công cụ tìm kiếm bảng dữ liệu linh kiện điện tử
  Vietnamese  ▼
ALLDATASHEET.VN

X  

Preview PDF HTML

L6238S bảng dữ liệu(PDF) 25 Page - STMicroelectronics

tên linh kiện L6238S
Giải thích chi tiết về linh kiện  12V SENSORLESS SPINDLE MOTOR CONTROLLER
PDF  31 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
nhà sản xuất  STMICROELECTRONICS [STMicroelectronics]
Trang chủ  http://www.st.com
Logo STMICROELECTRONICS - STMicroelectronics

L6238S bảng dữ liệu(HTML) 25 Page - STMicroelectronics

Back Button L6238S Datasheet HTML 21Page - STMicroelectronics L6238S Datasheet HTML 22Page - STMicroelectronics L6238S Datasheet HTML 23Page - STMicroelectronics L6238S Datasheet HTML 24Page - STMicroelectronics L6238S Datasheet HTML 25Page - STMicroelectronics L6238S Datasheet HTML 26Page - STMicroelectronics L6238S Datasheet HTML 27Page - STMicroelectronics L6238S Datasheet HTML 28Page - STMicroelectronics L6238S Datasheet HTML 29Page - STMicroelectronics Next Button
Zoom Inzoom in Zoom Outzoom out
 25 / 31 page
background image
The Valley current, Ib will thereforebe:
ib = 1.30 - 0.1A
ib = 1.20A
During the Align and Go Phase (where the power
dissipation requirements are highest, Eg is zero.
The initial time required to reach the Peak current
is:
tinit
= ±
L
R
ln
1
±
I,R
V
(5.1.7)
Substituting values:
tinit
= ±
880e
± 6
4.8
ln
1
±
1.3
⋅ 4.8
12
tinit = 134.6
µs
The ON time can be calculated from:
ton
=
L
Rs
ln
V
Rs
± ib
V
Rs
± it
(5.1.8)
Substituting values:
ton
=
880E
± 6
4.8
ln

12
4.8
± 1.2
12
4.8
± 1.3
ton = 14.67
µs
During the OFF time, the motor current continues
to flow through the DMOS transistors and threfore
the voltage drop remains constant across the
windings.
The time required for the inductor current to reach
the valley current is given by:
toff
=
L
R
ln
It
Ib
(5.1.9)
Substituting values:
toff
=
880e±
6
4.8
ln
1.3
1.2
toff = 14.67
µs
Note: that the parameters for this example were selected to arrive at
a 50% duty cycle. This will not always be the case due to factors such
as fixed motor parameters, etc.
The Constant Off timer period can be determined
from:
toff
= Rslew ⋅ Coff
⋅ ln
Vchrg
Vtrip
(5.1.10)
Where:
Toff
=
Constant-OFF Time
Rslew =
Slew Rate Resistor
Coff
=
Off Time Capacitor
Vchrg =
Initial Capacitor Charge Voltage
Vtrip
=
Capacitor Lower Trip Threshold
Substituting nominal values given:
Toff = 0.75
⋅ Rslew ⋅ Coff
Solving for Coff
Coff =
Toff
0.75Rslew
In the example, to set the OFF timer for a 50%
duty cycle:
Given:
Toff
=
14.67
µs
Rslew =
100K
Ω (typical Value)
Coff
=
14.67e±
6
100e
3
Coff
≈ 146pF
5.1.4 Minimum ON Time
The bandwidth of the PWM loop was optimized to
reject unwanted switching noise while providing
20
µs/DIV
Iout A
200mA
D95IN324
4
It=1.3A
Ib=1.2A
Iavg=1.25A
Figure 5-7
L6238S
25/31



Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31


bảng dữ liệu tải về

Go To PDF Page


Link URL



Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không?  [ DONATE ] 

Alldatasheet là   |   Quảng cáo   |   Liên lạc với chúng tôi   |   Chính sách bảo mật   |   Liên kết đến bảng dữ liệu    |   Trao đổi link   |   Tìm kiếm theo nhà sản xuất
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
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