поискавой системы для электроныых деталей |
|
L6228 датащи(PDF) 11 Page - STMicroelectronics |
|
L6228 датащи(HTML) 11 Page - STMicroelectronics |
11 / 26 page 11/26 L6228 PWM CURRENT CONTROL The L6228 includes a constant off time PWM current controller for each of the two bridges. The current control circuit senses the bridge current by sensing the voltage drop across an external sense resistor connected be- tween the source of the two lower power MOS transistors and ground, as shown in Figure 10. As the current in the motor builds up the voltage across the sense resistor increases proportionally. When the voltage drop across the sense resistor becomes greater than the voltage at the reference input (VREFA or VREFB) the sense comparator triggers the monostable switching the bridge off. The power MOS remain off for the time set by the monostable and the motor current recirculates as defined by the selected decay mode, described in the next section. When the monostable times out the bridge will again turn on. Since the internal dead time, used to pre- vent cross conduction in the bridge, delays the turn on of the power MOS, the effective off time is the sum of the monostable time plus the dead time. Figure 10. PWM Current Controller Simplified Schematic Figure 11 shows the typical operating waveforms of the output current, the voltage drop across the sensing re- sistor, the RC pin voltage and the status of the bridge. More details regarding the Synchronous Rectification and the output stage configuration are included in the next section. Immediately after the Power MOS turns on, a high peak current flows through the sensing resistor due to the reverse recovery of the freewheeling diodes. The L6228 provides a 1 µs Blanking Time tBLANK that inhibits the comparator output so that this current spike cannot prematurely re-trigger the monostable. DRIVERS + DEAD TIME S Q R DRIVERS + DEAD TIME 2H 1H 2L 1L OUT2A(or B) SENSEA(or B) RSENSE D01IN1332 RCA(or B) ROFF COFF VREFA(or B) IOUT OUT1A(or B) + + - - 1 µs 5mA BLANKER SENSE COMPARATOR COMPARATOR OUTPUT MONOSTABLE SET 2.5V 5V FROM THE LOW-SIDE GATE DRIVERS 2 PHASE STEPPER MOTOR BLANKING TIME MONOSTABLE VSA (or B) TO GATE LOGIC (0) (1) |
Аналогичный номер детали - L6228 |
|
Аналогичное описание - L6228 |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю 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 |