參數(shù)資料
型號: LT1303-5
廠商: Linear Technology Corporation
英文描述: Micropower High Efficiency DC/DC Converters with Low-Battery Detector Adjustable and Fixed 5V
中文描述: 微功耗高效率DC / DC轉(zhuǎn)換器與低電池檢測器可調(diào)和固定5V
文件頁數(shù): 7/12頁
文件大?。?/td> 280K
代理商: LT1303-5
7
LT1303/LT1303-5
Inductor Section
Inductors suitable for use with the LT1303 usually fall in
the 5
μ
H to 50
μ
H range. The inductor must: (1) handle
current of 1.25A without saturating, (2) have enough
inductance to provide a di/dt lower than 400mA/
μ
s, and
(3) have low enough DC resistance to avoid excessive
heating or efficiency losses. Higher value inductors will
deliver more power but tend to be physically larger. Most
ferrite core drum or rod inductors such as those specified
in Table 1 are suitable for use. It is acceptable to bias open-
flux inductors (e.g. Sumida CD54) into saturation by 10 to
20% without adverse effects.
OPERATIO
to about 2
μ
s. Response time of C2, which determines
minimum on-time, is approximately 300ns.
U
APPLICATIO
S I
N
FOR
ATIO
U
W
U
hysteresis built in, but hysteresis can be added by
connecting a high-value resistor from LBI to LBO as
shown in Figure 5. The internal reference can be accessed
via the comparator as shown in Figure 6.
Figure 7 shows inductor current of a suitable inductor,
di/dt is controlled at all times. The rapid rise in current
shown in Figure 8 results from this inductor saturating at
approximately 1A. Saturation occurs when the inductor
cannot hold any more magnetic energy in the core. Current
then increases rapidly, limited only by the resistance of the
winding. Figure 9’s inductor has high DC resistance which
results in the exponential time constant shape of the
inductor current.
Figure 7. Properly Chosen Inductor Does Not Saturate
I
L
500mA/DIV
5
μ
s/DIV
LT1303 F07
Figure 6. Accessing Internal Reference
Low Battery Detector
The low battery detector is enabled when SHDN is low and
disabled when SHDN is high. The comparator has no
Figure 5. R3 Adds Hysteresis to Low-Battery Detector
+
1.24V
LT1303
R4
47k
R1
R3
2M
R2
49.9k
1%
V
BAT
5V
R1 = (V
–1.24V) (43.5k)
HYSTERESIS
30mV
LT1303 F05
PHONE
VENDOR
Coilcraft
SERIES
D03316
D01608
OCTAPAK
CTX20-1
CTX20-2
CTX33-4
CD54
GA10
APPROPRIATE VALUES NUMBERS
10
μ
H to 47
μ
H
10
μ
H
(708) 639-6400
Coiltronics
(407) 241-7876
20
μ
H
20
μ
H
33
μ
H
10
μ
H to 33
μ
H
10
μ
H to 33
μ
H
Sumida
Gowanda
(708) 956-0666
(716) 532-2234
Table 1. Recommended Inductors
V
IN
V
IN
GND
LBO
LBI
LT1303
+
100k
R2
R1
2.2
μ
F
2N3906
V
OUTPUT
V
REF
= 1.24V 1 +
V
V
REF
+ 200mV
R1 + R2
33k
R2
R1
(
)
LT1303 F06
相關(guān)PDF資料
PDF描述
LT1303 Micropower High Efficiency DC/DC Converters with Low-Battery Detector Adjustable and Fixed 5V
LT1303CN8 Micropower High Efficiency DC/DC Converters with Low-Battery Detector Adjustable and Fixed 5V
LT1303CN8-5 Micropower High Efficiency DC/DC Converters with Low-Battery Detector Adjustable and Fixed 5V
LT1303CS8 Micropower High Efficiency DC/DC Converters with Low-Battery Detector Adjustable and Fixed 5V
LT1303CS8-5 Micropower High Efficiency DC/DC Converters with Low-Battery Detector Adjustable and Fixed 5V
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
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LT1303CN8-5 功能描述:IC REG BOOST 5V 0.2A 8DIP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:降壓(降壓) 輸出類型:固定 輸出數(shù):1 輸出電壓:1.2V,1.5V,1.8V,2.5V 輸入電壓:2.7 V ~ 20 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:50mA 同步整流器:是 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:10-TFSOP,10-MSOP(0.118",3.00mm 寬)裸露焊盤 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:10-MSOP 裸露焊盤
LT1303CN8-5#PBF 功能描述:IC REG BOOST 5V 0.2A 8DIP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:250 系列:- 類型:降壓(降壓) 輸出類型:固定 輸出數(shù):1 輸出電壓:1.2V 輸入電壓:2.05 V ~ 6 V PWM 型:電壓模式 頻率 - 開關(guān):2MHz 電流 - 輸出:500mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:6-UFDFN 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:6-SON(1.45x1) 產(chǎn)品目錄頁面:1032 (CN2011-ZH PDF) 其它名稱:296-25628-2
LT1303CN8PBF 制造商:Linear Technology 功能描述:LT1303CN8PBF