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参数资料
| 型号： | LT3092EST#TR |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 模拟信号调理 |
| 英文描述： | SPECIALTY ANALOG CIRCUIT, PDSO3 |
| 封装： | PLASTIC, SOT-223, 4 PIN |
| 文件页数： | 21/22页 |
| 文件大小： | 245K |
| 代理商： | LT3092EST#TR |
LT3092
8
3092fb
Introduction
The LT3092 is a versatile IC that operates as a 2-terminal
programmable current source with the addition of only
two external resistors; no external bypass capacitors are
needed for stability.
The LT3092 is easy to use and has all the protection fea-
tures expected in high performance products. Included
are reverse-voltage protection, reverse-current protec-
tion, short-circuit protection and thermal shutdown with
hysteresis.
The LT3092 operates with or without input and output
capacitors. The simplest current source application
requires only two discrete resistors to set a constant
output current up to 200mA. A variety of analog tech-
niques lend themselves to regulating and varying the
current source value.
The device utilizes a precision “0” TC 10μA reference cur-
rent source to program output current. This 10μA current
source connects to the noninverting input of a power
operational amplier. The power operational amplier
provides a low impedance buffered output of the voltage
on the noninverting input.
Many application areas exist in which operation without
input and output capacitors is advantageous. A few of
these applications include sensitive circuits that cannot
endure surge currents under fault or overload conditions
and intrinsic safety applications in which safety regulations
limit energy storage devices that may spark or arc.
Programming Output Current in 2-Terminal
Current Source Mode
Setting the LT3092 to operate as a 2-terminal current
source is a simple matter. The 10μA reference current from
the SET pin is used with one resistor to generate a small
voltage, usually in the range of 100mV to 1V (200mV is
a level that will help reject offset voltage, line regulation,
and other errors without being excessively large). This
voltage is then applied across a second resistor that
connects from OUT to the rst resistor. Figure 1 shows
connections and formulas to calculate a basic current
source conguration.
APPLICATIONS INFORMATION
With a 10μA current source generating the reference that
gains up to set output current, leakage paths to or from
the SET pin can create errors in the reference and output
currents. High quality insulation should be used (e.g.,
Teon, Kel-F). The cleaning of all insulating surfaces to
remove uxes and other residues may be required. Surface
coating may be necessary to provide a moisture barrier
in high humidity environments.
Minimize board leakage by encircling the SET pin and
circuitry with a guard ring operated at a potential close
to itself; tie the guard ring to the OUT pin. Guarding
both sides of the circuit board is required. Bulk leakage
reduction depends on the guard ring width. Ten nano-
amperes of leakage into or out of the SET pin and its as-
sociated circuitry creates a 0.1% reference current error.
Leakages of this magnitude, coupled with other sources
of leakage, can cause signicant offset voltage and refer-
ence current drift, especially over the possible operating
temperature range.
Figure 1. Using the LT3092 as a Current Source
ImA
VA R
I
V
R
A
OUT
SET
OUT
SET
OUT
≥
=
==
05
10
.
R
R
SET
OUT
IN
SET
OUT
+
–
LT3092
10μA
IOUT
VSET
RSET
3092 F01
+
–
ROUT
Selecting RSET and ROUT
In Figure 1, both resistors RSET and ROUT program the
value of the output current. The question now arises: the
ratio of these resistors is known, but what value should
each resistor be?
The rst resistor to select is RSET.Thevalueselectedshould
generate enough voltage to minimize the error caused by
the offset between the SET and OUT pins. A reasonable
starting level is 200mV of voltage across RSET (RSET equal
to 20k). Resultant errors due to offset voltage are a few
percent. The lower the voltage across RSET becomes, the
higher the error term due to the offset.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3092ESTTRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:200mA 2-Terminal Programmable Current Source |
| LT3092ETS8 | 制造商:LINER 制造商全称:Linear Technology 功能描述:200mA 2-Terminal Programmable Current Source |
| LT3092ETS8#PBF | 制造商:Linear Technology 功能描述:Adjustable Current Source 8-Pin TSOT-23 制造商:Linear Technology 功能描述:Adjustable Current Source 8-Pin TSOT-23 Bulk 制造商:Linear Technology 功能描述:PROG CURRENT SOURCE 0.2A 8SO 制造商:Linear Technology 功能描述:PROG CURRENT SOURCE, 0.2A, 8SOT23 |
| LT3092ETS8#TRMPBF | 功能描述:IC CURRENT SOURCE 1% TSOT23-8 RoHS:是 类别:集成电路 (IC) >> PMIC - 稳流/电流管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 功能:电流开关 检测方法:- 精确度:±10% 输入电压:1.7 V ~ 5.5 V 电流 - 输出:600mA 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-UFQFN 供应商设备封装:10-UTQFN（1.4x1.8） 包装:管件 |
| LT3092ETS8#TRPBF | 功能描述:IC PROG CURRENT SOURCE TSOT23-8 RoHS:是 类别:集成电路 (IC) >> PMIC - 稳流/电流管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 功能:电流开关 检测方法:- 精确度:±10% 输入电压:1.7 V ~ 5.5 V 电流 - 输出:600mA 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-UFQFN 供应商设备封装:10-UTQFN（1.4x1.8） 包装:管件 |
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