- 您现在的位置：买卖IC网 > PDF目录375260 > ADMC331BST (ANALOG DEVICES INC) Single Chip DSP Motor Controller PDF资料下载
参数资料
| 型号： | ADMC331BST |
| 厂商： | ANALOG DEVICES INC |
| 元件分类： | 数字信号处理 |
| 英文描述： | Single Chip DSP Motor Controller |
| 中文描述： | 0-BIT, 16.384 MHz, OTHER DSP, PQFP80 |
| 封装： | PLASTIC, TQFP-80 |
| 文件页数： | 15/36页 |
| 文件大小： | 248K |
| 代理商： | ADMC331BST |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页当前第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页
ADMC331
–15–
REV. B
Width of the PWMSYNC Pulse, PWMSYNCWT Register
The PWM controller of the ADMC331 produces an output
PWM synchronization pulse at a rate equal to the PWM switch-
ing frequency in single update mode and at twice the PWM
frequency in the double update mode. This pulse is available
for external use at the PWMSYNC pin. The width of this
PWMSYNC pulse is programmable by the 8-bit read/write
PWMSYNCWT register. The width of the PWMSYNC pulse,
T
PWMSYNC
, is given by:
T
PWMSYNC
=
t
CK
×
(
PWMSYNCWT
+ 1)
so that the width of the pulse is programmable from t
CK
to 256 t
CK
(corresponding to 38.5 ns to 9.84
μ
s for a CLKOUT rate of
26 MHz). Following a reset, the PWMSYNCWT register con-
tains 0x27 (= 39) so that the default PWMSYNC width is
1.54
μ
s, again for a 26 MHz CLKOUT.
PWM Duty Cycles, PWMCHA, PWMCHB, PWMCHC
Registers
The duty cycles of the six PWM output signals on pins AH to
CL are controlled by the three 16-bit read/write duty-cycle
registers, PWMCHA, PWMCHB, and PWMCHC. The integer
value in the register PWMCHA controls the duty cycle of the
signals on AH and AL, in PWMCHB, controls the duty cycle of
the signals on BH and BL and in PWMCHC, controls the duty
cycle of the signals on CH and CL. The duty-cycle registers are
programmed in integer counts of the fundamental time unit,
t
CK
, and define the desired on-time of the high side PWM signal
produced by the three-phase timing unit over half the PWM
period. The switching signals produced by the three-phase
timing unit are also adjusted to incorporate the programmed
dead time value in the PWMDT register. The three-phase
timing unit produces active LO signals so that a LO level corre-
sponds to a command to turn on the associated power device.
A typical pair of PWM outputs (in this case for AH and AL)
from the timing unit are shown in Figure 6 for operation in
single update mode. All illustrated time values indicate the
integer value in the associated register and can be converted to
time simply by multiplying by the fundamental time increment,
t
CK
. Firstly, it is noted that the switching patterns are perfectly
symmetrical about the midpoint of the switching period in
this single update mode since the same values of PWMCHA,
PWMTM and PWMDT are used to define the signals in both
half cycles of the period. It can be seen how the programmed
duty cycles are adjusted to incorporate the desired dead time
into the resultant pair of PWM signals. Clearly, the dead time is
incorporated by moving the switching instants of both PWM
signals (AH and AL) away from the instant set by the PWMCHA
register. Both switching edges are moved by an equal amount
(PWMDT
×
t
CK
) to preserve the symmetrical output patterns.
Also shown is the PWMSYNC pulse whose width is set by the
PWMSYNCWT register and Bit 3 of the SYSSTAT register,
which indicates whether operation is in the first or second half
cycle of the PWM period.
Obviously negative values of T
AH
and T
AL
are not permitted and
the minimum permissible value is zero, corresponding to a 0%
duty cycle. In a similar fashion, the maximum value is T
S
,
corresponding to a 100% duty cycle.
PWMCHA
2
PWMDT
PWMSYNCWT + 1
PWMCHA
PWMTM
PWMTM
AH
AL
PWMSYNC
SYSSTAT (3)
2
PWMDT
Figure 6. Typical PWM Outputs of Three-Phase Timing
Unit in Single Update Mode (Active LO Waveforms)
The resultant on-times of the PWM signals in Figure 6 may be
written as:
T
AH
= 2
×
(
PWMCHA
–
PWMDT
)
×
t
CK
T
AL
= 2
×
(PWMTM
–
PWMCHA
–
PWMDT)
×
t
CK
and the corresponding duty cycles are:
d
AH
=
T
AH
T
S
=
PWMCHA
–
PWMDT
PWMTM
d
AL
=
T
AL
T
S
=
PWMTM
–
PWMCHA
–
PWMDT
PWMTM
The output signals from the timing unit for operation in double
update mode are shown in Figure 7. This illustrates a com-
pletely general case where the switching frequency, dead time
and duty cycle are all changed in the second half of the PWM
period. Of course, the same value for any or all of these quanti-
ties could be used in both halves of the PWM cycle. However,
it can be seen that there is no guarantee that symmetrical PWM
signal will be produced by the timing unit in this double update
mode. Additionally, it is seen that the dead time is inserted into
the PWM signals in the same way as in the single update mode.
PWMCHA
2
PWMSYNCWT
2
+ 1
PWMCHA
1
PWMTM
1
PWMTM
2
PWMSYNCWT
1
+ 1
AH
AL
PWMSYNC
SYSSTAT (3)
2
PWMDT
1
2
PWMDT
2
Figure 7. Typical PWM Outputs of Three-Phase Timing
Unit in Double Update Mode (Active LO Waveforms)
In general, the on-times of the PWM signals in double update
mode can be defined as:
(
T
AH
=
PWMCHA
1
+
PWMCHA
2
PWMDT
1
PWMDT
2
)
×
t
CK
T
AL
=
(
PWMTM
1
+
PWMTM
2
–
PWMCHA
1
–
PWMCHA
2
–
PWMDT
1
–
PWMDT
2
)
×
t
CLK
相关PDF资料 |
PDF描述 |
|---|---|
| ADMC331-ADVEVALKIT | Single Chip DSP Motor Controller |
| ADMC331-PB | Single Chip DSP Motor Controller |
| ADMCF327 | 28-Lead Flash Memory DSP Switched Reluctance Motor Controller |
| ADMCF327BR | 28-Lead Flash Memory DSP Switched Reluctance Motor Controller |
| ADMCF327-EVALKIT | Circular Connector; No. of Contacts:13; Series:MS27497; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:10; Circular Contact Gender:Pin; Circular Shell Style:Wall Mount Receptacle; Insert Arrangement:10-35 RoHS Compliant: No |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ADMC331BSTZ | 制造商:Analog Devices 功能描述:DSP Motor Controller 80-Pin TQFP |
| ADMC331-PB | 制造商:AD 制造商全称:Analog Devices 功能描述:Single Chip DSP Motor Controller |
| ADMC340BST | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Controller Miscellaneous - Datasheet Reference |
| ADMC340VST-XXX-XXXX | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Controller Miscellaneous - Datasheet Reference |
| ADMC341YR-XXX-XXXX | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Controller Miscellaneous - Datasheet Reference |
发布紧急采购，3分钟左右您将得到回复。