BD7905BFS Datasheet, PDF (12/18 Pages) Rohm – 6CH Power Driver for CD-ROM, DVD-ROM

Optical disc ICs
BD7905BFS
!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)
INPUT CTL
SWITCH
Designation
VIN 1 2 RL SP SL IL
Conditions
Measure
point
Actuator driver block
VOFFT 1.65V H H 2 1 1 1
VO
VOHFT
3.3V
(0V)
HH1 1 1
2
IL=500mA
5−OUT+ (−)
VOLFT
0V
(3.3V)
H
H
1
1
1
2
IL=−500mA
OUT+ (−)
GVFT ±0.25V H H 2 1 1 1 20log |(VO − VOFFT) / ±0.25)|
VO
Loading driver block
VOFLD 1.65V H L 2 1 1 1
VO
VOHLD
3.3V
(0V)
HL 1 1 1
2
IL=500mA
12−OUT+ (−)
VOLLD
0V
(3.3V)
H
L
1
1
1
2
IL=−500mA
OUT+ (−)
GVLD _±0.25V H L 2 1 1 1 20log |(VO − VOFFT) / ±0.25)|
VO
CTL1, CTL2
VIH
1.65V L L 2 1 1 1 Check active at "H"=2.0
IQVC
VIL
1.65V H H 2 1 1 1 Check stand-by at "L"=0.5
IQVC
CTL1, CTL2
VMVC
1.65V H H 1 1 1 1 Check all output at VC=0.7V
OUTPUT
VMVCC
1.65V H H 1 1 1 1 Check all output at VCC=3.8V
OUTPUT
!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)
L
H
−
CTL2
(Pin23)
L
L
H
Spindle
Sled
Focus
Tracking
Loading
1)
2)
... ON
... OFF
CTL1
(Pin22)
CTL2
(Pin23)
input output gain (spindle driver)
SPIN > VC
SPIN < VC
L
H
245mArms/V (Typ.)
Forward-rotation
mode
Reverse-rotation
braking mode
3)
H
H
1.5Arms/V (Typ.)
Forward-rotation Short-circuit braking
4)
mode
mode
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.
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