ROHM BD8628EFV

System Power Supply for TV Series
FET Controller Type
3ch System Power Supply ICs
No.09034EAT06
BD8628EFV, BD8624EFV
●Description
BD8628EFV / BD8624EFV have realized the high performance and reliability required as a power supply for thin-screen
TV.
With built-in FET 1ch current mode control, the DC/DC Converter series has the advantage of high-speed load response
and wide phase margin.
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)
11ch synchronous rectification step-down system DC/DC converter
2) Soft start, soft off function
3) Built-in low voltage / overvoltage protection function
4) Built-in overcurrent protection function
5) Frequency setting by external resistance is available. (RT terminal)
6) Protection time setting by external resistance is available. (RSET terminal)
7) Built-in RT / RSET terminal open/short protection function
8) Protection control with built-in sequencer
9) Built-in adjustment function time of off latch
10) Built-in error state detection signal output function
11) Built-in tracking function
12) Corresponded to protecting bus
13) Load current Maximum 3A
14) HTSSOP-B24 Package
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© 2009 ROHM Co., Ltd. All rights reserved.
1/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
●Electric characteristic
(Ta=25℃, VCC=6.5V, GND=0V,CTL=6.5V unless otherwise specified.)
specification value
Parameter
Symbol
MIN
TYP
MAX
Circuit current 1
IQ1
0
10
Circuit current 2
IQ2
3.4
< Error amplifier part >
UNIT
μA
mA
Standard voltage (VREF)
VREF
0.792
0.8
0.808
V
Terminal FB Input bias current
Terminal FC Clamping voltage H
Terminal FC Clamping voltage L
Terminal FC Sink current
Terminal FC Source current
Open loop gain
<OSC part>
IFBB
VFCH
VFCL
IFCSINK
IFCSOURCE
AVERR
-1
1.8
0.5
-
0
100
1
0.2
-70
-
μA
V
V
mA
μA
dB
FOSC
400
500
600
kHz
Oscillation frequency
Condition
CTL=0V
CTL=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
When terminal RT 27kΩ is
connected
<Soft start >
Charging current
ISS
-3
-2.5
-2
μA
VSS=1.0V
Terminal SS Threshold voltage
VSSTH
0.98
1.08
1.18
V
VSS Voltage
Terminal SS Clamping voltage
VSSCLM
2.2
2.4
V
Terminal SS Standby voltage
VSSSTB
0.1
0.15
V
VSS Voltage (L to H)
Terminal SS Discharge resistance
RSS
49
70
91
kΩ
CTL=0V
Terminal SS Protection circuit start
VSSPON
1.0
1.1
1.2
V
VSS Voltage (L to H)
voltage
Terminal SS Protection circuit start
10
100
200
mV
VSS Voltage
voltage
VSSPON_HYS
Maximum hysteresis error
< Low voltage, over voltage detection part>
Terminal FB Low voltage detection
0.51
0.56
0.61
V
VFB Voltage
VLVP
voltage
Terminal FB Overvoltage detection
VOVP
0.86
0.96
1.06
V
VFB Voltage
voltage
< Over current detection part>
Output current limitation threshold
Ilmt
VCC-0.9 VCC-0.7 VCC-0.5
V
VSW Voltage
<Power MOS>
mΩ
Upper side MOS ON resistance
RONU
110
VBOOT-VSW =5V
Lower side MOS ON resistance
RONL
110
mΩ
VVREG5=5V
<Others>
Terminal PDET L output voltage
VOL_PDET
0.4
V
IOL=100uA
Terminal CTL input voltage H level
VIH_CTL
2.0
VCC
V
voltage
CTL terminal
Terminal CTL input voltage L level
0.5
V
VIL_CTL
CTL terminal
voltage
Terminal CTL input current
II_CTL
60
90
μA
CTL terminal, CTL=VCC
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.
2/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
Permissible loss
This package is a product of which the feature is the high heat radiation, and connect the back to GND
based on recommended land pattern when you mount.
T j max
T cmax
θ jc
[ ℃ /W]
19.0
θ ja
[ ℃ /W]
31.3
T STGmin
T STGmax
T a min
T a max
[℃ ]
[℃ ]
[℃ ]
[℃ ]
-50.0
150.0
-45.0
85.0
Destruction
temperature
Destruction
temperature
[℃]
[℃]
150.0
150.0
Permissible loss ： Pd [W]
5
4
ROHM standard
substrate mounting
θja=31.3℃/W
3
2
1
0
0
25
50
75
100
125
150
Ambient temperature ： Ta [℃]
ROHM standard substrate specification
Material 4 layer glass epoxy substrate(back copper foil70mm x 70mm)
Size 70mm x 70mm x 1.6mmt(Sarmalbiaing is in the substrate.)
Figure.1 Heat decrease curve
※These values are the actual measurement values, and no guarantee values.
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© 2009 ROHM Co., Ltd. All rights reserved.
3/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
●Block diagram
RT
VREF
RT
OPEN/SHORT
SS
OSC
12
OSC
RSET
FB
time
1
4
11
1
3
OSC
OVP
LVP
PDET
FC
10
1
5
PIO
PROTECT
BUS
I/F
SEQ
Control
GND
９
1
6
VREG5
CTL
VREG5
VCC
８
1
7
CTL
BOOT
７
18
Driver
Control
PVCC
SW
６
19
PVCC
SW
５
20
TEST2
N.C.
４
21
TEST1
N.C.
３
22
PGND
N.C.
２
23
PGND
N.C.
１
24
Figure.2 Block diagram, Application diagram
●Terminal explan ation
Table 1 Terminal explanation
No.
Symbol
1
PGND
2
PGND
3
N.C.
4
N.C
Description
No.
Symbol
Power GND terminal
13
RT
Power GND terminal
14
RSET
15
PDET
16
PIO
No wire connection.
(Connect to GND. )
No wire connection.
(Connect to GND. )
SW terminal
Description
Frequency adjustment resistance
connection terminal
Off latch effective time adjustment
resistance terminal
Error state notification terminal
17
CTL
Error state notification
and external IC error detection terminal
Enable input
SW terminal
High side Power MOS gate drive
power source terminal
Internal power supply (5.0V) output
terminal
GND
18
VCC
VCC power supply terminal
19
PVCC
Power VCC terminal
20
PVCC
Power VCC terminal
21
TEST2
Test terminal (Connect to GND. )
FC
Phase amends terminal
22
TEST1
11
FB
Feedback terminal
23
N.C.
12
SS
Soft start adjustment capacity
connection terminal
24
N.C.
Test terminal (Connect to GND. )
No wire connection.
(Connect to GND. )
No wire connection.
(Connect to GND. )
5
SW
6
SW
7
BOOT
8
VREG5
9
GND
10
※Please give to VCC+0.3V as an operation condition in all input terminals except the terminal BOOT.
However, please do not exceed the absolute maximum rating as VCC=PVCC.
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© 2009 ROHM Co., Ltd. All rights reserved.
4/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
●Terminal equivalent circuit chart
Terminal
No.
Terminal
name
1
PGND
2
PGND
Explanation
Terminal equivalent circuit chart
Power GND
(The same potential as the GND
terminal)
Power GND
(The same potential as the GND
terminal)
PVCC
5
SW
PVCC
SW terminal
⑤
⑥
6
SW
SW terminal
PGND
VREG5
7
BOOT
High side Power MOS gate drive
power source terminal
⑦
PGND
8
VREG5
9
GND
10
FC
Internal power supply (5.0V) output
terminal
GND
Phase amends terminal
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© 2009 ROHM Co., Ltd. All rights reserved.
5/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
Terminal
No.
Terminal
name
Explanation
Terminal equivalent circuit chart
VCC
VCC
11
FB
Voltage detection terminal
⑪
GND
12
SS
Soft start adjustment capacity
connection terminal
13
RT
Frequency adjustment resistance
connection terminal
14
RSET
Off latch effective time adjustment
resistance terminal
15
PDET
Error state notification terminal
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© 2009 ROHM Co., Ltd. All rights reserved.
6/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
Terminal
No.
Terminal
name
16
PIO
Error state notification and external
IC error detection terminal
17
CTL
Enable input
21
TEST2
Test terminal (Connect to GND. )
22
TEST1
Test terminal (Connect to GND. )
19
PVCC
Power VCC terminal
20
PVCC
Power VCC terminal
Explanation
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© 2009 ROHM Co., Ltd. All rights reserved.
Terminal equivalent circuit chart
7/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
●Operation description
ON/OFF control
DC/DC converter ON/OFF function
DC/DC converter controller can be controlled ON/OFF by CTL terminal.
Analog circuit starts operation at ON control (on mode), and goes down to setting output voltage.
Analog circuit should be standby at OFF control (off mode), and output voltage becomes 0V.
Table2 DC/DC converter ON/OFF function
CTL terminal voltage
>VIHCTL
ON control
<VILCTL
OFF control
Soft start time set function
DC/DC converter can do soft start without overshoot by charging soft start capacity (Css) connected between SS terminal
and GND 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 
VSSTH  CSS
ISS
Discharge function
DC/DC converter 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).
Figure.3
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© 2009 ROHM Co., Ltd. All rights reserved.
Wave form at ON/OFF control
8/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
OSC oscillation frequency setting function
SW output oscillation frequency of DC/DC converter can be set by installing resistance between RT terminal and GND
externally.
Switching frequency [KHz]
10000
1000
100
10
1
10
100
1000
*Reference date
RT
resistance[KΩ]
Figure.4
terminal
Terminal RT resistance-oscillation frequency
Range of terminal RT connection resistance setting
23kΩ≦Rrt≦135kΩ
(100kHz≦fosc≦600kHz)
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© 2009 ROHM Co., Ltd. All rights reserved.
9/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
PROTECT BUS Input/output function
The terminal PIO is PROTECT BUS Input/output terminal. The terminal PIO is Hi-Z when DC/DC usually operates. When the
terminal PIO becomes LOW by connecting PROTECT BUS, DC/DC is turned off. Afterwards, when the terminal PIO
becomes HIGH, it reactivates.
DC/DC is Off latch when DC/DC error detects it and the terminal PDET becomes LOW.
Table3 PIO terminal, PDET terminal output function
DC/DC
Error detection
Undetection
Undetection
Detection
PIO terminal
PDET terminal
DC/DC
Hi-Z
LOW
LOW
Hi-Z
Hi-Z
LOW
ON
OFF
Off latch
PROTECT BUS Timing chart
If two or more BD8628EFV//BD8624FV is connected in PROTECT BUS, and it uses at the same time,
when one IC error detects, all remaining IC becomes PIO = Low at the same time, and the output is turned off.
Protecting BUS part timing chart
IC_A detects error.
OFF LATCH
IC_A
PDET
High
PIO
LOW
High
IC_A
PIO
IC_A
PIO
IC_B
PIO
LOW
High
LOW
IC_B
IC_B
Vo
DC/DC OFF
0V
High
IC_B
PDET
When two or more BD8628EFV/BD8624FV is used at the same time,
If one IC error detects, all IC becomes DC/DC OFF at the same time.
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© 2009 ROHM Co., Ltd. All rights reserved.
10/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
●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 set output voltage VO from FB terminal and off-latched DC/DC converter compared
to internal reference level.
Low voltage protection function operates when FB terminal voltage falls below VLVP (=0.7 x VREF) and continues more than
set time in external resistance.
Table 4 Low voltage protection function
Low voltage
Low voltage
SS terminal
FB terminal
protection function
protection operation
<VLVP
ON
>1.1V(typ)
Enable
>VIHCTL
>VLVP+VLVP_HYS
OFF
<1.0V(typ)
Disable
OFF
<VILCTL
Disable
OFF
※Constant voltage protection function is enabled when SS terminal voltage becomes more than 1.1V (typ) in the
transition to ON control (during soft start).
CTL
terminal
Overvoltage protection function (OVP)
Overvoltage protection function detects set output voltage VO from FB terminal and off-latched DC/DC converter controller
compared to internal reference level.
Overvoltage protection function operates when FB terminal voltage exceeds VOVP (=1.2 x VREF) and continues more than
set time in external resistance.
Table 5 Overvoltage protection function
Overvoltage protection Overvoltage protection
SS terminal
FB terminal
function
operation
>VOVP
ON
>1.1V(typ)
Enable
>VIHCTL
<VOVP
OFF
<1.0V(typ)
Disable
OFF
<VILCTL
Disable
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
1.2×VREF
FB
terminal voltage
0.7×VREF+VLVP_HYS
VREF
0.7×VREF
0
Protection
ON
OFF
LVP
PDET
terminal
OVP
LVP
Hi-Z
LOW
Figure.5 Low voltage / overvoltage protection
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11/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
Overcurrent protection function (OCP)
Overcurrent protection function compared drain voltage (LX terminal voltage) with internal OCP terminal voltage when
internal Nch POWER MOS is ON. When LX terminal voltage becomes lower than OCP terminal voltage, external MOS
would be OFF.
Off latch by overcurrent protection function operates when LX terminal voltage falls below OCP terminal voltage and
continues more than set time in external resistance.
CTL
terminal
>VIHCTL
<VILCTL
SS terminal
>1.1V(typ)
<1.0V(typ)
-
Table 6 overcurrent protection function
Overcurrent
Output current
protection function
>Ilmt
Enable
<Ilmt
Disable
Disable
Overcurrent
protection operation
ON
OFF
OFF
OFF
LX terminal voltage
OCP
terminal
voltage
Immediately
off.
Immediately
off.
Immediately
off.
DRVA
DRVB
Output current
Protection
To an off latch in continuance
of set time (typ) in external
resistance
Set time in
external
resistance
Output
current
Rocp
LX
ON
OFF
OCP
Off operation immediately
Off latch
Figure.6 Overcurrent protection
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 error 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 more than set time in external
resistance.
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12/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
Soft start time-out function
DC/DC converter 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
Figure.7
About 50msec（ｔｙp）
At soft start time-out
Error detection (off latch) release method
DC/DC converter becomes off latch condition when protection function operates. Off latch can be released by the following
method. DC/DC converter controller of each Ch 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 2.7V(TYP).
Error detection time set function
Time from the error detection to the off latch can be set by putting resistance outside between GND and RSET terminal.
t offlatch  1.8  103  Rrset [usec]
Rset setting range
10kΩ≦Rset≦75kΩ
(18usec≦tofflach≦135usec)
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© 2009 ROHM Co., Ltd. All rights reserved.
13/14
2009.05 - Rev.A
Technical Note
BD8628EFV, BD8624EFV
●Ordering part number
B
D
8
Part No
6
2
8
E
Part No.
8628
8624
F
V
-
Package
EFV: HTSSOP-B24
E
2
Packaging and forming specification
E2: Embossed tape and reel
HTSSOP-B24
<Tape and Reel information>
<Dimension>
7.8 ± 0.1
0.53 ± 0.15
1 ± 0.2
13
7.6 ± 0.2
5.6 ± 0.1
24
4 +6
−4
1
12
E2
(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
1234
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© 2009 ROHM Co., Ltd. All rights reserved.
1234
（Unit:mm)
1pin
1234
Reel
1234
0.08 M
1234
+0.05
−0.04
2000pcs
1234
0.2
Quantity
Direction
of feed
+0.05
0.17 −0.03
0.08 S
0.65
Embossed carrier tape
1234
1.0Max.
0.85 ± 0.05
0.08 ± 0.05
0.325
Tape
Direction of feed
※When you order , please order in times the amount of package quantity.
14/14
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
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R0039A