参数资料
型号: LT1576CS8-5#PBF
厂商: Linear Technology
文件页数: 24/28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
with large inductors. Output ripple voltage for the positive-
to-negative converter will be much higher than a buck
converter. Ripple current in the output capacitor will also
be much higher. The following equations can be used to
calculate operating conditions for the positive-to-negative
converter.
Maximum load current:
This duty cycle is close enough to 50% that I P can be
assumed to be 1.5A.
OUTPUT DIVIDER
If the adjustable part is used, the resistor connected to
V OUT (R2) should be set to approximately 5k. R1 is
calculated from:
? I P ?
?
) (
( )(
) (
?
? V OUT V IN ? 0 . 35
I MAX =
?
?
?
2 ( V OUT + V IN )( f )( L ) ?
( V OUT + V IN ? 0 . 35 ) ( V OUT + V F )
V IN V OUT
)
R 1 = R 2 ( V OUT ? 1 . 21 )
1 . 21
INDUCTOR VALUE
I P = Maximum rated switch current
V IN = Minimum input voltage
V OUT = Output voltage
V F = Catch diode forward voltage
0.35 = Switch voltage drop at 1.5A
Example: with V IN(MIN) = 5.5V, V OUT = 5V, L = 30 μ H,
V F = 0.5V, I P = 1.5A: I MAX = 0.6A. Note that this equation
does not take into account that maximum rated switch
Unlike buck converters, positive-to-negative converters
cannot use large inductor values to reduce output ripple
voltage. At 200kHz, values larger than 75 μ H make almost
no change in output ripple. The graph in Figure 16 shows
peak-to-peak output ripple voltage for a 5V to – 5V con-
verter versus inductor value. The criteria for choosing the
150
current (I P ) on the LT1576 is reduced slightly for duty
cycles above 50%. If duty cycle is expected to exceed 50%
(input voltage less than output voltage), use the actual I P
value from the Electrical Characteristics table.
Operating duty cycle:
120
90
60
5V TO –5V CONVERTER
OUTPUT CAPACITOR’S
ESR = 0.1 ?
DISCONTINUOUS
I LOAD = 0.1A
DISCONTINUOUS
I LOAD = 0.25A
DC =
V OUT + V F
V IN ? 0 . 3 + V OUT + V F
30
CONTINUOUS
I LOAD > 0.38A
(This formula uses an average value for switch loss, so it
0
0
15
30
45
60
75
may be several percent in error.)
INDUCTOR SIZE ( μ H)
1576 F16
DC =
With the conditions above:
5 + 0 . 5
5 . 5 ? 0 . 3 + 5 + 0 . 5
24
= 51 %
Figure 16. Ripple Voltage on Positive-to-Negative Converter
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
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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