ROHM BD8606FV-E2

System Power Supply for TV Series
FET Controller Type
3ch System Power Supply ICs
No.09034EAT02
BD8606FV
●Description
BD8606FV has realized the high performance and reliability required as a power supply for thin-screen TV.
Due to the high-speed load response, it is most suitable for TV-purpose processors with increasingly high performance, and
due to the wide phase margin it leaves a good margin for board pattern & constant setting and so facilitates its application
design.
As a high-reliability design, it has various built-in protection circuits (overcurrent protection, output voltage abnormal
protection, thermal protection, and off-latch function at the time of abnormality etc.), therefore as an advantage it does not
easily damage in every possible abnormal condition such as all-pin short circuit test etc. and hence most suitable for
thin-screen TV which requires the high reliability.
●Features
1) 3ch synchronous rectification step-down system DC/DC converter controller
2) 3ch independent ON/OFF. controllable
3) Soft start, soft off function
4) Concentrated protection control with built-in sequencer
5) Built-in low voltage protection function
6) Built-in overvoltage protection function
7) Built-in overcurrent protection function
8) Built-in RT terminal open/short protection function
9) Frequency setting by external resistance is available.
10) Protection condition is output from PDET terminal.
11) Built-in external reset output function
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© 2009 ROHM Co., Ltd. All rights reserved.
1/22
2009.05 - Rev.A
Technical Note
BD8606FV
● Electric characteristic
(Ta=25℃, VIN1, VIN2, VIN3=5.0V, VCC=5.0V, and GND=0V unless otherwise specified.)
specification value
UNIT
Parameter
Symbol
MIN
TYP
MAX
Circuit current 1
IQ1
2.5
5
mA
Circuit current 2
IQ2
5.0
10
mA
< Error amplifier part Ch1,Ch2,Ch3 >
Standard voltage (VREF)
VREF
Condition
CTL1,2,3=0V
CTL1,2,3=VCC
Terminal FB and FC terminal
short
VFB=0.9V
VFB=0.7V
VFB=0.9V
VFB=0.9V, VFC=0.4V
VFB=0.7V, VFC=1.6V
0.792
0.8
0.808
V
Terminal FB Input bias current
IFBB
-1
Terminal FC Clamping voltage H
VFCH
1.8
Terminal FC Clamping voltage L
VFCL
Terminal FC Sink current
IFCSINK
0.5
Terminal FC Source current
IFCSOURCE
Open loop gain
AVERR
< OSC part >
Oscillation frequency
FOSC
100
< Soft start part Ch1,Ch2,Ch3 >
Charging current
ISS
-4.0
Terminal SS Threshold voltage
VSSTH
1.0
Terminal SS Clamping voltage
VSSCLM
1.44
Terminal SS Standby voltage
VSSSTB
0.11
Terminal SS Standby voltage
5
VSSSTB_HYS
Maximum hysteresis error
Terminal SS Discharge resistance
RSS
49
Terminal SS Protection circuit start
1.0
VSSPON
voltage
Terminal SS Protection circuit start
voltage
VSSPON_HYS
10
Maximum hysteresis error
< Low voltage, over voltage detection part Ch1,Ch2,Ch3 >
Terminal FB Low voltage detection
0.27
VLVP
voltage
Terminal FB Low voltage detection
VLVP_HYS
10
Maximum hysteresis error
Terminal FB Overvoltage detection
1.08
VOVP
voltage
< Over current detection part Ch1,Ch2,Ch3 >
Terminal LX input bias current
ILXB
-1
Terminal OCP input bias current
IOCPB
20
< Reset detection part >
Terminal MONVCC reset detection
0.98
VRSTO
voltage
Terminal MONVCC input bias
-1
IMONVCCB
current
Terminal RSTDLY charging current
IRSTDLY
-15
Terminal RESET L output voltage
VOL_RST
< Others >
Terminal PDET L output voltage
VOL_RDET
Terminal CTL input voltage H level
2.0
VIH_CTL
voltage
Terminal CTL input voltage L level
VIL_CTL
voltage
Terminal CTL input current
II_CTL
-
0
100
1
0.2
-70
-
μA
V
V
mA
μA
dB
-
600
kHz
-2.5
1.1
1.72
0.15
-1.0
1.2
2.0
0.19
μA
V
V
V
50
100
mV
70
91
kΩ
1.1
1.2
V
100
200
mV
VSS voltage
0.32
0.37
V
VFB voltage
100
200
mV
VFB voltage
1.2
1.32
V
VFB voltage
0
50
1
80
uA
uA
1.0
1.02
V
0
1
uA
-10
-
-5
0.4
uA
V
IOL=100uA
-
0.4
V
IOL=100uA
-
VCC
V
-
0.5
V
40
70
uA
VSS=1.0V
VSS voltage, VFC=0.8V
VSS voltage (L→H)
VSS voltage (L→H)
VMONVCC voltage (H→L)
Terminal CTL1,2,3
Terminal CTL1,2,3
Terminal CTL1,2,3, CTL=VCC
Terminal
Terminal DRV H output voltage
VOH_DRV
4.5
V
DRV1A,2A,3A,1B,2B,3B
Terminal
Terminal DRV L output voltage
VOL_DRV
0.5
V
DRV1A,2A,3A,1B,2B,3B
VFB : FB terminal voltage, VFC : FC terminal voltage, VSS : SS terminal voltage, VMONVCC : MONVCC terminal voltage
Not designed for radiation resistance.
Current capability should not exceed Pd.
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© 2009 ROHM Co., Ltd. All rights reserved.
2/22
2009.05 - Rev.A
Technical Note
BD8606FV
● Block diagram
21
PGND3
22
DRV3B
23
LX3
24
DRV3A
25
VIN3
26
OCP3
27
FB3
12
28
FC3
29
SS3
30
RT
31
GND
32
TEST1
33
TEST2
34
CTL1
35
CTL2
36
CTL3
37
VCC
38
RESET
RSTDLY
39
MONVCC
PDET
40
VRSTO
VREF
Delay
OVP1.5
LVP0.4
Driver
Control
SYSTEM CONTROL SEQUENCER
SS1 SS2 SS3
Driver
Control
Driver
Control
VREF
OVP1.5
LVP0.4
OVP1.5
LVP0.4
VREF
OSC
20
PGND2
19
DRV2B
18
LX2
17
DRV2A
16
VIN2
15
OCP2
14
FB2
13
FC2
11
SS2
10
GND
9
SS1
8
FC1
7
FB1
6
OCP1
5
VIN1
4
DRV1A
3
LX1
2
DRV1B
PGND1
1
Figure 1 Block char
● Terminal explanation
Table 1 terminal explanation
No.
Symbol
1
PGND1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Description
Ch1 power GND
(same potential as GND terminal)
DRV1B Ch1 Nch drive output terminal
LX1
Ch1 overcurrent detection terminal
DRV1A Ch1 Pch drive output terminal
VIN1 Ch1 power supply input terminal
Ch1 overcurrent detection level
OCP1
resistance connection terminal
FB1 Ch1 voltage detection terminal
FC1 Ch1 phase compensation terminal
Ch1 soft start adjustment capacity
SS1
connection terminal
GND GND (0V connection)
Frequency adjustment resistance
RT
connection terminal
Ch2 soft start adjustment capacity
SS2
connection terminal
FC2 Ch2 phase compensation terminal
FB2 Ch2 voltage detection terminal
Ch2 overcurrent detection level resistance
OCP2
connection terminal
VIN2 Ch2 power supply input terminal
DRV2A Ch2 Pch drive output terminal
LX2
Ch2 overcurrent detection terminal
No.
Symbol
21
PGND3
22
DRV3B
Ch3 power GND
(same potential as terminal GND)
Ch3 Nch drive output terminal
23
LX3
Ch3 overcurrent detection terminal
24
25
DRV3A
VIN3
26
OCP3
27
28
FB3
FC3
29
SS3
30
GND
Ch3 Pch drive output terminal
Ch3 power supply input terminal
Ch3 overcurrent detection level
resistance
Ch3 voltage detection terminal
Ch3 phase compensation terminal
Ch3 soft start adjustment capacity
connection terminal
GND (0V connection)
31
TEST1
Test terminal (Connect to GND)
32
TEST2
Test terminal (connect to GND)
33
34
CTL1
CTL2
Ch1 control terminal
Ch2 control terminal
35
CTL3
Ch3 control terminal
36
37
VCC
RESET
38
19
Description
Power supply input terminal
Reset output terminal
Reset delay adjustment capacity
RSTDLY
connection terminal
MONVCC VCC monitor terminal
DRV2B Ch2 Nch drive output terminal
39
Ch2 power GND
20 PGND2
40
PDET Off latch signal output
(same potential as terminal GND)
※Please give to VCC+0.3V as an operation condition in all input terminals.
However, please do not exceed the absolute maximum rating as VCC=VIN1=VIN2=VIN3.
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© 2009 ROHM Co., Ltd. All rights reserved.
3/22
2009.05 - Rev.A
Technical Note
BD8606FV
● Terminal equivalent circuit chart
Terminal
Terminal
No.
name
Explanation
Terminal equivalent circuit chart
1
PGND1
Ch1 Power GND
(GND Terminal and this potential)
20
PGND2
Ch2 Power GND
(GND Terminal and this potential)
21
PGND3
Ch3 Power GND
(GND Terminal and this potential)
2
DRV1B
Ch1 Nch Driving output terminal
19
DRV2B
Ch2 Nch Driving output terminal
VIN
VIN
②
⑲
22
22
DRV3B
Ch3 Nch Driving output terminal
PGND
PGND
VIN
3
18
LX1
LX2
Ch1 Over current detection
terminal
Ch2 Over current detection
terminal
VIN
VIN
③
⑱
23
23
LX3
Ch3 Over current detection
terminal
PGND
VIN1
4
DRV1A
Ch1 Pch Driving output terminal
17
DRV2A
Ch2 Pch Driving output terminal
VIN1
④
⑰
24
24
DRV3A
Ch3 Pch Driving output terminal
PGND
5
VIN1
Ch1 Power supply input terminal
16
VIN2
Ch2 Power supply input terminal
25
VIN3
Ch3 Power supply input terminal
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© 2009 ROHM Co., Ltd. All rights reserved.
4/22
PGND
2009.05 - Rev.A
Technical Note
BD8606FV
Terminal
No.
6
Terminal
name
Explanation
OCP1
Ch1 Over current detection level
Set resistance connection
terminal
Terminal equivalent circuit chart
VCC
VIN1
⑥
⑮
15
OCP2
26
Ch2 Over current detection level
Set resistance connection
terminal
GND
Ch3 Over current detection level
Set resistance connection
terminal
26
OCP3
7
FB1
Ch1 Voltage detection terminal
14
FB2
Ch2 Voltage detection terminal
VCC
⑦
⑭
27
27
FB3
Ch3 Voltage detection terminal
GND
VCC
8
FC1
Ch1 Phase amends terminal
⑧
⑬
28
13
FC2
Ch2 Phase amends terminal
28
FC3
Ch3 Phase amends terminal
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© 2009 ROHM Co., Ltd. All rights reserved.
5/22
GND
2009.05 - Rev.A
Technical Note
BD8606FV
Terminal
No..
Terminal
name
9
SS1
Ch1 Soft start
Adjustment capacity connection terminal
12
SS2
Ch2 Soft start
Adjustment capacity connection terminal
29
SS3
Ch3 Soft start
Adjustment capacity connection terminal
10
GND
GND (0V Connection)
30
GND
GND (0V Connection)
Explanation
Terminal equivalent circuit chart
VCC
⑨
⑫
29
GND
VCC
11
RT
Frequency adjustment resistance
connection terminal
⑪
GND
31
TEST1
Test terminal
VCC
32
TEST2
Test terminal
33
CTL1
Ch1 Control terminal
34
CTL2
Ch2 Control terminal
35
CTL3
Ch3 Control terminal
31
32
33
34
35
GND
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© 2009 ROHM Co., Ltd. All rights reserved.
6/22
2009.05 - Rev.A
Technical Note
BD8606FV
Terminal
No.
Terminal
name
36
VCC
Explanation
Terminal equivalent circuit chart
Power supply input terminal
VCC
37
RESET
37
Reset output terminal
GND
VCC
38
RSTDLY
Reset Delay
Adjustment capacity
connection terminal
38
GND
VCC
39
MONVCC
39
VCC Monitor terminal
GND
VCC
40
PDET
40
Off latch output terminal
GND
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© 2009 ROHM Co., Ltd. All rights reserved.
7/22
2009.05 - Rev.A
Technical Note
BD8606FV
● Circuit chart
PGND3
21
20
PGND2
DRV3B
19
22
DRV2B
Driver
Control
Driver
Control
LX3
18
23
LX2
DRV3A
17
24
DRV2A
VIN3
25
16
VIN2
OCP2
26
15
OCP3
VREF
VREF
FB2
27
14
FB3
FC3
28
13
FC2
OVP1.5
LVP0.4
29
SS2
12
OVP1.5
LVP0.4
SS3
GND
TEST1
31
10
GND
TEST2
FC1
36
VCC
7
6
OCP1
VIN1
DRV1A
4
37
RESET
VREF
5
35
CTL3
FB1
SS1 SS2 SS3
SYSTEM CONTROL SEQUENCER
8
33
34
CTL2
RSTDLY
3
DRV1B
2
Driver
Control
PWM
Counter
PGND1
1
40
VRSTO
PWM
Counter
LX1
Delay
38
MONVCC
39
9
32
SS1
OVP1.5
LVP0.4
CTL1
PDET
11
30
OSC
RT
※
※
It measures it by the static test mode.
The circuit chart of CH2 and CH3 is omitted.
Figure 2 Circuit chart
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© 2009 ROHM Co., Ltd. All rights reserved.
8/22
2009.05 - Rev.A
Technical Note
BD8606FV
● Application circuit chart
VCC
40uF
VIN
20
21
PGND3
PGND2
22μF×2
DRV3B
DRV2B
18
LX3
LX2
24
17
4.7μH
Driver
Control
23
10μF
19
22
VO 3 : 3.3V
Driver
Control
DRV3A
15
VREF
VREF
OCP3
OCP2
27
14
1000pF
FB3
FB2
13
28
180KΩ
FC3
FC2
12
29
6800pF
OVP1.5
LVP0.4
OVP1.5
LVP0.4
SS3
SS2
GND
RT
31
10
TEST1
6800pF
24KΩ5600pF
66KΩ
SS1 SS2 SS3
FB1
4.7KΩ
33KΩ
180pF
0Ω
OCP1
36
VIN
5
SYSTEM CONTROL SEQUENCER
VREF
VIN1
4
37
Driver
Control
10μF 4.7μH
VO 1 : 1.2V
LX1
2
39
22μF×2
DRV1B
1
40
VRSTO
3
38
Delay
DRV1A
RSTDLY
100KΩ
SS1
FC1
RESET
MONVCC
27KΩ
6
35
External PullUp VCC
100KΩ
100KΩ 33KΩ
110KΩ1000pF
6800pF
7
34
CTL3
0.1μF
72KΩ
8
33
CTL2
9
32
OVP1.5
LVP0.4
CTL1
0Ω
0Ω
47pF
4.7KΩ 153 KΩ
GND
TEST2
0Ω
0Ω
11
30
OSC
56KΩ
VO 2 : 2.5V
VIN2
26
0Ω
39pF
175KΩ
4.7μH
16
VIN3
4.7KΩ
22μF×2
DRV2A
25
VIN
10μF
TEST3
PGND1
Figure 3 Application circuit chart
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© 2009 ROHM Co., Ltd. All rights reserved.
9/22
2009.05 - Rev.A
Technical Note
BD8606FV
●Each characteristic reference data
600
550
500
450
SWITCHING FREQUENCY : fosc[kHz]
ERROR AMP REFERENCE VOLTAGE : VREF[V]
0.900
0.875
0.850
0.825
0.800
0.775
0.750
0.725
400
350
300
250
200
150
100
0.700
-40 -30 -20 -10
0
10
20
30
40
50
60
70
RT=27kΩ
-40 -30 -20 -10
80
Figure 4 Standard voltage-temperature characteristic
135
60
GAIN [dB]
40
20
45
0
0
Gain
-45
-40
Ph ase [de g]
90
-90
-60
-80
-135
-100
-180
1000
10000
100000
20
30
40
50
60
70
80
4.0
SS CHARGE CURRENT : Iss[μA]
Phase
-20
10
Figure 5 Switching frequency-temperature characteristic
180
100
80
0
AMBIENT TEMPERATURE : Ta[℃]
AMBIENT TEMPERATURE : Ta[℃]
1000000
3.5
3.0
2.5
2.0
1.5
1.0
-40 -30 -20 -10
0
10
20
30
40
50
60
70
80
AMBIENT TEMPERATURE : Ta[℃]
10000000
f [H z]
Figure 7 Terminal SS charge current-temperature
characteristic
Figure 6 Open loop characteristic
15
RSTDLY CHARGE CURRENT : Irstdly[μA]
OCP INPUT CURRENT : Iocp[μA]
80
70
60
50
40
30
20
-40 -30 -20
-10
0
10
20
30
40
50
60
70
14
13
12
11
10
9
8
7
6
5
-40 -30 -20 -10
80
AMBIENT TEMPERATURE : Ta[℃]
10
20
30
40
50
60
70
80
Figure 9 Terminal RSTDLY charge current-temperature
characteristic
Figure 8 Terminal OCP inflow current-temperature
characteristic
1.10
PWM FREQUENCY [kHz]
1000
1.05
Vrsto[V]
0
AMBIENT TEMPERATURE : Ta[℃]
1.00
0.95
0.90
-40 -30 -20 -10
0
10
20
30
40
50
60
70
100
10
80
10
AMBIENT TEMPERATURE : Ta[℃]
Figure 10 MONVCC reset detection voltage-temperature
characteristic
100
90
POWER EFFICIENCY[%]
3.4ms
1.72V
SS
3.3V
80
70
60
50
VIN=5.0V
Vo=3.3V
External FET:SP8M4 Drive
40
30
20
10
Vo
1000
Figure 11 Switching frequency-terminal RT resistance
characteristic
5V
CTL
100
RT RESISTANCE [kΩ]
Css=6800pF
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
LOAD CURRENT[A]
Figure 12 Soft start crimp
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Figure 13 Efficiency
10/22
2009.05 - Rev.A
Technical Note
BD8606FV
Reference data of dead time
90%
DRVA
(Pch Gate)
10%
90%
DRVB
(Nch Gate)
10%
Trdeat
Tfdeat
Figure 14 Dead time
(VCC=5.0V,VIN=5.0V,Ta=25℃)
Parameter
PchMOS OFF→NchMOS ON Dead time
NchMOS OFF→PchMOS ON Dead time
Symbol
Trdeat
Tfdeat
200
min
90
100
typ
120
140
max
160
190
UNIT
ns
ns
200
VCC=4.0V
VCC=4.0V
VCC=5.0V
Tfdeat [nsec]
150
Trdeat [nsec]
150
VCC=5.0V
VCC=7.0V
100
VCC=7.0V
100
50
50
-40
-20
0
20
40
60
80
-40
AMBIENT TEMPERATURE : Ta[℃]
-20
0
20
40
60
80
AMBIENT TEMPERATURE : Ta[℃]
Figure 15 Dead time Trdeat - Temperature characteristic
(pcs)
7
Figure 16 Dead time Tfdeat - Temperature characteristic
(pcs)
7
VCC=VIN=5.0V
Ta=25℃
n=12(2lot)
6
6
5
5
5
4
4
VCC=VIN=5.0V
Ta=25℃
n=12(2lot)
6
6
4
3
3
2
2
2
1
190
188
185
183
180
178
175
173
170
168
165
163
160
158
155
153
150
148
145
143
140
138
135
133
130
128
125
123
120
118
115
113
110
108
105
103
100
160
158
155
153
150
148
145
143
140
138
135
133
130
128
125
123
120
118
115
113
110
108
0
105
103
100
0
98
95
93
1
90
1
Trdeat[ns]
Tfdeat[ns]
Figure 17 Dead time Trdeat - Difference
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Figure 18 Dead time Tfdeat - Difference
11/22
2009.05 - Rev.A
Technical Note
BD8606FV
Reset detection data
VCC
100kΩ
RESET
MONVCC
1.235V
(typ)
1.0V
(typ)
RSTDLY
Figure 19 Circuit chart
RESET[V]
VRST_HYS
VOL_RST
MONVCC[V]
VRSTO
Figure 20 Reset detection
(VCC=5V,Ta=25℃)
Parameter
Terminal MONVCC reset detection voltage
Terminal MONVCC reset detection voltage
Maximum hysteresis error
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Symbol
VRSTO
min
0.98
typ
1.0
max
1.02
UNIT
V
VRST_HYS
20
72
180
mV
12/22
2009.05 - Rev.A
Technical Note
BD8606FV
Permissible loss
T cmax
θ jc
[ ℃ /W]
28.0
θ ja
[ ℃ /W]
111.1
T STGmin
T STGmax
T a min
T a max
[℃ ]
[℃ ]
[℃ ]
[℃ ]
-50.0
150.0
-45.0
T j max
Destruction Destruction
temperature temperature
85.0
[℃ ]
[℃ ]
150.0
150.0
1.2
Permissible loss : Pd [W]
1
ROHM standard
substrate mounting
θja=111.1℃/W
0.8
0.6
0.4
0.2
0
0
25
50
75
100
125
150
Ambient temperature : Ta [℃]
ROHM standard substrate specification
Material The glass epoxy
Size 70mm×70mm×1.6mmt
Figure 21Heat decrease curve
※These values are the example values, and no guarantee values.
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13/22
2009.05 - Rev.A
Technical Note
BD8606FV
● Operation description
ON/OFF control
DC/DC converter controller ON/OFF function
DC/DC converter controller of each Ch can be independently controlled ON/OFF by CTL1, CTL2, and CTL3 terminal.
Analog circuit of Ch interlocked to each CTL terminal starts operation at ON control (on mode), and goes down to setting
output voltage.
Analog circuit of Ch interlocked to each CTL terminal should be standby at OFF control (off mode), and output voltage
becomes 0V.
Table 2 DC/DC converter controller ON/OFF function
CTL1 terminal voltage
Ch1
CTL2 terminal voltage
Ch2
CTL3 terminal voltage
Ch3
>VIHCTL1
ON control
>VIHCTL2
ON control
>VIHCTL3
ON control
<VILCTL1
OFF control
<VILCTL2
OFF control
<VILCTL3
OFF control
Soft start time set function
DC/DC converter controller of each Ch can do soft start without overshoot by charging soft start capacity (Css) connected
between ss terminal and GND in each Ch by charging current at ON control.
The mute of the output is released when it reaches VSS=0.15V (VSSSTB), and the output voltage does the soft start
operation from the point of VSS=0.3V (typ) in proportion to the voltage of the terminal SS.
Also, soft start time (tss) can be set by setting soft start capacity arbitrarily.
Soft start time (tss) should be set at 3msec < tss < 30msec.
※Please note that the overshoot is not caused in the output setting voltage when setting it to tss≦3msec.
t SS  400us+
1.1V  CSS
2.5uA
Discharge function
DC/DC converter controller of each Ch can do soft off by discharging load discharged to soft start capacity connected
between SS terminal to GND by discharging resistance at OFF control.
Soft off operates in proportion to the voltage of the terminal SS the output voltage from the point of VSS=0.8V (typ).
2.0V
CTL terminal
voltage
0.5V
1.9V
1.1V
0.8V
SS terminal voltage
0.15V
0.3V
Output voltage
Mute
release
tss
Figure 22 Wave form at ON/OFF control
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14/22
2009.05 - Rev.A
Technical Note
BD8606FV
OSC oscillation frequency setting function
DRVA and DRVB output oscillation frequency of DC/DC converter controller of each Ch can be set by installing resistance
between RT terminal and GND externally.
Switching frequency[KHz]
10000
1000
100
10
1
10
RT terminal resistance[KΩ]
100
*reference data
1000
Figure 23 Terminal RT resistance-oscillation frequency
Off latch signal output function
PDET terminal outputs condition of off latch when protection operation of DC/DC converter controller of each Ch operates.
Table 3 PDET terminal off latch signal output function
Protection operation
Terminal PDET
ON
LOW
OFF
Hi-Z
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15/22
2009.05 - Rev.A
Technical Note
BD8606FV
Reset output function
Reset output function observes voltage value from MONVCC terminal and does reset operation compared to internal reference
level.
Set MONVCC terminal external resistance to make VCC voltage more than 5.0V at reset release.
Table 4 DC/DC converter controller ON/OFF function
MONVCC terminal voltage
RESET terminal
<1.0V(typ)
LOW
>1.072V(typ)
Hi-Z
Delay time until detecting reset release is settable by capacitor connected to RSTDLY terminal.
TRSTDLY 
1.235V  CRSTDLY
IRSTDLY
VCC
α(VRSTO+VRSTO_HYS)
(α=
R1+R2
R2
)
R1
MONVCC
α・VRSTO
VCC
R2
VRSTO
(1.0V)
Power supply in
reset input side
0
RESET
IRSTDLY
Hi Z
RESET
Low
TRSTDLY
1.235V
CRSTDLY
Figure 24 Reset operation
( TRSTDLY:Delay time until detecting reset release )
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© 2009 ROHM Co., Ltd. All rights reserved.
16/22
2009.05 - Rev.A
Technical Note
BD8606FV
Output Duty
Output Duty of DRVA of the DC/DC converter controller of each Ch is decided depending on the voltage of the terminal FC
of each Ch.
Setting output Duty 
Output setting voltage
 100 [%]
VIN voltage
9%  Setting output Duty  92%
100
Quality item
characteristic
(typ)
About 92%
Duty [%]
Output Duty
setting range
When FC=1.2V
Output Duty=50%±15%
50
About 9%
0.0
0.5
0.9
1.5
1.2
2.0
FC terminal Voltage [V]
Figure 25 FC Voltage-Output Duty Linearity
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17/22
2009.05 - Rev.A
Technical Note
BD8606FV
● Protection function
Protection circuit is effective for destruction prevention due to accident so that avoid using by continuous protection
operation.
Low voltage protection function(LVP)
Low voltage protection function detects output voltage VO set in each Ch from FB terminal of each Ch and off-latched all
DC/DC converter controller compared to internal reference level.
Low voltage protection function operates when FB terminal voltage falls below VLVP (=1.5 × VREF) and continues about
more than 400μsec (typ).
CTL
terminal
>VIHCTL
<VILCTL
Table 5 Low voltage protection function
Low voltage protection
FB terminal
function
<VLVP
Enable
>VLVP+VLVP_HYS
Disable
Disable
SS terminal
>1.1V(typ)
<1.0V(typ)
-
Low voltage protection
operation
ON
OFF
OFF
OFF
※Constant voltage protection function is enabled when SS terminal voltage of each Ch becomes more than 1.1V (typ) in the
transition to ON control (during soft start).
Overvoltage protection function(OVP)
Overvoltage protection function detects output voltage VO set in each Ch from FB terminal of each Ch and off-latched all
DC/DC converter controller compared to internal reference level.
Overvoltage protection function operates when FB terminal voltage exceeds VOVP (=1.5 × VREF) and continues about
more than 400μsec (typ).
Table 6 Overvoltage protection function
Overvoltage protection Overvoltage protection
SS terminal
FB terminal
function
operation
>VOVP
ON
>1.1V(typ)
Effective
>VIHCTL
<VOVP
OFF
<1.0V(typ)
Invalidity
OFF
<VILCTL
Invalidity
OFF
※Overvoltage protection function is enabled when SS terminal voltage of each Ch becomes more than 1.1V (typ) in
the transition to ON control (during soft start).
CTL
terminal
VFB
1.5×VREF
FB terminal
Voltage
0.4×VREF+VLVP_HYS
VREF
0.4×VREF
0
ON
Protection
OFF
LVP
PDET terminal
OVP
LVP
Hi-Z
LOW
Figure 26 Low voltage and over voltage protection
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18/22
2009.05 - Rev.A
Technical Note
BD8606FV
Overcurrent protection function(OCP)
Overcurrent protection function compared drain voltage (LX terminal voltage) with OCP terminal voltage when external Pch
POWER MOS is ON. When LX terminal voltage becomes lower than OCP terminal voltage, external MOS would be OFF. Up
to 50uA (typ) of constant current from OCP terminal is synchronized. Overcurrent detection level (OCP terminal voltage) can
be set arbitrarily by external resistance value.
Off latch by overcurrent protection function operates when LX terminal voltage falls below OCP terminal voltage and
continues about more than 400μsec (typ).
Table 7 overcurrent protection function
Overcurrent
SS terminal
LX terminal voltage
protection function
<VOCP
>1.1V(typ)
Enable
>VIHCTL
>VOCP
<1.0V(typ)
Disable
<VILCTL
Disable
※Set OCP terminal voltage to be more than VIN-2.5V (typ).
CTL
terminal
Overcurrent
protection operation
ON
OFF
OFF
OFF
LX terminal Voltage
OCP terminal
Voltage
Immediately
off
Immediately
off
Immediately
off
DRVA
DRVB
Output current
Output current
Rocp
LX
Protection
ON
OFF
400usec (typ) to an off latch in
continuance
400usec
OCP
Immediately off operation
Off latch
Figure 27 Overcurrent protection
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© 2009 ROHM Co., Ltd. All rights reserved.
19/22
2009.05 - Rev.A
Technical Note
BD8606FV
Terminal FC abnormality protection function
FC
FB
ErrAmp
FCP
To SEQ
DRVA
PWMCOMP
D
R
V
SS
DRVB
Internal
triangular wave
FCHP=1.95V(typ)
1.5V(typ)
Internal
triangular wave
FC
0.9V(typ)
FCLP=0.62V(typ)
About 400usec(typ) continuance
and an off latch.
About 400usec(typ)
Off latch
The terminal FC abnormality protection function Ofrattis it all DC/DC converter controller detecting the continuance of the
state that FC which is the difference input of PWMCOMP does not intersect with an internal triangular wave.
The terminal FC abnormality protection function is exceeded 1.95V(typ) by the voltage of the terminal FC or operates when it
falls below 0.62V(typ), and about 400usec(typ) or more continues.
CTL
terminal
SS terminal
Protection
operation
FC terminal
Terminal FC
abnormality protection operation
ON
> 1.95V(typ)
0.62V(typ) < , <
> VIHCTL
OFF
1.95V(typ)
< 1.0V(typ)
< 0.62V(typ)
ON
Disable
< VIHCTL
OFF
※Terminal FC abnormality protection function is enabled when SS terminal voltage of each Ch becomes more than
1.1V (typ) in the transition to ON control (during soft start).
> 1.1V(typ)
Enable
RT terminal open/short protection function
RT terminal open/shot protection function off-latches all DC/DC converter controller by detecting open/short condition
internally from RT terminal to prevent from output voltage error caused by abnormal oscillation of internal triangular wave at
RT terminal open/short.
RT terminal open/short protection function is regularly enabled after boot-up.
RT terminal open/short protection function operates when error detection condition continues about more than 400μsec
(typ).
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20/22
2009.05 - Rev.A
Technical Note
BD8606FV
Soft start time-out function
Each Ch DC/DC converter controller off-latch-controls when VSS does not exceed VSSPON from VSS > VSSSTB+VSSSTB_HYS after
50msec (typ) passed from soft start.
VSSCLM
VSSPON
SS terminal
VSSSTB+VSSSTB_HYS
0V
about 50msec( typ)
Figure 28 At soft start time-out
Error detection (off latch) release method
Each Ch DC/DC converter controller comes into off latch condition when protection function operates. Off latch can be
released by the following method. Each Ch DC/DC converter controller becomes able to do ON control transition by
releasing off latch.
1. Set all Ch CTL terminal voltage as < VILCTL and continue that condition about more than 200usec (typ).
2. Drop down power supply VCC to below 3.7V.
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21/22
2009.05 - Rev.A
Technical Note
BD8606FV
●Ordering part number
B
D
8
Part No.
6
0
6
F
Part No.
V
-
E
Package
FV: SSOP-B40
2
Packaging and forming specification
E2: Embossed tape and reel
SSOP-B40
<Dimension>
<Tape and Reel information>
13.6 ± 0.2
21
1
20
Direction
of feed
E2
0.3Min.
2000pcs
0.15 ± 0.1
1234
1234
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© 2009 ROHM Co., Ltd. All rights reserved.
1pin
1234
(Unit:mm)
Reel
1234
0.08 M
1234
0.22 ± 0.1
1234
0.1
0.65
(The direction is the 1pin of product is at the upper left when you hold
reel on the left hand and you pull out the tape on the right hand)
1234
0.1
Embossed carrier tape
Quantity
1234
1.8 ± 0.1
7.8 ± 0.3
5.4 ± 0.2
40
Tape
Direction of feed
※When you order , please order in times the amount of package quantity.
22/22
2009.05 - Rev.A
Notice
Notes
No copying or reproduction of this document, in part or in whole, is permitted without the
consent of ROHM Co.,Ltd.
The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specifications,
which can be obtained from ROHM upon request.
Examples of application circuits, circuit constants and any other information contained herein
illustrate the standard usage and operations of the Products. The peripheral conditions must
be taken into account when designing circuits for mass production.
Great care was taken in ensuring the accuracy of the information specified in this document.
However, should you incur any damage arising from any inaccuracy or misprint of such
information, ROHM shall bear no responsibility for such damage.
The technical information specified herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or
implicitly, any license to use or exercise intellectual property or other rights held by ROHM and
other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the
use of such technical information.
The Products specified in this document are intended to be used with general-use electronic
equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices).
The Products specified in this document are not designed to be radiation tolerant.
While ROHM always makes efforts to enhance the quality and reliability of its Products, a
Product may fail or malfunction for a variety of reasons.
Please be sure to implement in your equipment using the Products safety measures to guard
against the possibility of physical injury, fire or any other damage caused in the event of the
failure of any Product, such as derating, redundancy, fire control and fail-safe designs. ROHM
shall bear no responsibility whatsoever for your use of any Product outside of the prescribed
scope or not in accordance with the instruction manual.
The Products are not designed or manufactured to be used with any equipment, device or
system which requires an extremely high level of reliability the failure or malfunction of which
may result in a direct threat to human life or create a risk of human injury (such as a medical
instrument, transportation equipment, aerospace machinery, nuclear-reactor controller,
fuel-controller or other safety device). ROHM shall bear no responsibility in any way for use of
any of the Products for the above special purposes. If a Product is intended to be used for any
such special purpose, please contact a ROHM sales representative before purchasing.
If you intend to export or ship overseas any Product or technology specified herein that may
be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to
obtain a license or permit under the Law.
Thank you for your accessing to ROHM product informations.
More detail product informations and catalogs are available, please contact us.
ROHM Customer Support System
http://www.rohm.com/contact/
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R0039A