- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384510 > IRU3048CS (International Rectifier) DUAL SYNCHRONOUS PWM CONTROLLER CIRCUITRY AND LDO CONTROLLER PDF資料下載
參數(shù)資料
| 型號： | IRU3048CS |
| 廠商： | International Rectifier |
| 元件分類： | 基準電壓源/電流源 |
| 英文描述： | DUAL SYNCHRONOUS PWM CONTROLLER CIRCUITRY AND LDO CONTROLLER |
| 中文描述： | 雙同步PWM控制器電路和LDO控制器 |
| 文件頁數(shù)： | 10/18頁 |
| 文件大?。?/td> | 154K |
| 代理商： | IRU3048CS |
10
Rev. 1.7
09/12/02
IRU3048
www.irf.com
Cross Over Frequency:
The stability requirement will be satisfied by placing the
poles and zeros of the compensation network according
to following design rules. The consideration has been
taken to satisfy condition 14 regarding transconduc-
tance error amplifier.
1)
Select the crossover frequency:
2)
Select R
7
, so that R
7
>>
3)
Place first zero before LC’s resonant frequency pole.
F
Z1
75% F
LC
1
2
π ×
F
Z1
×
R
7
4)
Place third pole at the half of the switching frequency.
F
P3
=f
S
2
1
2
π ×
R
7
×
F
P3
C
12
> 50pF
If not, change R
7
selection.
5)
Place R
7
in (15) and calculate C
10
:
6)
Place second pole at ESR zero.
F
P2
= F
ESR
Check if R
8
>
If R
8
is too small, increase R
7
and start from step 2.
7)
Place second zero around the resonant frequency.
F
Z2
= F
LC
8)
Use equation (1) to calculate R
5
:
These design rules will give a crossover frequency ap-
proximately one-tenth of the switching frequency. The
higher the band width, the potentially faster the load tran-
sient speed. The gain margin will be large enough to
provide high DC-regulation accuracy (typically -5dB to -
12dB). The phase margin should be greater than 45
8
for
overall stability.
LDO Section
Output Voltage Programming
Output voltage for LDO is programmed by reference volt-
age and external voltage divider. The Fb3 pin is the in-
verting input of the error amplifier, which is internally ref-
erenced to 1.25V. The divider is ratioed to provide 1.25V
at the Fb3 pin when the output is at its desired value.
The output voltage is defined by using the following equa-
tion:
( )
R
LOW
Results to: R
HIGH
=1K
LDO Power MOSFET Selection
The first step in selecting the power MOSFET for the
linear regulator is to select the maximum R
DS(ON)
based
on the input to the dropout voltage and the maximum
load current.
Results to: R
DS(ON)(MAX)
= 0.4
Note that since the MOSFET R
DS(ON)
increases with tem-
perature, this number must be divided by ~1.5 in order
to find the R
DS(ON)(MAX)
at room temperature. The IRLR2703
has a maximum of 0.065
R
DS(ON)
at room temperature,
which meets our requirements.
1
g
m
C
12
=
C
10
≤
×
2
π ×
Lo
×
F
O
×
Co
R
7
V
OSC
V
IN
R
8
=
1
2
π ×
C10
×
F
P2
R
6
= 1
8
2
π ×
C10
×
F
Z2
R
5
= V
×
R
6
V
OUT
- V
REF
REF
R
DS(ON)
=V
IN3
- V
OUT2
I
OUT2
For:
V
IN3
= 3.3V
V
OUT2
= 2.5V
I
OUT2
= 2A
Where:
V
IN
= Maximum Input Voltage
V
OSC
= Oscillator Ramp Voltage
Lo = Output Inductor
Co = Total Output Capacitors
F
O1
= R
7
×
C
10
×
×
V
IN
V
OSC
1
2
π×
Lo
×
Co
---(15)
Fo < F
ESR
and Fo
≤
(1/10 ~ 1/6)
×
f
S
2
g
m
C
11
=
For:
V
OUT2
= 2.5V
V
REF
= 1.25V
R
LOW
= 1K
R
HIGH
V
OUT2
= V
REF
×
1+
相關PDF資料 |
PDF描述 |
|---|---|
| IRU3072C | 20-PIN SYNCHRONOUS PWM CONTROLLER/ 3 LDO CONTROLLER |
| IRU3072CH | 20-PIN SYNCHRONOUS PWM CONTROLLER/ 3 LDO CONTROLLER |
| IRU3137 | 8-PIN SYNCHRONOUS PWM CONTROLLER |
| IRU3137CS | 8-PIN SYNCHRONOUS PWM CONTROLLER |
| IRU3146 | DUAL SYNCHRONOUS PWM CONTROLLER WITH CURRENT SHARING CIRCUITRY AND AUTO-RESTART |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| IRU3048CSTR | 功能描述:IC REG CTRLR BUCK PWM VM 16-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標準包裝:75 系列:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:1MHz 占空比:81% 電源電壓:4.3 V ~ 13.5 V 降壓:是 升壓:是 回掃:是 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:0°C ~ 70°C 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 包裝:管件 產(chǎn)品目錄頁面:1051 (CN2011-ZH PDF) 其它名稱:296-2543-5 |
| 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 制造商全稱:International Rectifier 功能描述:5-BIT PROGRAMMABLE 3-PHASE SYNCHRONOUS BUCK CONTROLLER IC |
| IRU3055CQ | 制造商:IRF 制造商全稱: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 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 專用型 系列:- 標準包裝:2,000 系列:- 應用:控制器，DSP 輸入電壓:4.5 V ~ 25 V 輸出數(shù):2 輸出電壓:最低可調(diào)至 1.2V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:30-TFSOP（0.173"，4.40mm 寬） 供應商設備封裝:30-TSSOP 包裝:帶卷 (TR) |
發(fā)布緊急采購，3分鐘左右您將得到回復。