2.7V to 5.5V, 3A 1ch Synchronous Buck Converter integrated FET
BD8963EFJ
●General Description ROHM’s high efficiency step-down switching regulator BD8963EFJ is a power supply designed to produce a low voltage including 1 volts from 5.5/3.3 volts power supply line. Offers high efficiency with synchronous rectifier. Employs a current mode control system to provide faster transient response to sudden change in load. ●Features Offers fast transient response with current mode PWM control system. Offers highly efficiency for all load range with synchronous rectifier (Nch/Pch FET) Incorporates soft-start function. Incorporates thermal protection and ULVO functions. Incorporates short-current protection circuit with time delay function. Incorporates shutdown function ●Applications Power supply for LSI including DSP, Micro computer and ASIC ●Key Specification Input voltage range: Output voltage range: Average output Current: Switching frequency: Pch FET ON resistance: Nch FET ON resistance: Standby current: Operating temperature range: 2.7V to 5.5V 1.0V to 2.5V 3A(Max.) 1MHz(Typ.) 145mΩ(Typ.) 80mΩ(Typ.) 5μA (Typ.) -25℃ to +85℃
●Package HTSOP-J8
(Typ.) (Typ.) (Max.) 4.90mm x 6.00mm x 1.00mm
●Typical Application Circuit
HTSOP-J8
VCC
Cin EN VCC SW
L VOUT
VOUT
ADJ
ESR
RO
COMP
GND
CO
RCOMP
CCOMP
Fig.1 Typical Application Circuit
○Product structure：Silicon monolithic integrated circuit www.rohm.com ©2012 ROHM Co., Ltd. All rights reserved. TSZ22111･14･001
○This product is not designed protection against radioactive rays.
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●Pin configuration(TOP VIEW)
Datasheet
COMP GND EN VCC
ADJ N.C SW SW
Fig.2 Pin configuration
●Pin Description Pin No. Pin name 1 2 3 4 5 6 7 8 COMP GND EN VCC SW SW N.C ADJ Ground
PIN function GmAmp output pin/Connected phase compensation capacitor Enable pin(Active High, Open Active) VCC power supply input pin Pch/Nch FET drain output pin Pch/Nch FET drain output pin Non Connect Output voltage detect pin
●Block Diagram
VCC
SW SW
GND
Fig.3 Block Diagram
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●Absolute Maximum Ratings Parameter VCC Voltage EN Voltage SW,COMP Voltage Power Dissipation 1 Power Dissipation 2 Operating temperature range Storage temperature range Maximum junction temperature
*1 *2 *3
Datasheet
Symbol VCC VEN VSW,VCOMP Pd1 Pd2 Topr Tstg Tjmax
Ratings -0.3 to +7
*1
Unit V V V W W ℃ ℃ ℃
-0.3 to +7 -0.3 to +7 0.5
*2 *3
3.76
-25 to +85 -55 to +150 +150
Pd should not be exceeded. Reduced by 4.0mW for increase in Ta of 1℃ above 25℃. Reduced by 30.0mW for increase in Ta of 1℃ above 25℃. (when mounted on a board 70.0mm × 70.0mm × 1.6mm Glass-epoxy PCB)
●Recommended Operating Ratings (Ta=-25 to +85℃) Parameter Power Supply Voltage EN Voltage Output voltage range SW average output current
*4 *5
Symbol VCC VEN VOUT Isw
Ratings Min. 2.7 0 1.0 *5
Typ. 5.0 -
Max. 5.5 Vcc 2.5 3.0
*4 *5
Unit V V V A
In case set output voltage 1.6V or more, VccMin. = Vout +2.25V Pd should not be exceeded.
●Electrical Characteristics (Unless otherwise specified , Ta=25℃ VCC=5V, EN=VCC, R1=20kΩ, R2=7.5kΩ) Limit Parameter Symbol Unit Conditions Min. Typ. Max. Standby Current Bias Current EN Low Voltage EN High Voltage EN Current Oscillation Frequency Pch FET ON Resistance Nch FET ON Resistance ADJ Reference Voltage COMP SINK Current COMP Source Current UVLO Threshold Voltage UVLO Hysteresis Voltage Soft Start Time Timer Latch Time Output Short circuit Threshold Voltage ISTB ICC VENL VENH IEN FOSC RONP RONN VADJ ICOSI ICOSO VUVLO1 VUVLO2 TSS TLATCH VSCP 2.0 0.8 0.788 10 10 2.400 2.425 0.5 1 5 350 GND VCC 1.25 1 145 80 0.800 25 25 2.500 2.550 1 2 VOUT×0.5 20 600 0.3 10 1.2 290 160 0.812 2.600 2.700 2 4 VOUT×0.7 µA µA V V µA MHz mΩ mΩ V µA µA V V ms ms V VOUT=1.0V→0V VADJ=1.0V VADJ=0.6V Vcc=5V→0V Vcc=0V→5V VCC=5V VCC=5V Stand-by Mode Active Mode VEN=5V EN=GND
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●Typical Performance Curves
Datasheet
Fig.4 Vcc-Vout
Fig.5 VEN-Vout
Fig.6 IOUT-VOUT
Fig. 7 Ta-VOUT
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Datasheet
EFFICIENCY[%]
Fig.8 Efficiency
Fig.9 Ta-FOSC
Fig.10 Ta-RONN, RONP
Fig.11 Ta-VEN
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Datasheet
Fig.12 Ta-ICC
Fig.13 Vcc-FOSC
Fig.14 Soft start waveform
Fig.15 SW waveform Io=10mA
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Datasheet
Fig. 16 Transient response Io=0.5A→1.5A(10µs)
Fig. 17 Transient response Io=1.5A→0.5A(10µs)
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Application Information
Datasheet
●Operation ○Synchronous rectifier It does not require the power to be dissipated by a rectifier externally connected to a conventional DC/DC converter IC, and its P.N junction shoot-through protection circuit limits the shoot-through current during operation, by whic h the power dissipation of the set is reduced. ○Current mode PWM control Synthesizes a PWM control signal with a inductor current feedback loop added to the voltage feedback. ・PWM (Pulse Width Modulation) control The oscillation frequency for PWM is 1 MHz. SET signal form OSC turns ON a P-channel MOS FET (while a N-channel MOS FET is turned OFF), and an inductor current IL increases. The current comparator (Current Comp) receives two signals, a current feedback control signal (SENSE: Voltage converted fr om IL) and a voltage feedback control signal (FB), and issues a RESET signal if both input signals are identical to each other, and turns OFF the P-channel MOS FET (while a N-channel MOS FET is turned ON) for the rest of the fixed period. The PWM control repeat this operation.
SENSE Current Comp RESET Level Shift Gm Amp. COMP OSC RQ FB SET S Driver Logic SW Load IL VOUT
VOUT
Fig.18 Diagram of current mode PWM control
Current Comp SET
PVCC SENSE FB GND GND GND IL(AVE)
Current Comp SET
RESET SW IL
RESET SW
VOUT
VOUT(AVE)
VOUT
Fig.19 PWM switching timing chart
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Datasheet
●Description of operations ・Soft-start function EN terminal shifted to “High” activates a soft -starter to gradually establish the output voltage with the current limited during startup, by which it is possible to prevent an overshoot of output voltage and an inrush current. ・Shutdown function With EN terminal shifted to “Low”, the device turns to Standby Mode, and all the function blocks including referenc e voltage circuit, internal oscillator and drivers are turned to OFF. Circuit current during standby is 5µA (Typ.). ・UVLO function Detects whether the input voltage sufficient to secure the output voltage of this IC is supplied. of 50mV (Typ.) is provided to prevent output chattering.
Hysteresis 50mV
And the hysteresis width
VCC
EN
VOUT
Tss Soft start Standby mode Operating mode Standby mode
Tss
Tss
Operating mode
Standby mode
Operating mode
Standby mode
UVLO
UVLO
EN
UVLO
Fig.20 Soft start, Shutdown, UVLO timing chart ・Short-current protection circuit with time delay function Turns OFF the output to protect the IC from breakdown when the i ncorporated current limiter is activated continuously for the fixed time(TLATCH) or more. The output thus held tuned OFF may be recovered by restarting EN or by re-unlocking UVLO.
EN Output OFF latch
Output Short circuit Threshold Voltage VOUT IL Limit IL
Standby mode
t1 IRMS(max.) 2 If VCC=5V, VOUT=1.1V, and IOUTmax.= 3A, (BD8963EFJ) IRMS=3× When Vcc is twice the VOUT, IRMS=
Fig.28 Input capacitor
√ .1×(5-1.1) 1 =1.24[ARMS] 35 . A low ESR 22µF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better efficiency. 3
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Datasheet
4. Determination of RCOMP, CCOMP that works as a phase compensator As the Current Mode Control is designed to limit a inductor current, a pole (phase lag) appears in the low frequency area due to a CR filter consisting of a output capacitor and a load resistance, while a zero (phase lead) appears in the high frequency area due to the output capacitor and its ESR. So, the phases are easily compensated by adding a zero to the power amplifier output with C and R as described below to cancel a pole at the power amplifier.
fp(Min.) A Gain [dB] fp(Max.) 0 fz(ESR) IOUTMin. 0 IOUTMax.
1 2π×RO×CO 1 fz(ESR)= 2π×ESR×CO fp= Pole at power amplifier When the output current decreases, the load resistance Ro increases and the pole frequency lowers. fp(Min.)= 1 [Hz]←with lighter load 2π×ROMax.×CO 1 2π×ROMin.×CO [Hz] ←with heavier load
Phase [deg]
-90
Fig.29 Open loop gain characteristics fp(Max.)=
A fz(Amp.) Gain [dB] 0 0 Phase [deg] -90
Zero at power amplifier Increasing capacitance of the output capacitor lowers the pole frequency while the zero frequency does not change. (This is because when the capacitance is doubled, the capacitor ESR reduces to half.) 1 2π×RITH×CITH
fz(Amp.)=
Fig.30 Error amp phase compensation characteristics
VCC
Cin EN VOUT ADJ COMP RCOMP CCOMP
VCC
L SW ESR RO VOUT
GND
CO
Fig.31 Typical application Stable feedback loop may be achieved by canceling the pole fp (Min.) produced by the output capacitor and the load resistance with CR zero correction by the error amplifier. fz(Amp.)= fp(Min.) 1 2π×RCOMP×CCOMP = 1 2π×ROMax.×CO
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Datasheet
5. Determination of output voltage The output voltage VOUT is determined by the equation (6): VOUT=(R2/R1+1)×VADJ・・・(6) VADJ: Voltage at ADJ terminal (0.8V Typ.) With R1 and R2 adjusted, the output voltage may be determined as required.
5 L 6 SW 8 ADJ R1 Co R2 Output
Adjustable output voltage range : 1.0V to 2.5V
Fig.32 Determination of output voltage Use 1 kΩ to 100 kΩ resistor for R1. carefully for ripple voltage etc. If a resistor of the resistance higher than 100 kΩ is used, check the assembled set
IN PU T VOLTAGE : VCC [V]
The lower limit of input voltage depends on the output voltage. Basically, it is recommended to use in the condition : VCCmin = VOUT+2.25V. Fig.33. shows the necessary output current value at the lower limit of input voltage. (DCR of inductor : 0.05Ω) This data is the characteristic value, so it’ doesn’t guarantee the operation range,
4.7
Vo=2.5V
4.2
3.7
Vo=2.0V
Vo=1.5V
3.2
Vo=1.8V
2.7 0 0.5 1 1.5 2 2.5 3
OUTPUT CURRENT : IOUT[A]
Fig.33 minimum input voltage in each output voltage
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●Cautions on PC Board layout ① L1 VCC ①5 6 SW ②,④ 7 R2 8 N.C ADJ GND COMP 1 R3 ⑥ R1 ⑤ C1 ②,④ EN SW VCC 4 ①,③
Datasheet
Vout
3 2
C3 ①,③
C2 ①,③
Fig.34 Layout diagram
①To avoid conduction loss, please keep Black thick line as short and thick as possible. ②Don't close to switching current loop. ③Close to IC pin as possible. ④Keep PCB trace as short as possible. ⑤Use single point ground structure to connect with Pin2. ⑥Close to C2 as possible. ※ HTSOP-J8 (BD8963EFJ) has thermal PAD on the reverse of the package. The package thermal performance may be enhanced by bonding the PAD to GND plane which take a large area of PCB.
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Datasheet
Top Silkscreen Overlay
Top Layer
Middle Layer
Bottom Silkscreen Overlay Fig.35 Reference PCB Layout Pattern
Bottom Layer
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●Recommended components Lists on above application Symbol L CIN CO Part Coil Ceramic capacitor Ceramic capacitor VOUT=1.0V VOUT=1.1V CCOMP Ceramic capacitor VOUT=1.2V VOUT=1.5V VOUT=1.8V VOUT=2.5V VOUT=1.0V VOUT=1.1V RCOMP Resistance VOUT=1.2V VOUT=1.5V VOUT=1.8V VOUT=2.5V Value 1.5µH Vcc-VOUT>3V Vcc-VOUTTerminal A (at resistor side), or GND>Terminal B (at transistor side); and ○if GND>Terminal B (at NPN transistor side), a parasitic NPN transistor is activated by N-layer of other element adjacent to the above-mentioned parasitic diode. The structure of the IC inevitably forms parasitic elements, the activation of which may cause interference among circuits, and/or malfunctions contributing to breakdown. It is therefore requested to take care not to use the device in such manner that the voltage lower than GND (at P-substrate) may be applied to the input terminal, which may result in activation of parasitic elements.
Resistor Pin A Pin A
N N P
+
Transistor (NPN) Pin B
C B E B P P
+
Pin B
N P P
+
P+
N N
C E
N
P substrate Parasitic element
GND
Parasitic element Parasitic element
P substrate
GND GND GND
Parasitic element
Other adjacent elements
Fig.37 Simplified structure of monorisic IC 8. 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 th e small-signal GND. Pay attention not to cause fluctuations in the GND wiring patter n of external parts as well. 9. Selection of inductor It is recommended to use an inductor with a series resistance element (DCR) 0.1 Ω or less. Especially, in case output voltage is set 1.6V or more, note that use of a high DCR inductor will cause an induc tor loss, resulting in decreased output voltage. Should this condition continue for a specified period (soft start time + timer latch time), output short circ uit protection will be activated and output will be latched OFF. When using an inductor over 0.1 Ω, be careful to ensure adequate margins for variation between external devices and this IC, including transient as well as static characteristics. Furthermore, in any case, it is recommended to start up the output with EN after supply voltage is within oper ation range. Status of this document The Japanese version of this document is formal specification. A customer may use this translation version only for a reference to help reading the formal version. If there are any differences in translation version of this document formal version takes priority
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●Ordering Information
Datasheet
B
D
8
9
6
3
E
F
J
E2
Packaging and forming specification E2: Embossed tape and reel
Part Number
Package EFJ: HTSOP-J8
●Physical Dimension Tape and Reel Information
●Marking Diagram MSOP8(TOP VIEW) Part Number Marking
D 6
8
9 3
LOT Number
1PIN MARK
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●Revision History Date 17.Jan.2012 Revision 001 New Release Changes
Datasheet
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Datasheet Datasheet
Notice
●Precaution for circuit design 1) The products are designed and produced for application in ordinary electronic equipment (AV equipment, OA equipment, telecommunication equipment, home appliances, amusement equipment, etc.). If the products are to be used in devices requiring extremely high reliability (medical equipment, transport equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car accessories, safety devices, etc.) and whose malfunction or operational error may endanger human life and sufficient fail-safe measures, please consult with the ROHM sales staff in advance. If product malfunctions may result in serious damage, including that to human life, sufficient fail-safe measures must be taken, including the following: [a] Installation of protection circuits or other protective devices to improve system safety [b] Installation of redundant circuits in the case of single-circuit failure 2) The products are designed for use in a standard environment and not in any special environments. Application of the products in a special environment can deteriorate product performance. Accordingly, verification and confirmation of product performance, prior to use, is recommended if used under the following conditions: [a] Use in various types of liquid, including water, oils, chemicals, and organic solvents [b] Use outdoors where the products are exposed to direct sunlight, or in dusty places [c] Use in places where the products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [d] Use in places where the products are exposed to static electricity or electromagnetic waves [e] Use in proximity to heat-producing components, plastic cords, or other flammable items [f] Use involving sealing or coating the products with resin or other coating materials [g] Use involving unclean solder or use of water or water-soluble cleaning agents for cleaning after soldering [h] Use of the products in places subject to dew condensation The products are not radiation resistant. Verification and confirmation of performance characteristics of products, after on-board mounting, is advised. 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. De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual ambient temperature. Confirm that operation temperature is within the specified range described in product specification. Failure induced under deviant condition from what defined in the product specification cannot be guaranteed.
3) 4) 5)
6) 7) 8)
●Precaution for Mounting / Circuit board design 1) When a highly active halogenous (chlorine, bromine, etc.) flux is used, the remainder of flux may negatively affect product performance and reliability. 2) In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the Company in advance.
Regarding Precaution for Mounting / Circuit board design, please specially refer to ROHM Mounting specification ●Precautions Regarding Application Examples and External Circuits 1) If change is made to the constant of an external circuit, allow a sufficient margin due to variations of the characteristics of the products and external components, including transient characteristics, as well as static characteristics. 2) The application examples, their constants, and other types of information contained herein are applicable only when the products are used in accordance with standard methods. Therefore, if mass production is intended, sufficient consideration to external conditions must be made.
Notice - Rev.001
Datasheet Datasheet
●Precaution for Electrostatic This product is Electrostatic sensitive product, which may be damaged due to Electrostatic discharge. Please take proper caution during manufacturing and storing so that voltage exceeding Product maximum rating won't 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 following places: [a] Where the products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2 [b] Where the temperature or humidity exceeds those recommended by the Company [c] Storage in direct sunshine or condensation [d] Storage in 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 recommended storage time period . Store / transport cartons in the correct direction, which is indicated on a carton as a symbol. Otherwise bent leads may occur due to excessive stress applied when dropping of a carton. Use products within the specified time after opening a dry bag.
3) 4)
●Precaution for product label QR code printed on ROHM product label is only for internal use, and please do not use at customer site. It might contain a internal part number that is inconsistent with an product part number. ●Precaution for disposition When disposing products please dispose them properly with a industry waste company. ●Precaution for Foreign exchange and Foreign trade act Since concerned goods might be fallen under controlled goods prescribed by Foreign exchange and Foreign trade act, please consult with ROHM in case of export. ●Prohibitions Regarding Industrial Property 1) Information and data on products, including application examples, contained in these specifications are simply for reference; the Company does not guarantee any industrial property rights, intellectual property rights, or any other rights of a third party regarding this information or data. Accordingly, the Company does not bear any responsibility for: [a] infringement of the intellectual property rights of a third party [b] any problems incurred by the use of the products listed herein. 2) The Company prohibits the purchaser of its products to exercise or use the intellectual property rights, industrial property rights, or any other rights that either belong to or are controlled by the Company, other than the right to use, sell, or dispose of the products.
Notice - Rev.001
