 |
Zakładka z wyszukiwarką danych komponentów |
|
|
Zakładka z wyszukiwarką danych komponentów |
|
ADSP-21991BST Arkusz danych(PDF) 9 Page - Analog Devices |
|
||||||||||||||||||||||||||||||
ADSP-21991BST Arkusz danych(HTML) 9 Page - Analog Devices |
|
|
9 / 44 page  –9– REV. 0 ADSP-21991 The ADSP-21991 integrates a flexible and programmable, 3- phase PWM waveform generator that can be programmed to generate the required switching patterns to drive a 3-phase voltage source inverter for ac induction (ACIM) or permanent magnet synchronous (PMSM) motor control. In addition, the PWM block contains special functions that considerably simplify the generation of the required PWM switching patterns for control of the electronically commutated motor (ECM) or brushless dc motor (BDCM). Tying a dedicated pin, PWMSR, to GND, enables a special mode, for switched reluctance motors (SRM). The six PWM output signals consist of three high side drive pins (AH, BH, and CH) and three low side drive signals pins (AL, BL, and CL). The polarity of the generated PWM signals may be set via hardware by the PWMPOL input pin, so that either active HI or active LO PWM patterns can be produced. The switching frequency of the generated PWM patterns is pro- grammable using the 16-bit PWMTM register. The PWM generator is capable of operating in two distinct modes, single update mode or double update mode. In single update mode the duty cycle values are programmable only once per PWM period, so that the resultant PWM patterns are symmetrical about the midpoint of the PWM period. In the double update mode, a second updating of the PWM registers is implemented at the midpoint of the PWM period. In this mode, it is possible to produce asymmetrical PWM patterns that produce lower harmonic distortion in 3-phase PWM inverters. Auxiliary PWM Generation Unit Key features of the auxiliary PWM generation unit are: • 16-bit, programmable frequency, programmable duty cycle PWM outputs • Independent or offset operating modes • Double buffered control of duty cycle and period registers • Separate auxiliary PWM synchronization signal and asso- ciated interrupt (can be used to trigger ADC Convert Start). • Separate auxiliary PWM shutdown signal (AUXTRIP). The ADSP-21991 integrates a 2-channel, 16-bit, auxiliary PWM output unit that can be programmed with variable frequency, variable duty cycle values and may operate in two different modes, independent mode or offset mode. In independent mode, the two auxiliary PWM generators are completely independent and separate switching frequencies and duty cycles may be pro- grammed for each auxiliary PWM output. In offset mode the switching frequency of the two signals on the AUX0 and AUX1 pins is identical. Bit 4 of the AUXCTRL register places the auxiliary PWM channel pair in independent or offset mode. The Auxiliary PWM generation unit provides two chip output pins, AUX0 and AUX1 (on which the switching signals appear), and one chip input pin, AUXTRIP, which can be used to shut down the switching signals—for example in a fault condition. Encoder Interface Unit The ADSP-21991 incorporates a powerful encoder interface block to incremental shaft encoders that are often used for position feedback in high performance motion control systems. • Quadrature rates to 53 MHz (at 80 MHz HCLK rate). • Programmable filtering of all encoder input signals • 32-bit encoder counter • Variety of hardware and software reset modes • Two registration inputs to latch EIU count value with corresponding registration interrupt • Status of A/B signals latched with reading of EIU count value. • Alternative frequency and direction mode • Single north marker mode • Count error monitor function with dedicated error interrupt • Dedicated 16-bit loop timer with dedicated interrupt • Companion encoder event (1⁄T) timer unit. The encoder interface unit (EIU) includes a 32-bit quadrature up/down counter, programmable input noise filtering of the encoder input signals and the zero markers, and has four dedicated chip pins. The quadrature encoder signals are applied at the EIA and EIB pins. Alternatively, a frequency and direction set of inputs may be applied to the EIA and EIB pins. In addition, two north marker/strobe inputs are provided on pins EIZ and EIS. These inputs may be used to latch the contents of the encoder quadrature counter into dedicated registers, EIZLATCH and EISLATCH, on the occurrence of external events at the EIZ and EIS pins. These events may be programmed to be either rising edge only (latch event) or rising edge if the encoder is moving in the forward direction and falling edge if the encoder is moving in the reverse direction (software latched north marker functionality). The encoder interface unit incorporates programmable noise filtering on the four encoder inputs to prevent spurious noise pulses from adversely affecting the operation of the quadrature counter. The encoder interface unit operates at a clock frequency equal to the HCLK rate. The encoder interface unit operates correctly with encoder signals at frequencies of up to 13.25 MHz at the 80 MHz HCLK rate, corresponding to a maximum quadrature frequency of 53 MHz (assuming an ideal quadrature relationship between the input EIA and EIB signals). The EIU may be programmed to use the north marker on EIZ to reset the quadrature encoder in hardware, if required. Alternatively, the north marker can be ignored, and the encoder quadrature counter is reset according to the contents of a maximum count register, EIUMAXCNT. There is also a “single north marker” mode available in which the encoder quadrature counter is reset only on the first north marker pulse. |
Podobny numer części - ADSP-21991BST |
|
Podobny opis - ADSP-21991BST |
|
|
Link URL |
| Polityka prywatności |
| ALLDATASHEET.PL |
| Czy Alldatasheet okazała się pomocna? [ DONATE ] |
O Alldatasheet | Reklama | Kontakt | Polityka prywatności | Linki | Lista producentów 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 |
Polish ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
