- 您现在的位置：买卖IC网 > PDF目录1820 > LM3495MTCX/NOPB (National Semiconductor)IC REG BUCK SYNC ADJ 10A 16TSSOP PDF资料下载
参数资料
| 型号： | LM3495MTCX/NOPB |
| 厂商： | National Semiconductor |
| 文件页数： | 16/36页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 10A 16TSSOP |
| 标准包装： | 1 |
| 系列： | PowerWise® |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 5.5 V |
| 输入电压： | 2.9 V ~ 18 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 200kHz ~ 1.5MHz |
| 电流 - 输出： | 10A |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-TSSOP（0.173"，4.40mm 宽） |
| 包装： | 标准包装 |
| 供应商设备封装： | 16-TSSOP |
| 产品目录页面： | 1300 (CN2011-ZH PDF) |
| 配用： | LM3495EVAL-ND - BOARD EVALUATION LM3495 |
| 其它名称： | LM3495MTCXDKR |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页当前第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页
SNVS410F – FEBRUARY 2006 – REVISED APRIL 2013
If the external clock fails low, timeout circuits will prevent the high-side FET from staying off for longer than 1.5
times the switching period (Switching period T SW = 1/f SW ). At the end of this timeout period the regulator will
begin to switch at the frequency set by R FRQ .
If the external clock fails high, timeout circuits will again prevent the high-side FET from staying off longer than
1.5 times the switching period. After this timeout period, the internal oscillator takes over and switches at a fixed
1 MHz until the voltage on the FREQ/SYNC pin has decayed to approximately 0.6V. This decay follows the time
constant of C SYNC and R FRQ , and once it is complete the regulator will switch at the frequency set by R FRQ .
Care must be taken to prevent errant pulses from triggering the synchronization circuitry. In applications that will
not synchronize to an external clock, C SYNC should be connected from the FREQ/SYNC pin to signal ground as a
noise filter. When a clock pulse is first detected, the LM3495 begins switching at the external clock frequency.
Noise or a short burst of clock pulses can result in off times as long as 7.5 μs for the high-side FET if they occur
while the internal synchronization circuits are adjusting.
LM3495
FREQ/SYNC
C SYNC
100 pF
External
Clock
R FRQ
Figure 33. Clock Synchronization Circuit
MOSFET GATE DRIVE
The LM3495 has two gate drivers designed for driving N-channel MOSFETs in a synchronous mode. Power for
the high-side driver is supplied through the BOOST pin. For the high-side gate drive to fully turn on the top FET,
the BOOST pin voltage must be at least one threshold voltage, V GS(th) , greater than V IN . This voltage is supplied
from a local charge pump structure which consists of a Schottky diode and 0.1 μF capacitor, shown in Figure 34 .
Both the bootstrap and the low-side FET driver are fed from VLIN5, which is the output of a 4.7V internal linear
regulator. This regulator has a dropout voltage of approximately 1V. If V IN drops below 4V, an internal switch
shorts the VIN and VLIN5 pins together. The drive voltage for the top FET driver is therefore VLIN5-V D , where V D
is the drop across the Schottky diode D1. This information is needed to select the type of MOSFETs to be used.
D1
VLIN5
BOOST
C BOOT
V IN
HG
LM3495
SW/CSH
Q1
L1
LG
Q2
+
Co
Figure 34. Bootstrap Circuit
INPUT VOLTAGE BELOW 5.5V
The LM3495 includes an internal 4.7V linear regulator connected from the VIN pin to the VLIN5 pin. This linear
regulator feeds the logic and FET drive circuitry. For input voltages less than 5.5V, the VIN and VLIN5 pins can
be shorted together externally. The external short circuit bypasses both the internal linear regulator and the
internal PMOS switch, allowing the full input voltage to be used for driving the power FETs and minimizing
conduction loss in the LM3495 itself. For voltage inputs that range above and below 5.5V the LM3495 must not
use a short from VIN to VLIN5.
16
Product Folder Links: LM3495
Copyright ? 2006–2013, Texas Instruments Incorporated
相关PDF资料 |
PDF描述 |
|---|---|
| LM350T | IC REG LDO ADJ 3A TO220AB |
| LM350T | IC REG LDO ADJ 3A TO220-3 |
| LM3686TLE-AAED/NOPB | IC REG BUCK SYNC .9A TRPL 12USMD |
| LM399AH | IC VREF SHUNT PREC 6.95V TO-46-4 |
| LM4040A25IDBZT | IC VREF SHUNT PREC 2.5V SOT23-3 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM3497M/NOPB | 制造商:Texas Instruments 功能描述:IC LED DRIVER 制造商:Texas Instruments 功能描述:POWER REGULATOR/CONTROLLER IC |
| LM3497MM/NOPB | 功能描述:板上安装温度传感器 RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor |
| LM3497MMX/NOPB | 功能描述:板上安装温度传感器 RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor |
| LM3497MX/NOPB | 制造商:Texas Instruments 功能描述:IC LED DRIVER 制造商:Texas Instruments 功能描述:POWER REGULATOR/CONTROLLER IC |
| LM349J | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Voltage-Feedback Operational Amplifier |
发布紧急采购，3分钟左右您将得到回复。