- 您现在的位置：买卖IC网 > PDF目录13893 > LTC1174HVIS8#PBF (Linear Technology)IC REG BUCK INV ADJ 1A 8SOIC PDF资料下载
参数资料
| 型号： | LTC1174HVIS8#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 8/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK INV ADJ 1A 8SOIC |
| 标准包装： | 100 |
| 类型： | 降压（降压），反相 |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 1.25 V ~ 18 V |
| 输入电压： | 4 V ~ 18.5 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 200kHz |
| 电流 - 输出： | 1A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 8-SOIC |
LTC1174
LTC1174-3.3/LTC1174-5
APPLICATIO S I FOR ATIO
] 1 / 2 ( )
I OUT [ OUT ( V IN ? V OUT )
Inductor Core Selection
With the value of L selected, the type of inductor must be
chosen. Basically there are two kinds of losses in an
inductor, core and copper
Core losses are dependent on the peak-to-peak ripple
current and the core material. However it is independent of
the physical size of the core. By increasing the inductance
the inductor’s peak-to-peak ripple current will decrease,
therefore reducing core loss. Utilizing low core loss mate-
rial, such as molypermalloy or Kool M μ will allow users to
concentrate on reducing copper loss and preventing satu-
ration. Figure 1 shows the effect of different core material on
the efficiency of the LTC1174. The CTX core is Kool M μ and
the CTXP core is powdered iron (material 52).
Although higher inductance reduces core loss, it increases
copper loss as it requires more windings. When space is not
100
a premium larger gauge wire can be used to reduce the wire
resistance. This also prevents excessive heat dissipation.
C IN
In continuous mode the source current of the P-channel
MOSFET is a square wave of duty cycle V OUT /V IN . To prevent
large voltage transients, a low ESR input capacitor sized for
the maximum RMS current must be used. The C IN RMS
current is given by:
V
I RMS ≈ A RMS
V IN
This formula has a maximum at V IN = 2V OUT , where I RMS =
I OUT /2. This simple worst case is commonly used for design
because even significant deviations do not offer much relief.
Note that ripple current directly affects capacitor’s lifetime.
DO NOT UNDERSPECIFY THIS COMPONENT. An additional
0.1 μ F ceramic capacitor is also required on V IN for high
90
CTX100-4
frequency decoupling.
80
70
CTX100-4P
C OUT
To avoid overheating, the output capacitor must be sized to
handle the ripple current generated by the inductor. The
worst case RMS ripple current in the output capacitor is
60
V IN = 5V
V OUT = 3.3V
given by:
( A RMS )
I RMS ≈
50
100
1
I PGM = V IN
10 100
LOAD CURRENT (mA)
500
I PEAK
2
= 170 mA or 300mA
Although the output voltage ripple is determined by the
90
CTX50-4
hysteresis of the voltage comparator, ESR of the output
80
70
CTX50-4P
capacitor is also a concern. Too high of an ESR will create
a higher ripple output voltage and at the same time cause the
LTC1174 to sleep less often. This will affect the efficiency of
the LTC1174. For a given technology, ESR is a direct
60
50
V IN = 5V
V OUT = 3.3V
I PGM = V IN
function of the volume of the capacitor. Several small-sized
capacitors can also be paralleled to obtain the same ESR as
one large can. Manufacturers such as Nichicon, Chemicon
1
10 100
LOAD CURRENT (mA)
500
1174 F01
and Sprague should be considered for high performance
capacitors. The OS-CON semiconductor dielectric capaci-
Figure 1. Efficiency Using Different Types of
Inductor Core Material
tor available from Sanyo has the lowest ESR for its size, at
a higher price.
1174fe
8
相关PDF资料 |
PDF描述 |
|---|---|
| MAX6724AUTYHD1+T | IC SUPERVISOR MPU SOT23-6 |
| ABC17DREH | CONN EDGECARD 34POS .100 EYELET |
| LT1076IT-5 | IC REG MULTI CONFIG 5V TO220-5 |
| MAX6724AUTYHD5+T | IC SUPERVISOR MPU SOT23-6 |
| MAX6724AUTYVD5+T | IC SUPERVISOR MPU SOT23-6 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1174IN8 | 功能描述:IC REG BUCK INV ADJ 1A 8DIP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC1174IN8#PBF | 功能描述:IC REG BUCK INV ADJ 1A 8DIP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC1174IS8 | 功能描述:IC REG BUCK INV ADJ 1A 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC1174IS8#PBF | 功能描述:IC REG BUCK INV ADJ 1A 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC1174IS8#TR | 功能描述:IC REG BUCK INV ADJ 1A 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
发布紧急采购，3分钟左右您将得到回复。