参数资料
型号: IRU1260CPTR
厂商: International Rectifier
文件页数: 4/12页
文件大小: 0K
描述: IC CONV PENTIUM P55C 7-UTHINPAK
标准包装: 2,000
应用: 转换器,Intel Pentium?,P55C
输入电压: 3 V ~ 7 V
输出数: 2
输出电压: 1.2 V ~ 5.5 V
工作温度: 0°C ~ 150°C
安装类型: 表面贴装
封装/外壳: 7-超薄封装
供应商设备封装: 7-Ultra Thin-Pak?
包装: 带卷 (TR)
其它名称: IRU1260-CPTR
IRU1260-CPTR-ND
IRU1260
APPLICATION INFORMATION
Introduction
The IRU1260 is a dual adjustable Low Dropout (LDO)
regulator which can easily be programmed with the ad-
dition of two external resistors to any voltages within
the range of 1.20 to 5.5V. This voltage regulator is de-
signed specifically for applications that require two sepa-
rate regulators such as the Intel Pentium II TM proces-
sors requiring 1.5V and 2.5V supplies, eliminating the
need for a second regulator which results in lower over-
all system cost. When V CTRL pin is connected to a sup-
ply which is at least 1V higher than V IN , the dropout
voltage improves by 30% which makes it ideal for appli-
cations requiring less than the standard 1.3V dropout
given in the LDO products such as IRU10XX series. The
IRU1260 also provides an accurate 1.20V voltage refer-
ence common to both regulators for programming each
output voltage. Other features of the device include: fast
response to sudden load current changes, such as GTL+
termination application for Pentium II TM family of micro-
processors. The IRU1260 also includes thermal shut-
down protection to protect the device if an overload con-
dition occurs.
Output Voltage Setting
The IRU1260 can be programmed to any voltages in the
range of 1.20V to 5.5V with the addition of R1 and R2
external resistors according to the following formula:
The IRU1260 keeps a constant 1.2V between the V FB
pin and ground pin. By placing a resistor R1 across these
two pins a constant current flows through R1, adding to
the I FB current and into the R2 resistor producing a volt-
age equal to the (1.2/R1) 3 R2 + I FB 3 R2 which will be
added to the 1.2V to set the output voltage as shown in
the above equation. Since the input bias current of the
amplifier (I FB ) is only 0.02 m A typically, it adds a very
small error to the output voltage and for most applica-
tions can be ignored. For example, in a typical 1.5V
GTL+application if R1=10.2K V and R2=2.55K V the er-
ror due to the I ADJ is only 0.05mV which is less than
0.004% of the nominal set point. The effective input im-
pedance seen by the feedback pins (The parallel combi-
nation of R1 and R2) must always be higher than 1.8K V
in order for the regulator to start up properly.
Load Regulation
Since the IRU1260 does not provide a separate ground
pin for the reference voltage, it is not possible to provide
true remote sensing of the output voltage at the load.
Figure 4 shows that the best load regulation is achieved
when the bottom side of R1 resistor is connected di-
rectly to the ground pin of IRU1260 (preferably to the tab
of the device) and the top side of R2 resistor is con-
nected to the load. In fact, if R1 is connected to the load
side, the effective resistance between the regulator and
the load is gained up by the factor of (1+R2/R1), or the
(
) +R 3 I
V OUT = V REF 3 1+
R 2
R 1
2 B
effective resistance will be, R P(eff) =R P 3 (1+R2/R1). It is
important to note that for high current applications, this
Where:
V REF = 1.20V Typically
I B = 0.02 m A Typical
R1 and R2 as shown in Figure 3:
can represent a significant percentage of the overall load
regulation and one must keep the path from the regula-
tor to the load as short as possible to minimize this
effect.
V I N
V IN
V OUT
V IN
V IN
V OUT
V OUT
IRU1260
IRU1260
R2
V C T R L
V CTRL
V FB
R2
V CTRL
V CTRL
Gnd
V FB
I B
V REF
R1
Gnd
R1
R L
R P
Figure 3 - Typical application of the IRU1260
for programming the output voltage.
(Only one output is shown here)
PARASITIC LINE
RESISTANCE
Figure 4 - Schematic showing connection
for best load regulation.
(Only one output is shown here)
4
www.irf.com
Rev. 2.1
09/19/02
相关PDF资料
PDF描述
RBC15DRSN-S273 CONN EDGECARD 30POS DIP .100 SLD
ESM44DSEH-S13 CONN EDGECARD 88POS .156 EXTEND
IRU1075CT IC CONV PENTIUM P55C TO220-3
IRU1075CM IC CONV PENTIUM P55C TO263-3
RBC15DRSD-S273 CONN EDGECARD 30POS DIP .100 SLD
相关代理商/技术参数
参数描述
IRU1260CT 制造商:IRF 制造商全称:International Rectifier 功能描述:DUAL 6A AND 1A LOW DROPOUT POSITIVE ADJUSTABLE REGULATOR
IRU1261 制造商:IRF 制造商全称:International Rectifier 功能描述:DUAL 6A AND 1A LOW DROPOUT POSITIVE FIXED 1.5V AND 2.5V REGULATOR
IRU1261CM 制造商:IRF 制造商全称:International Rectifier 功能描述:DUAL 6A AND 1A LOW DROPOUT POSITIVE FIXED 1.5V AND 2.5V REGULATOR
IRU1261CMTR 功能描述:IC CONV PENTIUM II TO-263-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,000 系列:- 应用:电源,ICERA E400,E450 输入电压:4.1 V ~ 5.5 V 输出数:10 输出电压:可编程 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:42-WFBGA,WLCSP 供应商设备封装:42-WLP 包装:带卷 (TR)
IRU1261CP 制造商:IRF 制造商全称:International Rectifier 功能描述:DUAL 6A AND 1A LOW DROPOUT POSITIVE FIXED 1.5V AND 2.5V REGULATOR