- 您现在的位置：买卖IC网 > PDF目录79841 > LX1664ACN 1.5 A SWITCHING CONTROLLER, 200 kHz SWITCHING FREQ-MAX, PDIP16 PDF资料下载
参数资料
| 型号： | LX1664ACN |
| 元件分类： | 稳压器 |
| 英文描述： | 1.5 A SWITCHING CONTROLLER, 200 kHz SWITCHING FREQ-MAX, PDIP16 |
| 封装： | PLASTIC, DIP-16 |
| 文件页数： | 7/17页 |
| 文件大小： | 354K |
| 代理商： | LX1664ACN |
DUAL OUTPUT PWM CONTROLLERS WITH 5-BIT DAC
LX1664/1664A, LX1665/65A
PRODUCT DA T ABOOK 1996/1997
15
Copyright 1999
Rev. 1.2 11/99
P RODUCTION D ATA S HEET
USING THE LX1664/65 DEVICES
LINEAR REGULATOR
Referring to the front page Product Highlight, a schematic is
presented which uses a MOSFET as a series pass element for a
linear regulator. The MOSFET is driven by the LX1664 controller,
and down-converts a +5V or +3.3V supply to the desired V
OUT
level, between 1.5 & 3.5V, as determined by the feedback
resistors.
The current available from the Linear regulator is dictated by
the supply capability, as well as the MOSFET ratings, and will
typically lie in the 3-5 ampere range. This output is well suited
for I/O buffers, memory, chipset and other components. Using
3.3V supply to convert to 1.5V for GTL+ Bus will significantly
reduce heat dissipation in the MOSFET.
MOSFET Comments
Heatsinking the MOSFET becomes important, since the linear
stage output current could approach 5 amperes in some applica-
tions. Since there are no switching losses, power dissipation in
the MOSFET is simply defined by P
D = (VIN - VOUT) * I output
current. This means that a +5V
IN to +3.3VOUT at 5A will require that
the MOSFET dissipate (5-3.3) * 5 = 8.5 watts. This amount of
power in a MOSFET calls for a heatsink, which will be the same
physical size as that required for a monolithic LDO, such as the
LX8384 device.
The dropout voltage for the linear regulator stage is the product
of R
DS ON * IOUT.
Using a 2SK1388 device at 5A, the dropout
voltage will be (worst case) 37 milliohms x 5A = 185mV.
Note that the R
DS ON of the (linear regulator) MOSFET does not
affect heat dissipation, only dropout voltage.
For reasons of
economy, a FET with a higher resistance can be chosen for the
linear regulator, e.g. 2SK1388 or IRLZ44.
LINEAR REGULATOR (continued)
Device
R
DS(ON) @
I
D @
Max. Break-
10V (m
)T
C = 100°C
down Voltage
IRFZ24N
70
12
55
IRL2703
40
17
30
IRLZ44N
22
29
55
TABLE 5 - Linear Regulator MOSFET Selection Guide
FIGURE 13 — Typical Transient Response
Avoiding Crosstalk
To avoid a load transient on the switching output affecting the
linear regulator, follow these guidelines:
1) Separate 5V supply traces to switching & linear FETs as
much as possible.
2) Place capacitor C
9 as close to drain of Q4 as possible.
Typical transient response is shown in Figure 13.
Channel 2 = Linear Regulator Output.
Set point = 3.3V @ 2A (20mV/div.)
Channel 4 = Switching Regulator Output.
V
CC_CORE set point = 2.8V
Channel 3 = Switching Regulator Load Current
Transient 0 - 13A
Output Voltage Setting
As shown in Application Information Figures 6-9, two resistors (R
5
& R
6) set the linear regulator stage output voltage:
V
OUT = 1.5 * (R5 + R6) / R6
As an example, to set resistor magnitudes, assume a desired
V
OUT of 3.3 volts:
1.5 * (12.1k + 10k) / 10k = 3.3 volts (approximately)
In general, the divider resistor values should be in the vicinity
of 10-12k ohm for optimal noise performance. Please refer to
Table 6.
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3803HS6-3#TRMPBF | 1 A SWITCHING CONTROLLER, 330 kHz SWITCHING FREQ-MAX, PDSO6 |
| LSM-2/10-D12 | 1-OUTPUT DC-DC REG PWR SUPPLY MODULE |
| LS2812S | 1-OUTPUT 30 W DC-DC REG PWR SUPPLY MODULE |
| LTC3873EDDB-5#TRM | SWITCHING CONTROLLER, 240 kHz SWITCHING FREQ-MAX, PDSO8 |
| LES20A48-3V3REJ | 1-OUTPUT 66 W DC-DC REG PWR SUPPLY MODULE |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LX1664CD | 功能描述:IC PWM DUAL OUT 5BIT DAC 16SOIC RoHS:是 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) |
| LX1664CN | 功能描述:IC PWM DUAL OUT 5BIT DAC 16DIP RoHS:是 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) |
| LX1665 | 制造商:MICROSEMI 制造商全称:Microsemi Corporation 功能描述:DUAL OUTPUT PWM CONTROLLERS WITH 5-BIT DAC |
| LX1665A | 制造商:MICROSEMI 制造商全称:Microsemi Corporation 功能描述:DUAL OUTPUT PWM CONTROLLERS WITH 5-BIT DAC |
| LX1665ACDW | 功能描述:IC PWM DUAL OUT 5BIT DAC 18SOIC RoHS:是 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) |
发布紧急采购，3分钟左右您将得到回复。