Electronic Components Datasheet Search |
|
SA9105AFA Datasheet(PDF) 7 Page - Sames |
|
SA9105AFA Datasheet(HTML) 7 Page - Sames |
7 / 12 page SA9105A sames 7/12 TYPICAL APPLICATION In the Application Circuit (Figure 1), the components required for a three phase power metering application are shown. Terminated current transformers are used for current sensing. The most important external components for the SA9105A integrated circuit are: C 7, C9, C10 and C11 are the outer loop capacitors for the integrated oversampling A/D converters. The typical value of C 7 is 2.2nF and the value of C9, C10 and C11 is 560pF. The actual values determine the signal to noise and stability performance. The tolerances should be within ± 10%. C 4, C5, C6 and C8 are the inner loop capacitors for the integrated oversampling A/D converters. The typical value of C 4, C5, C6 and C8 is 3.3nF. Values smaller than 0.5nF and larger than 5nF should be avoided. Terminated current sensors (current transformers) are connected to the current sensor inputs of the SA9105A through current setting resistors (R 8 ..R13). The resistor values should be selected for an input current of 16 µA into the SA9105A at the rated line current. The values of these resistors should be calculated as follows: Phase 1: R 8 = R9 = (IL1/16µA) * R18/2 Phase 2: R 10 = R11 = (IL2/16µA) * R19/2 Phase 3: R 12 = R13 = (IL3/16µA) * R20/2 Where I LX = Secondary CT current at rated conditions. R 18, R19 and R20 = Current transformer termination resistors for the three phases. R 1 + R1A, R4 and R15 set the current for the phase 1 voltage sense input. R 2 + R2A, R5 + P 5 and R16 set the current for phase 2 and R3 + R3A, R6 + P6 and R17 set the current for phase 3. The values should be selected so that the input current into the voltage sense inputs (virtual ground) are set to 14 µA for nominal line voltage. Capacitors C1, C2 and C3 are for decoupling and phase compensation. R 14 + P14 defines all on-chip bias and reference currents. With R14+ P14 = 24kΩ, optimum conditions are set. R 14 may be varied within ± 10% for calibration purposes. Any changes to R 14 will affect the output quadratically (i.e: ∆R = +5%, ∆f = +10%). |
Similar Part No. - SA9105AFA |
|
Similar Description - SA9105AFA |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |