www.fairchildsemi.com
KA2811C
12V Spindle Motor and Voice Coil Motor Driver
Features
SMP Circuit
• 3 phase sensorless BLDC motor driver with speed
discriminator
• Built-in start-up circuit with WSS (Waltz step start)
method
• Suitable for high and middle end set
(Max. output current: 2A)
• Built-in dynamic brake circuit
Description
The KA2811C is a monolithic one-chip IC which includes
SPM (Spindle motor) driver, VCM (Voice coil motor) driver
and peripheral driver, designed for driving HDD motor. For
high starting torque and high speed, SPM circuit employes
WSS (Waltz step start) method for starting the motor and can
drive up to 2A. VCM circuit is designed to drive up to 1.5A
to meet the trends of HDD'S high speed. (Requires external
transistors).
Vcm Circuit
• High output current driver with external NPN
& PNP transistors. (Max. output current: 2A)
• No crossover distortion
• Low offset current
48-QFPH-1414
Other
• Low standby current
• Built-in precision power detector circuit
• Built-in TSD(Thermal Shut Down) circuit
Typical Applications
• Hard disk drive(HDD)
Ordering Information
Device
Package
Operating Temperature
0 ~ 70°C
KA2811C 48-QFPH-1414
Rev.1.0.1
May. 2000.
©2000 Fairchild Semiconductor International
1
KA2811C
Pin Assignments
48QFPH (48Quad Flat Package Heat-sink)
TAB
48
47
46
45
44
43
42
41
40
39
38
37
BRAKE
CPUMP
V
CC3
COSC
PC
GND
1
2
3
4
5
6
SINKAREF
SOURCEA
SOURCEB
CSTMON
DISABLE
SINKA1
SINKA2
SINKB2
SINKB1
CLOCK
CRST
V
CC
36
35
34
33
32
31
COMP2
COMP1
CTLN
CTLP
RESENSE
GAINSEL
TAB
KA2811C
TAB
V
CC1
MTRON
CE
CLREF
RSET
N
7
8
9
10
11
12
30
29
28
27
26
25
V
CC1
GND
CRET
PFAIL
READY
RETRACT
13
14
15
16
17
18
19
20
21
22
23
24
CS
SENSE12
SENSE5
RETSET
2
RPMSEL
VFLT
WFLT
UFLT
EFLT
W
TAB
V
U
KA2811C
Pin Definitions
Pin Number
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
32
Pin Name
BRAKE
CPUMP
V
CC3(VDD)
COSC
PC
GND
V
CC1
MTRON
CE
CLREF
RSET
N
WFLT
VFLT
UFLT
EFLT
W
CS
V
U
RETSET
SENSE12
SEMSE5
RPMSEL
RETRACT
READY
PFAIL
CRET
GND
V
CC1
GAINSEL
RSENSE
I/O
O
-
-
-
-
-
-
I
I
I
I
I
I
I
I
I
O
I
O
O
I
I
I
I
I
O
O
I
-
-
I
I
Brake output
Charge pump capacitor
5V power supply
Start-up OSC capacitor
Phase compensation capacitor
Ground
12V power supply
Motor on & off control input
Chip enable (Active low)
Current limit reference voltage
Current & voltage setting resistor
Neutral
Input filter of W-phase signal
Input filter of V-phase signal
Input filter of U-phase signal
Back EMF output filter
W-phase output
Current sensing resistor
V-phase output
U-phase output
Retract voltage setting resistor
V
CC
(12V) power supply sense
V
CC
(5V) power supply sense
RPM selection
Retract circuit control input
Targer RPM locking output signal
Power fail output
Retract power charging capacitor
Ground
12V power supply
VCM gain setting (High, Low)
Current sensing resistor
Pine Function Descrition
3
KA2811C
Pin Definitions (Continued)
Pin Number
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
Pin Name
CTLP
CTLN
COMP1
COMP2
SINKAREF
DISABLE
V
CC2
SINKB1
SOURCEB
SINKB2
SINKA2
SOURCEA
SINKA1
CLOCK
CSTMON
CRST
I/O
I
I
I
I
I
I
-
I
O
O
O
O
I
I
-
-
Pine Function Descrition
VCM amp positive input
VCM amp negative input
Compensation capacitor
Compensation capacitor
Kelvin sensing point for VCM amp
VCM part disable
VCM part power supply (12V)
External NPN-PNP transistor collector
External PNP transistor base
External NPN transistor base
External NPN transistor base
External PNP transistor base
External NPN-PNP transistor base
Reference clock input
Start-up monitoring
VCM amp gain adjustable resistor
4
KA2811C
Internal Block Diagram
COMP2
36
COMP1
35
V
CC
39
CTLP 33
44 SOURCEA
45 SINK1
CTLN 34
43 SINK2
48 CRST
GAINSEL 31
GAINSEL
37 SINKAREF
32 RESENSE
41 SOURCEB
40 SINKB1
42 SINKB2
DISABLE 38
DISABLE
RETRACT 25
RETSET 21
CSTMON 47
RETRACT
28 CRET
15 UFLT
STMON
Back-
EMI
Detector
14 VFLT
13 WFLT
12 N
16 EFLT
PFAIL 27
12V
+
+
−
+5V
Bandgap
WSS
Start-up
Circuit
Commutation
&
Control
3-phase
H-bridge
Drivers
30 V
CC
20 U
19 V
17 W
Logic
4 COSC
12V-SENSE 22
5V-SENSE 23
V
CC3
3
BRAKE 1
BRAKE
8 MTRON
5 PC
−
LVI
TSD
+
Control-amp
Speed
Detector
Divider1
READY
−
+
Buffer-amp
+
Sense-amp
F/V C.
26
READY
29
GND
TAB
GND
6
GND
2
CPUMP
10 CLREF
VREF
18 CS
CE 9
Power
Control
Bias
Z-cross
Detector
−
CLOCK 46
RPMSEL
Speed
Control
11
RSET
24
RPMSEL
5
京公网安备 11010802033920号
EEWORLD
