Single-chip Type with Built-in FET Switching Regulators
Low Noise High-efficiency Switching Regulator with Built-in Power MOSFET
BD8963EFJ
No.10027EAT43
●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 1) Offers fast transient response with current mode PWM control system. 2) Offers highly efficiency for all load range with synchronous rectifier (Nch/Pch FET) 3) Incorporates soft-start function. 4) Incorporates thermal protection and ULVO functions. 5) Incorporates short-current protection circuit with time delay function. 6) Incorporates shutdown function 7) Employs small surface mount package : HTSOP-J8 ●Applications Power supply for LSI including DSP, Micro computer and ASIC ●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
Symbol VCC VEN VSW,VCOMP Pd1 Pd2 Topr Tstg Tjmax
Ratings -0.3 ~ +7 *1 -0.3 ~ +7 -0.3 ~ +7 0.5
*2
Unit V V V W W ℃ ℃ ℃
3.76*3 -25 ~ +85 -55 ~ +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)
●Operating conditions (Ta=-25 ~ +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 *5 0 1.0 Typ. 5.0 Max. 5.5 Vcc 2.5
*4
Unit V V V A
3.0*5
In case set output voltage 1.6V or more, VccMin. = Vout +2.25V Pd should not be exceeded.
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BD8963EFJ
●Electrical characteristics ◎BD8963EFJ(Unless otherwise specified , Ta=25℃ VCC=5V, EN=VCC, R1=20kΩ, R2=7.5kΩ) Limits Parameter Symbol Unit 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
Technical Note
Conditions EN=GND Stand-by Mode Active Mode VEN=5V VCC=5V VCC=5V VADJ=1.0V VADJ=0.6V Vcc=5V→0V Vcc=0V→5V
VOUT=1.0V→0V
●Physical dimension
●Block diagram・Application circuit
V CC
4.9±0.1
Max5.25(include.BURR)
(3.2)
8 7 6 5
4
+6 -4
EN 3
VREF Current Comp + RQ S + OSC CLK Driver Logic Current Sense/ Protect
4
V CC
Input
6.0±0.2 3.9±0.1
0.65±0.15
1.05±0.2
BD8963
(2.4)
5 6
Gm Amp
Lot No.
1 2 3 4
SLOPE V CC
+ Soft Start
Output SW GND
0.545
0.17 -0.03
+0.05
UVLO TSD SCP
2
1.0Max.
S
0.85±0.05 0.08±0.05
1.27 0.42 -0.04
+0.05
0.08
M
8
1
0.08 S
ADJ
COMP
HTSOP-J8
(unit:mm)
Fig.1 BD8963EFJ TOP View ●Pin No. & function table Pin No. Pin name 1 2 3 4 5 6 7 8 COMP GND EN VCC SW SW N.C ADJ Ground 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
Fig.2 BD8963EFJ Block Diagram
PIN function GmAmp output pin/Connected phase compensation capacitor
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BD8963EFJ
●Characteristics data【BD8963EFJ】
Technical Note
3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 1 2 3 4 INPUT VOLTAGE:VCC[V] 5
2.0
3
OUTPUT VOLTAGE:VOUT[V]
1.5
OUTPUT VOLTAGE:VOUT[V]
【VOUT=2.5V】 Ta=25℃
OUTPUT VOLTAGE:VOUT[V]
【VOUT=1.1V】
2.5 2 1.5 1 0.5 0
1.0
【VOUT=2.5V】 VCC=5V Ta=25℃
0.5
【VOUT=1.1V】 Ta=25℃
0.0 0 1
VCC=5.0V Ta=25℃ Io=0A
2 3 EN VOLTAGE:VEN[V] 4 5
【VOUT=1.1V】 VCC=5.0V Ta=25℃
0 2 4 6 8 OUTPUT CURRENT:IOUT[A] 10
Fig.3 Vcc-Vout
Fig.4 VEN-Vout
Fig.5 IOUT-VOUT
1.15 1.14
OUTPUT VOLTAGE:VOUT[V]
100
1.20 1.15 FREQUENCY:FOSC[MHz] 1.10 1.05 1.00 0.95 0.90 0.85 0.80
【VOUT=1.1V】
EFFICIENCY:η[%]
90 80 70 60 50 40 30 20 10 0
VCC=5.0V
1.13 1.12 1.11 1.10 1.09 1.08 1.07 1.06 1.05 -25
VCC=5.0V Io=0A
【VOUT=1.1V】 VCC=5.0V Ta=25℃
10 100 1000 OUTPUT CURRENT:IOUT[mA] 10000
0
25 50 TEMPERATURE:Ta[℃]
75
-25
0
25 50 TEMPERATURE:Ta[℃]
75
Fig. 6 Ta-VOUT
Fig.7 Efficiency
Fig.8 Ta-FOSC
0.20
2.0
500
VCC=5.0V
ON RESISTANCE:RON[Ω]
1.8 1.6
EN VOLTAGE:VEN[V]
VCC=5.0V
CIRCUIT CURRENT:I CC [μA]
450 400 350 300 250 200 150 100 50
VCC=5.0V
0.15
PMOS
0.10
1.4 1.2 1.0 0.8 0.6 0.4 0.2
NMOS
0.05
0.00 -25 0 25 50 TEMPERATURE:Ta[℃] 75
0.0 -25 0 25 50 TEMPERATURE:Ta[℃] 75
0 -25
0
25 50 TEMPERATURE:Ta[℃]
75
Fig.9 Ta-RONN, RONP
Fig.10 Ta-VEN
Fig.11 Ta-ICC
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BD8963EFJ
Technical Note
1.2
Ta=25℃
FREQUENCY:FOSC[MHz] 1.1
EN
【VOUT=1.1V】
SW
[VOUT=1.1V】
1
0.9
VOUT VCC=5.0V Ta=25℃ Io=0A
2.7 3.1 3.5 3.9 4.3 4.7 INPUT VOLTAGE:VCC[V] 5.1 5.5
VOUT
0.8
VCC=5.0V Ta=25℃
Fig.12 Vcc-FOSC
Fig.13 Soft start waveform
Fig.14
SW waveform Io=10mA
VOUT
【VOUT=1.1V】 VOUT
【VOUT=1.1V】
IOUT
IOUT
VCC=5.0V Ta=25℃
VCC=5.0V Ta=25℃
Fig. 15 Transient response Io=0.5A→1.5A(10µs)
Fig. 16 Transient response Io=1.5A→0.5A(10µs)
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BD8963EFJ
●Information on advantages Advantage 1 : Offers fast transient response with current mode control system. Conventional product (Load response IO= 0.5A→1.5A)
VOUT VOUT 75mV
Technical Note
BD8963EFJ (Load response IO= 0.5A→1.5A)
36mV
IOUT
IOUT
Voltage drop due to sudden change in load was reduced by about 50%. Fig.17 Comparison of transient response Advantage 2 : Offers high efficiency with synchronous rectifier Utilizes the synchronous rectifying mode and the low on-resistance MOS FETs incorporated as power transistor. ON resistance of P-channel MOS FET : 145mΩ(Typ.) ON resistance of N-channel MOS FET : 80mΩ(Typ.)
EFFICIENCY:η[%] 100 90 80 70 60 50 40 30 20 10 0 10 100 1000 OUTPUT CURRENT:IOUT[mA] 10000
【VOUT=1.1V】 VCC=5.0V Ta=25℃
Fig.18 Efficiency Advantage 3 :・Supplied in smaller package due to small-sized power MOS FET incorporated. ・Output capacitor Co required for current mode control: 10μF ceramic capacitor ・Inductance L required for the operating frequency of 1 MHz: 1.5μH inductor Reduces a mounting area required.
VCC 15mm Cin RCOMP L VOUT Co 10mm CCOMP CO CIN L
RCOMP CCOMP
DC/DC Convertor Controller
Fig.19 Example application
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BD8963EFJ
Technical Note
●Operation BD8963EFJ is a synchronous rectifying step-down switching regulator that achieves faster transient response by employing current mode PWM control system. ○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 which 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 from 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.20 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.21 PWM switching timing chart
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BD8963EFJ
Technical Note
●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 reference voltage circuit, internal oscillator and drivers are turned to OFF. Circuit current during standby is 5µF (Typ.). ・UVLO function Detects whether the input voltage sufficient to secure the output voltage of this IC is supplied. And the hysteresis width of 50mV (Typ.) is provided to prevent output chattering.
Hysteresis 50mV
VCC
EN
VOUT
Tss Soft start Standby mode Operating mode Standby mode UVLO
Tss
Tss
Operating mode
Standby mode EN
Operating mode
Standby mode
UVLO
UVLO
Fig.22 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 incorporated 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× √ .1×(5-1.1) 1 5 =1.24[ARMS] When Vcc is twice the VOUT, IRMS=
Fig.27 Input capacitor
A low ESR 10µF/10V ceramic capacitor is recommended to reduce ESR dissipation of input capacitor for better efficiency.
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BD8963EFJ
Technical Note
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.
fp=
1 2π×RO×CO 1 fz(ESR)= 2π×ESR×CO 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.28 Open loop gain characteristics fp(Max.)=
A Gain [dB] 0 0 Phase [deg] -90
fz(Amp.)
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.) fz(Amp.)= 1 2π×RCOMP×CCOMP
Fig.29 Error amp phase compensation characteristics
VCC
Cin EN VOUT ADJ COMP RCOMP CCOMP
VCC
L SW ESR RO VOUT
GND
CO
Fig.30 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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BD8963EFJ
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. Adjustable output voltage range : 1.0V ~ 2.5V
5 L 6 SW 8 ADJ
Technical Note
Output Co R2
R1
Fig.31 Determination of output voltage Use 1 kΩ ~ 100 kΩ resistor for R1. If a resistor of the resistance higher than 100 kΩ is used, check the assembled set carefully for ripple voltage etc.
INPUT 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.32. 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.32 minimum input voltage in each output voltage
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BD8963EFJ
●BD8963EFJ Cautions on PC Board layout ① L1 VCC ①5 6 SW ②,④ 7 R2 8 N.C ADJ GND COMP EN SW VCC 4 3 2 1 R3 ⑥ R1 ⑤ C1 ②,④ ①,③
Technical Note
Vout
C3 ①,③
C2 ①,③
Fig.33 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.
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BD8963EFJ
Technical Note
Top Silkscreen Overlay
Top Layer
Middle Layer
Bottom Silkscreen Overlay Fig.34 Reference PCB Layout Pattern
Bottom Layer
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BD8963EFJ
●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
P+ N P P+ N N P+ N P P+ N
Transistor (NPN) Pin B
C B E B C E
Pin B
N
P substrate Parasitic element
GND
Parasitic element Parasitic element
P substrate
GND GND GND
Parasitic element
Other adjacent elements
Fig.36 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 the small-signal GND. Pay attention not to cause fluctuations in the GND wiring pattern of external parts as well. 9. Selection of inductor It is recommended to use an inductor with a series resistance element (DCR) 0.1Ω or less. Especially, in case output voltage is set 1.6V or more, note that use of a high DCR inductor will cause an inductor loss, resulting in decreased output voltage. Should this condition continue for a specified period (soft start time + timer latch time), output short circuit protection will be activated and output will be latched OFF. When using an inductor over 0.1Ω, 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 operation range.
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BD8963EFJ
●Ordering part number
Technical Note
B
D
8
Part No. 8963
9
6
3
E
F
J
-
E
2
Part No.
Package EFJ : HTSOP-J8
Packaging and forming specification E2: Embossed tape and reel
(63: Adjustable (1 ~ 2.5V))
HTSOP-J8
4.9±0.1 (MAX 5.25 include BURR) (3.2)
8765
Tape
0.65±0.15 1.05±0.2
Embossed carrier tape 2500pcs E2
The direction is the 1pin of product is at the upper left when you hold
+6° 4° −4°
(2.4)
Quantity Direction of feed
6.0±0.2
3.9±0.1
( reel on the left hand and you pull out the tape on the right hand
)
1
234
1PIN MARK 0.545
1.0MAX
+0.05 0.17 -0.03 S 1.27
0.85±0.05
0.08±0.08
+0.05 0.42 -0.04 0.08 S
0.08
M
1pin
Direction of feed
(Unit : mm)
Reel
∗ Order quantity needs to be multiple of the minimum quantity.
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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, fuelcontroller or other safety device). ROHM shall bear no responsibility in any way for use of any of the Products for the above special purposes. If a Product is intended to be used for any such special purpose, please contact a ROHM sales representative before purchasing. If you intend to export or ship overseas any Product or technology specified herein that may be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to obtain a license or permit under the Law.
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R1010A
