参数资料
型号: LT1576CS8-5#PBF
厂商: Linear Technology
文件页数: 13/28页
文件大小: 0K
描述: IC REG BUCK 5V 1.5A 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: 5V
输入电压: 5 V ~ 25 V
PWM 型: 电流模式
频率 - 开关: 200kHz
电流 - 输出: 1.5A
同步整流器:
工作温度: 0°C ~ 125°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
LT1576/LT1576-5
APPLICATIO N S I N FOR M ATIO N
0 . 29 ( V OUT ) ( V IN ? V OUT
( )( )( )
( )( ) ( )
V RIPPLE = I P-P ESR + ESL Σ
Output Capacitor Ripple Current (RMS):
I RIPPLE ( RMS ) = L f V
IN
)
dI
dt
Example: with V IN =10V, V OUT = 5V, L = 30 μ H, ESR = 0.1 ? ,
ESL = 10nH:
( ) ? 30 ? 10 200 ? 10 3 ?
? 6 ? ?
?
? ?
?
Ceramic Capacitors
Higher value, lower cost ceramic capacitors are now
becoming available in smaller case sizes. These are tempt-
I P-P =
10
( 5 ) ( 10 ? 5 )
= 0 . 42 A
= = 0 . 33 ? 10 6
Σ
30 ? 10 ? 6
V RIPPLE = ( 0 . 42 A )( 0 . 1 ) + ? 10 ? 10 0 . 33 ? 10 6 ?
ing for switching regulator use because of their very low
ESR. Unfortunately, the ESR is so low that it can cause
loop stability problems. Solid tantalum capacitor’s ESR
generates a loop “zero” at 5kHz to 50kHz that is instrumen-
tal in giving acceptable loop phase margin. Ceramic
capacitors remain capacitive to beyond 300kHz and usu-
ally resonate with their ESL before ESR becomes effective.
They are appropriate for input bypassing because of their
dI 10
dt
? ? ? ?
= 0 . 042 + 0 . 003 = 45 mV P-P
? 9 ? ?
high ripple current ratings and tolerance of turn-on surges.
OUTPUT RIPPLE VOLTAGE
Figure 3 shows a typical output ripple voltage waveform
for the LT1576. Ripple voltage is determined by the high
frequency impedance of the output capacitor, and ripple
20mV/DIV
200mA/DIV
20mV/DIV
V OUT AT
I OUT = 1A
INDUCTOR
CURRENT
AT I OUT = 1A
V OUT AT
I OUT = 50mA
( )( )( ) f
V L
currentthroughtheinductor.Peak-to-peakripplecurrent
through the inductor into the output capacitor is:
= ( V OUT )( V IN ? V OUT )
I P -P
IN
For high frequency switchers, the sum of ripple current
slew rates may also be relevant and can be calculated
from:
200mA/DIV INDUCTOR
CURRENT
AT I OUT = 50mA
2 μ s/DIV 1576 F03
Figure 3. LT1576 Ripple Voltage Waveform
CATCH DIODE
The suggested catch diode (D1) is a 1N5818 Schottky, or
its Motorola equivalent, MBR130. It is rated at 1A average
forward current and 30V reverse voltage. Typical forward
= IN
Σ
dI
dt
V
L
voltage is 0.42V at 1A. The diode conducts current only
during switch off time. Peak reverse voltage is equal to
regulator input voltage. Average forward current in normal
Peak-to-peak output ripple voltage is the sum of a triwave
operation can be calculated from:
created by peak-to-peak ripple current times ESR, and a
square wave created by parasitic inductance (ESL) and
ripple current slew rate. Capacitive reactance is assumed
to be small compared to ESR or ESL.
I D ( AVG ) =
I OUT ( V IN ? V OUT
V IN
)
13
相关PDF资料
PDF描述
LT1576CS8-5 IC REG BUCK 5V 1.5A 8SOIC
VE-JV3-CZ-F3 CONVERTER MOD DC/DC 24V 25W
LT1576CS8-SYNC#PBF IC REG BUCK ADJ 1.5A 8SOIC
LT1576CS8-SYNC IC REG BUCK ADJ 1.5A 8SOIC
VE-JV3-CZ-F2 CONVERTER MOD DC/DC 24V 25W
相关代理商/技术参数
参数描述
LT1576CS8-5SYNC 功能描述:IC REG BUCK 5V 1.5A 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: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
LT1576CS8-5SYNC#PBF 功能描述:IC REG BUCK 5V 1.5A 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:20 系列:SIMPLE SWITCHER® 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:12V 输入电压:4 V ~ 60 V PWM 型:电压模式 频率 - 开关:52kHz 电流 - 输出:1A 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:16-DIP(0.300",7.62mm) 包装:管件 供应商设备封装:16-DIP 其它名称:*LM2575HVN-12LM2575HVN-12
LT1576CS8-5SYNC#TR 功能描述:IC REG BUCK 5V 1.5A 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: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
LT1576CS8-5SYNC#TRPBF 功能描述:IC REG BUCK 5V 1.5A 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:20 系列:SIMPLE SWITCHER® 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:12V 输入电压:4 V ~ 60 V PWM 型:电压模式 频率 - 开关:52kHz 电流 - 输出:1A 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:16-DIP(0.300",7.62mm) 包装:管件 供应商设备封装:16-DIP 其它名称:*LM2575HVN-12LM2575HVN-12
LT1576CS8-SYNC 功能描述:IC REG BUCK ADJ 1.5A 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