- 您現(xiàn)在的位置：買賣IC網 > PDF目錄377784 > LTCHK (Linear Technology Corporation) 20mA, 3V to 80V Low Dropout Micropower Linear Regulator PDF資料下載
參數(shù)資料
| 型號： | LTCHK |
| 廠商： | Linear Technology Corporation |
| 英文描述： | 20mA, 3V to 80V Low Dropout Micropower Linear Regulator |
| 中文描述： | 20mA的，3V至80V的微功率低壓差線性穩(wěn)壓器 |
| 文件頁數(shù)： | 8/12頁 |
| 文件大?。?/td> | 176K |
| 代理商： | LTCHK |
8
LT3014B
3014bf
The LT3014B regulator has internal thermal limiting de-
signed to protect the device during overload conditions.
For continuous normal conditions the maximum junction
temperature rating of 125
°
C must not be exceeded. It is
important to give careful consideration to all sources of
thermal resistance from junction to ambient. Additional
heat sources mounted nearby must also be considered.
For surface mount devices, heat sinking is accomplished
by using the heat spreading capabilities of the PC board
and its copper traces. Copper board stiffeners and plated
through-holes can also be used to spread the heat gener-
ated by power devices.
The following table lists thermal resistance for several
different board sizes and copper areas. All measurements
were taken in still air on 3/32" FR-4 board with one ounce
copper.
Table 1. SOT-23 Measured Thermal Resistance
COPPER AREA
TOPSIDE
BACKSIDE
2500 sq mm
2500 sq mm
1000 sq mm
2500 sq mm
225 sq mm
2500 sq mm
100 sq mm
2500 sq mm
50 sq mm
2500 sq mm
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
125
°
C/W
125
°
C/W
130
°
C/W
135
°
C/W
150
°
C/W
BOARD AREA
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
Table 2. DFN Measured Thermal Resistance
COPPER AREA
TOPSIDE
BACKSIDE
2500 sq mm
2500 sq mm
1000 sq mm
2500 sq mm
225 sq mm
2500 sq mm
100 sq mm
2500 sq mm
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
40
°
C/W
45
°
C/W
50
°
C/W
62
°
C/W
BOARD AREA
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
For the DFN package, the thermal resistance junction-to-
case (
θ
JC
), measured at the exposed pad on the back of the
die, is 16
°
C/W.
Continuous operation at large input/output voltage differ-
entials and maximum load current is not practical due to
thermal limitations. Transient operation at high input/
output differentials is possible. The approximate thermal
time constant for a 2500sq mm 3/32" FR-4 board with
maximum topside and backside area for one ounce copper
is 3 seconds. This time constant will increase as more
thermal mass is added (i.e. vias, larger board, and other
components).
For an application with transient high power peaks, aver-
age power dissipation can be used for junction tempera-
ture calculations as long as the pulse period is significantly
less than the thermal time constant of the device and
board.
Calculating Junction Temperature
Example 1: Given an output voltage of 5V, an input voltage
range of 24V to 30V, an output current range of 0mA to
20mA, and a maximum ambient temperature of 50
°
C,
what will the maximum junction temperature be
The power dissipated by the device will be equal to:
I
OUT(MAX)
(V
IN(MAX)
– V
OUT
) + (I
GND
V
IN(MAX)
)
where:
I
OUT(MAX)
= 20mA
V
IN(MAX)
= 30V
I
GND
at (I
OUT
= 20mA, V
IN
= 30V) = 0.55mA
So:
P = 20mA
(30V – 5V) + (0.55mA
30V) = 0.52W
The thermal resistance for the DFN package will be in the
range of 40
°
C/W to 62
°
C/W depending on the copper area.
So the junction temperature rise above ambient will be
approximately equal to:
0.52W
50
°
C/W = 26
°
C
The maximum junction temperature will then be equal to
the maximum junction temperature rise above ambient
plus the maximum ambient temperature or:
T
JMAX
= 50
°
C + 26
°
C = 76
°
C
Example 2: Given an output voltage of 5V, an input voltage
of 48V that rises to 72V for 5ms(max) out of every 100ms,
and a 5mA load that steps to 20mA for 50ms out of every
250ms, what is the junction temperature rise above ambi-
ent Using a 500ms period (well under the time constant
of the board), power dissipation is as follows:
P1(48V in, 5mA load) = 5mA (48V – 5V)
+ (100
μ
A 48V) = 0.22W
APPLICATIOU
W
U
U
相關PDF資料 |
PDF描述 |
|---|---|
| LTCHN | 20mA, 3V to 80V Low Dropout Micropower Linear Regulator |
| LTG6 | Rail-to-Rail Input and Output, Ultralow 1.9n Root Hz Noise, Low Power Op Amps |
| LTI202D | 200 V - 1,000 V Doubler 10.0 A - 12.5 A Forward Current 70 ns - 3000 ns Recovery Time |
| LTI202FD | 200 V - 1,000 V Doubler 10.0 A - 12.5 A Forward Current 70 ns - 3000 ns Recovery Time |
| LTI202UFD | 200 V - 1,000 V Doubler 10.0 A - 12.5 A Forward Current 70 ns - 3000 ns Recovery Time |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LTCHN | 制造商:LINER 制造商全稱:Linear Technology 功能描述:20mA, 3V to 80V Low Dropout Micropower Linear Regulator |
| LTCK003CG | 功能描述:IC KIT MULTIPROTOCOL RoHS:否 類別:套件 >> 半導體產品 - IC 元件分類 系列:多協(xié)議 其它有關文件:NXPLOGIC2-KIT-ND Contents 標準包裝:1 系列:74AUP 套件類型:邏輯 值:180 件 - 18 種值各 10 件 包裝:- 安裝類型:表面貼裝 包括封裝:6-XSON，8-XSON，8-XQFN 產品目錄頁面:2653 (CN2011-ZH PDF) 工具箱內容:(10) 568-4391-1-ND - IC GATE MULT-FUNC CONFIG 6-XSON(10) 568-4390-1-ND - IC CONFIG MULT-FUNC GATE 6-XSON(10) 568-4389-1-ND - IC GATE DUAL FUNCTION 8-XSON(10) 568-4388-1-ND - IC GATE DUAL FUNCTION 8-XQFN(10) 568-4387-1-ND - IC F-F D-TYPE POS EDGE 8-XSON(10) 568-4386-1-ND - IC F-F D-TYPE POS EDGE 8-XQFN(10) 568-4385-1-ND - IC CONFIG MULTI-FUNC GATE 6-XSON(10) 568-4384-1-ND - IC EX-OR GATE 3-IN 6-XSON(10) 568-4383-1-ND - IC F-F D-TYPE POS EDGE 6-XSON(10) 568-4382-1-ND - IC LATCH D-TYPE 6-XSON更多... 其它名稱:NXPLOGIC2-KIT |
| LTCK003CG#PBF | 功能描述:IC KIT MULTIPROTOCOL RoHS:是 類別:套件 >> 半導體產品 - IC 元件分類 系列:多協(xié)議 其它有關文件:NXPLOGIC2-KIT-ND Contents 標準包裝:1 系列:74AUP 套件類型:邏輯 值:180 件 - 18 種值各 10 件 包裝:- 安裝類型:表面貼裝 包括封裝:6-XSON，8-XSON，8-XQFN 產品目錄頁面:2653 (CN2011-ZH PDF) 工具箱內容:(10) 568-4391-1-ND - IC GATE MULT-FUNC CONFIG 6-XSON(10) 568-4390-1-ND - IC CONFIG MULT-FUNC GATE 6-XSON(10) 568-4389-1-ND - IC GATE DUAL FUNCTION 8-XSON(10) 568-4388-1-ND - IC GATE DUAL FUNCTION 8-XQFN(10) 568-4387-1-ND - IC F-F D-TYPE POS EDGE 8-XSON(10) 568-4386-1-ND - IC F-F D-TYPE POS EDGE 8-XQFN(10) 568-4385-1-ND - IC CONFIG MULTI-FUNC GATE 6-XSON(10) 568-4384-1-ND - IC EX-OR GATE 3-IN 6-XSON(10) 568-4383-1-ND - IC F-F D-TYPE POS EDGE 6-XSON(10) 568-4382-1-ND - IC LATCH D-TYPE 6-XSON更多... 其它名稱:NXPLOGIC2-KIT |
| LTCK003CG#TR | 功能描述:IC KIT MULTIPROTOCOL RoHS:否 類別:套件 >> 半導體產品 - IC 元件分類 系列:多協(xié)議 其它有關文件:NXPLOGIC2-KIT-ND Contents 標準包裝:1 系列:74AUP 套件類型:邏輯 值:180 件 - 18 種值各 10 件 包裝:- 安裝類型:表面貼裝 包括封裝:6-XSON，8-XSON，8-XQFN 產品目錄頁面:2653 (CN2011-ZH PDF) 工具箱內容:(10) 568-4391-1-ND - IC GATE MULT-FUNC CONFIG 6-XSON(10) 568-4390-1-ND - IC CONFIG MULT-FUNC GATE 6-XSON(10) 568-4389-1-ND - IC GATE DUAL FUNCTION 8-XSON(10) 568-4388-1-ND - IC GATE DUAL FUNCTION 8-XQFN(10) 568-4387-1-ND - IC F-F D-TYPE POS EDGE 8-XSON(10) 568-4386-1-ND - IC F-F D-TYPE POS EDGE 8-XQFN(10) 568-4385-1-ND - IC CONFIG MULTI-FUNC GATE 6-XSON(10) 568-4384-1-ND - IC EX-OR GATE 3-IN 6-XSON(10) 568-4383-1-ND - IC F-F D-TYPE POS EDGE 6-XSON(10) 568-4382-1-ND - IC LATCH D-TYPE 6-XSON更多... 其它名稱:NXPLOGIC2-KIT |
| LTCK003CG#TRPBF | 功能描述:IC KIT MULTIPROTOCOL RoHS:是 類別:套件 >> 半導體產品 - IC 元件分類 系列:多協(xié)議 其它有關文件:NXPLOGIC2-KIT-ND Contents 標準包裝:1 系列:74AUP 套件類型:邏輯 值:180 件 - 18 種值各 10 件 包裝:- 安裝類型:表面貼裝 包括封裝:6-XSON，8-XSON，8-XQFN 產品目錄頁面:2653 (CN2011-ZH PDF) 工具箱內容:(10) 568-4391-1-ND - IC GATE MULT-FUNC CONFIG 6-XSON(10) 568-4390-1-ND - IC CONFIG MULT-FUNC GATE 6-XSON(10) 568-4389-1-ND - IC GATE DUAL FUNCTION 8-XSON(10) 568-4388-1-ND - IC GATE DUAL FUNCTION 8-XQFN(10) 568-4387-1-ND - IC F-F D-TYPE POS EDGE 8-XSON(10) 568-4386-1-ND - IC F-F D-TYPE POS EDGE 8-XQFN(10) 568-4385-1-ND - IC CONFIG MULTI-FUNC GATE 6-XSON(10) 568-4384-1-ND - IC EX-OR GATE 3-IN 6-XSON(10) 568-4383-1-ND - IC F-F D-TYPE POS EDGE 6-XSON(10) 568-4382-1-ND - IC LATCH D-TYPE 6-XSON更多... 其它名稱:NXPLOGIC2-KIT |
發(fā)布緊急采購，3分鐘左右您將得到回復。