參數(shù)資料
型號: LTC1775IGN
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS
中文描述: 2 A SWITCHING CONTROLLER, 165 kHz SWITCHING FREQ-MAX, PDSO16
封裝: 0.150 INCH, PLASTIC, SSOP-16
文件頁數(shù): 18/24頁
文件大?。?/td> 289K
代理商: LTC1775IGN
18
LTC1775
Design Example
As a design example, take a supply with the following
specifications: V
IN
= 6V to 22V (15V nominal), V
OUT
= 5V,
I
O(MAX)
= 10A. The required R
DS(ON)
can immediately be
estimated:
R
mV
)( . )
1 3
A
DS ON
(
)
(
.
=
=
240
10
0 018
A 0.019
Siliconix SUD50N03-10 MOSFET (
θ
JA
=
30
°
C/W) is close to this value.
For 40% ripple current at maximum V
IN
the inductor
should be:
L
V
)(0 4 10
kHz
A
V
V
H
=
μ
5
150
(
1
5
22
6 4
.
)
Choosing a Magnetics 55380-A2 core with 8 turns of 15
gauge wire yields a 6
μ
H inductor. The resulting maximum
ripple current will be:
I
V
kHz
H
V
V
A
L MAX
(
)
(
)(
)
.
=
μ
=
5
150
6
1
5
22
4 3
Next, check that the minimum value of the current limit is
acceptable. Assume a junction temperature about 20
°
C
above the 70
°
C ambient with
ρ
90
°
C
= 1.3.
I
mV
A
A
LIMIT
=
300
(0 019
1 3
1
2
4 3
.
10
)( . )–
Now double-check the assumed T
J
:
P
V
V
A
V
A
pF
kHz
W
W
mW
TOP
=
(
) ( )
) (
0 21
.
(
)
+
)(
( )(
0 56
.
)(
)
=
+
=
5
22
10
1 3 0 019
.
1 7 22
.
10
170
150
0 77
.
2
2
.
T
J
= 70
°
C + (0.77W)(30
°
C/W) = 93
°
C
Since
ρ
(93
°
C)
ρ
(90
°
C), the solution is self-consistent.
Automotive Considerations: Plugging into the
Cigarette Lighter
As battery-powered devices go mobile, there is a natural
interest in plugging into the cigarette lighter in order to
conserve or even recharge battery packs during opera-
tion. But before you connect, be advised: you are plug-
ging into the supply from hell. The main power line in an
automobile is the source of a number of nasty potential
transients, including load dump, reverse and double
battery.
Load dump is the result of a loose battery cable. When the
cable breaks connection, the field collapse in the alternator
can cause a positive spike as high as 60V which takes
several hundred milliseconds to decay. Reverse battery is
just what it says, while double battery is a consequence of
tow truck operators finding that a 24V jump start cranks
cold engines faster than 12V.
The network shown in Figure 10 is the most straightfor-
ward approach to protect a DC/DC converter from the
ravages of an automotive power line. The series diode
prevents current from flowing during reverse battery,
while the transient suppressor clamps the input voltage
during load dump. Note that the transient suppressor
should not conduct during double-battery operation, but
must still clamp the input voltage below breakdown of the
converter. Although the LTC1775 has a maximum input
voltage of 36V, most applications will be limited to 30V by
the MOSFET V
(BR)DSS
.
Figure 10. Automotive Application Protection
V
IN
TRANSIENT VOLTAGE
SUPPRESSOR
GENERAL INSTRUMENT
1.5KA24A
12V
LTC1775
50A I
RATING
1775 F10
PGND
APPLICATIOU
W
U
U
相關(guān)PDF資料
PDF描述
LTC1775CGN Quadruple 2-Input Positive-NAND Gate 14-TVSOP -40 to 85
LTC1775CS Quadruple 2-Input Positive-NAND Gate 14-SOIC -40 to 85
LTC1775I Quadruple 2-Input Positive-NAND Gate 14-SOIC -40 to 85
LTC1775IS Quadruple 2-Input Positive-NAND Gate 14-SOIC -40 to 85
LTC1775 High Power Current Mode Synchronous Step-Down Switching Regulator(大功率,同步電流模式步降開關(guān)穩(wěn)壓器)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC1775IGN#PBF 功能描述:IC REG CTRLR BUCK PWM CM 16-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1775IGN#TR 功能描述:IC REG CTRLR BUCK PWM CM 16-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1775IGN#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 16-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1775IS 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1775IS#PBF 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX