BD7905BFS
Optical disc ICs
1/17
6CH Power Driver for
CD-ROM, DVD-ROM
BD7905BFS
BD7905BFS is a 6-channel driver IC that integrates all drivers necessary for optical disc driver. Low vibration, low noise,
and low heat operation have been realized by adopting 180° PWM driving system for spindle motor driver. The built-in
2-channel sled motor driver is used for the stepping motor.
!
!!
!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 and gain 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 180deg PWM drive.
• Built in current limit, hall bias, short brake, FG 3-phase mixed signal output and reverse protection circuit.
• Low ON-Resistor. (RON=0.85Ω)
〈 Sled motor driver 〉
• Efficient drive by current feedback PWM drive.
• Built in 2channel for stepping motor.
〈 Actuator driver, Loading driver 〉
• Linear BTL drive system.
BD7905BFS
Optical disc ICs
2/17
!
!!
!Absolute maximum ratings (Ta=25°C)
Parameter Symbol Unit
POWER MOS
power suuply voltage
Preblock/BTL powerblock
power supply voltage
PWM control block
power supply voltage
Power dissipation
Operating temperature range
Storage temperature
SPV
M
1,2,SLRNF1,2
V
CC
,SLV
DD
,AV
M
DV
CC
Pd
Topr
Tstg
Limits
−55~+150
15∗1
15
7
2.6∗2
−40~+85
V
V
V
W
°C
°C
∗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 Max.Typ.Min. Unit
SPVM1, 2
−
SLRNF1, 2
−
V
CC∗3
−
SLVDD∗3
−
V
V
SLVDD, V
CC
V
CC
AVM
1412AVM
5.04.3
V
V
DV
CC
2.5∗4
Iosp
6.05.04.3
1.2
−
V
A
0.8Ioo 0.5
−A
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
SL/FO/TR/LO output current
∗3 Set the same supply voltage to V
CC
and SPVM1, 2 to SLV
DD
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.
BD7905BFS
Optical disc ICs
3/17
!
!!
!Block diagram
1 14 15 16 17 18 19 20 21 22 23 24 25 26 272 3 109 12 1311
6
457 8
54 41 40 39 38 37 36 35 34 33 32 31 30 29 2853 52 4546 43 4244
49
51 50 48 47
PRE
LOGIC
FF
FF LIMIT
Current
LIMIT
HALL
BIAS
FG REVERSE
DETECT
OSC Polarity
COMP
LIMIT
OSC
PRE
LOGIC
STBY/
BRAKE
CONTROL
LEVEL
SHIFT
LEVEL
SHIFT LEVEL
SHIFT
TSD
PRE LOGIC
+
−
+
−
67k
67k
188k
47k
112.5k
75k
47k
47k
+
−
+
−
+
−
+
−
117.5k
117.5k
47k
47k
FG
DVCCHU+
HU−
HV+
HV−
HW+
HW−
HB
PGND1
U
SPVM1
V
GND
GND
GND
GND
GND
PGND2
W
SPVM2
SPRNF
FG
CTL1
CTL2
SPIN
DGND
LDIN
VC
FCIN
TKIN
VCC
LDO+
LDO−
TKO+
TKO−
FCO+
FCO−
AVM
GND
GND
GND
GND
GND
AGND
SLO1+
SLO1−
SLO2+
SLO2−
SPCNF
SLRNF2
SLRNF1
SLVDD
SLIN2
SLIN1
BD7905BFS
Optical disc ICs
4/17
!
!!
!Pin descriptions
Pin No. Pin name Function
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
HU+
HU−
HV+
HV−
HW+
HW−
HB
PGND1
U
SPV
M
1
V
GND
GND
GND
GND
GND
PGND2
W
SPV
M
2
SPRNF
FG
CTL1
CTL2
SPIN
DGND
LDIN
V
C
Pin No. Pin name Function
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
SLV
DD
SLRNF1
SLRNF2
SPCNF
SLO2−
SLO2+
SLO1−
SLO1+
AGND
GND
GND
GND
GND
GND
AV
M
FCO−
FCO+
TKO−
TKO+
LDO−
LDO+
V
CC
TKIN
FCIN
DV
CC
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
Spindle driver power ground 1
Spindle driver output U
Spindle driver power supply 1
Spindle driver output V
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
Sled driver 1 input
Sled driver 2 input
Sled driver PowerMOS pre-supply
Sled driver 1 current sense
Sled driver 2 current sense
Spindle driver feedback filter
Sled driver 2 negative output
Sled driver 2 positive output
Sled driver 1 negative output
Sled driver 1 positive output
BTL block and sled driver power ground
GND
GND
GND
GND
GND
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
PWM block control power supply
∗ Positive/negative of the output terminals are determined in reference to those of the input terminals.
BD7905BFS
Optical disc ICs
5/17
!
!!
!Input output circuit
Three-phase motor driver output
Hall signal input Splindle driver feedback filter pin
PWM driver output SLED1, 2
BTL driver input FO, TK, LD PWM driver input SLED1, 2 PWM driver input Spindle
BTL driver output FO, TK BTL driver output LD
Spindle driver current detection input Hall bias
FG signal output
10
8 17
19
18 11 9
3
1
5
54pin 54pin 54pin
4
2
6
31 32
35
37
34
36 45
47 46
48
51pin 51pin
44pin
49 50
51pin 51pin
51pin
7
54pin
21
54pin
52
26
53
51pin
51pin
47kΩ
Reference voltage input
28
29
30pin
54pin
47kΩ
33
54pin
10kΩ
24
54pin
54pin
112.5kΩ
Control signal input
22
23
54pin
54pin
50kΩ
50kΩ
50kΩ
20
51pin
312.5Ω
27
51pin
×3ch ×2ch
10kΩ
50kΩ
50kΩ
112.5kΩ
47kΩ10kΩ150kΩ
BD7905BFS
Optical disc ICs
6/17
!
!!
!Electrical characteristics
(unless otherwise noted, Ta=25°C, SLVDD=VCC=12V, DVCC=AVM=5V, VC=1.65V, SPRNF=0.22Ω, SLRNF=0.5Ω)
IQ1
IQ2
IQ3
IST1
IST2
VDZSL
gmSL
RONUSL
RONLSL
ILIMSL
fosc
VHB
IHIB
VHIM
VHICM
VDZSP1
VDZSP2
gmSP1
gmSP2
RONUSP
RONLSP
ILIMSP1
ILIMSP2
fosc
VFGH
VFGL
VOFFT
VOHFT
VOLFT
GVFT
−
−
−
−
−
5
1.0
(0.50)
−
−
0.84
(0.42)
−
0.7
−
100
1
0
0
1.2
(0.264)
170
(37.4)
−
−
1.2
(0.264)
300
(66.0)
−
−
−
−70
−
−
17.7
13
9
2.5
−
0.2
30
1.3
(0.65)
1.8
0.8
1.0
(0.50)
100
1.15
1
−
−
10
30
1.5
(0.33)
245
(53.9)
0.6
0.25
1.5
(0.33)
440
(96.8)
100
4.9
0.1
0
0.45
0.45
19.5
22
16
4.5
0.1
0.4
55
1.6
(0.8)
2.3
1.4
1.16
(0.58)
−
1.6
5
−
4
40
120
1.8
(0.396)
320
(70.4)
1.0
0.5
1.8
(0.396)
580
(127.6)
−
−
−
70
0.8
0.8
21.3
mA
mA
mA
mA
mA
mV
A/V
(V/V)
Ω
Ω
A
(V)
kHz
V
µA
mV
PP
V
mV
mV
Arms/V
(Vrms/V)
mArms/V
(mVrms/V)
Ω
Ω
A
(V)
mA
(mV)
kHz
V
V
mV
V
V
dB
Parameter Symbol Min. Typ. Max. Unit Conditions Circuit
V
CC
(Loading OFF)
V
CC
(Loading ON)
DV
CC
V
CC
DV
CC
SLRNF=0.5Ω
IL=500mA
IL=−500mA
SLRNF=0.5Ω
IHB=10mA
CTL1="H", CTL2="H"
CTL1="L", CTL2="H"
Effective current
CTL1="H", CTL2="H"
Effective current
CTL1="L", CTL2="H"
IL=500mA
IL=−500mA
CTL1="H", CTL2="H"
CTL1="L", CTL2="H"
IL=500mA
IL=−500mA
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Circuit current
Quiescent current 1
Quiescent current 2
Quiescent current 3
Stanby-on current 1
Stanby-on current 2
Sled driver block
Input dead zone (one side)
Input output gain
Output ON resistor (upper)
Output ON resistor (lower)
Output limit current
PWM frequency
Spindle driver block 〈 Hall bias 〉
Hall bias voltage
Spindle driver block 〈 Hall amplifier 〉
Input bias current
Input level
Common mode input Range
Spindle driver block 〈 Torque control 〉
Input dead zone 1 (one side)
Input dead zone 2 (one side)
Input output gain 1
Input output gain 2
Output ON resistor (upper)
Output ON resistor (lower)
Output limit current 1
Output limit current 2
PWM frequency
Spindle driver block 〈 FG output 〉
High voltage
Low voltage
Actuator driver block
Output offset voltage
Output saturation voltage "H"
Output saturation voltage "L"
Voltage gain
This product is not designed for protection against redioactive rays.
BD7905BFS
Optical disc ICs
7/17
VOFLD
VOHLD
VOLLD
GVLD
VIH
VIL
VMV
C
VMV
CC
−100
−
−
21.5
2.0
−
0.4
3.4
0
1.1
0.45
23.5
−
−
0.7
3.8
100
1.4
0.8
25.5
−
0.5
1.0
4.2
mV
V
V
dB
V
V
V
V
Parameter Symbol Min. Typ. Max. Unit Conditions Circuit
IL=500mA
IL=−500mA
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Fig1, 2
Loading driver block
Output offset voltage
Output saturation voltage "H"
Output saturation voltage "L"
Voltage gain
CTL1, CTL2
Input high voltage
Input low voltage
Others
V
C
drop-muting
V
CC
drop-muting
This product is not designed for protection against radioactive rays.
BD7905BFS
Optical disc ICs
8/17
!
!!
!Measurement circuits
1 14 15 16 17 18 19 20 21 22 23 24 25 26 272 3 109 12 1311
6
457 8
54 41 40 39 38 37 36 35 34 33 32 31 30 29 2853 52 4546 43 4244
49
51 50 48 47
PRE
LOGIC
FF
FF LIMIT
Current
LIMIT
HALL
BIAS
FG REVERSE
DETECT
OSC Polarity
COMP
LIMIT
OSC
PRE
LOGIC
STBY/
BRAKE
CONTROL
LEVEL
SHIFT
LEVEL
SHIFT LEVEL
SHIFT
TSD
PRE LOGIC
+
−
+
−
67k
67k
188k
47k
112.5k
75k
47k
47k
+
−
+
−
+
−
+
−
117.5k
117.5k
47k
47k
FG
A
IU+
IU−IV−IW−
HU+
+
++ +
A
IV+
HV+
+
IW+
IHB
HW+
+
A
H−
A A V
A
SPV
M
VSPRNF
SPRNF
2
1
SW-SP
UV W
OUTSP
V
+100k
VFG CTL1 CTL2 VINSP VINLD V
C
DV
CC
A
DV
CC
VINFC
IQDV IQVC
VINTK
V
CC
AV
M
++
+
OUT-A5
OUT+
OUT−
LD OUT-A4
OUT+
OUT−
TK OUT-A3
OUT+
OUT−
FC OUT-A1
OUT+
OUT−
SL1 OUT-A2
OUT+
OUT−
SL2 SLED POWER
SUPPLY UNIT
SLRNF2
SLRNF1
SLV
DD
VINSL2
0.01µ
VINSL1
Fig.1
A
BD7905BFS
Optical disc ICs
9/17
Fig.2
SLRNF2
SLRNF1
SLVDD
V
SW-SL SW-SL
VSLRNF2
VSLRNF1
SLRNF2 SLRNF1
SLVM
V
SLED POWER SUPPLY
SW-RL
SW-ILSW-IL
OUT+
OUT−
VO
V
11
1
22
2
RL
47µH
IL IL
∗A3, A4 and A5 require no coil. (47µH)
OUT-A
SW-RL
1
247µH
RLSP
U V W
IL
OUTSP
SW-RL
SW-IL
1
1
247µH
RLSP
47µH
RLSP
2-W
2-V
2-U
BD7905BFS
Optical disc ICs
10/17
!
!!
!Table of measure circuit switches position 1
(VCC=SPVM=SLVM=12V, DVCC=AVM=5V, VC=1.65V, RL (SL) =8Ω+47µH, RL (SP) =2Ω+47µH, RL (ACT, LD) =8Ω,
SLRNF=0.5Ω, SPRNF=0.22Ω, H−=2.5V, HU+=2.6V, HV+=HW+=2.4V)
IQ1
IQ2
IQ3
IST1
IST2
gmSL
RONUSL
RONLSL
ILIMSL
fosc
−
−
−
−
−
1.45
*2
3.3V
(0V)
3.3V
(0V)
0V
(3.3V)
L
L
L
L
L
L
L
H
H
H
H
H
H
H
H
H
H
H
H
H
1
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
VDZSL *1 HH 2111
1
1
1
2
2
111
111
111
111
111
Designation INPUT
VIN SWITCHCTL
12RL
SP SL IL
Measure
point
Conditions
∗1 Check VSLRNF with no output at VIN=VC±5mV
Check VSLRNF with output at VIN=VC±55mV
See bellow
ILSL=500mA
ILSL=−500mA
RON=0.5A
VOSL + (−)
RON=0.5A
12V − VOSL + (−)
IQVC
IQVC
IQDV
IQVC
IQDV
VSLRNF
VSLRNF
VSLRNF
OUT+ (−)
OUT+ (−)
VOSL+
Circuit current
Sled driver block
VIN2VIN3
VRNF3/RNF VRNF2/RNF
VRNF1/RNF
lop
VRNF4/RNF
VIN4 VIN1 VIN
Dead zone
SPRNF=0.22Ω
SLRNF=0.5Ω
Iosp
Iosl
Iosp or Iosl
Iop
Time
∗2 Sled driver
VIN1=230mV, VIN2=130mV
VIN3=−130mV, VIN4=−230mV
gm (+) = ( ) / 0.5Ω
230mV − 130mV
VSLRNF1 − VSLRNF2
gm (−) = ( ) / 0.5Ω
230mV − 130mV
VSLRNF4 − VSLRNF3
∗4 Spindle driver
VIN1=300mV (gm1), 600mV (gm2)
VIN2=100mV (gm1), 300mV (gm2)
VIN3=−300mV (gm2), VIN4=−600mV (gm2)
gm1 (+) = ( ) / 0.22Ω
300mV − 100mV
VSPRNF1 − VSPRNF2
gm2 (+) = ( ) / 0.22Ω
600mV − 300mV
VSPRNF1 − VSPRNF2
gm2 (−) = ( ) / 0.22Ω
600mV − 300mV
VSPRNF4 − VSPRNF3
Iop...the peak current of Iosp or Iosl
BD7905BFS
Optical disc ICs
11/17
!
!!
!Table of measure circuit switches position 2
(VCC=SPVM=SLVM=12V, DVCC=AVM=5V, VC=1.65V, RL (SL) =8Ω+47µH, RL (SP) =2Ω+47µH, RL (ACT, LD) =8Ω,
SLRNF=0.5Ω, SPRNF=0.22Ω, H−=2.5V, HU+=2.6V, HV+=HW+=2.4V)
VHB
gmSP1
RONUSP
RONLSP
ILIMSP1, 2
fosc
1.65V
1.85
∗4
3.3V
3.3V
3.3V
H
H
H
H
H
H
H
H
H
H
H
H
2
2
2
1
1
1
1
1
1
2
2
1
1
1
1
1
VDZSP1 ∗3HH 2111
1
1
1
2
2
111
IHIB 1.65V HH1111
Designation INPUT
VIN SWITCHCTL
12RL
SP SL IL
Measure
point
Conditions
∗3 Check VRNF with no output at VIN=V
C
Check VRNF with output at VIN=V
C
+40mV
See 10 of 17
IHB=10mA
Current flowing in each terminal at H−=2.5V,
H+=2.6V (2.4V)
ILSP=500mA
ILSP=−500mA
RON = 0.5A
12V − VOSP
RON = 0.5A
VOSP
Pin 7
〈 FG 〉
VFGL 1.65V HH 1111HU+=2.6V, HV+=2.4V, HW+=2.6V
VFGH 1.65V HH 1111HU+=2.6V, HV+=2.4V, HW+=2.4V
VFG
VFG
IU+ (−),
IV+ (−),
IW+ (−)
VSPRNF
VDZSP2 ∗3HL 2111
∗3 Check VRNF with no output at VIN=V
C
Check VRNF with output at VIN=V
C
±120mV
VSPRNF
VSPRNF
ILIMSP1, 2 3.3V HL 2111
VSPRNF
VSPRNF
OUTU, V, W
OUTU, V, W
VOSPU
gmSP2 ∗4HL 2111See 10 of 17
VSPRNF
Spindle driver block
〈 Torque command 〉
〈 Hall bias 〉
〈 Hall amplifier 〉
HU+HV+HW+U V W Condition Measure point
2.4V 2.6V 2.6V Source Middle Sink
VOSPU
IOSPU=500mA
2.6V 2.4V 2.6V Sink Source Middle
VOSPV
IOSPV=500mA
2.6V 2.6V 2.4V Middle Sink Source
VOSPW
IOSPW=500mA
2.6V 2.4V 2.4V Sink Middle Source
VOSPU
IOSPU=−500mA
2.4V 2.6V 2.4V Source Sink Middle
VOSPV
IOSPV=−500mA
2.4V 2.4V 2.6V Middle Source Sink
VOSPW
IOSPW=−500mA
∗5 Condition of input
BD7905BFS
Optical disc ICs
12/17
!
!!
!Table of measure circuit switches position 3
(VCC=SPVM=SLVM=12V, DVCC=AVM=5V, VC=1.65V, RL (SL) =8Ω+47µH, RL (SP) =2Ω+47µH, RL (ACT, LD) =8Ω,
SLRNF=0.5Ω, SPRNF=0.22Ω, H−=2.5V, HU+=2.6V, HV+=HW+=2.4V)
VIH
VIL
VOFFT
VOHFT
VOLFT
GVFT
1.65V
1.65V
±0.25V
1.65V
3.3V
(0V)
0V
(3.3V)
H
L
H
H
H
H
H
L
H
H
H
H
2
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
2
2
111
111
Designation INPUT
VIN SWITCHCTL
12RL
SP SL IL
Measure
point
Conditions
20log |(VO − VOFFT) / ±0.25)|
IL=500mA
IL=−500mA
20log |(VO − VOFFT) / ±0.25)|
Check active at "H"=2.0
Check stand-by at "L"=0.5
IL=500mA
IL=−500mA
IQVC
IQVC
VO
5−OUT+ (−)
OUT+ (−)
VO
VO
12−OUT+ (−)
OUT+ (−)
VO
CTL1, CTL2
VMV
C
VMV
CC
1.65V
1.65V H
H
H
H1
1
111
111
Check all output at V
C
=0.7V
Check all output at V
CC
=3.8V
OUTPUT
OUTPUT
CTL1, CTL2
VOFLD
VOHLD
VOLLD
GVLD ±0.25V
1.65V
3.3V
(0V)
0V
(3.3V)
L
L
L
L
H
H
H
H
2
2
1
1
1
1
1
1
1
1
1
1
1
1
2
2
Actuator driver block
Loading driver block
!
!!
!Circuit operation
1. Driver control terminal 1 and 2 (pin22 and pin23)
All the drivers and spindle-drive braking mode and input output gain 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)
LL
HL
−H
CTL1
(Pin22) CTL2
(Pin23) SPIN > VC
input output gain (spindle driver)
SPIN < VC
L H 245mArms/V (Typ.)
1.5Arms/V (Typ.)
HH
Forward-rotation
mode Reverse-rotation
braking mode
Short-circuit braking
mode
Forward-rotation
mode
... ON ... OFF
1)
2)
3)
4)
Spindle Sled Focus Tracking Loading
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.
BD7905BFS
Optical disc ICs
13/17
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+
HV+
HW+
INSP
U
V
W
HU−
HV−
HW−
V
C
SOURCE
MID
SINK
SOURCE
MID
SINK
SOURCE
MID
SINK
ABCDEF GHI JKL
) Forward
rotation
mode
) Reverse
rotation
brake
) Reverse
protect ) Forward
rotation
torque
FWD FWD FWDREV
BD7905BFS
Optical disc ICs
14/17
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 and larger than
100mVPP.
HU HV HW
V
CC
7pin
V
CC
7pin
HU
HV
HW
〈 Parallel connection 〉〈 Series connection 〉
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:
VC SPIN
SLIN1, 2
SPRNF
SLRNF FWD rotation
Dead zone +
Dead zone −
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.
Spindle (CTL1="H") Sled
0.33/RNF (Arms/V)
0.33/RNF (A)
0.33×112.5k
/{SPRNF×(Rin+112.5k)}
(Arms/V)
53.9×112.5k
/{SPRNF×(Rin+112.5k)}
(mArms/V)
Spindle (CTL1="L")
53.9/RNF (mArms/V)
96.8/RNF (mA)
0.65/RNF (A/V)
0.5/RNF (A)
0.65×47k/
{SLRNF×(Rin+47k)}
(A/V)
Input-output gain
Output-limit current
Gain with the added resistor
Gain expression
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.).
BD7905BFS
Optical disc ICs
15/17
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.
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.
!
!!
!Application example
1 14 15 16 17 18 19 20 21 22 23 24 25 26 272 3 109 12 1311
6
457 8
54 41 40 39 38 37 36 35 34 33 32 31 30 29 2853 52 4546 43 4244
49
51 50 48 47
PRE
LOGIC
FF
FF LIMIT
Current
LIMIT
HALL
BIAS
FG REVERSE
DETECT
OSC Polarity
COMP
LIMIT
OSC
PRE
LOGIC
STBY/
BRAKE
CONTROL
LEVEL
SHIFT
LEVEL
SHIFT LEVEL
SHIFT
TSD
PRE LOGIC
+
−
+
−
67k
67k
188k
47k
112.5k
75k
47k
47k
+
−
+
−
+
−
+
−
117.5k
117.5k
47k
47k
FG
FG
LOADING
IN
V
C
FOCUS
IN
TRACKING
IN LOADING
TRACKING
DV
CC
=5V
V
CC
=12V AV
M
=5V
Fig.3
µ-COM
µ-COM SPINDLE
IN
5V
SPV
M
=12V
SPRNF
SPINDLE
HALL3
HALL2
HALL1
SLED
IN1
SLED
IN2
SLV
M
=12V
M
FOCUS
SLED1
SLED2
SLRNF2
SLRNF1
STM
BD7905BFS
Optical disc ICs
16/17
!
!!
!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.
(3) Filtering capacitor
It is recommended to connect 0.01µF filtering capacitor to SPCNF terminals. This capacitor filters PWM output carrier
frequency. Dispersion of the cut off frequency due to circuit board wiring layout is taken into consideration.
If it is difficult to filter at the recommended value due to circuit board wiring led round, the capacity can be increased.
In this case, note that the output transmission delay time may be longer.
(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
0 100755025 125 150
2
0
1
3
POWER DISSIPATION : Pd (W)
AMBIENT TEMPERATURE : Ta (°C)
2.6W
Fig.4 Power dissipation
∗ On less than 25.7% (percentage occupied by copper foil),
70×70mm
2
, t=1.6mm glass epoxy mounting.
BD7905BFS
Optical disc ICs
17/17
!
!!
!External dimensions (Units : mm)
SSOP-A54
0.1 11.4±0.2
13.4±0.3
2.2±0.1
0.1
0.8
127
54 28
22.0±0.2
4.0±0.2
6.0±0.2
0.36±0.1
0.15±0.1
0.3Min.
Appendix
Appendix1-Rev1.0
The products listed in this document are designed to be used with ordinary electronic equipment or devices
(such as audio visual equipment, office-automation equipment, communications devices, electrical
appliances and electronic toys).
Should you intend to use these products with equipment or devices which require an extremely high level of
reliability and the malfunction of with would directly endanger human life (such as medical instruments,
transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel controllers and other
safety devices), please be sure to consult with our sales representative in advance.
Notes
No technical content pages of this document may be reproduced in any form or transmitted by any
means without prior permission of ROHM CO.,LTD.
The contents described herein are subject to change without notice. The specifications for the
product described in this document are for reference only. Upon actual use, therefore, please request
that specifications to be separately delivered.
Application circuit diagrams and circuit constants contained herein are shown as examples of standard
use and operation. Please pay careful attention to the peripheral conditions when designing circuits
and deciding upon circuit constants in the set.
Any data, including, but not limited to application circuit diagrams information, described herein
are intended only as illustrations of such devices and not as the specifications for such devices. ROHM
CO.,LTD. disclaims any warranty that any use of such devices shall be free from infringement of any
third party's intellectual property rights or other proprietary rights, and further, assumes no liability of
whatsoever nature in the event of any such infringement, or arising from or connected with or related
to the use of such devices.
Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or
otherwise dispose of the same, no express or implied right or license to practice or commercially
exploit any intellectual property rights or other proprietary rights owned or controlled by
ROHM CO., LTD. is granted to any such buyer.
Products listed in this document use silicon as a basic material.
Products listed in this document are no antiradiation design.
About Export Control Order in Japan
Products described herein are the objects of controlled goods in Annex 1 (Item 16) of Export Trade Control
Order in Japan.
In case of export from Japan, please confirm if it applies to "objective" criteria or an "informed" (by MITI clause)
on the basis of "catch all controls for Non-Proliferation of Weapons of Mass Destruction.
