Electronic Components Datasheet Search |
|
SA9904B Datasheet(PDF) 10 Page - Sames |
|
SA9904B Datasheet(HTML) 10 Page - Sames |
10 / 18 page SPEC-0447 (REV. 7) 10/18 29-09-2017 SA9904B Voltage Sense Inputs (IVP1, IVP2, IVP3) Figure 8 shows the voltage sense input configuration for one channel. The circuit is identical for the other two channels. The voltage sense input saturates at an input current of ±17.6μARMS (±25μAPEAK). The current into the voltage sense input should therefore be set to 14 μARMS at nominal mains voltage (VNOM) to allow for a mains voltage variation of up to +15% and –50% without saturating the voltage sense input. For best performance the SA9904B also requires an anti- alias filter on the voltage sense inputs. Referring to Figure 8, the capacitor C1 is used to both implement the anti-alias filter as well as compensating for any phase shift caused by the current transformer. The resistor R4 defines the input current into the device. The optimum input network is achieved by setting R4 in the order of 100k . If R4 is made too large the capacitor C1 will be very small and the accuracy of the phase compensation could be affected by stray capacitances. Figure 8: Voltage sense input configuration Serial Clock (SCK) The SCK pin is used to synchronize data interchange between the microcontroller and the SA9904B. The clock signal on this pin is generated by the microcontroller and determines the data transfer rate of the DO and DI pins. Serial Data In (DI) The DI pin is the serial data input pin for the SA9904B. Data will be input at a rate determined by the Serial Clock (SCK). Data will be strobed by the SA9904B on the rising edge of SCK only during an active chip select (CS). Chip Select (CS) The CS input is used to address the SA9904B. A high level on this pin enables the SA9904B to initiate data exchange. OUTPUT SIGNALS Serial Data Out (DO) The DO pin is the serial data output pin for the SA9904B. The Serial Clock (SCK) determines the data output rate. Data is only transferred out on the rising edge of SCK during active chip select (CS). This output is tri-state when CS is inactive (low). It is recommended to use an external pull-up or pull- down resistor on DO to ensure its state is always valid. Mains Voltage Zero Crossover (F50) The F50 output generates a signal, which follows the mains voltage zero crossings as shown in Figure 9. This output generates a pulse on the rising edge of the mains voltage zero crossing point. The pulse width is between 1ms and 2ms. Internal logic ensures that this signal is generated from a valid phase. Should all three phases be missing but power still applied to the SA9904B this output will generate a constant 54Hz signal. The microcontroller can use this signal to extract the mains timing or synchronize to the mains voltage. Figure 9: Mains voltage zero crossover SPI INTERFACE Description A serial peripheral interface bus (SPI) is a synchronous bus used for data transfers between a microcontroller and the SA9904B. The pins DO (Serial Data Out), DI (Serial Data In), CS (Chip Select), and SCK (Serial Clock) are used in the bus implementation. The SA9904B is the slave device with the microcontroller being the bus master. The CS input initiates and terminates data transfers. A SCK signal (generated by the microcontroller) strobes data between the microcontroller and the SA9904B. The DI and DO pins are the serial data input and output pins for the SA9904B respectively. R4 R3 IVP GND C1 R2 R1 GND V NOM 14µA RMS Voltage In Neutral GND R5 R5 << R4 << (R1 + R2 + R3) t Phase Voltage 1ms – 2ms F50 |
Similar Part No. - SA9904B_17 |
|
Similar Description - SA9904B_17 |
|
|
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 |