参数资料
型号: LT1316IS8#PBF
厂商: Linear Technology
文件页数: 8/16页
文件大小: 0K
描述: IC REG BST FLYBK ADJ 0.5A 8SOIC
标准包装: 100
类型: 升压,反激式
输出类型: 可调式
输出数: 1
输出电压: 1.23 V ~ 30 V
输入电压: 1.5 V ~ 12 V
电流 - 输出: 500mA
同步整流器:
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: 管件
供应商设备封装: 8-SOIC
LT1316
APPLICATIO N S I N FOR M ATIO N
2(I OUT ) 2(10mA)
Discontinuous Mode Operation
A boost converter with a high V OUT :V IN ratio operates with
2. I PEAK =
= = 58mA
1 – DC 1 – 0.654
) )
V OUT – V IN + V D
)
)
= 5 – 2 + 0.4 2 μ s
a high duty cycle in continuous mode. For duty cycles
exceeding the LT1316’s guaranteed minimum specifica-
tion of 0.73, the circuit will need to be designed for
discontinuous operation. Additionally, very low peak cur-
rent limiting below 50mA may necessitate operating in this
mode unless high inductance values are acceptable. When
operating in discontinuous mode, a different equation
governs available output power. For each switch cycle, the
inductor current ramps down to zero, completely releas-
3. Find L
L=
0.4(I PEAK )
0.4(58mA)
= 293 μ H
t OFF
)
)
Where f = I PEAK (L)
V IN – V SAT
) )
V IN
)
)
=
330 μ H
) )
I PEAK ? L
) ) ) )
= 28 – 3.3 + 0.4 = 0.89
V OUT – V IN + V D
V OUT – V SAT + V D
) ) ) )
= 5 – 2 + 0.4 = 0.654
V OUT – V IN + V D
V OUT – V SAT + V D
(t ON2 )(V IN – V SAT ) 2
= 52 μ H
(3.4 μ s 2 )(3.3 – 0.2) 2
2(0.196W)(3.4 μ s + 2 μ s)
ing the stored energy. Energy stored in the inductor at any
time is equal to 1/2 LI 2 . Because this energy is released
each cycle, the equation for maximum power out is:
P OUT(MAX) = 1/2L(I PEAK2 )f
1
+ t OFF
When designing for very low peak currents (< 50mA), the
inductor size needs to be large enough so that on-time is
a least 1 μ s. On-time can be calculated by the equation:
On-Time =
(V IN – V SAT )
where V SAT = 0.2V.
Also, at these low current levels, current overshoot due to
power transistor turn-off delay will be a significant portion
of peak current. Increasing inductor size will keep this to
a minimum.
Design Example 1
Requirements: V IN = 2V, V OUT = 5V and I LOAD = 10mA.
1. Find duty cycle
DC =
5 – 0.2 + 0.4
Because duty cycle is less than the LT1316 minimum
specification (0.73), the circuit can be designed for
continuous operation.
8
4. Find R SET resistor
Overshoot = 300ns
L
2
= 1.8mA
Find R SET from Figure 3 for 58mA – 1.8mA = 56.2mA
R SET ≈ 47k
Design Example 2
Requirements: V IN = 3.3V, V OUT = 28V and I LOAD = 5mA.
1. Find duty cycle:
DC =
28 – 0.2 + 0.4
Because duty cycle exceeds LT1316 minimum specifi-
cation of 73%, the circuit must be designed for discon-
tinuous operation.
2. Find P OUT(MAX)
Multiply P OUT by 1.4 to give a safe operating margin
P OUT(MAX) = P OUT (1.4) = (5mA)(28V)(1.4) = 0.196W
3. Set the on-time to the data sheet minimum of 3.4 μ s and
find L
L=
2P OUT(MAX) (t ON + t OFF )
=
相关PDF资料
PDF描述
VE-JTV-CZ-F1 CONVERTER MOD DC/DC 5.8V 25W
LT1316IS8 IC REG BST FLYBK ADJ 0.5A 8SOIC
MAX6868UK40D1L+T IC MPU SUPERVISOR SOT23-5
MAX6868UK40D4S+T IC MPU SUPERVISOR SOT23-5
MAX6868UK40D2L+T IC MPU SUPERVISOR SOT23-5
相关代理商/技术参数
参数描述
LT1317 制造商:LINER 制造商全称:Linear Technology 功能描述:Constant-Current/ Constant-Voltage 1.4MHz Step-Up DC/DC Converter
LT1317B 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower, 600kHz PWM DC/DC Converters
LT1317BCMS8 功能描述:IC REG BOOST ADJ 0.5A 8MSOP 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
LT1317BCMS8#PBF 功能描述:IC REG BOOST ADJ 0.5A 8MSOP 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
LT1317BCMS8#TR 功能描述:IC REG BOOST ADJ 0.5A 8MSOP 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