参数资料
型号: LT3510EFE#PBF
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: 74
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:
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: 管件
供应商设备封装: 20-TSSOP-EP
产品目录页面: 1332 (CN2011-ZH PDF)
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
LT3686HDD#PBF IC REG BUCK ADJ 1.2A 10-DFN
380LX123M016H022 CAP ALUM 12000UF 16V 20% SNAP
EGM28DTKH CONN EDGECARD 56POS DIP .156 SLD
ECO-S1KA562EA CAP ALUM 5600UF 80V 20% SNAP
LT1308ACS8#PBF IC REG BOOST 5V 1A 8SOIC
相关代理商/技术参数
参数描述
LT3510EFE-TR 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic Dual Tracking 2A Step-Down Switching Regulator
LT3510EFE-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic Dual Tracking 2A Step-Down Switching Regulator
LT3510FE 制造商:LINER 制造商全称:Linear Technology 功能描述:Monolithic Dual Tracking 2A Step-Down Switching Regulator
LT3510IFE 制造商:Linear Technology 功能描述:Conv DC-DC Dual Step Down 3.1V to 25V 20-Pin TSSOP EP
LT3510IFE#PBF 功能描述:IC REG BUCK ADJ 2A DL 20TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:MIC23xxx HyperLight Load™ Regulators 标准包装:5,000 系列:HyperLight Load® 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.8V 输入电压:2.7 V ~ 5.5 V PWM 型:混合物 频率 - 开关:4MHz 电流 - 输出:2A 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:8-VFDFN 裸露焊盘,8-MLF? 包装:带卷 (TR) 供应商设备封装:8-MLF?(2x2) 产品目录页面:1094 (CN2011-ZH PDF) 其它名称:576-3303-2