- 您现在的位置：买卖IC网 > PDF目录15516 > IRU3048CSTR (International Rectifier)IC REG CTRLR BUCK PWM VM 16-SOIC PDF资料下载
参数资料
| 型号： | IRU3048CSTR |
| 厂商： | International Rectifier |
| 文件页数： | 6/18页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM VM 16-SOIC |
| 标准包装： | 1 |
| PWM 型： | 电压模式 |
| 输出数： | 3 |
| 频率 - 最大： | 220kHz |
| 占空比： | 90% |
| 电源电压： | 4.2 V ~ 25 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | 0°C ~ 70°C |
| 封装/外壳： | 16-SOIC（0.154"，3.90mm 宽） |
| 包装： | 剪切带 (CT) |
| 产品目录页面： | 1384 (CN2011-ZH PDF) |
| 其它名称： | *IRU3048CSTR IRU3048CSCT |
IRU3048
If the high value feedback resistors are used, the input
bias current of the Fb pin could cause a slight increase
in output voltage. The output voltage set point can be
more accurate by using precision resistor.
Soft-Start Programming
The soft-start timing can be programmed by selecting
the soft start capacitance value. The start up time of the
Output Capacitor Selection
The criteria to select the output capacitor is normally
based on the value of the Effective Series Resistance
(ESR). In general, the output capacitor must have low
enough ESR to meet output ripple and load transient
requirements, yet have high enough ESR to satisfy sta-
bility requirements. The ESR of the output capacitor is
calculated by the following relationship:
converter can be calculated by using:
t START = 75 3 Css (ms) ---(2)
ESR [
D V O
D I O
---(4)
Where:
C SS is the soft-start capacitor ( m F)
For a start-up time of 7.5ms, the soft-start capacitor will
be 0.1 m F. Choose a ceramic capacitor at 0.1 m F.
Boost Supply Vc
To drive the high-side switch it is necessary to supply a
gate voltage at least 4V greater than the bus voltage.
This is achieved by using a charge pump configuration
as shown in Figure 9. The capacitor is charged up to
approximately twice the bus voltage. A capacitor in the
range of 0.1 m F to 1 m F is generally adequate for most
Where:
D V O = Output Voltage Ripple
D I O = Output Current
D V O =75mV and D I O =3A, results to: ESR=25m V
The Sanyo TPC series, PosCap capacitor is a good
choice. The 6TPC150M 150 m F, 6.3V has an ESR 40m V .
Selecting two of these capacitors in parallel for each
output, results to an ESR of ? 20m V which achieves our
low ESR goal.
The capacitor value must be high enough to absorb the
inductor's ripple current. The larger the value of capaci-
tor, the lower will be the output ripple voltage.
applications.
The resulting output ripple current is smaller then each
Input Capacitor selection
The input filter capacitor should be based on how much
ripple the supply can tolerate on the DC input line. The
ripple current generated during the on time of control
MOSFET should be provided by input capacitor. The RMS
value of this ripple is expressed by:
channel ripple current due to the 180 8 phase shift. These
currents cancel each other. The cancellation is not the
maximum because of the different duty cycle for each
channel.
Inductor Selection
I RMS = I OUT
D 3 (1-D)
---(3)
The inductor is selected based on output power, operat-
ing frequency and efficiency requirements. Low induc-
Where:
D is the Duty Cycle, simply D=V OUT /V IN.
I RMS is the RMS value of the input capacitor current.
I OUT is the output current for each channel.
For V IN1 =12V, I OUT1 =4A and D1=0.275
tor value causes large ripple current, resulting in the
smaller size, but poor efficiency and high output noise.
Generally, the selection of inductor value can be reduced
to desired maximum ripple current in the inductor ( ? i);
the optimum point is usually found between 20% and
50% ripple of the output current.
Results to: I RMS1 =1.78A
For the buck converter, the inductor value for desired
And for V IN2 =5V, I OUT2 =4A and D2=0.36
Results to: I RMS2 =1.92A
operating ripple current can be determined using the fol-
lowing relation:
For higher efficiency, a low ESR capacitor is recom-
V IN - V OUT = L 3
D i
D t
; D t = D 3
1
f S
;D=
V OUT
V IN
mended.
For V I N 1 =12V, choose one Poscap from Sanyo
16TPB47M (16V, 47 m F, 70m V , 1.4A)
For V IN2 =5V, choose one 6TPC150M (6.3V, 150 m F,
40m V , 1.9A).
V OUT
L = (V IN - V OUT ) 3
V IN 3D i 3 f S
Where:
V IN = Max Input Voltage
V OUT = Output Voltage
? i = Inductor Ripple Current
f S = Switching Frequency
---(5)
? t = Turn On Time
D = Duty Cycle
6
www.irf.com
Rev. 1.7
09/12/02
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1714AEEP+ | IC REG CTRLR BUCK PWM CM 20-QSOP |
| NCP1562ADR2G | IC REG CTRLR PWM VM 16-SOIC |
| ISL6526CB-T | IC REG CTRLR BUCK PWM VM 14-SOIC |
| IR3621FTRPBF | IC REG CTRLR BUCK PWM VM 28TSSOP |
| MIC2193YM TR | IC REG CTRLR BUCK PWM CM 8-SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| IRU3048CSTRPBF | 制造商:International Rectifier 功能描述:Dual Synchronous PWM Controller Circuitry and LDO Controller 16-Pin SOIC N T/R |
| IRU3055 | 制造商:IRF 制造商全称:International Rectifier 功能描述:5-BIT PROGRAMMABLE 3-PHASE SYNCHRONOUS BUCK CONTROLLER IC |
| IRU3055CQ | 制造商:IRF 制造商全称:International Rectifier 功能描述:5-BIT PROGRAMMABLE 3-PHASE SYNCHRONOUS BUCK CONTROLLER IC |
| IRU3055CQTR | 功能描述:IC CTRL SYNC 3-PHASE 36-QSOP 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) |
| IRU3065 | 制造商:IRF 制造商全称:International Rectifier 功能描述:POSITIVE TO NEGATIVE DC TO DC CONTROLLER |
发布紧急采购，3分钟左右您将得到回复。