参数资料
型号: LM3420M5X-16.8/NOPB
厂商: NATIONAL SEMICONDUCTOR CORP
元件分类: 电源管理
英文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
封装: MINIATURE, SOT-23, 5 PIN
文件页数: 3/17页
文件大小: 441K
代理商: LM3420M5X-16.8/NOPB
Compensation (Continued)
where R
f
≈ 75 k for the 4.2V part, R
f
≈ 181 k for the 8.4V
part, R
f
≈ 287 k for the 12.6V part, and R
f
≈ 392 k for the
16.8V part.
The resistor (R
f) in the formula is an internal resistor located
on the die. Since this resistor value will affect the phase
margin, the worst case maximum and minimum values are
important when analyzing closed loop stability. The minimum
and maximum room temperature values of this resistor are
specified in the Electrical Characteristics section of this data
sheet, and a curve showing the temperature coefficient is
shown in the curves section. Minimum values of R
f result in
lower phase margins.
Test Circuit
The test circuit shown in Figure 2 can be used to measure
and verify various LM3420 parameters. Test conditions are
set by forcing the appropriate voltage at the V
OUT Set test
point and selecting the appropriate R
L or IOUT as specified in
the Electrical Characteristics section. Use a DVM at the
“measure” test points to read the data.
V
REG External Voltage Trim
The regulation voltage (V
REG) of the LM3420 can be exter-
nally trimmed by adding a single resistor from the COMP pin
to the +IN pin or from the COMP pin to the GND pin,
depending on the desired trim direction. Trim adjustments up
to ±10% of V
REG can be realized, with only a small increase
in the temperature coefficient. (See temperature coefficient
curve shown in Figure 3 below.)
01235907
FIGURE 2. LM3420 Test Circuit
01235908
Normalized Temperature Drift with
Output Externally Trimmed
FIGURE 3.
LM3420-4.2/LM3420-8.2/LM3420-8.4/LM3420-12.6/LM3420-16.8
www.national.com
11
相关PDF资料
PDF描述
LM3420AM5-4.2/NOPB 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
LM3420M5-8.4/NOPB 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
LM3420M5-8.2/NOPB 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
LM3420AM5X-8.4/NOPB 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
LM3460-1.5MWC 1-OUTPUT THREE TERM VOLTAGE REFERENCE, 1.5 V, UUC
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LM3420M5X-8.2 功能描述:IC CTRLR LI-ION BAT CHRG SOT23-5 RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 标准包装:1 系列:- 功能:充电管理 电池化学:锂离子(Li-Ion)、锂聚合物(Li-Pol) 电源电压:3.75 V ~ 6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SC-74A,SOT-753 供应商设备封装:SOT-23-5 包装:剪切带 (CT) 产品目录页面:669 (CN2011-ZH PDF) 其它名称:MCP73831T-2ACI/OTCT
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