数据搜索系统,热门电子元器件搜索 |
|
AD2S82ALP 数据表(PDF) 8 Page - Analog Devices |
|
AD2S82ALP 数据表(HTML) 8 Page - Analog Devices |
8 / 16 page REV. B –8– AD2S81A/AD2S82A COMPONENT SELECTION The following instructions describe how to select the external components for the converter in order to achieve the required bandwidth and tracking rate. In all cases the nearest “preferred value’’ component should be used and a 5% tolerance will not degrade the overall performance of the converter. Care should be taken that the resistors and capacitors will function over the required operating temperature range. The components should be connected as shown in Figure 1. PC compatible software is available to help users select the optimum component values for the AD2S81A and AD2S82A, and display the transfer gain, phase and small step response. For more detailed information and explanation, see the Circuit Functions and Dynamic Performance section. 1. HF Filter (R1, R2, C1, C2) The function of the HF filter is to remove any dc offset and to reduce the amount of noise present on the signal inputs to the AD2S81A/AD2S82A, reaching the Phase Sensitive Detector and affecting the outputs. R1 and C2 may be omit- ted—in which case R2 = R3 and C1 = C3, calculated below— but their use is particularly recommended if noise from switch mode power supplies and brushless motor drive is present. Values should be chosen so that 15 k Ω≤ R1 = R2 ≤ 56 kΩ C1 = C2 1 2 π R1 f REF and fREF = Reference Frequency (Hz) This filter gives an attenuation of three times at the input to the phase sensitive detector. 2. Gain Scaling Resistor (R4) If R1, C2 are fitted, then: R4 = E DC 100 × 10− 9 × 1 3 Ω where 100 × 10–9 = current/LSB If R1, C2 are not fitted, then: R4 = E DC 100 × 10 –9 Ω where EDC = 160 × 10–3 for 10 bits resolution = 40 × 10–3 for 12 bits = 10 × 10–3 for 14 bits = 2.5 × 10–3 for 16 bits = Scaling of the DC ERROR in volts 3. AC Coupling of Reference Input (R3, C3) Select R3 and C3 so that there is no significant phase shift at the reference frequency. That is, R 3 = 100 kΩ C 3 > 1 R 3 × f REF F with R3 in Ω. 4. Maximum Tracking Rate (R6) The VCO input resistor R6 sets the maximum tracking rate of the converter, and hence the velocity scaling as at the max tracking rate, the velocity output will be 8 V. Decide on your maximum tracking rate, “T,” in revolutions per second. Note that “T” must not exceed the maximum tracking rate or 1/16 of the reference frequency. R6 = 6. 32 × 10 10 T × n Ω where n = bits per revolution = 1,024 for 10 bits resolution = 4,096 for 12 bits = 16,384 for 14 bits = 65,536 for 16 bits 5. Closed-Loop Bandwidth Selection (C4, C5, R5) a. Choose the closed-loop bandwidth (fBW) required ensuring that the ratio of reference frequency to band- width does exceed the following guidelines: Resolution Ratio of Reference Frequency/Bandwidth 10 2.5 : 1 12 4 : 1 14 6 : 1 16 7.5 : 1 Typical values may be 100 Hz for a 400 Hz reference fre- quency and 500 Hz to 1000 Hz for a 5 kHz reference frequency. b. Select C4 so that C4 = 21 R6 × f BW 2 F with R6 in Ω and f BW, in Hz selected above. c. C5 is given by C5 = 5 × C4 F d. R5 is given by R5 = 4 2 ×π × f BW × C 5 Ω 6. VCO Phase Compensation The following values of C6 and R7 should be fitted. C6 = 470 pF, R7 = 68 Ω 7. Offset Adjust Offsets and bias currents at the integrator input can cause an additional positional offset at the output of the converter of 1 arc minute typical, 5.3 arc minutes maximum. If this can be tolerated, then R8 and R9 can be omitted from the circuit. If fitted, the following values of R8 and R9 should be used: R8 = 4.7 MΩ, R9 = 1 MΩ potentiometer To adjust the zero offset, ensure the resolver is disconnected and all the external components are fitted. Connect the COS pin to the REFERENCE I/P and the SIN pin to the SIGNAL GND and with the power and reference applied, adjust the potentiometer to give all “0s” on the digital output bits. The potentiometer may be replaced with select on test resistors if preferred. |
类似零件编号 - AD2S82ALP |
|
类似说明 - AD2S82ALP |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
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 | 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 |