- 您现在的位置：买卖IC网 > PDF目录13882 > LTC3605EUF#TRPBF (Linear Technology)IC REG BUCK SYNC ADJ 5A 24QFN PDF资料下载
参数资料
| 型号： | LTC3605EUF#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 11/22页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 5A 24QFN |
| 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 ~ 14.9 V |
| 输入电压： | 4 V ~ 15 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 1MHz |
| 电流 - 输出： | 5A |
| 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： | 24-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 24-QFN（4x4） |
LTC3605
OPERATION
C OUT ≈ 2.5
V OUT ? V OUT ?
f ? L ?
V IN(MAX) ?
V OUT ?
V OUT
f ? D I L(MAX) ?
V IN(MAX) ?
UsingCeramicInputandOutputCapacitors
Higher values, lower cost ceramic capacitors are now
becoming available in smaller case sizes. Their high ripple
current, high voltage rating and low ESR make them ideal
for switching regulator applications. However, care must
be taken when these capacitors are used at the input and
output. When a ceramic capacitor is used at the input
and the power is supplied by a wall adapter through long
wires, a load step at the output can induce ringing at the
V IN input. At best, this ringing can couple to the output and
be mistaken as loop instability. At 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 and X7R dielectric formulations. These
dielectrics have the best temperature and voltage charac-
teristics of all the ceramics for a given value and size.
Since the ESR of a ceramic capacitor is so low, the input
and output capacitor must instead fulfill a charge storage
requirement. During a load step, the output capacitor must
instantaneously supply the current to support the load
until the feedback loop raises the switch current enough
to support the load. The time required for the feedback
loop to respond is dependent on the compensation and the
output capacitor size. Typically, 3 to 4 cycles are required
to respond to a load step, but only in the first cycle does
the output drop linearly. The output droop, V DROOP , is
usually about 2 to 3 times the linear drop of the first cycle.
Thus, a good place to start with the output capacitor value
is approximately:
D I OUT
f O ? V DROOP
More capacitance may be required depending on the duty
cycle and load step requirements.
In most applications, the input capacitor is merely required
to supply high frequency bypassing, since the impedance to
the supply is very low. A 22μF ceramic capacitor is usually
enough for these conditions. Place this input capacitor as
close to the PV IN pins as possible.
Inductor Selection
Given the desired input and output voltages, the induc-
tor value and operating frequency determine the ripple
current:
D I L = ? 1– ?
Lower ripple current reduces core losses in the inductor,
ESR losses in the output capacitors and output voltage
ripple. Highest efficiency operation is obtained at low
frequency with small ripple current. However, achieving
this requires a large inductor. There is a trade-off between
component size, efficiency and operating frequency.
A reasonable starting point is to choose a ripple current
that is about 50% of I OUT(MAX) . This is especially impor-
tant at low V OUT operation where V OUT is 1.8V or below.
Care must be given to choose an inductance value that
will generate a big enough current ripple (40% to 50%)
so that the chip’s valley current comparator has enough
signal-to-noise ratio to force constant switching frequency.
Meanwhile, also note that the largest ripple current occurs
at the highest V IN . To guarantee that ripple current does
not exceed a specified maximum, the inductance should
be chosen according to:
?
L = ? ? 1– ?
Once the value for L is known, the type of inductor must
be selected. Actual core loss is independent of core size
for a fixed inductor value, but is very dependent on the
inductance selected. As the inductance or frequency in-
creases, core losses decrease. Unfortunately, increased
inductance requires more turns of wire and therefore
copper losses will increase.
Ferrite designs have very low core losses and are pre-
ferred at high switching frequencies, so design goals can
concentrate on copper loss and preventing saturation.
Ferrite core material saturates “hard”, which means that
3605fc
11
相关PDF资料 |
PDF描述 |
|---|---|
| ASM11DRXS | CONN EDGECARD 22POS DIP .156 SLD |
| VI-J3B-EZ-F3 | CONVERTER MOD DC/DC 95V 25W |
| 35MS7100MEFC8X7 | CAP ALUM 100UF 35V 20% RADIAL |
| LT3972EDD#TRPBF | IC REG BUCK ADJ 3.5A 10DFN |
| FSM08DSEH | CONN EDGECARD 16POS .156 EYELET |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3605IUF#PBF | 功能描述:IC REG BUCK SYNC ADJ 5A 24QFN 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 |
| LTC3605IUF#TRPBF | 功能描述:IC REG BUCK SYNC ADJ 5A 24QFN 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 |
| LTC3606BEDD#PBF | 功能描述:IC REG BUCK SYNC ADJ 0.8A 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 |
| LTC3606BEDD#PBF | 制造商:Linear Technology 功能描述:IC SYNC STEP-DOWN DC/DC CONVERTER DFN8 |
| LTC3606BEDD#TRPBF | 功能描述:IC REG BUCK SYNC ADJ 0.8A 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 |
发布紧急采购，3分钟左右您将得到回复。