Rohm BD6076GUT White backlight led drivers for small to medium lcd panels (switching regulator type) Datasheet

BD6076GUT
LED Drivers for LCD Backlights
White Backlight LED Drivers
for Small to Medium LCD Panels
(Switching Regulator Type)
No.11040EAT40
BD6076GUT
●Description
The BD6076GUT is a white LED driver IC with synchronous rectification that can drive up to 4LEDs.
With synchronous rectification (no external schottky diode required) and small package, they can save mount space.
And the brightness of LED can be adjusted by using PWM pulse on EN pin.
●Features
1) Synchronous rectification Boost DC/DC converter
2) No external schottky diode required
3) Driving 4 series white LEDs
4) Internal Load Disconnect SW
5) Over voltage protection
6) Protect open and short output
7) Thermal shut down
8) Brightness adjustment by external PWM pulse
9) Small and Thin CSP package in 8pins
●Applications
White LED Backlight
Torch light and easy flash for camera of mobile phone
●Absolute maximum ratings (Ta=25℃)
Parameter
Symbol
Ratings
Unit
Maximum applied voltage 1
VMAX1
7 *1
V
Vin, EN, VFB, TEST
Maximum applied voltage 2
VMAX2
20 *1
V
SW, Vout, Voutput
Pd
800 *2
mW
Operating temperature range
Topr
-30~+85
℃
Storage temperature range
Tstg
-55~+150
℃
Power dissipation
Condition
*1 These values are based on GND and GNDA pins.
*2 50mm×58mm×1.75mm At glass epoxy board mounting. When it’s used by more than Ta=25 ℃, it’s reduced by 6.4mW/℃.
●Operating range（Ta=-30℃~+85℃）
Parameter
Power supply voltage
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Symbol
Vin
Ratings
Min.
Typ.
Max.
2.7
3.6
5.5
1/15
Unit
Condition
V
2011.12 - Rev.A
Technical Note
BD6076GUT
●Electrical characteristics
Unless otherwise specified Ta =-30℃ ~+85℃, Vin=3.1~5.5V
Limits
Parameter
Symbol
Min.
Typ.
Max.
Unit
Condition
[ EN terminal ]
EN threshold voltage (Low)
VthL
-
-
0.4
V
EN threshold voltage (High)
VthH
1.2
-
-
V
Iin
-
18.3
30.0
µA
EN=5.5V
Iout
-2.0
0.0
-
µA
EN=0V
Quiescent Current
Iq
-
0.1
2.0
µA
EN=0V
Current Consumption
Idd
-
1.0
1.5
mA
EN=2.6V,VFB=1.0V,VIN=3.6V
Feedback voltage
Vfb
0.47
0.50
0.53
V
Inductor current limit
Icoil
310
400
490
mA
Vin=3.6V *1
SW saturation voltage
Vsat
-
0.14
0.28
V
Isw=200mA
Vout PMOS resistance
Ronp
-
2.1
3.2
Ω
Ipch=200mA,Vout=13V
Voutput PMOS resistance
Rpsw
-
1.8
2.0
Ω
Ipsw=20mA,Vout=13V
Switching frequency
fSW
1.0
1.25
1.5
MHz
Duty cycle limit
Duty
83.0
91.0
99.0
%
Output voltage range
Vo
-
-
18.0
V
Over voltage limit
Ovl
18.0
18.5
19.0
V
VFB=0V
UVLOD
1.75
-
2.25
V
Falling Vin level
EN terminal input current
EN terminal output current
[ Switching regulator ]
UVLO detect voltage
VFB=0V
*1 This parameter is tested with DC measurement.
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2/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●Test circuit
*Test circuit A (for Inductor current limit, Feedback voltage.)
Procedure
~Inducton current limit~
1. Start to increase Iout from 0mA gradually.
2. You will find that Vout will start to go down and the duty will be decreased.
3. Then, you can measure the coil current as “inductor current limit”
~VFB voltage~
1. Supply 0mA to Iout
2. Then, you can measure the VFB voltage as “Feedback voltage”.
Icoil
3.1~5.5V
VIN
10µH or 22µH
1µF
SW
VIN
Tall
monitor
A
Duty=
Ton
VOUT
Ton
Tall
1µF
VOUTPUT
EN
Iout
GNDA
GND
VFB
RFB
24Ω
V
Fig.1 Test Circuit A
*Test circuit B (for Over voltage limit,Duty cycle limit, Switching frequency)
Procedure
~Over voltage limit~
1. Start to increase VOUT from 9V to 20V
2. You will find frequency change from around 1MHz to 0Hz
3. Then,it is “Over Voltage limit”
~Duty cycle limit, Switching frequency ~
1. Supply 9V to VOUT terminal
2. Then,you can measure the duty as “Duty cycle limit” and the frequency and “Switching frequency”.
monitor
3.1~5.5V
VIN
Ton
SW
VIN
VOUT
1µF
EN
Tall
1µF
Duty=
Ton
Tall
9V to 20V
VOUTPUT
GNDA
GND
VFB
Fig.2 Test Circuit B
*TEST circuit C
(for Quiescent current, current comsumption, EN Terminal input/output current, EN threshold voltage(Low/High))
ICC
3.1~5.5V
1uF
A
VIN
SW
A
EN
VOUT
IEN
VOUTPUT
0.0~5.5V
GNDA
GND VFB
1.0V(current comsumption)
Fig.3 Test Circuit C
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3/15
2011.12 - Rev.A
Technical Note
BD6076GUT
1,0
1,5
8
0,8
1,4
6
0,6
4
Ta=85℃
0,4
Ta=85℃
Ta=25℃
Ta=-30℃
2
Ta=25℃
0,2
1
2
3
4
5
VIN[ V]
6
1,2
2
3
4
5
VIN[V]
6
7
2,5
Fig.5 Quiescent current
vs.
Power supply voltage
500
490
Ta=-30℃
Ta=85℃
450
4
4,5
VIN[V]
400
Ta=-30℃
Ta=25℃
350
75
TDK : VLS3010T220M
70
65
VIN=3.6V
55
300
Fig.7 Feedback voltage
vs.
Power supply voltage
3,5
3,9
4,3 4,7
Ta [deg]
5,1
5,5
10
Fig.8 Inductor current limit
vs.
Temperature
90
80
1200
VIN=3.6V
70
VIN=5.5V
VIN=3.1V
VIN=4.2V
65
60
55
50
10
15
20
25
30
Iout [mA]
35
Fig.10 Efficiency vs. LED current
(4LED=VOUT13V)
coil : TDK VLS3010T220M
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35
40
Ta=-30℃
1000
800
Ta=85℃
Ta=25℃
600
80
Ta=25℃
75
Ta=85℃
70
400
65
0
40
25
30
Iout[mA]
85
200
Ta=25℃
20
90
Ta=-30℃
Eff iciency[%]
1400
Output Power[mW]
85
15
Fig.9 Efficiency vs. LED current
(4LED=VOUT13V)
1600
75
Ta=25℃
50
3,1
2,7 3,1 3,5 3,9 4,3 4,7 5,1 5,5
VIN[V]
5,5
60
480
470
5
80
Efficiency[%]
Inductor current [mA]
Ta=85℃
3,5
TOKO : DB3015CK220M
85
Ta=25℃
3
90
520
510
Ta=-30℃
Fig.6 Oscillation frequency
vs.
Power supply voltage
500
530
Ta=85℃
1,0
1
7
Fig.4 Current consumption
vs.
Power supply voltage
Ef ficiency [%]
Ta=25℃
1,3
1,1
Ta=-30℃
0,0
0
VFB[mV]
Frequency [MHz]
10
IIN[uA]
IIN[mA]
●Electrical characteristic curves (Reference data)
60
3,0
3,2
3,4
3,6 3,8
VIN[V]
4,0
4,2
Fig.11 Output power
vs.
Power supply voltage
coil : TDK VLS3010T220M
4/15
3,1
3,5
3,9
4,3 4,7
VIN[V]
5,1
5,5
Fig.12 Efficiency
vs.
Power supply voltage
(Load=30mA)
coil : TDK VLS3010T220M
2011.12 - Rev.A
Technical Note
BD6076GUT
●Electrical characteristic curves (Reference data) – Continued
1.EN
1.VOUT
1.EN
VoutDrop=76mVpp
Δ=1.66V
2.VOUT
2.VOUT
5.3ms
Peak=155mA
3. VFB
1.VOUT
2.IIN
4. IIN
4.Icoil
Idd=1.5mA
(4ms/div)
Vin=3.6V
Ta=25℃
(3ms/div)
100mV/div AC
200mA/div DC
1.EN 2V/div DC 2.VOUT
3.VFB 0.5V/div DC 4.II N
1V/div AC
200mA/div DC
Fig.13 LED Open output voltage
1.EN 5V/div DC 2.VOUT
3.VFB 0.5V/div DC 4.IIN
Fig.14 LED brightness adjustment
(Cout=4.7µH, ILED=15mA)
500
(200µs/div
)
5V/div DC
200mA/div DC
Fig.15 Soft Start
(Cout=4.7µH, ILED=15mA)
50
VIN=4.2V
40
400
3.1V
600µs
1.VIN
450
2.8V
VIN=3.6V
350
10µs
VIN=3.1V
30
250
VFB[mV]
300
VFB[mV]
Peak=410mA
3.VFB
2.IIN
VIN=5.5V
200
2.VOUT
VIN=3.1V
VIN=5.2V
Vfb=30mVpp
VIN=3.6V
3. VFB
10
100
Vout=100mVpp
20
VIN=4.2V
150
10µs
50
0
0
0
10
20
30
40
50
60
70
80
90
100
0
2
Duty[%]
Fig.16 LED brightness adjustment
for PWM control
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4
Duty[%]
6
8
10
Fig.17 LED brightness adjustment
for PWM control (Expansion)
5/15
1.VIN 200mV/div DC 2.VOUT 100mV/div AC
3.VFB 50mV/div AC
Fig.18 VBAT Line Transient
(Cout=4.7µH, ILED=15mA)
Vin: 3.1V  2.8V
2011.12 - Rev.A
Technical Note
BD6076GUT
●Block diagram and pin configuration
CIN
10μH or
22μH
L
SW
VIN
Vout
over voltage
protect
Q2
Thermal
Shutdown
TSD
UVLO
short protect
short protect
Q1
Q
S
Q
R
PWMcomp
Current
Sence
Voutput
+
+
-
white LED
ERRAMP
V FB
+
+
Control
COUT
+
-
+
R FB
OSC
GND
GNDA
EN
Fig.19 Block diagram and recommended circuit diagram
C1
C2
B3
B1
A1
C3
A2
A3
Fig.20 Pin location diagram VCSP60N1( 8 pin )
●Pin assignment table
PIN Name
In/Out
Ball number
Function
GNDA
-
A1
Analog GND
EN
In
A2
Enable control
(pull down by inner resistor)
VOUTPUT
In
A3
Switching output
VIN
In
B1
Power supply input
VFB
In
B3
Feedback voltage input
VOUT
Out
C1
Vout, connected to output capacitor
SW
In
C2
Switching terminal
GND
-
C3
Power GND
●Operation
BD6076GUT is PWM current mode DC/DC converter with fixed frequency. It adopts synchronous rectification architecture.
The feature of the PWM current mode is that input is the combination of error components from the error amplifier, and a
current sense signal that controls the inductor current into Slope waveform for sub harmonic oscillation prevention.
This output controls Q1 and Q2 via the RS latch (Fig19). Timing of Q1 and Q2 is precisely adjusted so that they will not turn
ON at the same time, thus putting them into non-overlapped relation. In the period when Q1 is ON, energy is accumulated
in the external inductor, and in the period when Q1 is OFF, energy is transferred to the capacitor of VOUT via Q2. Further
more, BD6076GUT has many safety functions, and their detection signals stop switching operation at once.
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6/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●Functional descriptions
1) Soft start and off status
BD6076 has soft start function and off status function.
The soft start function and the off status function prevent large current from flowing to the IC via coil.
Occurrence of rush current at turning on is prevented by the soft start function, and occurrence of invalid current at
turning off is prevented by the off status function.
As for detailed actions, refer to the block diagram (Fig. 21) and the timing chart (Fig. 22).
･Soft start
When VOUT is smaller than Vshort, to decrease charge current PMOS is set to off by PMOS Startup Control (in Term
“I”). Vshort means “VOUT short detect voltage”. After VOUT is bigger than Vshort, PMOS is turned on and start
switching. In term “II” (Vshort < VOUT < VIN), status of Current Limiter is “soft mode”. So “A” voltage is restricted and
“D” duty is kept low. Therefore VOUT voltage goes up slowly and coil current is restricted. In term III (VOUT > VIN),
status of Current Limiter is “normal mode”. So “A” voltage goes up suitable voltage, and “D” duty goes up slowly. And
then VOUT voltage goes up to required voltage.
Operation
Current at start
Current at PWM
Max current
450mA
300mA
Fig. 21 lock diagram of soft start and off status
Vout
L
ERRAMP
PWM comp
SW
A
R Q
Soft
Current
limit
S
B
D
LED current
Q
C
PMOS
Startup
Off Status
Soft Reference
Charge
current
FB
Control
OSC
Rfb
EN
I
II
III
VIN
Vshort
VOUT
Normal
mode
Cu r r en t
Limit
Soft
mode
D
Fig. 22 timing chart
・Off status
The gate voltage of the switching Tr either "H" or "L" at power off depends on the operation conditions at that time.
When it is fixed to "H", the switching Tr remains to be ON, and invalid current from the battery is consumed. In order to
prevent this, at power off, D is always fixed to L level. So that, it is possible to prevent invalid current at power off.
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2011.12 - Rev.A
Technical Note
BD6076GUT
2) Isolation control
BD6076GUT has isolation control to prevent LED wrong lighting at power off.
The cause of the LED wrong lighting is leak current from VIN to the white LED.
Therefore, when BD6076GUT powered off (EN = L), the isolation control cuts the DC path between SW and Vout, so that,
it prevents from leak current from VIN to LED.
VIN
SW
Vout
Voutput
White
LED
VFB
Fig.23 Isolation control
3) Short-circuit protection and over voltage protection
BD6076 has short-circuit protection and over voltage protection. These detect the voltage of VOUT,Voutput, and at error,
they stop the output Tr. Details are as shown below.
・Short-circuit protection
In the case of short-circuit of the DC/DC output (VOUT) and switched output (Voutput) to GND, the coil or the IC may
be destructed.
Therefore, at such an error as VOUT, Voutput becoming 0.7V or below, the Under Detector shown in the figure works,
and turns off the output Tr, and prevents the coil and the IC from being destructed.
And the IC changes from its action condition into its non action condition, and current does not flow to the coil (0mA).
・Over voltage protection
In a case of error as the IC and the LED being cut off, over voltage causes the SW terminal and the VOUT terminal
exceed the absolute maximum ratings, and may destroy the IC. Therefore, when VOUT becomes 18.5V or higher, the
over voltage limits works, and turns off the output Tr, and prevents the SW terminal and the VOUT terminal from
exceeding the absolute maximum ratings.
At this moment, turns into non operation condition from operation condition, and the output voltage goes down slowly.
And, when the output voltage becomes the hysteresis of the over voltage limit or below, the output voltage goes on up
to 18.5V once again.
This protection action is shown in Fig.24.
Cout
SW
Voutput
Vout
OVER Detector
OVER VOLTAGE REF
driver
UNDER Detector
UNDER Detector
UNDER VOLTAGE REF
UNDER VOLTAGE REF
Control
Fig.24 Block diagram of short-circuit protection and over voltage
4) Thermal shut down
BD6076GUT has thermal shut down function.
The thermal shut down works at 175C or higher, and while holding the setting of EN control from the outside, turns into
non operation condition from operation condition. And at 175C or below, the IC gets back to its normal operation.
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8/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●Start control and brightness control
BD6076GUT can control the start conditions by its EN terminal, and power off at 0.4V or below, and power on at 1.2V or
higher. And by changing the duty of power on and off by PWM control, the LED brightness can be adjusted.
1. PWM brightness adjustment is done by giving PWM signal to EN as shown in Fig.25.
The BD6076GUT is powered on/off by the PWM signal. By this method, LED current is controlled from 0 to the maximum
current. The average LED current increases with proportion to the duty cycle of PWM signal. While in PWM off-cycle mode,
the IC and LED both consume no currents, thus providing a high-efficiency operation. The recommended PWM frequency
is 100Hz ~ 300Hz.
10µH or 22µH
VIN
4.7µF
VOUT
SW
VIN
EN
PWM
4.7µF
Voutput
GNDA
GND
VFB
33ohm
Fig.25 The brightness adjustment example of EN terminal by PWM (fPWM = 100 ~ 300Hz)
High Pulse
Minimum High Pulse = 13µs
(Duty = 1/256)
Range of Period = 3.3 ~ 10 ms
EN
Period
Low Pulse
Minimum Low Pulse = 13µs
(Duty = 255/256)
Range of Period = 3.3 ~ 10 ms
EN
Period
Fig.26 The Rule of PWM signal of EN
●FB characteristic on PWM function
BD6076GUT constantly controls the rising time to decrease the tolerance of the FB voltage at PWM function.
FB [mV]
EN
13μs typ
Max
150mV(average)
Typ
-3%
Min
VFB
Typical
Target Spec
+3%
Fig.27 VFB signal at PWM
3.1
3.6
5.5
VIN [V]
FB [mV]
Duty 30%
500mV
150mV
(Average)
time
Fig.28. VFB Voltage Line Regulation (PWM Duty=30%)
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9/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●VBAT characteristic in Battery charge
Transient during Battery charger is normally +300mV, 250Hz(duty 85%) from a baseline Battery Voltage 3.1 to 2.8V. In this
term, it is necessary that VOUT Voltage noise is less than 200mVp-p.
VBAT [V ]
10 µ s
V BAT [V]
10 µ s
4m s
3.1V
3 .1V
2 .8V
300m Vp-p
2.8V
600 µs
time
tim e
VOU T [V]
less than 200m Vp-p
time
Fig.29. Battery Voltage transient during charger
●Setting range of LED current
LED current is determined by the voltage of VFB
and the resistor connected to VFB terminal.
ILED is given as shown below.
ILED=VFB/RFB
The current in the standard application is as shown below.
VFB=0.5V, RFB=33Ω
ILED=15.2mA
10µH or 22µH
VIN
4.7µF
VIN
PWM
SW
VOUT
4.7µF
Voutput
EN
ILED
GNDA
GND
VFB
33ohm
Fig.30 standard application
The shaded portion in the figure below is the setting range of LED current to become the standard. Depending on coils and
white LEDs to be used, however, some ICs may not be used at desired currents. Consequently, for the proper setting of
LED current, thoroughly check it for the suitability under use conditions including applicable power supply voltage and
temperature.
80
70
ILED[mA]
60
50
40
30
20
10
Min 16µA
0
7
8
9 10 11 12 13 14 15 16 17 18
VOUT[V]
Fig.31 Setting range of LED current
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10/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●Selection of external parts
Recommended external parts are listed as below.
When to use other parts than these, select the following equivalent components.
・Coil
Value
Tolerance
Manufacturer
Product number
Vertical
size
Size
Horizontal
size
22µH
±20%
MURATA
LQH3NPN220MGOL
3.0
10µH
±20%
MURATA
LQH3NPN100MGOL
22µH
±20%
TDK
10µH
±20%
22µH
Height
DCR
(Ω)
3.0
0.9
1.10
3.0
3.0
0.9
0.57
VLF3010ST220M
2.8
3.0
1.0
0.90
TDK
VLF3010ST100M
2.8
3.0
1.0
0.49
±20%
TOKO
DB3015C220M
2.6
2.8
1.5
0.60
10µH
±20%
TOKO
DB3015C100M
2.6
2.8
1.5
0.29
22µH
±20%
Taiyo Yuden
NR3010T220M
3.0
3.0
1.0
1.24
10µH
±20%
Taiyo Yuden
NR3010T100M
3.0
3.0
1.0
0.54
22µH
±20%
Panasonic
ELLVEG220NN
3.0
3.0
0.9
1.44
10µH
±20%
Panasonic
ELLVEG100NN
3.0
3.0
0.9
0.48
Please refer to the reference data of p.4 for the change in the efficiency when the coil is changed.
・Capacitor
Manufacturer
Product number
Vertical
size
Size
Horizontal
size
1µF
MURATA
GRM188B11A105K
1.6
4.7µF
MURATA
GRM21BB31A475K
1µF
MURATA
4.7µF
MURATA
Value
Height
Temperature
range
0.8
0.8
-25℃~+85℃
2.0
1.25
1.25
-25℃~+85℃
GRM188B31E105K
1.6
0.8
0.8
-25℃~+85℃
GRM21BB31E475K
2.0
1.25
1.25
-25℃~+85℃
【 CIN 】
【 COUT 】
・Resistor
Value
Tolerance
Manufacturer
Product number
Vertical
size
Size
Horizontal
size
±1%
ROHM
MCR006YZPF□□□□
0.6
0.3
Height
【 RFB 】
24Ω
0.23
Value □□□□
15Ω
15R0
24Ω
24R0
33Ω
33R0
The coil is the component that is most influential to efficiency. Select the coil which direct current resistor (DCR) and current
- inductance characteristic are excellent. Select a capacitor of ceramic type with excellent frequency and temperature
characteristics. Further, select Capacitor to be used for CIN/COUT with small direct current resistance, and pay much
attention to the PCB layout shown in the next page.
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11/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●PCB Layout
In order to make the most of the performance of this IC, PCB layout is very important.
Please note that characteristics such as efficiency and ripple will likely to change greatly depending on PCB layout.
To battery power source
CIN
GNDA
EN
VOUTPUT
VIN
VOUT
VFB
SW
RLED
GND
To battery GND
COUT
L1
Fig.32 PCB layout
Connect the input bypath capacitor CIN between VIN and GNDA pin closely, as shown in the upper diagram. Thereby, the
input voltage ripple of the IC can be reduced. And, connect the output capacitor COUT between VOUT and GND pin closely.
Thereby, the output voltage ripple of the IC can be reduced. Connect the current setting RLED FB pin closely. Connect the
GND closely connection side of RLED directly to GND pin. Connect the GNDA pin directly to GND pin. When those pins are
not connected directly near the chip, the performance of BD6076GUT shall be influenced and may limit the current drive
performance. As for the wire to the inductor, make its resistance component small to reduce electric power consumption
and increase the entire efficiency. Please keep away which are subject to be influenced like FB pin in wire connection with
SW.
The layout pattern in consideration of these is shown in the next page.
112mVpp
VOUT
(VBAT=3.6V, Ta=25 oC, VOUT=14V. 20mA Load)
Fig.33 Output noise
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12/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●Recommended PCB layout
VOUTPUT
LED
EN
AGND
VFB
RFB
CIN
LED
GND
COUT
VOUT
LED
L1
VBAT
LED
Fig.34 Front surface (TOP VIEW)
GND
SW
Fig.35 Rear surface (TOP VIEW)
●Attention point for PCB layout
For PCB layout design, the wire of power supply line should be low Impedance, and put bypass capacitor if necessary.
Especially the wiring impedance must be low around DC/DC converter.
●About heat loss
For heat design, operate DC/DC converter in the following condition.
(The following temperature is a guaranteed temperature, margin will be needed.)
1. Periphery temperature Ta must be less than 85℃.
2. The loss of IC must be less than dissipation Pd.
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13/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●Notes for use
1) Absolute Maximum Ratings
An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc.,
can break down devices, thus making impossible to identify breaking mode such as a short circuit or an open circuit. If
any special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical
safety measures including the use of fuses, etc.
2) Operating conditions
These conditions represent a range within which characteristics can be provided approximately as expected. The
electrical characteristics are guaranteed under the conditions of each parameter.
3) Reverse connection of power supply connector
The reverse connection of power supply connector can break down ICs. Take protective measures against the
breakdown due to the reverse connection, such as mounting an external diode between the power supply and the IC’s
power supply terminal.
4) Power supply line
Design PCB pattern to provide low impedance for the wiring between the power supply and the GND lines. In this
regard, for the digital block power supply and the analog block power supply, even though these power supplies has
the same level of potential, separate the power supply pattern for the digital block from that for the analog block, thus
suppressing the diffraction of digital noises to the analog block power supply resulting from impedance common to the
wiring patterns. For the GND line, give consideration to design the patterns in a similar manner.
Furthermore, for all power supply terminals to ICs, mount a capacitor between the power supply and the GND terminal.
At the same time, in order to use an electrolytic capacitor, thoroughly check to be sure the characteristics of the
capacitor to be used present no problem including the occurrence of capacity dropout at a low temperature, thus
determining the constant.
5) GND voltage
Make setting of the potential of the GND terminal so that it will be maintained at the minimum in any operating state.
Furthermore, check to be sure no terminals are at a potential lower than the GND voltage including an actual electric
transient.
6) Short circuit between terminals and erroneous mounting
In order to mount ICs on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous mounting
can break down the ICs. Furthermore, if a short circuit occurs due to foreign matters entering between terminals or
between the terminal and the power supply or the GND terminal, the ICs can break down.
7) Operation in strong electromagnetic field
Be noted that using ICs in the strong electromagnetic field can malfunction them.
8) Inspection with set PCB
On the inspection with the set PCB, if a capacitor is connected to a low-impedance IC terminal, the IC can suffer stress.
Therefore, be sure to discharge from the set PCB by each process. Furthermore, in order to mount or dismount the set
PCB to/from the jig for the inspection process, be sure to turn OFF the power supply and then mount the set PCB to
the jig. After the completion of the inspection, be sure to turn OFF the power supply and then dismount it from the jig. In
addition, for protection against static electricity, establish a ground for the assembly process and pay thorough attention
to the transportation and the storage of the set PCB.
9) Input terminals
In terms of the construction of IC, parasitic elements are inevitably formed in relation to potential. The operation of the
parasitic element can cause interference with circuit operation, thus resulting in a malfunction and then breakdown of
the input terminal. Therefore, pay thorough attention not to handle the input terminals, such as to apply to the input
terminals a voltage lower than the GND respectively, so that any parasitic element will operate. Furthermore, do not
apply a voltage to the input terminals when no power supply voltage is applied to the IC. In addition, even if the power
supply voltage is applied, apply to the input terminals a voltage lower than the power supply voltage or within the
guaranteed value of electrical characteristics.
10) Ground wiring pattern
If small-signal GND and large-current GND are provided, It will be recommended to separate the large-current GND
pattern from the small-signal GND pattern and establish a single ground at the reference point of the set PCB so that
resistance to the wiring pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of
the small-signal GND. Pay attention not to cause fluctuations in the GND wiring pattern of external parts as well.
11) External capacitor
In order to use a ceramic capacitor as the external capacitor, determine the constant with consideration given to a
degradation in the nominal capacitance due to DC bias and changes in the capacitance due to temperature, etc.
12) Thermal shutdown circuit (TSD)
When junction temperatures become 175°C (typ) or higher, the thermal shutdown circuit operates and turns a switch
OFF. The thermal shutdown circuit, which is aimed at isolating the LSI from thermal runaway as much as possible, is
not aimed at the protection or guarantee of the LSI. Therefore, do not continuously use the LSI with this circuit
operating or use the LSI assuming its operation.
13) Thermal design
Perform thermal design in which there are adequate margins by taking into account the permissible dissipation (Pd) in
actual states of use.
14) Selection of coil
Select the low DCR inductors to decrease power loss for DC/DC converter.
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14/15
2011.12 - Rev.A
Technical Note
BD6076GUT
●Ordering part number
B
D
6
Part No.
0
7
6
G
Part No.
6076
U
T
Package
GUT : VCSP60N1
-
E
2
Packaging and forming specification
E2: Embossed tape and reel
(BD6076GUT)
VCSP60N1 (BD6176GUT)
<Tape and Reel information>
1.68±0.05
1.68±0.05
0.2MIN
0.6±0.075
1PIN MARK
Tape
Embossed carrier tape
Quantity
3000pcs
Direction
of feed
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
)
0.08 S
8-φ0.3±0.05
0.05 A B
(φ0.15)INDEX POST
A
C
0.34±0.05
S
B
A
1
0.34±0.05
2
3
P=0.5×2
P=0.5×2
B
(Unit : mm)
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© 2011 ROHM Co., Ltd. All rights reserved.
1pin
Reel
15/15
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
2011.12 - 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
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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
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R1120A