ROHM BD8179MUV

Power Supply IC Series for TFT-LCD Panels
5V Input Multi-channel
System Power Supply IC
BD8179MUV
No.09035EBT04
●Description
The BD8179MUV is a system power supply IC for TFT panels.
A 1-chip IC providing a total of three voltages required for TFT panels, i.e., source voltage, gate high-level, and gate low-level
voltage, thus constructing a TFT panel power supply with minimal components required.
●Features
1) Step Up DC/DC Converter.
2) Incorporates 18V, 3.0A N-channel FET
3) Linear-Regulator Controllers for VGON and VGOFF
4) 5 channel Operational Amplifiers/±150mA Output Short-Circuit Current 40V / µs Slew Rate
5) Switching Frequency: 1200 kHz.
6) Gate Shading Function Included.
7) Protection Circuits
8) Over Current Protection
9) Timer Latch Mode Short Current Protection.
10) Thermal Shut Down.
11) Under Voltage Protection.
12) Over Voltage Protection
13) VQFN032V5050 Package
●Applications
Liquid crystal TV, PC monitor, and TFT-LCD panel
●Absolute maximum ratings (Ta = 25℃)
Parameter
Power Supply Voltage
VMAIN Voltage
SUP Voltage
DRVP Voltage
DRVN Voltage
SRC Voltage
CTL Voltage
Junction Temperature
Power Dissipation
Operating Temperature Range
Storage Temperature Range
Symbol
Limit
Unit
VIN
VMAIN
VSUP
VDRVP
VDRVN
VSRC
VCTL
Tjmax
Pd
Topr
Tstg
7
20
20
40
-30
40
7
150
4560
-40~85
-55~150
V
V
V
V
V
V
V
℃
mW
℃
℃
* Reduced by 19.52 mW/℃ over 25℃, when mounted on a glass epoxy board.
(4-layer 74.2 mm  74.2 mm  1.6 mm).
●Operating Condition
Parameter
Power Supply Voltage
VMAIN Voltage
SUP Voltage
DRVP Voltage
DRVN Voltage
SRC Voltage
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Limit
Symbol
Min.
2.6
8
-
VIN
VMAIN
VSUP
VDRVP
VDRVN
VSRC
1/12
Max.
5.5
18
18
38
-20
38
Unit
V
V
V
V
V
V
2009.07 - Rev.B
Technical Note
BD8179MUV
●Electrical Characteristics (Unless otherwise specified, VIN = 3.3V; VSUP = 12 V; VGON = 25 V; VGOFF = -6V; Ta = 25℃)
1 DC/DC CONVERTER CONTROLLER BLOCK
Limit
Parameter
Symbol
Unit
Conditions
Min.
Typ.
Max.
[ ERROR AMPLIFIER BLOCK ]
FB Input Bias Current
IFB
-
0.1
-
µA
Feed Back Voltage
VFB
1.221
1.233
1.245
V
Buffer, No load
Comp Sink Current
Ioi
1
5
10
µA
VFB=1.5V VCOMP=0.5V
Comp Source Current
Ioo
-10
-5
-1
µA
VFB=1.0V VCOMP=0.5V
[ LX BLOCK ]
LX ON-Resistance
Ron
-
200
-
mΩ
LX Leak Current
Ileak
-
0
10
µA
MAX Duty Cycle
DMAX
-
90
-
%
LX Current Limit
ILX
2.5
-
-
A
3.25
-
ms
VLX=18V
[ INTERNAL SOFT START BLOCK ]
Soft Start Delay Time
tss
2. GATE-ON LINEAR REGULATOR CONTROLLER
Parameter
Symbol
Limit
Unit
Min.
Typ.
Max.
1.275
V
FBP Voltage
VFBP
1.225
1.25
FBP Input Bias Current
IFBP
-
0.1
-
µA
5
10
mA
DRVP Current Limit
IDRVP
1
3. GATE-OFF LINEAR REGULATOR CONTROLLER
Parameter
FBN Voltage
FBN Input Bias Current
Symbol
VFBN
Limit
Min.
Typ.
Max.
0.235
0.25
0.265
Unit
IFBN
-
0.1
-
µA
IDRVN
1
5
10
mA
Parameter
Symbol
Input Offset Voltage
Input Range
DRIVE Current
Voff
Typ.
Max.
-
0
-
Unit
mV
VRANGE
0
VSUP
V
Idrv
50
-
-
mA
-
40
-
V/us
Slew Rate
SR
5. GATE SHADING CONTROLLER BLOCK
Parameter
Limit
Symbol
Limit
Min.
Typ.
Max.
Unit
DEL Start Period
tdd
-
15
-
ms
DEL Source Current
Idls
-8
-5
-2
µA
DEL Threshold Voltage
Vdls
1.2
1.25
1.3
V
CTL Input Low Voltage
Vctll
-
-
VIN x 0.3
V
CTL Input High Voltage
Vchlh
VIN x 0.7
-
-
V
Ictl
8
16.5
25
µA
SRC ON Resistance
RonSRC
-
5
-
Ω
DRN ON Resistance
RonDRV
-
30
-
Ω
CTL Input Current
Conditions
V
DRVN Current Limit
4. OPERATIONAL AMPLIFIERS
Min.
Conditions
Conditions
VPOS1~5 = 6V
Conditions
VCTL=3.3V
This product is not designed for protection against radioactive rays.
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2/12
2009.07 - Rev.B
Technical Note
BD8179MUV
●Electrical Characteristics (Unless otherwise specified, VIN = 3.3V; VSUP = 12 V; VGON = 25 V; VGOFF = -6V; Ta = 25℃)
6. WHOLE DEVICE
Limit
Parameter
Symbol
Unit
Conditions
Min.
Typ.
Max.
[ REFERENCE BLOCK ]
Reference Voltage
VREF
1.231
1.25
1.269
V
FOSC
1020
1200
1380
kHz
2.25
2.4
2.55
V
18
19
20
V
Tscp
-
150
-
ms
VFB OFF Threshold Voltage
Vthfb
0.9
1.0
1.1
V
VFBP OFF Threshold Voltage
Vthfbp
0.9
1.0
1.1
V
VFBN OFF Threshold Voltage
Vthfpn
0.4
0.5
0.6
V
[ OSCILLATION BLOCK ]
Oscillation Frequency
[ VIN UNDER VOLTAGE LOCK OUT BLOCK ]
Detect Voltage
Vuvlo
[ SUP OVER VOLTAGE LOCK OUT BLOCK ]
Detect Voltage
Vovp
[ SHORT CURRENT PROTECTION BLOCK ]
Fault Delay Time
[ DETECTOR BLOCK ]
This product is not designed for protection against radio active rays.
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3/12
2009.07 - Rev.B
Technical Note
BD8179MUV
●Reference Data (Unless otherwise specified, Ta = 25℃, VIN=5V)
1000
2
3
2.5
100
Frequency[MHz]
IIN (mA)
2
1.5
1
DELAY TIME [ms]
1.5
1
1
0.5
0.5
0
0
1
2
3
4
5
6
0.1
0
7
-40
VIN (V)
10
0.001
60
0.01
Ta[℃]
94
1
92
0.8
90
0.6
⊿VMAIN[%]
86
84
82
1
Fig.3 Delay Time
vs Capacitor
VIMAIN
0.4
88
0.1
DEL CAPACITOR [uF]
Fig.2 Switching Frequency
vs Temperature
Fig.1 Supply Current
(No switching)
efficency[%]
10
LX
0.2
0
-0.2
0
100
200
300
400
500
-0.4
80
-0.6
78
-0.8
-1
76
0
100
200
300
400
500
Io[mA]
Io[mA]
1
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
0
20
40
60
80
100
⊿VGL[%]
⊿VGH[%]
1
0.8
-0.2
Fig.6 Over Voltage Protect
waveform
Fig.5 VMAIN Voltage
Load Regulation
Fig.4 Efficiency vs Output Current
(VMAIN)
COM
0
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
0
20
40
60
80
100
CTL
-1
-1
Io[mA]
Io[mA]
Fig.7 Gate-ON Voltage
Load Regulation
IN
Fig.8 Gate-OFF Voltage
Load Regulation
IN
OUT
IN
OUT
OUT
IN
OUT
300Ω
300Ω
100pF
100pF
Fig.10 AMP Slew Rate
(Rise)
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Fig.9 Gate Shading Output
waveform
Fig.11 AMP Slew Rate
(Fall)
4/12
Fig.12 Start Up Sequence
waveform
2009.07 - Rev.B
Technical Note
BD8179MUV
●Pin Assignments Diagram
●Block Diagram
VCP
POS5
VMAIN
OUT4
NEG5
OUT5
LX
IN
VIN
FB
COMP
VCN
LX
IN
24 23 22 21 20 19 18 17
FBP
25
16
NEG4
DRVP
26
15
POS4
FBN
27
14
SUP
DRVN
28
13
OUT3
DEL
29
12
POS3
GATE-ON
CTL
30
11
BGND
CONTROLLER
DRN
31
10
POS2
COM
32
9
NEG2
1
2
3
4
5
6
7
8
SRC
REF
AGND
PGND
OUT1
NEG1
POS1
OUT2
BD8179MUV
FB
STEP-UP
CONTROLLER
COMP
PGND
AGND
VCP
DRVP
VGON
FBP
SRC
DEL
GATE SHADING
COM
CONTROLLER
CTL
VCN
DRN
DRVN
GATE-OFF
VGOFF
CONTROLLER
SUP
FBN
NEG1
OUT1
-
OP1
REF
REF
+
POS1
NEG2
OUT2
NEG4
-
OP2
POS4
+
-
OP3
OUT2
OUT4
-
OP4
+
POS2
+
NEG5
OP5
+
-
POS3
BGND
OUT5
POS5
●Pin Assignments
PIN
NO.
Pin
Name
PIN
NO.
Pin
Name
1
SRC
Highside Input for Gate Shading switch
17
OUT4
Operational
Amplifier 4 Output
2
REF
Reference for VGOFF
18
POS5
Operational
Amplifier 5 Noninverting Input
3
AGND
Ground
19
NEG5
Operational
Amplifier 5 Inverting Input
4
PGND
Power Ground
20
OUT5
Operational
Amplifier 5 Output
5
OUT1
Operational
Amplifier 1 Output
21
LX
Nch Power MOS FET Drain and Switching Node
6
NEG1
Operational
Amplifier 1 Inverting Input
22
IN
Power Supply voltage Input
7
POS1
Operational
Amplifier 1 Noninverting Input
23
FB
Feedback Input for step up DC/DC
8
OUT2
Operational
Amplifier 2 Output
24
9
NEG2
Operational
Amplifier 2 Inverting Input
25
FBP
10
POS2
Operational
Amplifier 2 Noninverting Input
26
DRVP
11
BGND
Ground
27
FBN
12
POS3
Operational
Amplifier 3 Noninverting Input
28
DRVN
13
OUT3
Operational
Amplifier 3 Output
29
DEL
Delay Input for Gate Shading
14
SUP
Power Supply voltage Input for operational Amplifier
30
CTL
Switch Control Input for Gate Shading
15
POS4
Operational
Amplifier 4 Noninverting Input
31
DRN
Lowside Input for Gate Shading switch
16
NEG4
Operational
Amplifier 4 Inverting Input
32
COM
Gate Shading Output
Function
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5/12
Function
COMP Error Amplifier Compensation Point for step up DC/DC
Feedback Input for Gate-ON Linear-Regulator
Gate-ON Linear-Regulator Base Drive
Feedback Input for Gate-OFF Linear-Regulator
Gate-OFF Linear-Regulator Base Drive
2009.07 - Rev.B
Technical Note
BD8179MUV
●Block Function
 Step-up Controller
A controller circuit for DC/DC boosting.
The switching duty is controlled so that the feedback voltage FB is set to 1.233 V (typ.).
A soft start operates at the time of starting.
 Gate-on Controller
A controller circuit for the positive-side charge pump.
The liner regulator controls so that the feedback voltage FBP will be set to 1.25 V (typ.).
 Gate-off Controller
A controller circuit for the negative-side charge pump.
The liner regulator controls so that the feedback voltage FBN will be set to 0.25 V (Typ.).
 Gate Shading Controller
A controller circuit for MOS FET Switch
The COM switching synchronize with CTL input.
 Start-up Controller
A control circuit for the starting sequence.
Controls to start in order of VCC VMAIN VGOFF/VGONVCOM
 REF
A block that generates internal reference voltage. 1.25V (Typ.) is output.
 TSD/UVLO/OVP
Thermal shutdown/Under-voltage lockout protection/circuit blocks.
The thermal shutdown circuit is shut down at an IC internal temperature of 175°C and reactivate at 160°C.
The under-voltage lockout protection circuit shuts down the IC when the VIN is 2.4 V (typ.) or below.
The over-voltage lockout protection circuit shuts down the IC when the SUP is 19.0 V (typ.) or over.
 OP1~OP5
Operational amplifier block
●Starting sequence
①
VIN
②
③
④
2.4
VMAIN
VGON
3.25ms
VGON/VGOFF
VGOFF
15ms
1.25V
VDEL
VCOM
①UVLO released when VIN voltage reaches 2.4V
②Step up DCDC converter starts switching, and VGON and VGOFF starts.
③VDEL starts.
④VCOM ON when VDEL reaches 1.25V
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6/12
2009.07 - Rev.B
Technical Note
BD8179MUV
●Under Voltage Lock Out (UVLO)
The UVLO circuit compares the input voltage at IN with the UVLO threshold (2.4V rising, 2.2V falling, typ) to ensure the input
voltage is high enough for reliable operation.
The 200mV (typ) hysteresis prevents supply transients from causing a restart. Once the input voltage exceeds the UVLO
rising threshold, startup begins. When the input voltage falls below the UVLO falling threshold, the controller turns off the
main step-up regulator, turns off the linear-regulator outputs, and disables the Gate Shading controller.
●Thermal Shut Down (TSD)
The TSD prevents excessive power dissipation from overheating the BD8179MUV. When the junction temperature exceeds
Tj=175℃(Typ), a thermal sensor immediately activates. The fault protection, which shuts down all outputs except the
reference, allowing the device to cool down. Once the device cools down by approximately 15℃ reactivate the device.
●Over Voltage Protection (OVP)
The Step up DC/DC converter has OVP circuit.
The OVP circuit compares the input Voltage at SUP with the OVP threshold (19V rising, 18.5V falling, Typ) to protect the step
up DC/DC output exceed the absolute maximum voltage. Once the SUP Voltage exceeds the OVP rising threshold, turn off
the main Step-up regulator.
Then, the SUP Voltage falls bellow the OVP falling threshold,reactivate the main Step-Up regulator.
●Over Current Protection (OCP)
The Step-Up DC/DC converter, linear-regulator and Operational Amplifier have OCP circuit respectively.
The OCP circuit restricts to load current, when an OCP activated, one’s own output only restricted.
However, if the output continue to overload, the device is possible to activate thermal shutdown or short current protection.
●Timer Latch Mode Short Current Protection (SCP)
BD8179MUV has SCP circuit feature to prevent the large current flowing when the output is shorted to GND.
This function is monitoring VMAIN, VGON, and VGOFF Voltage and starts the timer when at least one of the outputs operating
properly (when the output voltage was lower than expected).
After 150ms (Typ.) of this abnormal state, the device will shutdown the all outputs and latch the state.
VMAIN
FB
+
-
VGON
FBP
+
-
150ms typ
Counter
all outputs
shut down.
reset
VGOFF
FBN
-
+
Fig.13 SCP Block Diagram
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7/12
2009.07 - Rev.B
Technical Note
BD8179MUV
●Selecting Application Components
(1) Setting the Output L Constant
The coil to use for output is decided by the rating current ILR and input current maximum value IINMAX of the coil.
IINMAX + ∆IL should not reach
the rating value level
IL
VCC
ILR
IINMAX
average current
L
IL
Vo
Co
Fig.14 Coil Current Waveform
Fig. 15 Output Application Circuit Diagram
Adjust so that IINMAX +∆IL does not reach the rating current value ILR. At this time, ∆IL can be obtained by the following
equation.
1 Vcc
Vo-Vcc
1
ΔIL =

[A]
Here, f is the switching frequency.
L 
Vcc
f
Set with sufficient margin because the coil value may have the dispersion of 30%. If the coil current exceeds the rating
current ILR of the coil, it may damage the IC internal element.
BD8179MUV uses the current mode DC/DC converter control and has the optimized design at the coil value. A coil
inductance (L) of 4.7 µH to 15 µH is recommended from viewpoints of electric power efficiency, response, and stability.
(2) Output Capacity Settings
For the capacitor to use for the output, select the capacitor which has the larger value in the ripple voltage VPP allowance
value and the drop voltage allowance value at the time of sudden load change. Output ripple voltage is decided by the
following equation.
1
Vcc
⊿IL
= ILMAX  RESR +

 (ILMAX ) [V] Here, f is the switching frequency.
⊿VPP
fCo
Vo
2
Perform setting so that the voltage is within the allowable ripple voltage range. For the drop voltage during sudden load
change; VDR, please perform the rough calculation by the following equation.
⊿I
VDR =
 10 us
[V]
Co
However, 10 µs is the rough calculation value of the DC/DC response speed. Please set the capacitance considering the
sufficient margin so that these two values are within the standard value range.
(3) Selecting the Input Capacitor
Since the peak current flows between the input and output at the DC/DC converter, a capacitor is required to install at the
input side. For the reason, the low ESR capacitor is recommended as an input capacitor which has the value more than
10 µF and less than 100 mΩ. If a capacitor out of this range is selected, the excessive ripple voltage is superposed on the
input voltage, accordingly it may cause the malfunction of IC.
However these conditions may vary according to the load current, input voltage, output voltage, inductance and switching
frequency. Be sure to perform the margin check using the actual product.
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8/12
2009.07 - Rev.B
Technical Note
BD8179MUV
(4) Setting RC, CC of the Phase Compensation Circuit
In the current mode control, since the coil current is controlled, a pole (phase lag) made by the CR filter composed of the
output capacitor and load resistor will be created in the low frequency range, and a zero (phase lead) by the output
capacitor and ESR of capacitor will be created in the high frequency range. In this case, to cancel the pole of the power
amplifier, it is easy to compensate by adding the zero point with CC and RC to the output from the error amp as shown in
the illustration.
Open loop gain characteristics
Fp =
fp(Min)
A
fp(Max)
Gain
fz(ESR) =
0
[dB]
fz(ESR)
0
Phase
[deg]
[Hz]
1
[Hz]
2π ESR  CO
Pole at the power amplification stage
When the output current reduces, the load resistance
Ro increases and the pole frequency lowers.
lOUTMin
lOUTMax
1
2 π  RO  CO
fp(Min) =
-90
1
[Hz]←at light load
2   R OMax  C O
1
fz(Max) =
Error amp phase
compensation characteristics
[Hz]←at heavy load
2   R OMin  C O
A
Zero at the power amplification stage
When the output capacitor is set larger, the pole
frequency lowers but the zero frequency will not
change. (This is because the capacitor ESR
becomes 1/2 when the capacitor becomes 2 times.)
Gain
[dB]
0
Phase
[deg]
0
-90
fp(Amp.) =
Fig. 16 Gain vs Phase
L
VCC
Rc
ESR
SW
COMP
2   Rc  Cc
[Hz]
Vo
Vcc,PVcc
Cin
1
Ro
Co
GND,PGND
Cc
Fig. 17 Application Circuit Diagram
It is possible to realize the stable feedback loop by canceling the pole fp(Min.), which is created by the output capacitor
and load resistor, with CR zero compensation of the error amp as shown below.
fz(Amp.) = fp(Min.)
1
2 π  Rc  Cc
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1
2π Romax  C
9/12
[Hz]
2009.07 - Rev.B
Technical Note
BD8179MUV
(5) Design of the Feedback Resistor Constant
Refer to the following equation to set the feedback resistor. As the setting range, 10 kΩ to 330 kΩ is recommended. If the
resistor is set lower than a 10 kΩ, it causes the reduction of power efficiency. If it is set more than 330 kΩ, the offset
voltage becomes larger by the input bias current 0.4 µA(Typ.) in the internal error amplifier.
VMAIN =
R1 + R2
R2
Reference voltage 1.233 V
 1.233
Vo
[V]
R1
+
ERR
23
-
FB
R2
(6) Positive-side Charge Pump Settings
BD8179MUV incorporates a charge pump controller, thus making it possible to generate stable gate voltage.
The output voltage is determined by the following formula. As the setting range, 10 kΩ to 330 kΩ is recommended. If the
resistor is set lower than a 10kΩ, it causes the reduction of power efficiency. If it is set more than 330 kΩ, the offset
voltage becomes larger by the input bias current 0.4 µA (Typ.) in the internal error amp.
VGON =
R3 + R4
R4
VGON
 1.25
Reference voltage 1.25 V
[V]
C3
R3
+
25
1000 pF to 4700 pF
R4
FBP
ERR
-
In order to prevent output voltage overshooting, add capacitor C3 in parallel with R3. The recommended capacitance is
1000 pF to 4700 pF. If a capacitor outside this range is inserted, the output voltage may oscillate.
By connecting capacitance to the DEL, a rising delay time can be set for the positive-side charge pump.
The delay time is determined by the following formula.
 Delay time of charge pump block t DELAY
t DELAY = ( CDEL  1.25 )/5 µA [s]
Where, CDEL is the external capacitance.
(7) Negative-side Charge Pump Settings
BD8179MUV incorporates a charge pump controller for negative voltage, thus making it possible to generate stable gate voltage.
The output voltage is determined by the following formula. As the setting range, 10 kΩ to 330 kΩ is recommended. If the
resistor is set lower than a 10 kΩ, it causes the reduction of power efficiency. If it is set more than 330 kΩ, the offset
voltage becomes larger by the input bias current 0.4 µA (Typ.) in the internal error amp.
VGOFF
C5
VGOFF =
-
R5
R6
 1.0 + 0.25 V
0.25 V
R5
1000 pF to 4700 pF
[V]
R6
-
27
FBN
ERR
+
2
REF
1.25 V
The delay time is internally fixed at 200 us.
In order to prevent output voltage overshooting, insert capacitor C5 in parallel with R5. The recommended capacitance is
1000 pF to 4700 pF. If a capacitor outside this range is inserted, the output voltage may oscillate.
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10/12
2009.07 - Rev.B
Technical Note
BD8179MUV
●Notes for use
1) Absolute maximum ratings
Use of the IC in excess of absolute maximum ratings such as the applied voltage or operating temperature range may
result in IC damage. Assumptions should not be made regarding the state of the IC (short mode or open mode) when such
damage is suffered. A physical safety measure such as a fuse should be implemented when use of the IC in a special
mode where the absolute maximum ratings may be exceeded is anticipated.
2) GND potential
Ensure a minimum GND pin potential in all operating conditions.
3) Setting of heat
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions.
4) Pin short and mistake fitting
Use caution when orienting and positioning the IC for mounting on printed circuit boards. Improper mounting may result in
damage to the IC. Shorts between output pins or between output pins and the power supply and GND pins caused by the
presence of a foreign object may result in damage to the IC.
5) Actions in strong magnetic field
Use caution when using the IC in the presence of a strong magnetic field as doing so may cause the IC to malfunction.
6) Testing on application boards
When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress.
Always discharge capacitors after each process or step. Ground the IC during assembly steps as an antistatic measure,
and use similar caution when transporting or storing the IC. Always turn the IC's power supply off before connecting it to or
removing it from a jig or fixture during the inspection process.
7) Ground wiring patterns
When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns,
placing a single ground point at the application's reference point so that the pattern wiring resistance and voltage
variations caused by large currents do not cause variations in the small signal ground voltage. Be careful not to change the
GND wiring patterns of any external components.
~
~
(Pin B)
C
E
B
~
~
(Pin A)
~
~
8) This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them isolated.
P/N junctions are formed at the intersection of these P layers with the N layers of other elements to create a variety of
parasitic elements.For example, when the resistors and transistors are connected to the pins as shown in Fig. 18, a
parasitic diode or a transistor operates by inversing the pin voltage and GND voltage.
The formation of parasitic elements as a result of the relationships of the potentials of different pins is an inevitable result
of the IC's architecture. The operation of parasitic elements can cause interference with circuit operation as well as IC
malfunction and damage. For these reasons, it is necessary to use caution so that the IC is not used in a way that will
trigger the operation of parasitic elements, such as the application of voltages lower than the GND (P board) voltage to
Resistor
Transistor (NPN)
(Pin B)
input and output pins.
B
GND
N
N
N
Parasitic elements
P+
N
N
(Pin A)
P substrate
Parasitic element
GND
P
P+
~
~
P+
N
P
GND
N
P
P+
Parasitic elements
C
E
Parasitic element
GND
Fig.18 Example of a Simple Monolithic IC Architecture
GND
9) Overcurrent protection circuits
An overcurrent protection circuit designed according to the output current is incorporated for the prevention of IC
destruction that may result in the event of load shorting. This protection circuit is effective in preventing damage due to
sudden and unexpected accidents. However, the IC should not be used in applications characterized by the continuous
operation or transitioning of the protection circuits. At the time of thermal designing, keep in mind that the current capability
has negative characteristics to temperatures.
10) Thermal shutdown circuit
This IC incorporates a built-in thermal shutdown circuit for the protection from thermal destruction. The IC should be used
within the specified power dissipation range. However, in the event that the IC continues to be operated in excess of its
power dissipation limits, the attendant rise in the chip's temperature Tj will trigger the thermal shutdown circuit to turn off all
output power elements. The circuit automatically resets once the chip's temperature Tj drops.
Operation of the thermal shutdown circuit presumes that the IC's absolute maximum ratings have been exceeded.
Application designs should never make use of the thermal shutdown circuit.
11) Testing on application boards
At the time of inspection of the installation boards, when the capacitor is connected to the pin with low impedance, be sure
to discharge electricity per process because it may load stresses to the IC. Always turn the IC's power supply off before
connecting it to or removing it from a jig or fixture during the inspection process. Ground the IC during assembly steps as
an antistatic measure, and use similar caution when transporting or storing the IC.
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11/12
2009.07 - Rev.B
Technical Note
BD8179MUV
●Ordering part number
B
D
8
Part No.
1
7
9
Part No.
M
U
V
-
Package
MUV:VQFN032V5050
E
2
Packaging and forming specification
E2: Embossed tape and reel
VQFN032V5050
<Tape and Reel information>
5.0 ± 0.1
5.0±0.1
1.0MAX
3.4±0.1
0.4 ± 0.1
1
8
9
32
16
25
24
0.75
0.5
2500pcs
E2
The direction is the 1pin of product is at the upper left when you hold
)
(0.22)
( reel on the left hand and you pull out the tape on the right hand
3.4 ± 0.1
+0.03
0.02 -0.02
S
C0.2
Embossed carrier tape
Quantity
Direction
of feed
1PIN MARK
0.08 S
Tape
17
+0.05
0.25 -0.04
1pin
(Unit : mm)
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© 2009 ROHM Co., Ltd. All rights reserved.
Reel
12/12
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
2009.07 - Rev.B
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.
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More detail product informations and catalogs are available, please contact us.
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