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参数资料
| 型号： | MAX1804EUB+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 10/11页 |
| 文件大小： | 0K |
| 描述： | IC FEEDBACK INTERGRATOR 10UMAX |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| 应用： | 反馈发生器 |
| 电流 - 电源： | 25µA |
| 电源电压： | 2.7 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 供应商设备封装： | 10-µMAX |
| 包装： | 管件 |
External Four-Input Feedback Integrator for
Power Supplies
Choose feedback resistors (R TOP and R BOTTOM ) for
about 25μA current in the resistive divider for noise
R TOP
immunity.
MAX1653
FB
R OUT
TO
MAX1804
Therefore:
(R TOP + R BOTTOM ) = 4.8V / 25μA = 192k ?
R BOTTOM
For the MAX1653, the voltage at its feedback point
G ND
SHORT COMPACT PLACEMENT
V FB = 2.5V.
Choose R TOP = 91k ? and therefore, R BOTTOM =
100k ? .
OF FEEDBACK RESISTORS
REDUCES NOISE PICKUP
Figure 5. Proper Layout of Feedback Resistors for Regulator
Applications Information
Layout Information
Proper layout is essential due to high current levels and
switching waveforms that generate noise. Place the
regulator ’ s feedback resistors and R OUT (from the reg-
ulator feedback point to OUT of MAX1804) close to the
regulator ’ s feedback point to prevent noise pickup
(Figure 5). Minimize leakage of the COMP capacitor and
traces around COMP because they cause IN_ set-point
errors according to the IN_ transconductance. A leakage
of I COMP at COMP will result in an error given by:
IN_ error voltage = I COMP / (IN_ transconductance)
If the desired adjustment range is +400mV, max OUT
current (MAX1804) is given by:
I OUT (MAX) = 0.4V / 91k ? = 4.4μA
R OUT = V FB / I OUT (MAX) = 2.5V / 4.4μA = 562k ?
To guarantee that the output will not go below the tar-
get of 4.75V, including all error sources, set the
MAX1804 nominal regulation point to 4.85V.
Since:
IN_scale factor = 4 x V ADJ , V ADJ = 1.2125V
Divide the reference voltage down and bypass as
required if using the MAX1653 reference voltage as
shown in Figure 2. Assuming 0.1% resistor accuracy
and using the MAX1653 reference, the error budget
can be calculated as:
For a typical value of IN_ transconductance of 30μS, a
leakage of 0.1μA will result in an IN_ error voltage of
3mV in the set point.
Reference Accuracy
ADJ Divider Accuracy
Scale Factor Error
-1.6%
-0.2%
-0.4%
Design Example (Step-Down
Converter Application)
Figure 2 is an example of an application circuit using
the MAX1804 for point-of-load regulation when using a
step-down controller (MAX1653). Use the following
design procedure to optimize the basic schematic.
Begin the design by establishing the following:
? Input voltage to the MAX1653 controller (7V to 20V)
? Typical output voltage and accuracy of MAX1653
(5V ±5%)
This gives a target of:
V OUT, min = 5V - 5% = 4.75V
To minimize power dissipation, set regulator output
V OUT, R = 4.8V with MAX1653 feedback resistors.
IN_ Offset Voltage (-15mV) -0.3%
Total -2.5%
This gives a worst-case output voltage of 4.73V, which is
below the target of 4.75V. The most-significant error
source is the MAX1653 reference. Therefore, use a better
reference, if available, in the system or increase the VADJ
to increase the worst-case output voltage to 4.75V.
The MAX1653 works well with the MAX1804 ’ s GBW
product set at 40kHz, so use a 470pF capacitor on
COMP.
Chip Information
TRANSISTOR COUNT: 636
10
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相关代理商/技术参数 |
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|---|---|
| MAX1804EUB+ | 功能描述:电流和电力监控器、调节器 Feedback Integrator for Power Supply RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1804EUB+T | 功能描述:电流和电力监控器、调节器 Feedback Integrator for Power Supply RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1804EUB-T | 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1805EEE | 制造商:Maxim Integrated Products 功能描述: |
| MAX1805MEE | 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 |
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