参数资料
| 型号： | IRU3034CS |
| 厂商： | International Rectifier |
| 文件页数： | 9/12页 |
| 文件大小： | 0K |
| 描述： | IC CTRL/REG PWM SWITCH 8-SOIC |
| 标准包装： | 95 |
| 应用： | 控制器，Intel Pentium?，II，P55C |
| 输入电压： | 12V |
| 输出数： | 1 |
| 输出电压： | 2 V ~ 3.5 V |
| 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） |
| 供应商设备封装： | 8-SOIC |
| 包装： | 管件 |
| 产品目录页面： | 1384 (CN2011-ZH PDF) |
| 其它名称： | *IRU3034CS IRU3034-CS IRU3034-CS-ND |
IRU3034 & (PbF)
Ppk = I CL × Rs = 20 × 0.005 = 2W
The peak power dissipated in the CS resistor is:
2 2
However, the average power dissipated is much lower
than 2W due to the long off time caused by the hiccup
circuit of IRU3034. The average power is in fact the short
circuit period divided by the short circuit period plus the
off time or "Hiccup" period. For example, if the short
circuit lasts for Tsc=100 μ s before the IRU3034 enters
hiccup, the average power is calculated as:
P AVG = 0.5 × Ppk × Dsc
Where:
Dsc = Tsc / T HCP
T HCP = Css × M
M = 200ms/ μ F
Css = The soft-start capacitor
The bottom resistor of the divider is then calculated us-
ing the following equations:
R B = Rt / X
Where:
R B = Bottom resistor of the divider
V REF = 1.25V Typical
X = [ (Vo + ( ? Vo/2)) / V REF ] - 1
X= [ (3.38+ (0.044/2)) / 1.25 ] - 1 = 1.72
R B = 1000 / 1.72 = 580 ?
Select R B = 576 ? , 1%
Frequency Calculation
The IRU3034 frequency of operation is calculated using
the following formula:
For example:
Fs = [ (Vo × (1-D) × ESR) ] / (L ×? Vo)
(MHz)
For Css=0.1 μ F and Tsc=500 μ s=0.5ms
T HCP = 0.1 × 200 = 20ms
P AVG = 0.5 × 2 × (0.5/20) = 25mW
Without "Hiccup" technique, the power dissipation of the
resistor is 2W.
Switcher Output Voltage Setting
The output voltage can be set using the following
equations:
Assuming, Vo=3.38V and the selected output ripple is ≈
1.3%(44mV) of the output voltage, a set of equations
are derived that selects the resistor divider and the hys-
Where:
Vo = Output voltage (V)
D = Duty cycle
ESR = Output capacitor ESR (V)
L = Output inductance ( μ H)
? Vo = Output ripple voltage (V)
For our example:
D ≈ (Vo + Vf) / V IN
Where:
Vf = Forward voltage drop of the Schottky diode.
D = (3.38 + 0.5) / 5 = 0.78
teresis resistor:
The ESR=18m ?
for 2 of the Sanyo 1500 μ F,
6MV1500GX caps. If L=3.5 μ H then, Fs is calculated as
Assuming, Rt = 1K ? , 1%:
follows:
R H = (11 × Rt) / ? Vo
Where:
Fs =
[ (3.38 × (1-0.78) × 0.018) ]
(3.5 × 0.044)
= 0.087
Rt = Top resistor of the resistor divider
R H = Hysteresis resistor connected between pins 3
and 4 of the IRU3034
? Vo = Selected output ripple (typically 1% to 2% of
output voltage)
Assuming, ? Vo=44mV:
R H = (11 × 1000) / 0.044 = 250K ?
Select R H = 249K ? , 1%
Fs = 87KHz
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| IRU3037ACFTRPBF | IC REG CTRLR BUCK PWM VM 8-TSSOP |
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| IRU3039CHTR | IC REG CTRLR BUCK PWM VM 20-MLPQ |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| IRU3034CSPBF | 制造商:International Rectifier 功能描述:PWM CONTROLLER SMD 3034 SOIC8 |
| IRU3034CSTR | 功能描述:IC CNTRL PWM SYNC SWITCH 8-SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:2,000 系列:- 应用:控制器，DSP 输入电压:4.5 V ~ 25 V 输出数:2 输出电压:最低可调至 1.2V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:30-TFSOP（0.173"，4.40mm 宽） 供应商设备封装:30-TSSOP 包装:带卷 (TR) |
| IRU3034PBF | 制造商:IRF 制造商全称:International Rectifier 功能描述:8-PIN PWM SWITCHER CONTROLLER IC WITH CURRENT LIMITING |
| IRU3037 | 制造商:IRF 制造商全称:International Rectifier 功能描述:8-PIN SYNCHRONOUS PWM CONTROLLER |
| IRU3037A | 制造商:IRF 制造商全称:International Rectifier 功能描述:8-PIN SYNCHRONOUS PWM CONTROLLER |
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