参数资料
型号: IR3637STRPBF
厂商: International Rectifier
文件页数: 8/21页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM VM 8-SOIC
标准包装: 1
PWM 型: 电压模式
输出数: 1
频率 - 最大: 440kHz
占空比: 85%
电源电压: 4.5 V ~ 5.5 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: 0°C ~ 125°C
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
包装: 标准包装
配用: IRPP3637-12A-ND - KIT REF DES 12A 1PH SYNC BUCK
IRDC3637-ND - BOARD EVAL SYNC BUCK REGULATOR
其它名称: IR3637STRPBFDKR
IR3637SPBF
For this design, IRF8910 is a good choice. The device
provides two N-MOSFETs in a compact SOIC 8-Pin pack-
These values are taken under a certain condition test.
For more detail please refer to the IRF8910 data sheet.
age.
By using equation (6), we can calculate the switching
The IRF8910 has the following data:
V DSS = 20V
I D = 10A
R DS(onh) =18.3 ? @ V GS =4.5V (Lower FET)
R DS(on) =13.4 ? @ V GS =10V (Upper FET)
The total conduction losses will be:
P CON(TOTAL) =P CON (Upper Switch)+P CON (Lower Switch)
? = 1.4 according to the IRF8910 data sheet for
150 C junction temperature
losses.
P SW = 95mW
Feedback Compensation
The IR3637 is a voltage mode controller; the control loop
is a single voltage feedback path including error ampli-
fier and error comparator. To achieve fast transient re-
sponse and accurate output regulation, a compensation
circuit is necessary. The goal of the compensation net-
work is to provide a closed loop transfer function with the
highest 0dB crossing frequency and adequate phase
margin (greater than 45 ).
P CON(TOTAL) =0.83W
The output LC filter introduces a double pole, –40dB/
The switching loss is more difficult to calculate, even
though the switching transition is well understood. The
reason is the effect of the parasitic components and
decade gain slope above its corner resonant frequency,
and a total phase lag of 180 (see Figure 8). The Reso-
nant frequency of the LC filter expressed as follows:
switching times during the switching procedures such
as turn-on / turnoff delays and rise and fall times. The
control MOSFET contributes to the majority of the switch-
F LC =
2 π×
1
L O × C O
---(7)
ing losses in synchronous Buck converter. The synchro-
nous MOSFET turns on under zero voltage conditions,
therefore, the turn on losses for synchronous MOSFET
can be neglected. With a linear approximation, the total
switching loss can be expressed as:
Figure 8 shows gain and phase of the LC filter. Since we
already have 180 phase shift just from the output filter,
the system risks being unstable.
t r + t f × I LOAD
×
V DS(OFF)
P SW = ---(6)
2 T
Where:
V DS(OFF) = Drain to Source Voltage at off time
Gain
0dB
-40dB/decade
Phase
0
t r = Rise Time
t f = Fall Time
T = Switching Period
I LOAD = Load Current
F LC Frequency
-180
F LC
Frequency
The switching time waveform is shown in figure 7.
V DS
90%
10%
V GS
Figure 8 - Gain and phase of LC filter.
The IIR3637’s error amplifier is a differential-input transcon-
ductance amplifier. The output is available for DC gain
control or AC phase compensation.
The E/A can be compensated with or without the use of
local feedback. When operated without local feedback
the transconductance properties of the E/A become evi-
dent and can be used to cancel one of the output filter
t d (ON)
t r
t d (OFF)
t f
poles. This will be accomplished with a series RC circuit
from Comp pin to ground as shown in Figure 9.
Figure 7 - Switching time waveforms.
From IRF8910 data sheet:
t r = 10ns
t f = 4.1ns
8
www.irf.com
Rev.1.1
06/16/05
相关PDF资料
PDF描述
IR3638STRPBF IC REG CTRLR BUCK PWM VM 14-SOIC
IR3640MPBF IC REG CTRLR BUCK PWM VM 20-MLPQ
IR3651STRPBF IC REG CTRLR BUCK PWM VM 14-SOIC
IR3710MTRPBF IC REG CTRLR BUCK PWM 16-MLPQ
IR3720MTRPBF IC POWER SUPPLY MONITOR 10-DFN
相关代理商/技术参数
参数描述
IR3638 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:High Frequency Synchronous
IR3638DR2G 制造商:ON Semiconductor 功能描述:
IR3638SPBF 制造商:IRF 制造商全称:International Rectifier 功能描述:HIGH FREQUENCY SYNCHRONOUS PWM BUCK CONTROLLER FOR TRACKING APPLIACTIONS
IR3638STRPBF 功能描述:电压模式 PWM 控制器 HI FREQ SYNC PWM 400kHz 0.6V Track RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
IR3640MPBF 功能描述:IC REG CTRLR BUCK PWM VM 20-MLPQ RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:4,000 系列:- PWM 型:电压模式 输出数:1 频率 - 最大:1.5MHz 占空比:66.7% 电源电压:4.75 V ~ 5.25 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:-40°C ~ 85°C 封装/外壳:40-VFQFN 裸露焊盘 包装:带卷 (TR)