- 您现在的位置：买卖IC网 > PDF目录1829 > LTC3448EMS8E#TRPBF (Linear Technology)IC REG BUCK SYNC ADJ 0.6A 8MSOP PDF资料下载
参数资料
| 型号： | LTC3448EMS8E#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 11/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 0.6A 8MSOP |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 5.2 V |
| 输入电压： | 2.5 V ~ 5.5 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 1.5MHz ~ 2.25MHz |
| 电流 - 输出： | 600mA |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-TSSOP，8-MSOP（0.118"，3.00mm 宽）裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 8-MSOP-EP |
LTC3448
APPLICATIO S I FOR ATIO
worst, a sudden inrush of current through the long wires
can potentially cause a voltage spike at V IN , large enough
to damage the part.
When choosing the input and output ceramic capacitors,
choose the X5R or X7R dielectric formulations. These
dielectrics have the best temperature and voltage charac-
teristics of all the ceramics for a given value and size.
Output Voltage Programming
loss dominates the efficiency loss at low load currents,
whereas the I 2 R loss dominates the efficiency loss at
medium to high load currents. At very low load currents
with the part operating in LDO mode, efficiency can be
dominated by I 2 R losses in the pass transistor and is a
strong function of (V IN – V OUT ). In a typical efficiency plot,
the efficiency curve at very low load currents can be
misleading since the actual power lost is of little conse-
quence as illustrated in Figure 6.
The output voltage is set by tying V FB to a resistive divider
according to the following formula:
1
V IN = 3.6V
FREQ = 0V
LDOCNTRL = V OUT(AUTO)
= 0 . 6 V ? 1 +
R 1 ?
V OUT
?
?
R 2 ?
?
(2)
0.1
0.01
The external resistive divider is connected to the output,
allowing remote voltage sensing as shown in Figure 5.
0.001
1.2V
0.6V ≤ V OUT ≤ 5.5V
0.0001
1.5V
1.8V
R2
0.0001
0.001 0.01
LOAD CURRENT (A)
0.1
1
V FB
3448 F06
LTC3448
GND
R1
3448 F05
Figure 6. Power Loss vs Load Current
1. The V IN quiescent current is due to two components:
the DC bias current as given in the Electrical Character-
Figure 5. Setting the LTC3448 Output Voltage
Efficiency Considerations
The efficiency of a switching regulator is equal to the
output power divided by the input power times 100%. It is
often useful to analyze individual losses to determine what
is limiting the efficiency and which change would produce
the most improvement. Efficiency can be expressed as:
Efficiency = 100% – (L1 + L2 + L3 + ...)
where L1, L2, etc. are the individual losses as a percentage
of input power.
Although all dissipative elements in the circuit produce
losses, two main sources usually account for most of the
losses in LTC3448 circuits: V IN quiescent current and I 2 R
losses. When in switching mode, V IN quiescent current
istics and the internal main switch and synchronous
switch gate charge currents. The gate charge current
results from switching the gate capacitance of the
internal power MOSFET switches. Each time the gate is
switched from high to low to high again, a packet of
charge, dQ, moves from V IN to ground. The resulting
dQ/dt is the current out of V IN that is typically larger than
the DC bias current and proportional to frequency. Both
the DC bias and gate charge losses are proportional to
V IN and thus their effects will be more pronounced at
higher supply voltages.
2. I 2 R losses are calculated from the resistances of the
internal switches, R SW , and external inductor R L . In
continuous mode, the average output current flowing
through inductor L is “chopped” between the main
switch and the synchronous switch. Thus, the series
resistance looking into the SW pin is a function of both
3448f
11
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3450EUD#TRPBF | IC CONV PS TRIPLE TFT/LCD 16QFN |
| LTC3458EDE#TRPBF | IC REG BOOST SYNC ADJ 1.4A 12DFN |
| LTC3459EDCB#TRPBF | IC REG BOOST SYNC ADJ 6DFN |
| LTC3499BEDD#TRPBF | IC REG BOOST SYNC ADJ 0.75A 8DFN |
| LTC3520EUF#PBF | IC REG BUCK BOOST SYNC ADJ 24QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3450 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Triple Output Power Supply for Small TFT-LCD Displays |
| LTC3450EUD | 功能描述:IC CONV PS TRIPLE TFT/LCD 16QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| LTC3450EUD#PBF | 功能描述:IC CONV PS TRIPLE TFT/LCD 16QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:2,000 系列:- 应用:控制器，DSP 输入电压:4.5 V ~ 25 V 输出数:2 输出电压:最低可调至 1.2V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:30-TFSOP（0.173"，4.40mm 宽） 供应商设备封装:30-TSSOP 包装:带卷 (TR) |
| LTC3450EUD#TR | 功能描述:IC CONV PS TRIPLE TFT/LCD 16QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| LTC3450EUD#TRPBF | 功能描述:IC CONV PS TRIPLE TFT/LCD 16QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
发布紧急采购，3分钟左右您将得到回复。