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参数资料
| 型号： | LM4051CEM3X-1.2/NOPB |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 基准电压源/电流源 |
| 英文描述： | 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 1.225 V, PDSO3 |
| 封装： | 3 X 1.30 MM, PLASTIC, TO-236AB, SOT-23, SMT-3 |
| 文件页数： | 14/14页 |
| 文件大小： | 746K |
| 代理商： | LM4051CEM3X-1.2/NOPB |
Functional Block Diagram
10122221
*LM4051-ADJ only
**LM4051-1.2 only
Applications Information
The LM4051 is a precision micro-power curvature-corrected
bandgap shunt voltage reference. For space critical applica-
tions, the LM4051 is available in the sub-miniature SOT-23
surface-mount package. The LM4051 has been designed for
stable operation without the need of an external capacitor
connected between the “+” pin and the “” pin. If, however, a
bypass capacitor is used, the LM4051 remains stable. De-
sign effort is further reduced with the choice of either a fixed
1.2V or an adjustable reverse breakdown voltage. The mini-
mum operating current is 60 A for the LM4051-1.2 and the
LM4051-ADJ. Both versions have a maximum operating
current of 12 mA.
LM4051s using the SOT-23 package have pin 3 connected
as the (-) output through the package’s die attach interface.
Therefore, the LM4051-1.2’s pin 3 must be left floating or
connected to pin 2 and the LM4051-ADJ’s pin 3 is the (-)
output.
The typical thermal hysteresis specification is defined as the
change in +25C voltage measured after thermal cycling.
The device is thermal cycled to temperature -40C and then
measured at 25C. Next the device is thermal cycled to
temperature +125C and again measured at 25C. The re-
sulting V
OUT delta shift between the 25C measurements is
thermal hysteresis. Thermal hysteresis is common in preci-
sion references and is induced by thermal-mechanical pack-
age stress. Changes in environmental storage temperature,
operating temperature and board mounting temperature are
all factors that can contribute to thermal hysteresis.
In a conventional shunt regulator application (Figure 1), an
external series resistor (R
S) is connected between the sup-
ply voltage and the LM4051. R
S determines the current that
flows through the load (I
L) and the LM4051 (IQ). Since load
current and supply voltage may vary, R
S should be small
enough to supply at least the minimum acceptable I
Q to the
LM4051 even when the supply voltage is at its minimum and
the load current is at its maximum value. When the supply
voltage is at its maximum and I
L is at its minimum, RS should
be large enough so that the current flowing through the
LM4051 is less than 12 mA.
R
S should be selected based on the supply voltage, (VS), the
desired load and operating current, (I
L and IQ), and the
LM4051’s reverse breakdown voltage, V
R.
The LM4051-ADJ’s output voltage can be adjusted to any
value in the range of 1.24V through 10V. It is a function of the
internal reference voltage (V
REF) and the ratio of the external
feedback resistors as shown in Figure 2 . The output voltage
is found using the equation
V
O =VREF[(R2/R1) + 1]
(1)
(2)
where V
O is the output voltage. The actual value of the
internal V
REF is a function of VO. The “corrected” VREF is
determined by
V
REF =VO (
V
REF/
V
O)+VY
(3)
where
V
Y = 1.22V
V
REF/
V
O is found in the Electrical Characteristics and is
typically 1.55 mV/V. You can get a more accurate indication
of the output voltage by replacing the value of V
REF in
equation (1) with the value found using equation (3).
LM4051
www.national.com
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相关PDF资料 |
PDF描述 |
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| LM4051BEM3X-ADJ/NOPB | 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 1.212 V, PDSO3 |
| LM4051AEM3-1.2/NOPB | 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 1.225 V, PDSO3 |
| LM431ACMD-T | 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 2.495 V, PDSO8 |
| TL431AID5 | 1-OUTPUT THREE TERM VOLTAGE REFERENCE, 2.495 V, PDSO5 |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LM4051CEM3X-ADJ/NOPB | 功能描述:IC VREF SHUNT PREC ADJ SOT-23-3 RoHS:是 类别:集成电路 (IC) >> PMIC - 电压基准 系列:- 标准包装:3,000 系列:- 基准类型:旁路，精度 输出电压:5V 容差:±0.5% 温度系数:100ppm/°C 输入电压:- 通道数:1 电流 - 阴极:80µA 电流 - 静态:- 电流 - 输出:15mA 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:TO-236-3，SC-59，SOT-23-3 供应商设备封装:SOT-23-3 包装:带卷 (TR) 其它名称:LM4040CIM3-5.0MLTRLM4040CIM3-5.0MLTR-ND |
| LM4051CEX3-1.2 | 制造商:Maxim Integrated Products 功能描述:50PPM/+C PRECISION MICROPOWER SHUNT - Rail/Tube |
| LM4051CEX3-1.2+ | 制造商:Maxim Integrated Products 功能描述:V-REF PRECISION 1.225V 15MA 3PIN SC-70 - Cut Tape Product |
| LM4051CEX3-1.2+T | 功能描述:基准电压& 基准电流 50ppm/C Prec uPower Shunt V-Ref w/Rev RoHS:否 制造商:STMicroelectronics 产品:Voltage References 拓扑结构:Shunt References 参考类型:Programmable 输出电压:1.24 V to 18 V 初始准确度:0.25 % 平均温度系数（典型值）:100 PPM / C 串联 VREF - 输入电压（最大值）: 串联 VREF - 输入电压（最小值）: 分流电流（最大值）:60 mA 最大工作温度:+ 125 C 封装 / 箱体:SOT-23-3L 封装:Reel |
| LM4051CEX3-1.2-T | 功能描述:基准电压& 基准电流 RoHS:否 制造商:STMicroelectronics 产品:Voltage References 拓扑结构:Shunt References 参考类型:Programmable 输出电压:1.24 V to 18 V 初始准确度:0.25 % 平均温度系数（典型值）:100 PPM / C 串联 VREF - 输入电压（最大值）: 串联 VREF - 输入电压（最小值）: 分流电流（最大值）:60 mA 最大工作温度:+ 125 C 封装 / 箱体:SOT-23-3L 封装:Reel |
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