参数资料
型号: LT1021DCH-10#TR
厂商: LINEAR TECHNOLOGY CORP
元件分类: 基准电压源/电流源
英文描述: 1-OUTPUT THREE TERM VOLTAGE REFERENCE, 10 V, MBCY8
封装: 0.200 INCH, METAL CAN, TO-5, 8 PIN
文件页数: 3/16页
文件大小: 228K
代理商: LT1021DCH-10#TR
11
LT1021
1021fc
APPLICATIONS INFORMATION
WU
U
Effects of Air Movement on Low Frequency Noise
The LT1021 has very low noise because of the buried zener
used in its design. In the 0.1Hz to 10Hz band, peak-to-peak
noise is about 0.5ppm of the DC output. To achieve this
low noise, however, care must be taken to shield the
reference from ambient air turbulence. Air movement can
create noise because of thermoelectric differences
between IC package leads (especially kovar lead TO-5) and
printed circuit board materials and/or sockets. Power
dissipation in the reference, even though it rarely exceeds
20mW, is enough to cause small temperature gradients in
the package leads. Variations in thermal resistance, caused
by uneven air flow, create differential lead temperatures,
thereby causing thermoelectric voltage noise at the output
of the reference. The following XY plotter trace dramati-
cally illustrates this effect. The first half of the plot was
done with the LT1021 shielded from ambient air with a
small foam cup. The cup was then removed for the second
half of the trace. Ambient in both cases was a lab environ-
ment with no excessive air turbulence from air condition-
ers, opening/closing doors, etc. Removing the foam cup
increases the output noise by almost an order of magni-
tude in the 0.01Hz to 1Hz band! The kovar leads of the
TO-5 (H) package are the primary culprit. Alloy 42 and
copper lead frames used on dual-in-line packages are not
nearly as sensitive to thermally generated noise because
they are intrinsically matched.
There is nothing magical about foam cups—any enclo-
sure which blocks air flow from the reference will do.
Smaller enclosures are better since they do not allow the
build-up of internally generated air movement. Naturally,
heat generating components external to the reference
itself should not be included inside the enclosure.
Noise Induced By Air Turbulence (TO-5 Package)
TIME (MINUTES)
06
10
1021 AI07
24
812
OUTPUT
VOLTAGE
NOISE
(20
V/DIV)
20
V
FOAM CUP
REMOVED
LT1021-7 (TO-5 PACKAGE)
f = 0.01Hz TO 10Hz
TYPICAL APPLICATIONS
U
Restricted Trim Range for Improved
Resolution, 10V, “C” Version Only
LT1021C-10
OUT
VIN
IN
10.000V
TRIM RANGE
≈ ±10mV
GND
TRIM
R2
50k
1021 TA11
R1
75k
1021 TA03
LT1021-10
OUT
IN
GND
TRIM
R1*
10k
VOUT
*CAN BE RAISED TO 20k FOR
LESS CRITICAL APPLICATIONS
VIN
LT1021-10
OUT
IN
GND
LT1021 TA04
D1
15V
R1
4.7k
–10V AT 50mA
R2
4.7k
–15V
15V
Q1
2N2905
Negative Series Reference
LT1021-10 Full Trim Range (
±0.7%)
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相关代理商/技术参数
参数描述
LT1021DCH-5 制造商:Linear Technology 功能描述:V-Ref Precision 5V 10mA 8-Pin TO-5
LT1021DCH-7 制造商:Linear Technology 功能描述:V-Ref Precision 7V 10mA 8-Pin TO-5
LT1021DCN8-10 功能描述:IC VREF SERIES SHUNT ZNR 8-PDIP RoHS:否 类别:集成电路 (IC) >> PMIC - 电压基准 系列:- 产品培训模块:Voltage Reference Basics 标准包装:100 系列:- 基准类型:旁路,精度 输出电压:4.096V 容差:±0.075% 温度系数:50ppm/°C 输入电压:- 通道数:1 电流 - 阴极:1µA 电流 - 静态:- 电流 - 输出:10mA 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:8-SOIC(0.154",3.90mm 宽) 供应商设备封装:8-SOIC 包装:管件
LT1021DCN8-10#PBF 功能描述:IC VREF SERIES SHUNT ZNR 8-PDIP 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:3V 容差:±0.5% 温度系数:100ppm/°C 输入电压:- 通道数:1 电流 - 阴极:82µA 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:6-TSSOP(5 引线),SC-88A,SOT-353 供应商设备封装:SC-70-5 包装:带卷 (TR) 其它名称:296-20888-2
LT1021DCN8-10PBF 制造商:Linear Technology 功能描述:Voltage Reference Prec. 10V 10mA PDIP8