 |
数据搜索系统，热门电子元器件搜索 |
|
|
数据搜索系统，热门电子元器件搜索 |
|
TS615IPWT 数据表(PDF) 21 Page - STMicroelectronics |
|
|
|||||||||||||||||||||||||||||
TS615IPWT 数据表(HTML) 21 Page - STMicroelectronics |
|
|
21 / 27 page  TS615 21/27 NOISE MEASUREMENT Figure 62 : Noise Model eN : input voltage noise of the amplifier iNn : negative input current noise of the amplifier iNp : positive input current noise of the amplifier The closed loop gain is : The six noise sources are : Assuming the thermal noise of a resistance R as: with ∆F the specified bandwidth. On 1Hz bandwidth the thermal noise is reduced to k is the Boltzmann’s constant equals to 1,374.10-23J/°K. T is the temperature (°K). The output noise eNo is calculated using the Su- perposition Theorem. But it is not the sum of all noise sources. The output noise is the square root of the sum of the square of each noise source. The input noise of the instrumentation must be ex- tracted from the measured noise value. The real output noise value of the driver is: The input noise is called the Equivalent Input Noise as it is not directly measured but it is evalu- ated from the measurement of the output divided by the closed loop gain (eNo/g). After simplification of the fourth and the fifth term of (eq2) we obtain: Measurement of eN: We assume a short-circuit on the non-inverting in- put (R3=0). (eq4) comes: In order to easily extract the value of eN, the resis- tance R2 will be chosen as low as possible. In the other hand, the gain must be large enough. R1=10 Ω, R2=910Ω, R3=0, Gain=92 Equivalent Input Noise: 2.57nV/ √Hz Input Voltage Noise: eN=2.5nV/ √Hz Measurement of iNn: R3=0 and the output noise equation is still the (eq5). This time the gain must be decreased to de- crease the thermal noise contribution. R1=100 Ω, R2=910Ω, R3=0, Gain=10.1 Equivalent Input Noise: 3.40nV/ √Hz Negative Input Current Noise: iNn =21pA/ √Hz Measurement of iNp: To extract iNp from (eq3), a resistance R3 is con- nected to the non-inverting input. The value of R3 must be chosen in order to keep its thermal noise contribution as low as possible against the iNp contribution. R1=100 Ω, R2=910Ω, R3=100Ω, Gain=10.1 Equivalent Input Noise: 3.93nV/ √Hz Positive Input Current Noise: iNp=15pA/ √Hz Conditions: frequency=100kHz, VCC=±2.5V Instrumentation: Spectrum Analyzer HP3585A (input noise of the HP3585A: 8nV/ √Hz) + _ R3 R1 output R2 iN- iN+ HP3577 Input noise: 8nV/ √Hz N1 N2 N3 TS615 eN + _ R3 R1 output R2 iN- iN+ HP3577 Input noise: 8nV/ √Hz N1 N2 N3 TS615 eN A V g1 R fb R g ---------- + == V1 eN 1 R2 R1 ------- + × = V2 iNn R 2 × = V3 iNp R31 R2 R1 ------- + × × = V4 R2 R1 ------- 4kTR1 × – = V54 kTR2 = V61 R2 R1 ------- + 4kTR3 = 4kTR F ∆ 4kTR eNo V1 2 V2 2 V3 2 V4 2 V5 2 V6 2 +++ ++ eq1 ( ) , = eNo 2 eN 2 g 2 iNn 2 R2 2 iNp 2 + × + × R 3 2 × g 2 × = … R2 R1 ------- 2 4kTR14kTR21 R 2 R 1 ------- + 2 4kTR3 × ++ × eq2 ( ) , + eNo Measured () 2 instrumentation () 2 – eq3 () , = eNo 2 eN 2 g 2 iNn 2 R2 2 iNp 2 + × + × R3 2 × g 2 × = … g 4kTR21 R2 R1 ------- + 2 4kTR3 × + × eq 4 () , + eNo eN 2 g 2 iNn 2 R2 2 g 4kTR2 × + × + × eq5 () , = |
|
|
链接网址 |
| ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 数据表链接 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Chinese ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
