参数资料
型号: LT1533CS#PBF
厂商: Linear Technology
文件页数: 11/20页
文件大小: 0K
描述: IC REG PUSH-PLL CTRLR ISO 16SOIC
标准包装: 50
类型: 推挽式控制器,隔离式
输出类型: 可调式
输出数: 1
输出电压: 1.3 V ~ 30 V
输入电压: 2.7 V ~ 23 V
PWM 型: 电流模式
频率 - 开关: 200kHz ~ 250kHz
电流 - 输出: 1A
同步整流器:
工作温度: 0°C ~ 100°C
安装类型: 表面贴装
封装/外壳: 16-SOIC(0.154",3.90mm 宽)
包装: 管件
供应商设备封装: 16-SOIC
产品目录页面: 1327 (CN2011-ZH PDF)
LT1533
APPLICATIO N S I N FOR M ATIO N
R VC
2k
C VC
0.01 μ F
C VC2
4.7nF
V C PIN
1533 F03
turns ratio of the transformer. The turns ratio must be
large enough to ensure that the transformer can put out a
voltage equal to the output voltage plus the diode under
minimum input conditions.
Figure 3
To prevent irregular switching, V C pin ripple should be
N =
2 ? DC MAX ( V IN ( MIN ) ? V SW
V OUT + V F
)
kept below 50mV P-P . Worst-case V C pin ripple occurs at
maximum output load current and will also be increased if
poor quality (high ESR) output capacitors are used. The
addition of a 0.0047 μ F capacitor on the V C pin reduces
switching frequency ripple to only a few millivolts. A low
value for R VC will also reduce V C pin ripple, but loop phase
margin may be inadequate.
DC MAX is the maximum duty cycle of each driver with
respect to the entire cycle which consists of two periods
(Q1A on and Q1B on). So the effective duty cycle is
2 ? DC MAX . The controller, in general, determines maxi-
mum duty cycle. A 44% maximum duty cycle is a guaran-
teed value for this part.
Some Common Turns Ratios
Magnetics
Design of magnetics is dependent on topology. The fol-
lowing details the design of the magnetics for a push-pull
converter. In this converter the transformer usually stores
V IN
5 ± 10%
5 ± 10%
5 ± 10%
V OUT
12
15
3.3
N
3.6
4.4
1.1
little energy. The following equations should be consid-
ered as the starting point to building a prototype.
Remember to add sufficient margin in the turns ratio to
account for IR drops in the transformer windings, worst-
V IN
T1
1:N
D S1
V SEC
D S2
L O
+
C O
V OUT
case diode forward drop (V F ) and switch-on voltage (V SW ).
There are a number of ways to choose the inductance
value for L O . We suggest as a starting point that L O be
Q1A
selected such that the converter is continuous at
Q1B
1533 F04
I OUT(MAX) /4. If your minimum I OUT is higher than this, or
you are operating at low currents such that the IC and
components can handle higher peak currents, then use a
Figure 4
The following definitions will be used:
V IN = Input supply voltage
V SW = Switch-on voltage
V OUT = Desired output voltage
I OUT = Output current
f = Oscillator frequency
V F = Forward drop of the rectifier
Duty cycle is the major defining equation for this topology.
Note that the output L and C basically filter the chopped
higher number.
Continuous operation occurs when the current in the
inductor never goes to zero. Discontinuous operation
occurs when the inductor current drops to zero before the
start of the next cycle and can occur with small inductors
and light loads. There is nothing inherently bad about
discontinuous operation, however, the converter control
and operation is somewhat different. The inductor is
smaller for discontinuous operation but the peak currents
in the switch, the transformer, the diodes, inductor and
capacitor will be higher. But for low power situations these
may not present a big constraint.
voltage so duty cycle controls output voltage. N is the
11
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LT1533I 制造商:LINER 制造商全称:Linear Technology 功能描述:Ultralow Noise 1A Switching Regulator
LT1533IS 功能描述:IC REG PUSH-PLL CTRLR ISO 16SOIC RoHS:否 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
LT1533IS#PBF 功能描述:IC REG PUSH-PLL CTRLR ISO 16SOIC 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
LT1533IS#TR 功能描述:IC REG PUSH-PLL CTRLR ISO 16SOIC RoHS:否 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
LT1533IS#TRPBF 功能描述:IC REG PUSH-PLL CTRLR ISO 16SOIC 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