- 您现在的位置：买卖IC网 > PDF目录14106 > LT3473AEDE#TRPBF (Linear Technology)IC REG BOOST ADJ 1A 12DFN PDF资料下载
参数资料
| 型号： | LT3473AEDE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 9/12页 |
| 文件大小： | 0K |
| 描述： | IC REG BOOST ADJ 1A 12DFN |
| 标准包装： | 2,500 |
| 类型： | 升压（升压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 可调至 34V |
| 输入电压： | 2.2 V ~ 16 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 1.2MHz |
| 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： | 12-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 12-DFN（4x3） |
LT3473/LT3473A
APPLICATIO S I FOR ATIO
Inrush Current
The LT3473 has an integrated Schottky power diode.
When supply voltage is abruptly applied to the V IN pin
while the output capacitor is discharged, the voltage
difference between V IN and CAP generates inrush current
flowing from the input through the inductor and the
internal Schottky diode to charge the output capacitor at
the CAP pin. The maximum current the LT3473’s Schottky
can sustain is 2A. The selection of inductor and capacitor
values should ensure that the peak inrush current is less
than 2A. Peak inrush current can be calculated as follows:
Setting the Output Voltages
The LT3473 has both an internal 1.25V reference and an
external reference input. This allows the user to select
between using the built-in reference and supplying an
external reference voltage. The voltage at the CTRL pin can
be adjusted while the device is operating to alter the output
voltage for purposes such as display dimming or contrast
adjustment. To use the internal 1.25V reference, the CTRL
pin must be held higher than 1.5V. When the CTRL pin is
held between 0V and 1.2V, the LT3473 will regulate the
output such that the FB pin voltage is equal to the CTRL pin
voltage.
? exp ? – ? arctan ? ? ? ? sin ? arctan ? ? ?
I P =
V IN – 0 . 6
L ? ω
? α ? ω ? ? ? ? ω ? ?
? ω ? α ? ? ? ? α ? ?
The CAP pin should be used as the feedback node. To set
the output voltage, select the values of R1 and R2 accord-
V INT REF ? ? 1 +
? R 2 ?
α =
ω =
r + 1 . 5
2 ? L
1
L ? C
–
r
4 ? L 2
ing to the following equation.
= V ?
? R 1 ?
where V REF = 1.25V if the internal reference is used, or
where L is the inductance, r is the resistance of the
inductor and C is the output capacitance. For a low DCR
inductor, which is usually the case for this application, the
peak inrush current can be simplified as follows:
V REF = V CTRL if V CTRL is between 0V and 1.2V.
To maintain output voltage accuracy, 1% resistors are
recommended.
Soft-Start
? exp ? – ? ?
I P =
V IN – 0 . 6
L ? ω
? α π ?
? ω 2 ?
The SHDN pin also functions as soft-start. Use an RC filter
at the SHDN pin to limit the start-up current. The small bias
A large abrupt voltage step at V IN and/or a large capacitor
at the CAP pin generate larger inrush current. Table 3 gives
current of the SHDN pin allows using a small capacitor for
a large RC time constant.
inrush peak currents for some component selections. An
inductor with low saturation current could generate very
ON/OFF
20k
LT3473
SHDN
large inrush current. For this case, inrush current should
be measured to ensure safe operation. Note that inrush
current is not a concern if the input voltage rises slowly.
100nF
3473 F04
Figure 4. Soft-Start Circuitry
Table 3. Inrush Peak Current
V IN (V) R ( ? )
5 0.05
L ( μ H)
6.8
C ( μ F)
0.47
I P (A)
0.86
Output Disconnect Considerations
The LT3473 has an output disconnect PNP that isolates
10
3.6
3.6
0.05
0.05
0.05
6.8
6.8
4.7
0.47
0.47
0.47
1.83
0.58
0.67
the load from the input during shutdown. The drive circuit
maintains the PNP at the edge of saturation, adaptively
according to the load, thus yielding the best compromise
between V CESAT and quiescent current to minimize power
loss. To remain stable, it requires a bypass capacitor
connected between the OUT pin and the CAP pin or
3473f
9
相关PDF资料 |
PDF描述 |
|---|---|
| CGH103T250X4L | CAP ALUM 10000UF 250V SCREW |
| MAX6868UK22D2L+T | IC MPU SUPERVISOR SOT23-5 |
| LTC3448EDD#TRPBF | IC REG BUCK SYNC ADJ 0.6A 8DFN |
| MAX6868UK23D5S+T | IC MPU SUPERVISOR SOT23-5 |
| CGS123T250X5C | CAP ALUM 12000UF 250V SCREW |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3473EDD | 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower 1A Boost Converter with Schottky and Output Disconnect |
| LT3473EDD#PBF | 功能描述:IC REG BOOST ADJ 1A 8DFN 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:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 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:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
| LT3473EDD#PBF | 制造商:Linear Technology 功能描述:Switching Regulator IC 制造商:Linear Technology 功能描述:IC, DC/DC BOOST CONVERTER, DFN-8 |
| LT3473EDD#TRPBF | 功能描述:IC REG BOOST ADJ 1A 8DFN 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:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 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:带卷 (TR) 供应商设备封装:8-SOIC |
| LT3473EDDPBF | 制造商:Linear Technology 功能描述:1A Boost Converter, LT3473EDD |
发布紧急采购，3分钟左右您将得到回复。