参数资料
| 型号： | LT3510IFE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 16/30页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 2A DL 20TSSOP |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 2 |
| 输出电压： | 0.8 V ~ 23.8 V |
| 输入电压： | 3.1 V ~ 25 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 250kHz ~ 1.5MHz |
| 电流 - 输出： | 2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-TSSOP（0.173"，4.40mm 宽）裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 20-TSSOP-EP |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页当前第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页
LT3510
APPLICATIONS INFORMATION
?
? I
> 10 L ? LIM ?
? V OUT ?
=
inputvoltageanddamagingtheLT3510.Thesolutionisto
either clamp the input voltage or dampen the tank circuit
by adding a lossy capacitor in parallel with the ceramic
capacitor. For details, see Application Note 88.
Output Capacitor Selection
Typically step-down regulators are easily compensated with
an output crossover frequency that is 1/10 of the switch-
ing frequency. This means that the time that the output
capacitor must supply the output load during a transient
step is ~2 or 3 switching periods. With an allowable 5%
drop in output voltage during the step, a good starting
value for the output capacitor can be expressed by:
Max Load Step
C VOUT
Frequency ? 0.05 ? V OUT
Example:
V OUT = 3.3V, Frequency = 1MHz, Max Load Step = 2A
The RMS content of this ripple is very low, and the RMS
current rating of the output capacitor is usually not of
concern.
Another constraint on the output capacitor is that it must
have greater energy storage than the inductor; if the stored
energy in the inductor is transferred to the output, you
would like the resulting voltage step to be small compared
to the regulation voltage. For a 5% overshoot, this require-
ment becomes:
2
C OUT
Finally, there must be enough capacitance for good transient
performance. The last equation gives a good starting point.
Alternatively, you can start with one of the designs in this
data sheet and experiment to get the desired performance.
This topic is covered more thoroughly in the section on
loop compensation.
C VOUT =
2
1e6 ? 0.05 ? 3.3V
= 12 μ F
The high performance (low ESR), small size and robustness
of ceramic capacitors make them the preferred type for
LT3510 applications. However, all ceramic capacitors are
The calculated value is only a suggested starting value.
Increase the value if transient response needs improvement
or reduce the capacitance if size is a priority.
The output capacitor ?lters the inductor current to generate
an output with low voltage ripple. It also stores energy in
order to satisfy transient loads and to stabilize the LT3510’s
control loop. The switching frequency of the LT3510 deter-
mines the value of output capacitance required. Also, the
current mode control loop doesn’t require the presence
of output capacitor series resistance (ESR). For these
reasons, you are free to use ceramic capacitors to achieve
very low output ripple and small circuit size.
Estimate output ripple with the following equations:
V RIPPLE = ? I L /(8f C OUT ) for ceramic capacitors,
and
V RIPPLE = ? I L ESR for electrolytic capacitors (tantalum
and aluminum)
not the same. As mentioned above, many of the high value
capacitors use poor dielectrics with high temperature and
voltage coef?cients. In particular, Y5V and Z5U types lose
a large fraction of their capacitance with applied voltage
and temperature extremes. Because the loop stability and
transient response depend on the value of C OUT , you may
not be able to tolerate this loss. Use X7R and X5R types.
You can also use electrolytic capacitors. The ESRs of most
aluminum electrolytics are too large to deliver low output
ripple. Tantalum and newer, lower ESR organic electrolytic
capacitors intended for power supply use, are suitable
and the manufacturers will specify the ESR. The choice of
capacitor value will be based on the ESR required for low
ripple. Because the volume of the capacitor determines
its ESR, both the size and the value will be larger than a
ceramic capacitor that would give you similar ripple per-
formance. One bene?t is that the larger capacitance may
give better transient response for large changes in load
current. Table 2 lists several capacitor vendors.
where ? I L is the peak-to-peak ripple current in the
inductor.
3510fe
16
相关PDF资料 |
PDF描述 |
|---|---|
| LT3511MPMS#PBF | IC REG FLYBK ISO ADJ .24A 16MSOP |
| LT3512MPMS#TRPBF | IC REG FLYBK ISO ADJ .42A 16MSOP |
| LT3513IUHF#PBF | IC REG 5-OUT FOR TFT-LCD 38QFN |
| LT3571IUD#TRPBF | IC REG BOOST ADJ 0.47A 16QFN |
| LT3573IMSE#TRPBF | IC REG FLYBACK ISO ADJ 16MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3511 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic High Voltage Isolated Flyback Converter No External Start-Up Resistor |
| LT3511EMS#PBF | 功能描述:IC REG FLYBACK ISOLATD 16-MSOP 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 |
| LT3511EMS#TRPBF | 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP 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 |
| LT3511HMS#PBF | 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 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:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LT3511HMS#TRPBF | 功能描述:IC REG FLYBK ISO ADJ .24A 16MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 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:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
发布紧急采购，3分钟左右您将得到回复。