Datasheet Download

Datasheet
2.7V to 14V
Synchronous Buck-Boost Controller
BD8303MUV
General Description
Key Specifications
BD8303MUV is ROHM’s high efficiency step-up/step-down
switching regulator IC. It produces output of 3.3V / 5V from
1 cell of lithium battery, 4 batteries, or 2 cells of Li batteries
with just one inductor.
This IC uses an original step-up/step-down drive system
and provides a higher efficient power supply than
conventional SEPIC-system or H-bridge system switching
regulators.




Input Voltage Range:
Reference Volatage Accuracy :
Standby Current:
Operating Temperature Range:
Package
+2.7V to +14V
1.25%
0μA(Typ)
-25°C to +85°C
W(Typ) x D(Typ) x H(Max)
Features




Highly-Efficient Step-Up/Step-Down DC/DC
Converter Implemented with Just One Inductor
Supports High-Current Applications with External
N-Channel FET
Incorporates a Soft-Start Function
Incorporates a Timer-Latch System with Short
Circuit Protection Function
Applications
VQFN016V3030
3.00mm x 3.00mm x 1.00mm
General Portable Equipment
 DVC
 Single-Lens Reflex Cameras
 Portable DVDs
 Mobile PCs
Typical Application Circuit
VCC=4.0~14V,
VOUT=8.4V, IOUT=100mA ~ 1500mA
VCC =
4.0V – 14V
Insert a filter
as required.
1μF
RB521CS-30
47μF
0.1μF
RB521CS-30
HG1
(TDK SLF10165) RSS065N03
VOUT (set at 8.4 V)
47μF x 2
SW1
RSS065N03
PGND
RSS065N03
SW2
LG2
HG2
BOOT2
GND
RSS065N03
4.7μH
LG1
FB
STB
100pF
3.9kΩ
200kΩ
BOOT1
INV
4700pF
7.5kΩ
RT
VREG
100kΩ
27kΩ
VCC
0.1μF
0.1μF
ON/OFF
○Product structure:Silicon monolithic integrated circuit
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・14・001
○This product has no designed protection against radioactive rays
1/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Pin Configuration
Pin Descriptions
Pin No.
RT
INV
FB
RT
Oscillation frequency set terminal
INV
Error AMP input terminal
3
FB
Error AMP output terminal
4
GND
Ground terminal
5
STB
ON/OFF terminal
SW1
6
BOOT2
LG1
7
HG2
Output side high-side FET gate drive terminal
PGND
8
SW2
Output side coil connecting terminal
9
LG2
Output side low-side FET gate drive terminal
10
PGND
11
LG1
Input side low-side FET gate drive terminal
12
SW1
Input side coil connecting terminal
13
HG1
Input side high-side FET gate drive terminal
14
BOOT1
15
REG
5V Internal regulator output terminal
16
VCC
Power input terminal
SW2
HG2
BOOT2
STB
Function
2
LG2
GND
Pin Name
1
HG1
BOOT1
REG
VCC
TOP VIEW
Output side high-side driver input terminal
Driver part ground terminal
Input side high-side driver input terminal
REG
Block Diagram
REG
TIMING
CONTROL
TIMING
CONTROL
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
2/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Description of Blocks
1. VREF
This block generates ERROR AMP reference voltage. The reference voltage is set to 1.0V.
2. VREG
This is a voltage regulator block which outputs 5.0V and is used as power supply for IC internal circuit and BOOT pin
supply. Follows power supply voltage when 5.0V or below while the output voltage drops at the same time.
An external 1.0µF capacitor is recommended to prevent oscillation.
3. UVLO
This block prevents the malfunction of the internal circuitry during start-up or when the supply drops below a certain
voltage. When VREG is below 2.4V, the HG1, HG2, LG1 and LG2 pin is low, this block turns OFF all FET and DC/DC
converter outputs and resets the timer latch of the internal SCP circuit and soft-start circuit
4. SCP
This block is the Short Circuit Protection that uses a Timer Latch System. It has an internal counter that is in synch with
OSC. When the INV pin is set to 1.0V or lower voltage, the internal counter will count about 8200 pulses after which the
latch circuit will activate Turning OFF the DC/DC converter output (13.6msec when RRT = 51kΩ). Restarting the STB pin
or the supply voltage will reset the latch circuit.
5. OSC
The OSC block generates the internal frequency of the IC. The frequency can be varied depending on the value of the
external resistance of the RT pin (Pin 1).When RRT = 51kΩ, the operation frequency is set to 600kHz.
6. ERROR AMP
The ERROR AMP block detects output signals and PWM control signals and compares them with an internal reference
voltage set at 1.0V.
7.
PWM COMP
The PWM COMP block is a Voltage-to-Pulse Width converter that controls the output voltage depending on the input
voltage. This block controls the pulse width by comparing the internal SLOPE waveform with the ERROR AMP output
voltage. The output signal of the PWM COMP block is then fed to the driver. Max Duty and Min Duty are set at the
primary side and the secondary side of the inductor respectively, which are as follows:
Primary side (SW1)
Secondary side (SW2)
HG1 Max Duty
HG1 Min Duty
LG2 Max Duty
LG2 Min Duty
:
:
:
:
About 90%,
0%
About 90%,
About 10%,
8. SOFT START
This block prevents in-rush current during start-up by bringing the output voltage of the DCDC converter into a soft-start.
The Soft-Start block is in synch with the internal OSC block. This block enables the output voltage of the DCDC
converter to reach the set voltage after about 2400 pulses (4msec when RRT = 51kΩ).
9. N-Channel DRIVER
This block consists of a CMOS inverter circuit that drives the built-in N-Channel FET. It provides dead time for preventing
feed through during switching of HG1 = L to LG1 = H to HG2 = L to LG2 = H and LG1 = L to HG1 = H, LG2 = L to HG2 =
H. The dead time is set at about 100nsec for each individual SWs
10. ON/OFF LOGIC
This block enables and disables the IC depending on the voltage applied at STB pin (Pin 5). The IC Turns ON when STB
voltage is 2.5 V or higher and it Turns OFF when STB is open or when 0V is applied. The STB pin has a pull-down
resistor of approximately 400kΩ.
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
3/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Absolute Maximum Ratings
Parameter
Maximum Applied Power Voltage
Power Dissipation
Operating Temperature Range
Storage Temperature Range
Junction Temperature
Symbol
VCC
VREG
Between
VBOOT1 , VBOOT2
and VSW1, VSW2
Between
VBOOT1 , VBOOT2
and GND
VSW1 and VSW2
Pd
Rating
15
7
Unit
V
V
7
V
20
V
15
(Note 1)
0.62
V
W
Topr
-25 to +85
°C
Tstg
-55 to +150
°C
Tjmax
+150
°C
(Note 1) When installed on a 70.0 mm x 70.0 mm x 1.6 mm glass epoxy board. The rating is reduced by 4.96 mW/°C at Ta = 25°C or more.
Caution: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit
between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over the
absolute maximum ratings.
Recommended Operating Conditions
Parameter
Symbol
Standard Value
Min
Typ
Max
-
14
Unit
Power Supply Voltage Range
VCC
2.7
Output Voltage Range
VOUT
1.8
-
12
V
Oscillation Frequency Range
fOSC
0.2
0.6
1.0
MHz
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
4/23
V
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Electrical Characteristics (Unless otherwise specified, Ta = 25°C, VCC = 7.4V)
Parameter
Symbol
Target Value
Unit
Conditions
Minimum
Typical
Maximum
VUV
-
2.4
2.6
V
ΔVUVHY
50
100
200
mV
fOSC
480
600
720
kHz
VREG
4.7
5.1
5.5
V
INV Threshold Voltage
VINV
0.9875
1.00
1.0125
V
Input Bias Current
IINV
-50
0
+50
nA
Soft-Start Time
tSS
2.4
4.0
5.6
msec
Output Source Current
IEO
10
20
30
μA
VINV=0.8V , VFB=1.5V
Output Sink Current
IEI
0.6
1.3
3
mA
VINV=1.2V , VFB=1.5V
SW1 Max Duty
DMAX1
85
90
95
%
HG1 ON
SW2 Max Duty
DMAX2
85
90
95
%
LG2 ON
SW2 Min Duty
DMIN2
5
10
15
%
LG2 OFF
HG1, 2 High side ON-Resistance
RONHP
-
4
8
Ω
HG1, 2 Low side ON-Resistance
RONHN
-
4
8
Ω
LG1, 2 High side ON-Resistance
RONLP
-
4
8
Ω
LG1, 2 Low side ON-Resistance
RONLN
-
4
8
Ω
HG1-LG1 Dead Time
tDEAD1
50
100
200
nsec
HG2-LG2 Dead Time
tDEAD2
50
100
200
nsec
UVLO
Detection Threshold Voltage
Hysteresis Range
VREG monitor
Oscillator
Oscillation Frequency
RRT=51kΩ
Regulator
Output Voltage
Error AMP
VCC=12.0V, VINV=6.0V
RRT=51kΩ
PWM Comparator
Output
STB
Operation
VSTBH
2.5
-
VCC
V
No-Operation
VSTBL
-0.3
-
+0.3
V
RSTB
250
400
700
kΩ
ISTB
-
-
1
μA
VCC Circuit Current
ICC1
-
650
1000
μA
VINV=1.2V
BOOT1 and BOOT2 Circuit Current
ICC2
-
120
240
μA
VINV=1.2V
STB pin
Control Voltage
STB Pin Pull-Down Resistance
Circuit Current
Standby Current
VCC Pin
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
5/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
1.050
1.050
1.025
1.025
VREF Voltage [V]
VREF Voltage [V]
Typical Performance Curves
(Unless otherwise specified, Ta = 25°C, VCC = 7.4V)
1.000
0.975
0.950
1.000
0.975
0.950
0
5
10
15
-40
40
80
120
Ambient Temperature [°C]
VCC Voltage [V]
Figure 2. VREF Voltage vs Ambient Temperature
Figure 1. VREF Voltage vs VCC Voltage
6.0
5.300
5.0
5.200
REG Voltage : VREG [V]
REG Voltage : VREG [V]
0
4.0
3.0
2.0
1.0
5.100
5.000
4.900
4.800
0.0
4.700
0
5
10
15
-40
VCC Voltage [V]
40
80
120
Ambient Temperature [°C]
Figure 3. REG Voltage vs VCC Voltage
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
0
Figure 4. REG Voltage vs Ambient Temperature
6/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Typical Performance Curves - continued
800
700
660
700
Oscillation Frequency [kHz]
Oscillation Frequency [kHz]
680
600
500
640
620
600
580
560
540
520
400
500
0
5
10
15
-40
VCC Voltage [V]
0
40
80
120
Ambient Temperature [°C]
Figure 5. Oscillation Frequency vs VCC Voltage
Figure 6. Oscillation Frequency
vs Ambient Temperature
900
800
800
750
600
VCC Current [μA]
VCC Current [μA]
700
500
400
300
700
650
600
200
550
100
0
500
0
5
10
15
-40
VCC Voltage [V]
40
80
120
Ambient Temperature [°C]
Figure 7. VCC Current vs VCC Voltage
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
0
Figure 8. VCC Current vs Ambient Temperature
7/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Typical Performance Curves - continued
5.050
140
5.025
100
OUT Voltage : VOUT [V]
BOOT Pin Current [μA]
120
80
60
40
5.000
4.975
20
4.950
0
0
1
2
3
4
5
0
6
5
10
15
BOOT Pin Voltage [V]
VCC Voltage [V]
Figure 9. BOOT Pin Current vs BOOT Pin Voltage
Figure 10. OUT Voltage vs VCC Voltage
(Line Regulation)
100
5.050
SW1 Max Duty
90
SW2 Max Duty
70
60
Duty [%]
OUT Voltage : VOUT [V]
80
5.025
5.000
50
40
30
4.975
20
SW2 Min Duty
10
0
4.950
0
500
1000
-40
1500
Load Current [mA]
40
80
120
Ambient Temperature [℃]
Figure 11. OUT Voltage vs Load Current
(Load Regulation)
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
0
Figure 12.
MAX Duty / MIN Duty vs Ambient Temperature
8/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Typical Performance Curves - continued
100
100
VCC=7.4V
VCC=5.0V
90
90
VCC=3.7V
80
80
VCC=3.0V
VCC=4.0V
VCC=4.2V
70
Efficiency [%]
Efficiency [%]
70
60
50
40
VCC=14V
60
50
40
30
30
20
20
10
10
0
0
0
1000
2000
0
3000
Load Current [mA]
500
1000
1500
Load Current [mA]
Figure 13. Efficiency vs Load Current
(Example of Application Circuit [1]
(VOUT = 3.3V))
Figure 14. Efficiency vs Load Current
(Example of Application Circuit [2]
(VOUT = 5.0V))
100
90
VCC=7.4V
80
VCC=4.0V
VCC=10V
Efficiency [%]
70
60
50
40
30
20
10
0
0
500
1000
1500
2000
Load Current [mA]
Figure 15. Efficiency vs Load Current
(Example of Application Circuit [3]
(VOUT = 8.4V)
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
9/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Typical Waveforms
VOUT (2.0V/div)
200μsec/div
500nsec/div
Figure 16. Starting Waveform
Example of Application Circuit [2]
(L=10µH, COUT = 47µH, fOSC = 750 kHz, unloaded)
Figure 17. Oscillation Waveform
(VCC = 5.0V, VOUT = 5.0V, ILOAD = 1000mA)
VOUT (100mV/div)
ILOAD(500mA/div)
500μsec/div
Figure 18. Load Variation Waveform
Example of Application Circuit [2]
(VCC = 7.4V, VOUT = 5.0V,
ILOAD = 200mA ↔1000mA :40 mA/µsec)
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
10/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Application Information
Power Dissipation [mW]
1. Package Heat Reduction Curve
Ambient Temperature [°C]
Figure 19. Power Dissipation vs Ambient Temperature
Heat Reduction Curve (IC alone)
when used at Ta = 25°C or more, it is reduced by 4.96 mW/°C.
2. Example of Application Circuit
(1) Application Circuit [1]: Input: 2.7V to 5.5V, Output: 3.3V / 100mA to 2000mA
VCC =
2.7 V – 5.5 V
Insert a filter as
required.
RB521CS-30
1μF
0.1μF
22μF
RB521CS-30
RTQ045N03
LG2
RTQ045N03
SW2
GND
HG2
100kΩ
47μF
SW1
PGND
BOOT2
6.2kΩ
VOUT (set at 3.3 V)
(TDK SLF10165) RTQ045N03
LG1
FB
STB
150pF
HG1
INV
10000pF
7.5kΩ
RT
BOOT1
43kΩ
VREG
51kΩ
VCC
0.1μF
RTQ045N03
4.7μH
0.1μF
ON/OFF
Figure 20. Example of Application Circuit [1]
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
11/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
(2) Application Circuit [2]: Input: 2.7V to 14 V, Output : 5.0V / 100 mA to 1500 mA
VCC =
2.7 V –14 V
Insert a filter
as required.
1μF
RB521CS-30
0.1μF
47μF
RB521CS-30
RTQ045N03
4.7μH
INV
4700pF
SW1
VOUT (set at 5.0 V)
47μF
RTQ045N03
RTQ045N03
HG2
SW2
LG2
BOOT2
STB
120pF
RTQ045N03
PGND
GND
120kΩ
(TDK SLF10165)
LG1
FB
4.7kΩ
5.1kΩ
HG1
RT
30kΩ
BOOT1
51kΩ
VREG
VCC
0.1μF
0.1μF
ON/OFF
Figure 21. Example of Application Circuit [2]
(3) Application Circuit [3]: Input : 4.0V to 14V, Output : 8.4V / 100mA to 1500mA
VCC =
4.0V – 14V
Insert a filter
as required.
1μF
RB521CS-30
47μF
0.1μF
RB521CS-30
HG1
(TDK SLF10165) RSS065N03
VOUT (set at 8.4 V)
47μF x 2
SW1
RSS065N03
PGND
RSS065N03
SW2
LG2
HG2
BOOT2
200kΩ
GND
RSS065N03
4.7μH
LG1
FB
STB
100pF
3.9kΩ
BOOT1
INV
4700pF
7.5kΩ
RT
VREG
100kΩ
27kΩ
VCC
0.1μF
0.1μF
ON/OFF
Figure 22. Example of Application Circuit [3]
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
12/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
(4) Application Circuit [4]: Input : 2.7V to 14V, Output : 12V / 100mA to 1500mA
VCC =
4.0 V – 14 V
Insert a filter
as required.
1μF
RB521CS-30
0.1μF
10μF
RB521CS-30
RSS065N03
10μH
HG1
BOOT1
(TDK SLF10165) RSS065N03
VOUT(set at 12 V)
47μF
SW1
LG1
FB
RSS065N03
RSS065N03
SW2
LG2
HG2
GND
BOOT2
PGND
STB
15kΩ
330kΩ
180pF
RT
INV
1500pF
5.1kΩ
VREG
27kΩ
30kΩ
VCC
0.1μF
0.1μF
ON/OFF
Figure 23. Example of Application Circuit (4)
3.
Selection of Parts for Applications
(1) Output Inductor
A shielded inductor that satisfies the current rating (current value, I PEAK as shown in Figure 24 Ripple Current) and
has a low DCR (direct current resistance component) is recommended. Inductor values greatly affect the output ripple
current. Ripple current can be reduced as the coil (L) value becomes larger and the switching frequency becomes
higher as shown in the equations below
Δ IL
Figure 24. Ripple Current
I PEAK  IOUT  VOUT / VIN  / 
I L 
I L 
I L 
VIN  VOUT   VOUT
L
VIN  VOUT 
L
VIN

1
f
VIN
1

VOUT f
[ A]
(1)
[ A]
[ A]
VOUT  2  0.8 1

VIN  VOUT  f
VOUT  VIN  
L

I L
2
[ A]
;
(in step-down mode)
(2)
;
(in step-up/down mode)
(3)
; (in step-up mode)
(4)
where:
η is the efficiency
∆IL is the output ripple current
f is the switching frequency
As a guide, output ripple current should be set at about 20% to 50% of the maximum output current. Current flow that
exceeds the coil rating brings the coil into magnetic saturation which may lead to lower efficiency or output oscillation.
Select an inductor with an adequate margin so that the peak current does not exceed the rated current of the coil.
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
13/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
(2) Output Capacitor
A ceramic capacitor with low ESR is recommended at the output to reduce ripple. There must be an adequate margin
between the maximum rating and output voltage of the capacitor, taking the DC bias property into consideration.
Output ripple voltage when ceramic capacitor is used is obtained by the following equation.
1
VPP  I L 
 I L  RESR
[V ]
(5)
2  f  CO
Setting must be performed so that output ripple is within the allowable ripple voltage.
(3) External FET
An external FET which satisfies the following items and has small C iss (input capacitance), Qg (total gate charge
quantity) and ON-Resistance should be selected. There must be an adequate margin between the turn OFF time of
MOS and the dead time to prevent through-current.
Drain-source voltage rating: Output voltage + Body Diode (VF) of MOS or higher
Gate-source voltage rating: 7.0 V or higher
Drain-source current rating: IPEAK of Output inductor paragraph or higher
(4) BOOT-SW Capacitor
The capacitor between BOOT and SW should be designed so that the gate drive voltage will not be below VGS
necessary for the FET to use, taking circuit current input to the BOOT pin into consideration. There must be an
adequate margin between the maximum rating and gate drive voltage.
Gate Drive Voltage
 VREG voltage  VF of Di  Voltagedrop by BOOT pin consumptio
n
[V ]
(6)
Voltage Drop by BOOT Pin Consumption

  Qg of external FET 
  I BOOT   1


 fOSC 


CBOOT
(7)
[V ]
(5) REG-BOOT Diode
A Schottky diode which has less forward voltage drop (VF) and satisfies the following items:
Average rectified current: There must be an adequate margin against the current consumed by MOSFET switching.
DC inverse voltage: Input voltage or higher
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
14/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
(6) Setting of Oscillation Frequency
Oscillation frequency can be set using a resistance value connected to the RT pin (Pin 1). Oscillation frequency is set
at 600 kHz when RRT = 51kΩ, and frequency is inversely proportional to RT value (See Figure 25 for the relationship
between RT and frequency) as a result, Soft-start time changes along with oscillation frequency (See Figure 26 for
the relationship between RT and soft-start time)
100
Start Time
Soft START
[msec]
TIME[msec]
SOFT
Frequency [kHz]
SwitchingFREQUENCY
[kHz]
SWITCHNG
10000
1000
100
10
1
10
10
100
10
1000
100
1000
RT
[kΩ ]
RTPIN
PinRESISTANCE
Resistance [kΩ]
RT PIN
[kΩ ]
RT
PinRESISTANCE
Resistance [kΩ]
Figure 25. Switching Frequency vs RT Pin Resistance
Figure 26. Soft-Start Time vs RT Pin Resistance
(Note) Note that the above example of frequency setting is just a design target value, and may differ from the actual
equipment.
(7) Output Voltage Setting
The internal reference voltage of the ERROR AMP is 1.0V. Output voltage should be obtained by referring to
Equation (8) of Figure 27.
VOUT
ERROR AMP
R1
INV
VOUT 
R2
R1  R2   1.0
R2
[V ]
(8)
VREF
1.0V
Figure 27. Setting of Feedback Resistance
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
15/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
(8) Determination of External Phase Compensation
Condition for stable application
The condition for feedback system stability under negative feedback is as follows:
Phase delay is 135 °or less when gain is 1 (0 dB) (Phase margin is 45° or higher). Since DC/DC converter application
is sampled according to the switching frequency, the GBW of the whole system (frequency at which gain is 0 dB) must
be set to be equal to or lower than 1/5 of the switching frequency.
(a) Phase delay must be 135°or lower when gain is 1 (0dB) (Phase margin is 45° or higher).
(b) The GBW at that time (frequency when gain is 0 dB) must be equal to or lower than 1/5 of the switching
frequency.
For this reason, switching frequency must be increased to improve responsiveness.
One of the points to secure stability by phase compensation is to cancel secondary phase delay (-180°) generated by
LC resonance by the secondary phase lead (i.e. put two phase leads).
Since Gain-BW is determined by the phase compensation capacitor attached to the error amplifier, when it is
necessary to reduce Gain-BW, the capacitor should be made larger.
-20dB/decade
(A)
C
A
GAIN
[dB]
R
FB
-
(B)
0
+
0°
PHASE
[degree] -90°
Phase margin
-180°
Figure 28. General Integrator
Error AMP is a low-pass filter because phase compensation such as
(1) and (2) is performed. For DC/DC converter application, R is a
parallel feedback resistance.
1
2RCA
Po int ( A)
fp 
Point ( B)
fGBW 
1
2RC
[ Hz]
[ Hz]
(9)
(10)
Figure 29. Frequency Property of Integrator
Phase compensation when output capacitor with low ESR such as ceramic capacitor is used is as follows:
When output capacitor with low ESR (several tens of mΩ) is used for output, secondary phase lead (two phase leads)
must be put to cancel secondary phase lead caused by LC. One of the examples of phase compensation methods is
as follows:
VOUT
C1
R1
R4
Phaselead fz1 
1
2R1C1
Hz
(11)
Phaselead fz2 
1
2R4 C 2
Hz
(12)
C2
R3
FB
R2
Phasedelay fp1 
+
LC resonance frequency 
Figure 30. Example of Setting of Phase Compensation
1
2R3 C1
Hz
1
[ Hz]
2 LCout 
(13)
(14)
Cout:Output Capacitor
For setting of phase-lead frequency, both of them should be put near LC resonance frequency.
When GBW frequency becomes too high due to the secondary phase lead, it may get stabilized by putting the primary
phase delay in a frequency slightly higher than the LC resonance frequency to compensate it.
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
16/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
4.
Example of Board Layout
Figure 31. Example of Board Layout
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
17/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
I/O Equivalent Circuits
VREG
VREG
FB
BOOT1
BOOT2
HG1, HG2
SW1, SW2
V
VREG
REG
BOOT1,2
HG1,2
FB
SW1,2
GND
PGND
STB
RT
VREG
VREG
VCC
VREG
VREG
VCC
STB
RT
GND
GND
INV
LG1, LG2
PGND
V
REG
VREG
V
VREG
REG
REG
VREG
INV
LG1,2
PGND
GND
VCC, REG
GND
VCC
REG
VREG
GND
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
18/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Operational Notes
1.
Reverse Connection of Power Supply
Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when
connecting the power supply, such as mounting an external diode between the power supply and the IC’s power
supply pins.
2.
Power Supply Lines
Design the PCB layout pattern to provide low impedance supply lines. Separate the ground and supply lines of the
digital and analog blocks to prevent noise in the ground and supply lines of the digital block from affecting the analog
block. Furthermore, connect a capacitor to ground at all power supply pins. Consider the effect of temperature and
aging on the capacitance value when using electrolytic capacitors.
3.
Ground Voltage
Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition.
4.
Ground Wiring Pattern
When using both small-signal and large-current ground traces, the two ground traces should be routed separately but
connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal
ground caused by large currents. Also ensure that the ground traces of external components do not cause variations
on the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance.
5.
Thermal Consideration
Should by any chance the power dissipation rating be exceeded the rise in temperature of the chip may result in
deterioration of the properties of the chip. In case of exceeding this absolute maximum rating, increase the board size
and copper area to prevent exceeding the Pd rating.
6.
Recommended Operating Conditions
These conditions represent a range within which the expected characteristics of the IC can be approximately
obtained. The electrical characteristics are guaranteed under the conditions of each parameter.
7.
Inrush Current
When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush current may
flow instantaneously due to the internal powering sequence and delays, especially if the IC has more than one power
supply. Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring,
and routing of connections.
8.
Operation Under Strong Electromagnetic Field
Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction.
9.
Testing on Application Boards
When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may
subject the IC to stress. Always discharge capacitors completely after each process or step. The IC’s power supply
should always be turned off completely before connecting or removing it from the test setup during the inspection
process. To prevent damage from static discharge, ground the IC during assembly and use similar precautions during
transport and storage.
10. Inter-pin Short and Mounting Errors
Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in
damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin.
Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment)
and unintentional solder bridge deposited in between pins during assembly to name a few.
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
19/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Operational Notes – continued
11. Unused Input Pins
Input pins of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance and
extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small
charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and
cause unexpected operation of the IC. So unless otherwise specified, unused input pins should be connected to the
power supply or ground line.
12. Regarding the Input Pin of the IC
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 the P layers with the N layers of other elements, creating a
parasitic diode or transistor. For example (refer to figure below):
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to
operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should
be avoided.
Resistor
Transistor (NPN)
Pin A
Pin B
C
E
Pin A
N
P+
P
N
N
P+
N
Pin B
B
Parasitic
Elements
N
P+
N P
N
P+
B
N
C
E
Parasitic
Elements
P Substrate
P Substrate
GND
GND
Parasitic
Elements
GND
Parasitic
Elements
GND
N Region
close-by
Figure 32. Example of monolithic IC structure
13. Thermal Shutdown Circuit(TSD)
This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always
be within the IC’s power dissipation rating. If however the rating is exceeded for a continued period, the junction
temperature (Tj) will rise which will activate the TSD circuit that will turn OFF all output pins. When the Tj falls below
the TSD threshold, the circuits are automatically restored to normal operation.
Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no
circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from
heat damage.
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
20/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Ordering Information
B
D
8
3
0
3
M
U
V
Package
MUV: VQFN016V3030
Part Number
-
E2
Packaging and forming specification
E2: Embossed tape and reel
Marking Diagram
VQFN016V3030 (TOP VIEW)
Part Number Marking
BD8
LOT Number
303
1PIN MARK
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
21/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Physical Dimension, Tape and Reel Information
Package Name
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
VQFN016V3030
22/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
BD8303MUV
Revision History
Date
Revision
Changes
26.Nov.2014
001
New Release
16.Feb.2015
002
Correction of the writing.
www.rohm.com
© 2014 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
23/23
TSZ02201-0Q3Q0NZ00320-1-2
16.Feb.2015 Rev.002
Datasheet
Notice
Precaution on using ROHM Products
1.
Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
(Note 1)
, transport
intend to use our Products in devices requiring extremely high reliability (such as medical equipment
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
2.
ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3.
Our Products are designed and manufactured for use under standard conditions and not under any special or
extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
special or extraordinary environments or conditions. If you intend to use our Products under any special or
extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8.
Confirm that operation temperature is within the specified range described in the product specification.
9.
ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1.
When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2.
In principle, the reflow soldering method must be used on a surface-mount products, the flow soldering method must
be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products,
please consult with the ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice-GE
© 2013 ROHM Co., Ltd. All rights reserved.
Rev.004
Datasheet
Precautions Regarding Application Examples and External Circuits
1.
If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2.
You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1.
Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2.
Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3.
Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4.
Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
QR code printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since our Products might fall under controlled goods prescribed by the applicable foreign exchange and foreign trade act,
please consult with ROHM representative in case of export.
Precaution Regarding Intellectual Property Rights
1.
All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data. ROHM shall not be in any way responsible or liable
for infringement of any intellectual property rights or other damages arising from use of such information or data.:
2.
No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the information contained in this document.
Other Precaution
1.
This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2.
The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3.
In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4.
The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
Notice-GE
© 2013 ROHM Co., Ltd. All rights reserved.
Rev.004
Datasheet
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3.
The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or
concerning such information.
Notice – WE
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.001
Similar pages