参数资料
型号: LTC1504ACS8-3.3#PBF
厂商: Linear Technology
文件页数: 7/12页
文件大小: 0K
描述: IC REG BUCK SYNC 3.3V 0.5A 8SOIC
标准包装: 100
类型: 降压(降压)
输出类型: 固定
输出数: 1
输出电压: 3.3V
输入电压: 4 V ~ 10 V
频率 - 开关: 200kHz
电流 - 输出: 500mA
同步整流器:
工作温度: 0°C ~ 70°C
安装类型: 表面贴装
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
包装: 管件
供应商设备封装: 8-SOIC
LTC1504A
APPLICATIO N S I N FOR M ATIO N
Ideally, the LTC1504A requires a low impedance bypass
Table 1. Representative Surface Mount Input Bypass Capacitors
right at the chip and a larger reservoir capacitor that can be
PART
VALUE
ESR
MAX RMS
TYPE
HEIGHT
located somewhat farther away. This requirement usually
can be met with a ceramic capacitor right next to the
LTC1504A and an electrolytic capacitor (usually 10 μ F to
100 μ F, depending on expected load current) located some-
where nearby. In certain cases, the bulk capacitance
AVX
TPSC226M016R0375 22 μ F 0.38 ?
TPSD476M016R0150 47 μ F 0.15 ?
TPSE107M016R0125 100 μ F 0.13 ?
1206YC105M 1 μ F Low
1210YG106Z 10 μ F Low
0.54A
0.86A
1.15A
>1A
>1A
Tantalum
Tantalum
Tantalum
X7R Ceramic
Y5V Ceramic
2.6mm
2.9mm
4.1mm
1.5mm
1.7mm
requirement can be met by the output bypass of the input
supply. Applications running at very high load currents or
at input supply voltages greater than 6V may require the
local ceramic capacitor to be 1 μ F or greater. In some
Sanyo
16SN33M
16SN68M
16CV100GX
16CV220GX
33 μ F 0.15 ?
68 μ F 0.1 ?
100 μ F 0.44 ?
220 μ F 0.34 ?
1.24A
1.65A
0.23A*
0.28A*
OS-CON 7mm
OS-CON 7mm
Electrolytic 6mm
Electrolytic 7.7mm
cases, both the low impedance and bulk capacitance
Sprague
requirements can be met by a single capacitor, mounted
very close to the LTC1504A. Low ESR organic semicon-
593D476X0016D2W
593D107X0016E2W
47 μ F
100 μ
0.17 ?
0.15 ?
0.93A
1.05A
Tantalum
Tantalum
2.8mm
4mm
ductor (OS-CON) electrolytic capacitors or surge tested
surface mount tantalum capacitors can have low enough
impedance to keep the LTC1504A happy in some circuits.
Often the RMS current capacity of the input bypass capaci-
tors is more important to capacitor selection than value.
Buck converters like the LTC1504A are hard on input
capacitors, since the current flow alternates between the
full load current and near zero during every clock cycle. In
the worst case (50% duty cycle or V OUT = 0.5V IN ) the RMS
current flow in the input capacitor is half of the total load
current plus half the ripple current in the inductor—
perhaps 300mA in a typical 500mA load current applica-
tion. This current flows through the ESR of the input
bypass capacitor, heating it up and shortening its life,
sometimes dramatically. Many ordinary electrolytic ca-
pacitors that look OK at first glance are not rated to
withstand such currents —check the RMS current rating
before you specify a device! If the RMS current rating isn’t
specified, it should not be used as an input bypass capaci-
tor. Again, low ESR electrolytic and surge tested tantalums
usually do well in LTC1504A applications and have high
RMS current ratings. The local ceramic bypass capacitor
usually has negligible ESR, allowing it to withstand large
RMS currents without trouble. Table 1 shows typical
surface mount capacitors that make acceptable input
bypass capacitors in LTC1504A applications.
Inductor
*Note: Use multiple devices in parallel or limit output current to prevent capacitor overload.
where the load is connected. Inductor requirements are
fairly straightforward; it must be rated to handle continu-
ous DC current equal to the maximum load current plus
half the ripple current and its value should be chosen
based on the desired ripple current and/or the output
current transient requirements. Large value inductors
lower ripple current and decrease the required output
capacitance, but limit the speed that the LTC1504A can
change the output current, limiting output transient re-
sponse. Small value inductors result in higher ripple
currents and increase the demands on the output capaci-
tor, but allow faster output current slew rates and are often
smaller and cheaper for the same DC current rating. A
typical inductor used in an LTC1504A application might
have a maximum current rating between 500mA and 1A
and an inductance between 33 μ H and 220 μ H.
Different core materials and shapes will change the size/
current and price/current relationship of an inductor.
Toroid or shielded pot cores in ferrite or permalloy mate-
rials are small and don’t radiate much energy, but gener-
ally cost more than powdered iron rod core inductors with
similar electrical characteristics. The choice of which style
inductor to use often depends more on the price vs size
requirements and any radiated field/EMI requirements
than on what the LTC1504A requires to operate. Table 2
shows some typical surface mount inductors that work
well in LTC1504A applications.
The LTC1504A requires an external inductor to be con-
nected from the switching node SW to the output node
7
相关PDF资料
PDF描述
LTC1504ACS8-3.3 IC REG BUCK SYNC 3.3V 0.5A 8SOIC
VI-J2W-EZ CONVERTER MOD DC/DC 5.5V 25W
HMC17DRTF-S13 CONN EDGECARD 34POS .100 EXTEND
VI-J24-EZ CONVERTER MOD DC/DC 48V 25W
HSC17DREF-S13 CONN EDGECARD 34POS .100 EXTEND
相关代理商/技术参数
参数描述
LTC1504AIS8 功能描述:IC REG BUCK SYNC ADJ 0.5A 8SOIC RoHS:否 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
LTC1504AIS8#PBF 功能描述:IC REG BUCK SYNC ADJ 0.5A 8SOIC 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
LTC1504AIS8#TR 功能描述:IC REG BUCK SYNC ADJ 0.5A 8SOIC RoHS:否 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
LTC1504AIS8#TRPBF 功能描述:IC REG BUCK SYNC ADJ 0.5A 8SOIC 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
LTC1504AIS8-3.3 功能描述:IC REG BUCK SYNC 3.3V 0.5A 8SOIC RoHS:否 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