參數(shù)資料
型號: LT1961IMS8E#TR
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: 3 A SWITCHING REGULATOR, 1500 kHz SWITCHING FREQ-MAX, PDSO8
封裝: PLASTIC, MSOP-8
文件頁數(shù): 15/16頁
文件大?。?/td> 154K
代理商: LT1961IMS8E#TR
8
LT1961
1961fa
APPLICATIONS INFORMATION
WU
U
INDUCTOR CHOICE AND MAXIMUM OUTPUT
CURRENT
When choosing an inductor, there are 2 conditions that
limit the minimum inductance; required output current,
and avoidance of subharmonic oscillation. The maximum
output current for the LT1961 in a standard boost con-
verter configuration with an infinitely large inductor is:
IA
V
OUT MAX
IN
OUT
()
.
= 15
η
Where
η = converter efficiency (typically 0.87 at high
current).
As the value of inductance is reduced, ripple current
increases and IOUT(MAX) is reduced. The minimum induc-
tance for a required output current is given by:
L
VV
V
Vf
VI
V
MIN
IN OUT
IN
OUT
IN
=
(–
)
() . –
()(
)
21 5
η
The second condition, avoidance of subharmonic oscilla-
tion, must be met if the operating duty cycle is greater than
50%. The slope compensation circuit within the LT1961
prevents subharmonic oscillation for inductor ripple cur-
rents of up to 0.7AP-P, defining the minimum inductor
value to be:
L
VV
V
Vf
MIN
IN OUT
IN
OUT
=
(–
)
.( )
07
These conditions define the absolute minimum induc-
tance. However, it is generally recommended that to
prevent excessive output noise, and difficulty in obtaining
stability, the ripple current is no more than 40% of the
average inductor current. Since inductor ripple is:
I
VV
V
VL f
P P RIPPLE
IN OUT
IN
OUT
=
(–
)
()( )
The recommended minimum inductance is:
L
VV
V
VI
f
MIN
IN
OUT
IN
OUT
=
() (
)
. (
) (
)( )
2
04
The inductor value may need further adjustment for other
factors such as output voltage ripple and filtering require-
ments. Remember also, inductance can drop significantly
with DC current and manufacturing tolerance.
The inductor must have a rating greater than its peak
operating current to prevent saturation resulting in effi-
ciency loss. Peak inductor current is given by:
I
VI
V
VV
V
VL f
LPEAK
OUT
IN
IN OUT
IN
OUT
=+
()(
)
()
()( )
η
2
Also, consideration should be given to the DC resistance
of the inductor. Inductor resistance contributes directly to
the efficiency losses in the overall converter.
Suitable inductors are available from Coilcraft, Coiltronics,
Dale, Sumida, Toko, Murata, Panasonic and other manu-
factures.
Table 2
PART NUMBER
VALUE (uH) ISAT(DC) (Amps) DCR (Ω) HEIGHT (mm)
Coiltronics
TP1-2R2
2.2
1.3
0.188
1.8
TP2-2R2
2.2
1.5
0.111
2.2
TP3-4R7
4.7
1.5
0.181
2.2
TP4- 100
10
1.5
0.146
3.0
Murata
LQH1C1R0M04
1.0
0.51
0.28
1.8
LQH3C1R0M24
1.0
0.06
2.0
LQH3C2R2M24
2.2
0.79
0.1
2.0
LQH4C1R5M04
1.5
1
0.09
2.6
Sumida
CD73- 100
10
1.44
0.080
3.5
CDRH4D18-2R2
2.2
1.32
0.058
1.8
CDRH5D18-6R2
6.2
1.4
0.071
1.8
CDRH5D28-100
10
1.3
0.048
2.8
Coilcraft
1008PS-272M
2.7
1.3
0.14
2.7
LPO1704-222M
2.2
1.6
0.12
1.0
LPO1704-332M
3.3
1.3
0.16
1.0
相關(guān)PDF資料
PDF描述
LT3092ITS8#PBF SPECIALTY ANALOG CIRCUIT, PDSO8
LT3092ETS8#TRPBF SPECIALTY ANALOG CIRCUIT, PDSO8
LT3092EST#PBF SPECIALTY ANALOG CIRCUIT, PDSO3
LT3092ETS8 SPECIALTY ANALOG CIRCUIT, PDSO8
LT3092IST#PBF SPECIALTY ANALOG CIRCUIT, PDSO3
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LT1961IMS8ETRPBF 制造商:LINER 制造商全稱:Linear Technology 功能描述:1.5A, 1.25MHz Step-Up Switching Regulator
LT1962 制造商:LINER 制造商全稱:Linear Technology 功能描述:Micropower Low Dropout Regulators with Shutdown
LT1962EMS8 功能描述:IC REG LDO ADJ .3A 8-MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 產(chǎn)品培訓(xùn)模塊:More Information on LDOs 標(biāo)準(zhǔn)包裝:50 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:3.3V 輸入電壓:最高 15V 電壓 - 壓降(標(biāo)準(zhǔn)):1.1V @ 800mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:800mA 電流 - 限制(最小):800mA 工作溫度:0°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:TO-263-4,D²Pak(3 引線+接片),TO-263AA 供應(yīng)商設(shè)備封裝:D2PAK-3 包裝:管件
LT1962EMS8#PBF 功能描述:IC REG LDO ADJ .3A 8-MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 產(chǎn)品培訓(xùn)模塊:MIC5365/66 Ultra-small LDO Regulators 標(biāo)準(zhǔn)包裝:1 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:3V 輸入電壓:最高 5.5V 電壓 - 壓降(標(biāo)準(zhǔn)):0.155V @ 150mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:150mA 電流 - 限制(最?。?200mA 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:4-UDFN 裸露焊盤,4-TMLF? 供應(yīng)商設(shè)備封裝:4-TMLF?(1x1) 包裝:Digi-Reel® 其它名稱:576-3192-6
LT1962EMS8#PBF 制造商:Linear Technology 功能描述:Linear Voltage Regulator IC 制造商:Linear Technology 功能描述:IC, ADJ LDO REG 1.22V TO 20V 0.3A MSOP-8