造商:Aleph America Corporation 功能描述: |
| DC1561W-COM | 制造商:Aleph America Corporation 功能描述: |
| DC1562A-A | 功能描述:BOARD EVAL LTC6990 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估演示板和套件 系列:TimerBlox® 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:電信，線路接口單元（LIU） 嵌入式:- 已用 IC / 零件:IDT82V2081 主要屬性:T1/J1/E1 LIU 次要屬性:- 已供物品:板，電源，線纜，CD 其它名稱:82EBV2081 |
| DC1562A-B | 功能描述:BOARD EVAL LTC6991 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估演示板和套件 系列:TimerBlox® 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:電信，線路接口單元（LIU） 嵌入式:- 已用 IC / 零件:IDT82V2081 主要屬性:T1/J1/E1 LIU 次要屬性:- 已供物品:板，電源，線纜，CD 其它名稱:82EBV2081 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。