Electronic Components Datasheet Search |
|
L6238SQT Datasheet(PDF) 9 Page - STMicroelectronics |
|
L6238SQT Datasheet(HTML) 9 Page - STMicroelectronics |
9 / 31 page used in an application, it may either be connected to ground or VLOGIC as required, It may also be simply left unconnected. If no connection is made, the pin is either pulled high or low by internal constant current gener- ators as shown above. A listing of the logic and clock inputs is shown in Table 1 with the corresponding default state. 1.3 Modes of Operation There are 5 basic modes of operation. 1) Tristate When Output Enable is low, the output power drivers are tristated. 2) Start-Up With Output Enable high, bringing Run/Brake from a low to a high will energize the motor and the system will be driven by the Fully-Integrated StartUp Algorithm. A user-defined Start-Up Algorithm, under control of a MicroProcessor, can also be achieved via the sequence increment input. 3) Run Run mode is achieved when the motor speed (controlled by the external microprocessor) reaches the nominal speed. 4) Park When Run/Brake is brought low, energy to park the heads may be derived from the rectified Bemf. The energy recovery time is a function of the Brake Delay Time Constant. In this state, the qui- escent current of the device is minimized (sleep mode). 5) Brake After the Energy Recovery Time-Out, the device is in Brake, with all lower Drivers in full conduc- tion. There are two mutually exclusive conditions which may be present during the Tristate Mode (wake up): a)the spindle is stopped. b)the system is still running at a speed that allows for resynchronization. In order to minimize the ramp up time, the micro- controller has the possibility to: check the SPIN SENSE pin, (which toggles at the Bemf zero crossing frequency) enable the power to the motor based on the previous information. Otherwise the µP may is- sue a Brake command, followed by the start- up procedure after the motor has stopped spin- ning. 2.0 STATE DIAGRAMS 2.1 State Diagram Figure 2-1 is a complete State Diagram of the controller depicting the operational flow as a func- tion of the control pins and motor status. The flow can be separated into four distinct operations. 2.2 Align + Go Figure 2-2 represent the normal flow that will achieve a spin-up of the spindle motor using the internally generated start up algorithm. Upon power up, or from any state with Run/Brake low the controller first sets the state machine for State=1 with the Outputs Tristated. The period counter that monitors the time be- tween zero crossing is stopped, analog with the phase and mask delay counters. When Run/Brake is brought high, the motor is in the first part of the align mode at State 2 (Output A high and Output C low). If Output Enable is high, the controller first checks to determine if the motor is still spinning for a time of 21 Ω (with Sys_Clk = 10MHz). The drivers are now enabled and after the align time-out, (64/Falign), the se- quencer double increments the outputs to State 4 (Output B high and Output A low). The first part of this align mode is used to reduce the effects of stiction Pin Function Configuration Tdly (0,1,2) Pull-Down Select Pole Pull-Down PWM/Linear Pull-Down Output Enable Pull-Down Run/Brake Pull-Up Sequence Increment Pull-Down System Clock Pull-Up Faling Pull-Up Table 1 330 VLOGIC 10 µA 330 VLOGIC 10 µA PULL-UP PULL-DOWN D95IN279 Figure 1-2 L6238S 9/31 |
Similar Part No. - L6238SQT |
|
Similar Description - L6238SQT |
|
|
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 |