BD7902CFS-E1 [ROHM]
Motion Control Electronic, BIPolar, PDSO54;
| 型号： | BD7902CFS-E1 |
| 厂家： | 
ROHM |
| 描述： | Motion Control Electronic, BIPolar, PDSO54 光电二极管 |
| 文件： | 总17页 (文件大小：190K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
BD7902CFS
Optical disc ICs
6CH Power Driver for
CD-ROM, DVD-ROM
BD7902CFS
BD7902CFS is a 6-channel driver IC that integrates all drivers necessary for CD-ROM, and DVD-ROM systems into a
single chip. The built-in 2-channel sled motor driver is used for the stepping motor. Low heat operation can be achieved
by applying the PWM driving system for sled and spindle motor drivers.
!Applications
CD-ROM, DVD-ROM
!Features
1) 3channel BTL driver, 2channel PWM driver and 3phase motor driver.
- ALL of the motor and actuator for CD-ROM, DVD-ROM etc.
2) These mode is able to be selected by the two control terminals.
- ON/OFF of loading, and other 5channels, brake mode select of spindle driver and standby mode.
3) Built-in triangular-wave generator.
4) Package SSOP-A54 has large power dissipation.
5) Built in thermal-shut-down circuit.
〈 Spindle driver 〉
• Efficient drive by current feedback PWM drive.
• Built in current limit, hall bias, short brake, FG output and reverse protection circuit.
• Low ON-Resistor. (RON=0.95Ω)
〈 Sled motor driver 〉
• Efficient drive by current feedback PWM drive.
• Built in 2channel for stepping motor.
〈 Actuator driver, Loading driver 〉
• Linear BTL drive system.
1/17
BD7902CFS
Optical disc ICs
!Absolute maximum ratings (Ta=25°C)
Parameter
Symbol
Unit
V
Limits
POWER MOS
power suuply voltage
∗
1
SPVM1,2,SLRNF1,2
15
Preblock/BTL powerblock
power supply voltage
V
CC,SLVDD,AVM
DVCC
15
7
V
V
PWM control block
power supply voltage
∗2
2.6
Power dissipation
Pd
W
°C
°C
Operating temperature range
Storage temperature
Topr
Tstg
−35~+85
−55~+150
∗1 POWER MOS output terminals (9, 11, 18, 34~37pin) is contained.
∗2 PCB (70mm×70mm×1.6mm glass epoxy) mounting.
Reduced by 20.8mW for each increase in Ta of 1°C over 25°C.
!Recommended operating conditions (Ta=25°C)
(Set the power supply voltage taking allowable dissipation into considering)
Parameter
Symbol
SPVM1, 2
SLRNF1, 2
SLVDD, VCC
AVM
Min.
−
Typ.
Max.
Unit
V
∗3
POWER MOS Power supply voltage 1
POWER MOS Power supply voltage 2
Preblock Power supply voltage
Power block Power supply voltage
PWM control block Power supply voltage
Spindle output current
VCC
−
−
−
SLVDD∗3
12
V
AVM
4.3
4.3
−
14
V
5.0
V
CC
V
DVCC
5.0
6.0
2.5∗4
0.8
V
Iosp
1.2
A
SL/FO/TR/LO output current
Ioo
−
0.5
A
∗3 Set the same supply voltage to VCC and SPVM1, 2 to SLVDD and SLRNF1, 2.
∗4 The current is guaranteed 3.0A in case of the current is turned on/off in a duty-ratio of
less than 1/10 with a maximum on-time of 5msec.
2/17
BD7902CFS
Optical disc ICs
!Block diagram
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
47k
−
47k
47k
LEVEL
SHIFT
LEVEL
SHIFT
LEVEL
SHIFT
PRE
LOGIC
PRE
LOGIC
−
94k
47k
−
+
TSD
FF
47k
94k
LIMIT
LIMIT
47k
−
FF
+
OSC
Current
COMP
FF
Current
LIMIT
OSC
Polarity
REVERSE
DETECT
PWM
OUT
FG
COMP
94k
−
3-phase
MATRIX
15k
−
47k
15k
FG
STBY/
BRAKE
CONTROL
HALL
BIAS
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
3/17
BD7902CFS
Optical disc ICs
!Pin descriptions
Pin No. Pin name
Function
Pin No. Pin name
Function
Sled driver 1 input
Sled driver 2 input
Sled driver PowerMOS pre-supply
1
HU+
HU−
Hall amp. U positive input
Hall amp. U negative input
Hall amp. V positive input
Hall amp. V negative input
Hall amp. W positive input
Hall amp. W negative input
Hall bias
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
SLIN1
SLIN2
SLVDD
2
3
HV+
4
HV−
SLRNF1 Sled driver 1 current sense
SLRNF2 Sled driver 2 current sense
5
HW+
HW−
HB
6
SLGND
SLO2−
SLO2+
SLO1−
SLO1+
AGND
GND
Sled driver power ground
Sled driver 2 negative output
Sled driver 2 positive output
Sled driver 1 negative output
Sled driver 1 positive output
Ground
7
8
PGND1
U
Spindle driver power ground 1
Spindle driver output U
Spindle driver power supply 1
Spindle driver output V
GND
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
SPVM1
V
GND
GND
GND
GND
GND
PGND2
W
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
Spindle driver power ground 2
Spindle driver output W
Spindle driver power supply 2
Spindle driver current sense
Frequency generator output
Driver logic control input 1
Driver logic control input 2
Spindle driver input
PWM block pre-ground
Loading driver input
Reference voltage input
AVM
Actuator driver block power supply
Focus driver negative output
Focus driver positive output
Tracking driver negative output
Tracking driver positive output
Loading driver negative output
Loading driver positive output
BTL pre and Loading power supply
Tracking driver input
Focus driver input
FCO−
FCO+
TKO−
TKO+
LDO−
LDO+
SPVM2
SPRNF
FG
CTL1
CTL2
SPIN
DGND
LDIN
VC
V
CC
TKIN
FCIN
DVCC
PWM block control power supply
∗ Positive/negative of the output terminals are determined in reference to those of the input terminals.
4/17
BD7902CFS
Optical disc ICs
!Input output circuit
Three-phase motor driver output
Spindle driver current detection input
Hall bias
19
10
54pin
51pin
7
20
18
11
9
17
FG signal output
Hall signal input
54pin
54pin
54pin
54pin
1
3
5
2
4
6
21
BTL driver output FO, TK
BTL driver output LD
PWM driver output SLED1, 2
31 32
44pin
51pin
51pin
51pin
51pin
49
51pin
34
36
35
37
45
47
46
48
50
33
BTL driver input FO, TK, LD
PWM driver input SLED1, 2
PWM driver input Spindle
51pin
54pin
54pin
51pin
30pin
54pin
26
52
53
28
29
24
47kΩ
47kΩ
15kΩ
Control signal reference voltage input
Control signal input
54pin
51pin
54pin
10kΩ
15kΩ
50kΩ
50kΩ
50kΩ
27
22
23
50kΩ
50kΩ
5/17
BD7902CFS
Optical disc ICs
!Electrical characteristics
(unless otherwise noted, Ta=25°C, SLVDD=VCC=12V, DVCC=AVM=5V, VC=1.65V, SPRNF=0.33Ω, SLRNF=0.5Ω)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Conditions
Circuit
Circuit current
Quiescent current 1
Quiescent current 2
Quiescent current 3
Stanby-on current 1
Stanby-on current 2
Sled driver block
IQ1
IQ2
−
−
−
−
−
12
9
20
16
mA
mA
mA
mA
mA
V
CC (Loading OFF)
CC (Loading ON)
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
V
IQ3
2.7
0.09
0
4.9
0.2
0.1
DVCC
IST1
IST2
VCC
DVCC
Input dead zone (one side)
Input output gain
VDZSL
gmSL
15
0.8
(0.4)
40
1.0
(0.5)
65
1.2
(0.6)
mV
A/V
(V/V)
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
SLRNF=0.5Ω
IL=500mA
−
1.8
2.3
Ω
Output ON resistor (upper)
Output ON resistor (lower)
Output limit current
RONUSL
RONLSL
ILIMSL
fosc
−
0.8
(0.4)
0.85
0.94
(0.47)
1.5
1.08
(0.54)
Ω
A
(V)
IL=−500mA
SLRNF=0.5Ω
−
100
−
kHz
PWM frequency
Spindle driver block 〈 Hall bias 〉
Hall bias voltage
0.7
1.15
1.6
V
VHB
IHB=10mA
Fig1, 2
Spindle driver block 〈 Hall amplifier 〉
−
50
1
1
−
−
5
−
4
µA
mVPP
V
Input bias current
IHIB
Fig1, 2
Fig1, 2
Fig1, 2
Minimum input level
Common mode input Range
VHIM
VHICM
Spindle driver block 〈 Torque control 〉
20
2.4
(0.8)
50
3.0
(1.0)
90
3.6
(1.2)
mV
A/V
(V/V)
Input dead zone (one side)
Input output gain
VDZSP
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
gmSP
RONUSP
RONLSP
ILIMSP
fosc
SPRNF=0.33Ω
IL=500mA
0.6
1.0
Ω
−
Output ON resistor (upper)
Output ON resistor (lower)
Output limit current
0.35
1.42
(0.47)
0.7
1.64
(0.54)
Ω
A
(V)
−
1.2
(0.4)
IL=−500mA
SPRNF=0.33Ω
−
100
−
kHz
PWM frequency
Spindle driver block 〈 FG output 〉
High voltage
−
−
4.9
0.1
−
−
V
V
VFGH
VFGL
100kΩ pull up to DVCC
Fig1, 2
Fig1, 2
Low voltage
Actuator driver block
−50
−
0
50
0.8
mV
V
Output offset voltage
VOFFT
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
0.45
0.45
17.5
Output saturation voltage "H" VOHFT
IL=500mA
−
0.8
V
Output saturation voltage "L"
Voltage gain
VOLFT
GVFT
IL=−500mA
16.0
19.0
dB
This product is not designed for protection against redioactive rays.
6/17
BD7902CFS
Optical disc ICs
Parameter
Loading driver block
Output offset voltage
Symbol
VOFLD
Min.
Typ.
Max.
Unit
Conditions
Circuit
−50
−
0
50
1.4
mV
V
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Output saturation voltage "H" VOHLD
1.1
IL=500mA
Output saturation voltage "L"
Voltage gain
VOLLD
GVLD
−
0.45
17.5
0.8
V
IL=−500mA
16.0
19.0
dB
CTL1, CTL2
Input high voltage
Input low voltage
Others
VIH
VIL
2.0
−
−
−
V
V
Fig1, 2
Fig1, 2
−
0.5
VC drop-muting
VMVC
VMVCC
0.4
3.4
0.7
3.8
1.0
4.2
V
V
Fig1, 2
Fig1, 2
V
CC drop-muting
This product is not designed for protection against radioactive rays.
7/17
BD7902CFS
Optical disc ICs
!Measurement circuits
SLED POWER
VINSL2 VINSL1
SUPPLY UNIT
DVCC VINFC VINTK
LD
TK
FC
SL1
SL2
OUT-A5
OUT-A4
OUT-A3
OUT-A1
OUT-A2
AVM
V
CC
+
+
A
A
IQDV
IQVC
54 53
52
51 50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
47k
−
47k
47k
LEVEL
SHIFT
LEVEL
SHIFT
LEVEL
SHIFT
PRE
LOGIC
PRE
LOGIC
−
94k
47k
−
+
TSD
FF
47k
94k
LIMIT
LIMIT
47k
−
FF
+
OSC
Current
COMP
FF
Current
LIMIT
OSC
Polarity
REVERSE
DETECT
PWM
OUT
FG
COMP
94k
−
3-phase
MATRIX
15k
−
47k
15k
FG
STBY/
BRAKE
CONTROL
HALL
BIAS
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
IU+
IV+
IW+
A
A
A
+
+
+
IHB
HU+
HV+
HW+
100k
+
2
SW-SP
1
V
CTL1 CTL2 VINSP
DVCC
VINLD VC
A
A
A
VFG
VSPRNF
IU−
IV−
IW−
+
+
+
V
H−
SPRNF
SPVM
U
V
W
OUTSP
Fig.1
8/17
BD7902CFS
Optical disc ICs
SLED POWER SUPPLY
SW-SL
SW-SL
VSLRNF1
V
V
VSLRNF2
SLRNF2
SLRNF1
SLVM
OUT-A
V
VO
SW-RL
2
47µH
RL
1
2
2
1
SW-IL
1
SW-IL
IL
IL
∗A3, A4 and A5 require no coil. (47µH)
OUTSP
V
U
W
47µH
RLSP
SW-RL
2
1
47µH
RLSP
2
SW-RL
RLSP
1
47µH
2-V
2-W
2-U
1
SW-IL
IL
Fig.2
9/17
BD7902CFS
Optical disc ICs
!Table of measure circuit switches position 1
(VCC=SPVM=SLVM=12V, DVCC=AVM=5V, VC=1.65V, RL (act) =8Ω, RL (SL) =8Ω+47µH, RL (SP) =2Ω+47µH,
SLRNF=0.5Ω, SPRNF=0.33Ω, H−=2.5V, HU+=2.6V, HV+=HW+=2.4V)
INPUT
VIN
CTL
SWITCH
Measure
point
Designation
Conditions
1
2
RL SP SL IL
Circuit current
IQ1
IQ2
IQ3
−
−
−
−
−
L
H
L
L
L
H
L
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
IQVC
IQVC
IQDV
IQVC
IQDV
H
L
IST1
IST2
L
Sled driver block
VDZSL
∗1 Check VSLRNF with no output at VIN=VC 15mV
Check VSLRNF with output at VIN=VC 65mV
H
H
H
H
2
2
1
1
1
1
1
1
VSLRNF
VSLRNF
*1
*2
gmSL
See bellow
12V − VOSL + (−)
3.3V
(0V)
ILSL=500mA
RON=
RONUSL
RONLSL
H
H
H
H
1
1
1
1
2
2
2
2
OUT+ (−)
OUT+ (−)
0.5A
VOSL + (−)
0V
(3.3V)
ILSL=−500mA
RON=
0.5A
3.3V
(0V)
ILIMSL
fosc
H
H
H
H
2
2
1
1
1
1
1
1
VSLRNF
VOSL+
1.45
lop
Iosp
Iosl
VRNF4/RNF
VRNF1/RNF
Iop
VRNF3/RNF
VRNF2/RNF
Iosp or Iosl
SPRNF=0.33Ω
SLRNF=0.5Ω
VIN
Time
VIN4
VIN3
VIN2
VIN1
Iop...the peak current of Iosp or Iosl
Dead zone
∗2 Sled driver
∗4 Spindle driver
VIN1=240mV, VIN2=140mV
VIN3=−140mV, VIN=−240mV
VIN1=150mV, VIN2=100mV
VIN3=−100mV, VIN=−150mV
VSLRNF1 − VSLRNF2
VSPRNF1 − VSPRNF2
gm (+) =
gm (−) =
(
(
) / 0.5Ω
gm (+) =
gm (−) =
(
(
) / 0.33Ω
240mV − 140mV
150mV − 100mV
VSLRNF4 − VSLRNF3
240mV − 140mV
VSPRNF4 − VSPRNF3
150mV − 100mV
) / 0.5Ω
) / 0.33Ω
10/17
BD7902CFS
Optical disc ICs
!Table of measure circuit switches position 2
(VCC=SPVM=SLVM=12V, DVCC=AVM=5V, VC=1.65V, RL (act) =8Ω, RL (SL) =8Ω+47µH, RL (SP) =2Ω+47µH,
SLRNF=0.5Ω, SPRNF=0.33Ω, H−=2.5V, HU+=2.6V, HV+=HW+=2.4V)
INPUT
CTL
SWITCH
Measure
point
Designation
Conditions
VIN
1
2
RL SP SL IL
Spindle driver block
〈 Hall bias 〉
VHB
1.65V
H
H
H
H
1
1
1
1
1
1
1
1
IHB=10mA
Pin 7
〈 Hall amplifier 〉
IU+ (−),
IV+ (−),
IW+ (−)
Current flowing in each terminal at H−=2.5V,
HW+=2.7V (2.3V), HV=2.5V
1.65V
IHIB
〈 Torque command 〉
∗2 Check VRNF with no output at VIN=VC 20mV
Check VRNF with output at VIN=VC 90mV
VDZSP
L
L
H
H
2
2
1
1
1
1
1
1
VSPRNF
VSPRNF
∗3
gmSP
See 15 of 20
∗4
ILSP=500mA
12V − VOSP
RONUSP
RONLSP
3.3V
3.3V
H
H
H
H
1
1
2
2
1
1
2
2
RON =
RON =
OUTU, V, W
OUTU, V, W
0.5A
VOSP
0.5A
ILSP=−500mA
ILIMSP
fosc
3.3V
1.85
H
H
H
H
2
2
1
1
1
1
1
1
VSPRNF
VOSPU
〈 FG 〉
VFGH
VFGL
1.65V
1.65V
H
H
H
H
1
1
1
1
1
1
1
1
HW+=2.4V
HW+=2.6V
VFG
VFG
∗5 Condition of input
HU+
2.4V
2.6V
2.6V
2.6V
2.4V
2.4V
HV+
2.6V
2.4V
2.6V
2.4V
2.6V
2.4V
HW+
2.6V
2.6V
2.4V
2.4V
2.4V
2.6V
U
V
W
Condition
Measure point
VOSPU
Source
Sink
Hi-Z
Sink
IOSPU=500mA
IOSPV=500mA
IOSPW=500mA
IOSPU=−500mA
IOSPV=−500mA
IOSPW=−500mA
Source
Sink
Hi-Z
VOSPV
Hi-Z
Source
Source
Hi-Z
VOSPW
VOSPU
Sink
Hi-Z
Source
Hi-Z
Sink
VOSPV
Source
Sink
VOSPW
11/17
BD7902CFS
Optical disc ICs
!Table of measure circuit switches position 3
(VCC=SPVM=SLVM=12V, DVCC=AVM=5V, VC=1.65V, RL (act) =8Ω, RL (SL) =8Ω+47µH, RL (SP) =2Ω+47µH,
SLRNF=0.5Ω, SPRNF=0.33Ω, H−=2.5V, HU+=2.6V, HV+=HW+=2.4V)
INPUT
CTL
SWITCH
Measure
point
Designation
Conditions
VIN
1
2
RL SP SL IL
Actuator driver block
VOFFT
1.65V
H
H
H
H
2
1
1
1
1
1
1
2
VO
3.3V
VOHFT
IL=500mA
5−OUT+ (−)
(0V)
0V
VOLFT
H
H
H
H
1
2
1
1
1
1
2
1
IL=−500mA
OUT+ (−)
(3.3V)
GVFT
0.25V
20log |(VO − VOFFT) / 0.25)|
VO
Loading driver block
VOFLD
1.65V
H
H
L
L
2
1
1
1
1
1
1
2
VO
3.3V
VOHLD
IL=500mA
12−OUT+ (−)
(0V)
0V
VOLLD
H
H
L
L
1
2
1
1
1
1
2
1
IL=−500mA
OUT+ (−)
(3.3V)
GVLD
CTL1, CTL2
VIH
20log |(VO − VOFFT) / 0.25)|
VO
0.25V
1.65V
1.65V
L
L
2
2
1
1
1
1
1
1
Check active at "H"=2.0
IQVC
IQVC
VIL
H
H
Check stand-by at "L"=0.5
CTL1, CTL2
VMVC
1.65V
1.65V
H
H
H
H
1
1
1
1
1
1
1
1
Check all output at VC=0.7V
Check all output at VCC=3.8V
OUTPUT
OUTPUT
VMVCC
!Circuit operation
1. Driver control terminal 1 and 2 (pin22 and pin23)
All the drivers and spindle-drive braking mode can be switched on/off by inputting combinations of H-level signal
(higher than 2V) and L-level signal (lower than 0.5V) to these terminals.
CTL1
(Pin22)
CTL2
(Pin23)
Spindle
Sled
Focus
Tracking
Loading
1)
2)
L
H
−
L
L
... ON
... OFF
H
CTL1
CTL2
SPIN > VC
SPIN < VC
Reverse-rotation braking mode 3)
Short-circuit braking mode
(Pin22)
(Pin23)
L
H
H
Forward-rotation mode
Forward-rotation mode
H
4)
1) Standby mode
The IC is brought into standby state, and its power dissipation can be limited.
2) Drivers muting
All the output channels except the loading are muted and their outputs are turn off.
12/17
BD7902CFS
Optical disc ICs
3) Reverse-rotation braking mode (spindle)
A reverse-rotation torque is applied when SPIN < VC.
Reverse-rotation is detected with SPIN input and Hall input. If the spindle detects reverse rotation when SPIN < VC,
all the outputs are shorted out to GND.
4) Short-circuit braking mode (spindle)
All the spindle driver outputs are shorted out to GND when SPIN < VC.
2. Input/output timing chart
HU−
HU+
FWD
FWD
REV
FWD
HV−
HW−
Vref
HV+
HW+
SPIN
U
SOURCE
Hi-Z
SINK
SOURCE
Hi-Z
V
SINK
SOURCE
Hi-Z
W
SINK
A
B
C
D
E
F
G
H
I
J K L
) Forward
rotation
mode
) Reverse
rotation
brake
) Reverse
protect
) Short
brake
13/17
BD7902CFS
Optical disc ICs
Ι ) Forward-rotation mode
In this mode, the disc rotation is started and accelerated.
When forward-rotation signal inputs from the Hall elements to the positive spindle-drive input terminals
(SPIN > VC), the spindle-drive output terminals output forward torque signal.
Hall amplifier input (forward rotation)
SPIN > VC
V
HU+
L
HU−
H
HV+
L
HV−
H
HW+
H
HW−
L
U
W
A
B
C
D
E
F
Hi-Z
Source
Hi-Z
Sink
L
H
H
L
H
L
Source
Source
Hi-Z
Sink
L
H
H
L
L
H
Sink
Hi-Z
H
L
H
L
L
H
Sink
Source
Source
Hi-Z
H
L
L
H
L
H
Sink
Hi-Z
H
L
L
H
H
L
Sink
Source
Source=PWM
ΙΙ, ΙΙΙ ) Braking mode
In this mode, the disc rotation is decelerated and stopped.
〈 Reverse-rotation braking 〉
When the forward-rotation signal inputs from the Hall elements to the negative spindle-drive input terminals
(SPIN < VC), the spindle-drive output terminals output reverse torque signal.
Hall amplifier input (forward rotation)
SPIN < VC
V
HU+
L
HU−
H
HV+
L
HV−
H
HW+
H
HW−
L
U
W
G
H
I
Hi-Z
Sink
Source
Source
Hi-Z
L
H
H
L
H
L
Sink
Hi-Z
L
H
H
L
L
H
Sink
Source
Source
Hi-Z
J
H
L
H
L
L
H
Hi-Z
Sink
K
L
H
L
L
H
L
H
Source
Source
Sink
H
L
L
H
H
L
Sink
Hi-Z
Source=PWM
3. Hall inputs (pin 1 to 6) and Hall bias (pin 7)
(Spindle)
Hall elements can be connected either in series or in parallel. Set the Hall input voltage to 1.0 to 4.0V.
V
CC
VCC
HU
HV
HU
HV
HW
HW
7pin
〈 Parallel connection 〉
7pin
〈 Series connection 〉
14/17
BD7902CFS
Optical disc ICs
4. Torque command (spindle: pin 24, sled motor: pin 28 and 29) / output current detection terminals (spindle: pin 20, sled
motor: pin 31 and 32)
The relation between the torque command input and the output current detection terminals input is expressed as
shown below:
SPRNF
SLRNF
FWD rotation
Dead zone +
Dead zone −
SPIN
SLIN1, 2
VC
The input-output gain (gm) and the output-limit current (ILIM) depend on the resistance of RNF (output current
detection resistor). Please refer to the following expression.
The gain to drive the spindle or the sled motor can be decreased by connecting a resistor in series to each input
terminal.
Gain expression
Spindle
1.0/RNF
0.47/RNF
Sled
Input-output gain gm (A/V)
Output-limit current Ilim (A)
0.5/RNF
0.47/RNF
Gain with the added resistor gm (A/V) 15k/{SPRNF×(Rin+15k)} 0.5×47k/{SLRNF×(Rin+47k)}
Rin : added series resistor
5. PWM oscillation frequency
The PWM oscillation for driving the spindle and sled is free running. The oscillating frequency is 100kHz (typ.).
6. Muting functions
a) VC-drop muting
When the voltage at VC terminal (pin 27) drops to a value lower than 0.7V (typ.), the outputs of all the channels are
turned off. Set the VC terminal voltage to larger than 1.0V.
b) VCC-drop muting
When the voltages at DVCC terminal (pin 54) and VCC terminal (pin 51) drop to lower than 3.8V (typ.), the outputs of
all the channels are turned off.
c) Over voltage protection circuit
When the voltages at VCC terminal (pin 51) drop to uper than 15.5V (typ.), the output of only the spindle block is
turned off.
7. Thermal-shutdown
A thermal-shutdown circuit (over-temperature protection circuit) is built in to prevent the IC from thermal breakdown.
Use the IC under the thermal loss allowed to the package. In case the IC is left running over the allowable loss, the
junction temperature rises, and the thermal-shutdown circuit works at the junction temperature of 175°C (typ.) (the
outputs of all the channels are turned off). When the junction temperature drops to 150°C (typ.), the IC start operating
again.
15/17
BD7902CFS
Optical disc ICs
!Application example
SLVM=12V
TRACKING
FOCUS
TRACKING
FOCUS
IN
SLED SLED
IN
LOADING
IN2
29
−
IN1
DVCC=5V
M
V
CC=12V
AVM=5V
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
28
47k
47k
47k
LEVEL
SHIFT
LEVEL
SHIFT
LEVEL
SHIFT
PRE
LOGIC
PRE
LOGIC
−
94k
47k
−
+
TSD
FF
47k
94k
LIMIT
LIMIT
47k
−
+
FF
OSC
Current
COMP
FF
Current
LIMIT
OSC
Polarity
REVERSE
DETECT
PWM
OUT
FG
COMP
94k
−
3-phase
MATRIX
15k
−
47k
15k
FG
STBY/
BRAKE
CONTROL
HALL
BIAS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
FG
23
24
25
26
27
VC
µ-COM
µ-COM
SPINDLE
SPINDLE
IN
LOADING
IN
5V
SPRNF
SPVM=12V
Fig.3
!Operation notes
(1) Wiring for SPRNF and SLRNF
Considering the wiring resistance, connect each detecting resistor as close as possible to the current detection
terminals for the spindle drive SPRNF (pin 20) and the sled motor drive SLRNF 1 and 2 (pin 31 and 32) of the IC.
(2) Current detection reference voltage
The detection of current in the spindle and sled involves the detection of voltage between the detection resistances,
but as the reference voltage of internal circuit, the voltage applied to VCC (pin 51) is used by the spindle and that
applied to SLVDD (pin 30) by the sled.
For this reason, be sure to apply VCC (pin 51) to the spindle and SLVDD (pin 30) to the sled according to the
corresponding power supply voltages to prevent voltage differences.
16/17
BD7902CFS
Optical disc ICs
(3) Reverse-rotation braking
In the case of reverse-rotation braking from high speed rotation, pay good attention to reverse electromotive force.
Furthermore, fully check the voltage to be applied to the output terminal and consider the revolutions applied to the
reverse-rotation brake.
(4) Bypass capacitor
Please connect a bypass capacitor (0.1µF) across the supply voltage lines close to the IC pins.
(5) Supply fault, ground fault, and short-circuit between output terminals
Do not short-circuit between any output pin and supply pin (supply fault) or ground (ground fault), or between any
output pins (load short-circuit). When mounting the IC on the circuit board, be extremely cautions about the
orientation of the IC. If the orientation is mistaken, the IC may break down, and produce smoke in some cases.
!Electrical characteristic curves
3
2.6W
2
1
0
0
25
50
75 100 125 150
AMBIENT TEMPERATURE : Ta (°C)
∗ On less than 25.7% (percentage occupied by copper foil),
70×70mm2, t=1.6mm glass epoxy mounting.
Fig.4 Power dissipation
!External dimensions (Units : mm)
22.0 0.2
54
28
1
27
0.15 0.1
6.0 0.2
0.1
0.8 0.36 0.1
SSOP-A54
17/17
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