- 您现在的位置：买卖IC网 > PDF目录44549 > LM2639M/NOPB (NATIONAL SEMICONDUCTOR CORP) SWITCHING CONTROLLER, 8700 kHz SWITCHING FREQ-MAX, PDSO24 PDF资料下载
参数资料
| 型号： | LM2639M/NOPB |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 稳压器 |
| 英文描述： | SWITCHING CONTROLLER, 8700 kHz SWITCHING FREQ-MAX, PDSO24 |
| 封装： | PLASTIC, SOIC-24 |
| 文件页数： | 2/11页 |
| 文件大小： | 198K |
| 代理商： | LM2639M/NOPB |
National P/N LM2639 - 5-Bit Programmable, High Frequency Multi-phase PWM Controller
LM2639M
24 MSL
Full
production
N/A
1K+
$2.8500
rail
of
30
[logo]UZ2T
LM2639M
LM2639MX
24 MSL
Full
production
N/A
1K+
$2.8500
reel
of
1000
[logo]UZ2T
LM2639M
LM2639 MDC
Full
production
N/A
N/A Samples
tray
of
N/A
-
LM2639 MWC
Full
production
N/A
wafer
jar
of
N/A
-
General Description
The LM2639 provides an attractive solution for power supplies of high power microprocessors (such as
Pentium II, M II, K6-2, K6-3, etc.) exhibiting ultra fast load transients. Compared to a conventional
single-phase supply, an LM2639 based multi-phase supply distributes the thermal and electrical loading
among components in multiple phases and greatly reduces the corresponding stress in each component. The
LM2639 can be programmed to control either a 3-phase converter or a 4-phase converter. Phase shift among
the phases is 120° in the case of three phase and 90° with four-phase. Because the power channels are out
of phase, there can be significant ripple cancellation for both the input and output current, resulting in
reduced input and output capacitor size. Due to the nominal operating frequency of 2 MHz per phase, the
size of the output inductors can be greatly reduced which results in a much faster load transient response
and a dramatically shrunk output capacitor bank. Microprocessor power supplies with all surface mount
components can be easily built.
The internal high speed transconductance amplifier guarantees good dynamic performance. The output drive
voltages can be adjusted through a resistor divider to control switching loss in the external FETs.
The internal master clock frequency of up to 8 MHz is set by an external reference resistor. An external clock
of 10 MHz can also be used to drive the chip to achieve frequency control and multi-chip operation.
The LM2639 also provides input under-voltage lock-out with hysteresis and input over-current protection.
Features
q
Ultra fast load transient response
q
Enables all surface-mount-design
q
Selectable 2, 3, 4 phase operation
q
Clock frequency from 40 kHz to 10 MHz
q
Precision load current sharing
q
5-bit programmable from 3.5V to 1.3V
q
VID code compatible to VRM 8.X specification
q
Output voltage is 2.0V for VID code 11111
q
Selectable internal or external clock
q
Digital 16-step soft start
q
Input under-voltage lock-out, over-current protection
Applications
file:///H|/imaging/BITTING/cpl/20020808_1/08062002_10/NATL/08062002_HTML/LM2639.html (2 of 3) [Aug-09-2002 2:39:11 PM]
相关PDF资料 |
PDF描述 |
|---|---|
| LM2639MWC | SWITCHING CONTROLLER, 8700 kHz SWITCHING FREQ-MAX, UUC |
| LM2641-ADJMDC | DUAL SWITCHING CONTROLLER, 345 kHz SWITCHING FREQ-MAX, UUC |
| LM2645MTD/NOPB | SWITCHING CONTROLLER, 335 kHz SWITCHING FREQ-MAX, PDSO48 |
| LM2651MTCX-2.5/NOPB | 2.6 A SWITCHING REGULATOR, 345 kHz SWITCHING FREQ-MAX, PDSO16 |
| LM2651MTC-2.5/NOPB | 2.6 A SWITCHING REGULATOR, 345 kHz SWITCHING FREQ-MAX, PDSO16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM2639MX | 制造商:Texas Instruments 功能描述: |
| LM2639MX/NOPB | 功能描述:IC CTRLR MULTIPHASE PWM 24-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 电源管理 - 专用 系列:- 应用说明:Ultrasound Imaging Systems Application Note 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:37 系列:- 应用:医疗用超声波成像，声纳 电流 - 电源:- 电源电压:2.37 V ~ 6 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:56-WFQFN 裸露焊盘 供应商设备封装:56-TQFN-EP（8x8） 包装:管件 |
| LM2640 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Dual Adjustable Step-Down Switching Power Supply Controller |
| LM26400Y | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Dual 2A, 500kHz Wide Input Range Buck Regulator |
| LM26400Y_0708 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Dual 2A, 500kHz Wide Input Range Buck Regulator |
发布紧急采购，3分钟左右您将得到回复。