- 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： | 24/36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页第16页第17页第18页第19页第20页第21页第22页第23页当前第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
And the higher frequency pole is:
Z L =
f SW
m C ± 0.5
(29)
In the equation for A PS , the output resistance, R O , is the output voltage divided by output current. DC gain is
highest when output current is lowest. In order to design for the worst case, R O should be calculated for the
minimum load current. For this example, no minimum load has been specified, so a load of 100 mA will be used
(R O = 12 ? ).
For this example, the value of DC gain is 24dB. The low frequency pole f P = ω P / 2 π is at 2.7kHz, the ESR zero f Z
= ω Z / 2 π is at 1.06 MHz, and the higher frequency pole is at 48 kHz. Gain and phase plots for the power stage
30
15
0
-15
-30
-45
-60
0
-30
-60
-90
-120
-150
-180
100
1k
10k
100k
1M
100
1k
10k
100k
1M
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 37. Power Stage Gain and Phase
The low frequency pole and higher frequency pole cause a roll-off in the gain of -20 dB/decade at lower
frequency that increases to -40 dB/decade at higher frequency. The effect of the ESR zero is not seen because
its frequency is beyond the switching frequency. If this loop were left uncompensated, the bandwidth would be 39
kHz and the phase margin 58°. This loop would be stable, but would suffer from poor regulation of the output
voltage due to the low DC gain. In practice, this loop could change significantly due to the tolerances in the
output inductor, output capacitor, changes in output current, or input voltage. Therefore, the loop is compensated
using the error amplifier and a few passive components.
In general the goal of the compensation circuit is to give high DC gain, a bandwidth that is between one-fifth and
one-tenth of the switching frequency, and at least 45° of phase margin. The majority of both peak current mode
and emulated peak current mode buck regulators can be compensated with just two components, R 1 and C 1 , as
shown in the Typical Application Circuit . For power stages where the ESR zero frequency is below one-half of
the switching frequency a second capacitor, C 2 , may be needed to add another pole to the compensation. For
power stages where the ESR zero frequency is beyond the control loop bandwidth, a compromise in bandwidth
is needed to maintain good phase margin. The transfer function of the compensation block, G EA , can be derived
by multiplying the impedance Z C = (R 1 + 1/s C1 )ll( 1/s C2 ) times the DC gain of the error amp to give the following
equation:
G EA = g m x
V FB
V O
x
sR 1 C 1 + 1
s x (sR 1 C 1 C 2 + C 1 + C 2 )
(30)
This transfer function provides one pole at the origin, one zero at 1/(2 π R 1 C 1 ), and another pole at approximately
1/(2 π R 1 C 2 ) if C 2 is used. If C 2 is not used, a default value of 10 pF is substituted, representing the parasitic
capacitance from the COMP/SD pin to ground.
The value for R 1 can be calculated using the following equation:
R 1 =
B
g m
(31)
24
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。