Electronic Components Datasheet Search |
|
SA306-IHZ Datasheet(PDF) 10 Page - Cirrus Logic |
|
SA306-IHZ Datasheet(HTML) 10 Page - Cirrus Logic |
10 / 14 page SA306 0 SA306U P r o d u c t I n n o v a t i o n F r o m 2.LAYOUTCONSIDERATIONS Output traces carry signals with very high dV/dt and dI/dt. Proper routing and adequate power supply bypassing ensures normal operation. Poor routing and bypassing can cause erratic and low efficiency operation as well as ringing at the outputs. The V S supply should be bypassed with a surface mount ceramic capacitor mounted as close as possible to the VS pins. Total inductance of the routing from the capacitor to the V S and GND pins must be kept to a minimum to pre- vent noise from contaminating the logic control signals. A low ESR capacitor of at least 25μF per ampere of output current should be placed near the SA306 as well. Capacitor types rated for switching applications are the only types that should be considered. Note that phases B & C share a V S connection and the bypass recommendation should reflect the sum of B & C phase current. The bypassing requirements of the V DD supply are less stringent, but still necessary. A 0.1μF to 0.47μF surface mount ceramic capacitor (X7R or NPO) connected directly to the V DD pin is sufficient. SGND and PGND pins are connected internally. However, these pins must be connected externally in such a way that there is no motor current flowing in the logic and signal ground traces as parasitic resistances in the small signal routing can develop sufficient voltage drops to erroneously trigger input transitions. Alternatively, a ground plane may be separated into power and logic sections connected by a pair of back to back Schottky diodes. This isolates noise between signal and power ground traces and prevents high currents from passing between the plane sections. Unused area on the top and bottom PCB planes should be filled with solid or hatched copper to minimize inductive coupling between signals. The copper fill may be left unconnected, although a ground plane is recommended. 2.2FAULTINDICATIONS In the case of either an over-temperature or short circuit fault, the SA306 will take no action to disable the outputs. Instead, the SC and TEMP signals are provided to an external controller, where a determination can be made re- garding the appropriate course of action. In most cases, the SC pin would be connected to a FAULT input on the processor, which would immediately disable its PWM outputs. The TEMP fault does not require such an immediate response, and would typically be connected to a GPIO, or keyboard Interrupt pin of the processor. In this case, the processor would recognize the condition as an external interrupt, which could be processed in software via an Interrupt Service Routine. The processor could optionally bring all inputs low, or assert a high level to either of the disable inputs on the SA306. Figure 6 shows an external SR flip-flop which pro- vides a hard wired shutdown of all outputs in re- sponse to a fault indication. An SC or TEMP fault sets the latch, pulling the disable pin high. The processor clears the latched condition with a GPIO. This circuit can be used in safety critical applications to remove software from the fault-shutdown loop, or simply to reduce processor overhead. In applications which may not have available GPIO, the TEMP pin may be externally connected to the adjacent DIS1 pin. If the device temperature reaches ~135ºC all outputs will be disabled, de-energizing the motor. The SA306 will re-energize the motor when the device temperature falls below approximately 95ºC. The TEMP pin hysteresis is wide to reduce the likelihood of thermal oscillations which can greatly reduce the life of the device. 2.3 UNDER-VOLTAGE LOCKOUT The undervoltage lockout condition results in the SA306 unilaterally disabling all output FETs until V S is above the UVLO threshold indicated in the spec table. There is no external signal indicating that an undervoltage lock- FIgURE6.ExTERNALFAULTLATCh CIRCUIT SA306 PROCESSOR INTERRUPT GPIO PWM SC DIS2 TEMP LATCHED FAULT FAULT RESET |
Similar Part No. - SA306-IHZ |
|
Similar Description - SA306-IHZ |
|
|
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 |