參數(shù)資料
型號： 33991
廠商： Motorola, Inc.
英文描述： Gauge Driver Integrated Circuit
中文描述： 儀表驅(qū)動集成電路
文件頁數(shù)： 25/36頁
文件大?。?/td> 660K
代理商： 33991
MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
33991
25
Internal Clock Calibration
Timing related functions on the 33991 device (e.g., pointer
velocities, acceleration and Return To Zero Pointer speeds)
depend upon a precise, consistent time reference to control the
pointer accurately and reliably. Generating accurate time
references on an Integrated Circuit can be accomplished;
however, they tend to be costly due to the large amount of die
area required for trim pads and the associated trim procedure.
One possibility to reduce cost is an externally generated clock
signal. An external generated clock requires a dedicated pin on
the device and on the controller. Another inexpensive approach
would be to require the use of an additional crystal or resonator.
The internal clock in the 33991 is temperature independent
and area efficient; however, it can vary by as much as + 70
percent to - 35 percent due to process variation. Using the
existing SPI inputs and the precision timing reference already
available to the controller, the 33991allows clock calibration to
within ± 10 percent.
Calibrating the internal 1 MHz clock is initiated by writing a
logic [1] to PECR bit D3. See Figure 7. The 8 μs calibration
pulse is provided by the controller. It is ideally results in an
internal 33991 clock speed of 1 MHz. The pulse is sent on the
CS pin immediately after the SPI word is launched. No other
SPI lines must be toggled. At the moment the CS pin transitions
from logic [1] to [0], an internal 7-bit counter counts the number
of cycles of an internal, non-calibrated, and temperature
independent, 8 MHz clock. The counter stops when the CS pin
transitions from logic [0] to logic [1]. The value in the counter
represents the number of cycles of the 8 MHz clock occurring in
the 8 μs window; it should range from 32 to 119. An offset is
added to this number to help center or skew the calibrated
result to generate a desired maximum or nominal frequency.
The modified counter value is truncated by four bits, generating
the calibration divisor, ranging from four to 15. The 8 MHz clock
is divided by the calibration divisor, resulting in a calibrated 1
MHz clock. If the calibration divisor lies outside the range of four
to 15, then the 33991 device flags the ST7 bit, indicating the
48
447
2256.30
120
280
3587.05
192
221
4543.45
49
442
2280.11
121
279
3602.07
193
220
4555.32
50
437
2303.67
122
278
3617.03
194
220
4567.15
51
433
2326.99
123
277
3631.93
195
219
4578.96
52
429
2350.09
124
275
3646.77
196
219
4590.74
53
425
2372.95
125
274
3661.54
197
218
4602.49
54
420
2395.60
126
273
3676.26
198
218
4614.21
55
417
2418.04
127
272
3690.92
199
217
4625.89
56
413
2440.27
128
271
3705.52
200
216
4637.55
57
409
2462.30
129
270
3720.07
201
216
4649.18
58
405
2484.13
130
269
3734.56
202
215
4660.78
59
402
2505.77
131
268
3748.99
203
215
4672.36
60
398
2527.23
132
267
3763.36
204
214
4683.90
61
395
2548.51
133
266
3777.68
205
214
4695.41
62
392
2569.61
134
265
3791.95
206
213
4706.90
63
389
2590.54
135
264
3806.17
207
213
4718.36
64
385
2611.30
136
263
3820.33
208
212
4729.79
65
382
2631.90
137
262
3834.44
209
212
4741.19
66
379
2652.34
138
261
3848.49
210
211
4752.57
67
376
2672.62
139
260
3862.50
211
211
4763.92
68
374
2692.75
140
259
3876.45
212
210
4775.24
69
371
2712.73
141
258
3890.36
213
210
4786.53
70
368
2732.56
142
257
3904.22
214
209
4797.80
71
366
2752.25
143
256
3918.02
215
209
4800.00
Table 14. Velocity Ramp
Velocity
Position
Time Between
Steps (
μ
s)
Velocity
(
μ
Steps/s)
Velocity
Position
Time Between
Steps (
μ
s)
Velocity
(
μ
Steps/s)
Velocity
Position
Time Between
Steps (
μ
s)
Velocity
(
μ
Steps/s)
F
Freescale Semiconductor, Inc.
Go to: www.freescale.com
n
.
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
33-991 制造商:Ideal Industries Inc 功能描述:LTKII,350MHZ,CAT6 W/CAT6 ADPT
3399-1 制造商:3M 功能描述:3399-1
33992 制造商:Ideal Industries Inc 功能描述:LTKII500MHZ,CAT6A W/CAT6A ADPT
33992510000001 功能描述:電纜組件 CABLE KIT RoHS:否 制造商:Molex 產(chǎn)品:Power Assemblies 類型:Cable Assembly 連接器端口 A:No Connector 連接器端口 A 管腳計數(shù):4 連接器端口 B:No Connector 連接器端口 B 管腳計數(shù): 型式:Male 線規(guī) - 美國線規(guī)（AWG）:20, 28 長度:0.305 m 顏色:Black, Red
33993 制造商:Ideal Industries Inc 功能描述:LTKII1000MHZ,CAT7A W/CAT6AADPT
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