參數(shù)資料
型號(hào): L7250
廠商: 意法半導(dǎo)體
英文描述: 5V & 12V SPINDLE AND VCM MOTORS DRIVER
中文描述: 5V的
文件頁數(shù): 27/46頁
文件大?。?/td> 478K
代理商: L7250
27/46
L7250
3
The VCM driver is configured as a transconductance amp, with an n-channel DMOS H-bridge power output,
current sense amp, error amp, and 15 bit linear DAC for command input. The power stage is a class AB voltage
amp. The error amp closes the transconductance loop around the power amp, using feedback from the current
sense amp. The VCM block is shown below.
VOICE COIL MOTOR DRIVER
Figure 7. VCM Driver Block Diagram
The current flowing into the voice coil is equal to:
Where G
s
is the sensing opamp gain (programmable via serial port
Considering a typical application where Rf = 5.6k, Ri = 2.5k, Rs = 0.25
and Gs = 4.5V/V we obtain a maximum
current equal to about 2A for 1V DAC output (Vin). The sense amplifier input range is about 0.55V. The power
stages assure this current requirement and they have a differential gain of 16.
The loop is compensated through the RC network Rc and Cc that cancels out the motor pole Lm/Rm.
This graphic shows the theoretic Gloop Bode diagram and put in evidence the second pole of the loop that is
strictly related to the error amplifier bandwidth.
Figure 8. Gloop
VM/2
VM/2
38
39
37
VM
VM
52/53
3/4
5/6
42
41
40
DAC 15
DACREF
AGND
VCMP
VCMN
DACREF
DACREF
DACREF
DACREF
VCM GND
SenseAmp
ErrorAmp
VCV
VCM
GND
43/44
45/46
Tristate
Tristate
S1
S2
1/2/54/55
POR
Rc
Cc
Ri
Rf
Gs
Gpow
Gpow
Rs
Rm
Lm
I
coil
R
R
i
------
R
s
G
s
-------1
in
=
Fdt error
R
c
R
f
-----
R
c
C
c
------1
R
f
C
c
------1
ω
t
R
R
R
f
R
c
R
i
+
(
)
--------------------------------
2G
R
G
s
R
s
+
R
m
--------------------------------------
R
f
C
c
-------1
Gloop
A
0
R
+
R
i
R
f
-----------------
A
2G
R
G
s
R
s
+
R
m
-------------------------------------------------
R
+
R
i
R
f
-----------------
ω
t
R
+
R
i
R
f
-----------------
相關(guān)PDF資料
PDF描述
L7805ABD2T-TR Precision 1A regulators
L7805ACD2T-TR Precision 1A regulators
L7806ABD2T-TR Precision 1A regulators
L7806ACD2T-TR Precision 1A regulators
L7808ABD2T-TR Precision 1A regulators
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L7250E1.2 功能描述:電源開關(guān) IC - 配電 DSD POWER RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻(最大值):85 mOhms 開啟時(shí)間(最大值):400 us 關(guān)閉時(shí)間(最大值):20 us 工作電源電壓:3.2 V to 6.5 V 電源電流(最大值): 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-5
L7252E2.6 功能描述:電源開關(guān) IC - 配電 DSD POWER RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻(最大值):85 mOhms 開啟時(shí)間(最大值):400 us 關(guān)閉時(shí)間(最大值):20 us 工作電源電壓:3.2 V to 6.5 V 電源電流(最大值): 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-5
L725MAG 制造商:Apex Tool Group 功能描述:TAPE, 1 IN. X 25 FT, 700 SERIES, MAGNETIC END HOOK 制造商:Lufkin 功能描述:TAPE MEASURE, MAGNETIC END HOOK 25FT 1IN; Tape Measure Type:Manual; Measuring Range Max:25ft; Blade Width:1"; Case Color:Orange; Tool Body Material:ABS; Blade Finish:Yellow Clad; Blade Length:25ft ;RoHS Compliant: NA
L728 制造商:BURNDY 功能描述:L-DIE
L7290 制造商:CIPS 功能描述:CUTTER OBLIQUE SEMI FLUSH 109MM