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intersil EL7515 Manual (1)

1. FIGURE 8 STEADY STATE OPERATION INDUCTOR CONTINUOUS CONDUCTION Vin 5V Vo 12V lo 50mA TO 300mA one TOOMA DIV 0 5VIDIV 0 2ms DIV FIGURE 10 LOAD TRANSIENT RESPONSE capacitor This in turn controls the rising rate of the output voltage The regulator goes through the start up sequence as well after the EN signal is pulled to HI Steady State Operation When the output reaches the preset voltage the regulator operates at steady state Depending on the input output conditions and component values the inductor operates at either continuous conduction mode or discontinuous conduction mode In the continuous conduction mode the inductor current is a triangular waveform and LX voltage a pulse waveform In the discontinuous conduction mode the inductor current is completely dried out before the MOSFET is turned on again The input voltage source the inductor and the MOSFET and output diode parasitic capacitors form a resonant circuit Oscillation will occur in this period This oscillation is normal and will not affect the regulation 6 intersil FN7120 2 August 10 2007 EL7515 At very low load the MOSFET will skip pulses sometimes This is normal Current Limit The MOSFET current limit is nominally 1 4A and guaranteed 1A This restricts the maximum output current loMAx based on Equation 1
2. DETAIL X All Intersil U S products are manufactured assembled and tested utilizing ISO9000 quality systems Intersil Corporation s quality certifications can be viewed at www intersil com design guality Intersil products are sold by description only Intersil Corporation reserves the right to make changes in circuit design software and or specifications at any time without notice Accordingly the reader is cautioned to verify that data sheets are current before placing orders Information furnished by Intersil is believed to be accurate and reliable However no responsibility is assumed by Intersil or its subsidiaries for its use nor for any infringements of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries For information regarding Intersil Corporation and its products see www intersil com 9 intersil FN7120 2 w August 10 2007
3. 8 where Vgpg slightly changes with Vpp The curve is shown in this data sheet RC Filter The maximum voltage rating for the VDD pin is 12V and is recommended to be about 10V for maximum efficiency to drive the internal MOSFET The series resistor R4 in the RC filter connected to Vpp can be utilized to reduce the voltage If Vo is larger than 10V then Equation 9 shows a Yo51 EQ 9 4 pp where Ipp is shown in Ipp vs fs curve Otherwise R4 can be 109 to 51Q with Cy 0 1pF Thermal Performance The EL7515 uses a fused lead package which has a reduced 034 of 100 C W on a four layer board and 115 C W on a two layer board Maximizing copper around the ground pins will improve the thermal performance This chip also has internal thermal shut down set at around Layout Considerations The layout is very important for the converter to function properly Power Ground and Signal Ground should be separated to ensure that the high pulse current in the Power Ground never interferes with the sensitive signals connected to Signal Ground They should only be connected at one point The trace connected to pin 8 FB is the most sensitive trace It needs to be as short as possible and in a quiet place preferably between PGND or SGND traces In addition the bypass capacitor connected to the VDD pin needs to be as close to the pin as possible The heat of the chip is mainly dissipated through the SGND pin Maxim
4. gt t YIN EQ 1 lomax 1 5 where Al is the inductor peak to peak current ripple and is decided by Equation 2 v Al IN D EQ 2 Dis the MOSFET turn on ratio and is decided by Equation 3 _ Vo ViN Vo D EQ 3 fs is the switching frequency The following table gives typical values TABLE 1 MAX CONTINUOUS OUTPUT CURRENTS VIN Vo lone 2 9 10 1000 190 2 12 10 1000 140 3 3 5 10 1000 600 3 3 9 10 1000 310 3 3 12 10 1000 230 5 9 10 1000 470 5 12 10 1000 340 9 12 10 1000 630 12 15 10 100 670 Component Considerations It is recommended that CiN is larger than 10pF Theoretically the input capacitor has a ripple current of Al Due to high frequency noise in the circuit the input current ripple may exceed the theoretical value A larger capacitor will reduce the ripple further The inductor has peak and average current decided by Equations 4 and 5 s EQ 4 LAVG 3 2 9 LPK 7 l _ 0 ka EQ 5 The inductor should be chosen to be able to handle this current Furthermore due to the fixed internal compensation it is recommended that maximum inductance of 10uH and 154H to be used in the 5V and 12V or higher output voltage respectively The output diode has an average current of Io and peak current the same as the inductor s peak current A Schottky diode is recommended and it should be able to handle those currents Th
5. EFERENCE GENERATOR 4 intersil FN7120 2 ww August 10 2007 EL7515 Typical Performance Curves Vin 3 3V Vo 12V Vin 3 3V Vo 5V 2 VIN o 92 VIN o 90 30 88 88 86 gt 2 x a 84 g 86 s i 82 82 ul gg 82 78 76 80 O 50 100 150 200 250 300 350 0 100 200 300 400 500 600 700 lout mA lout mA FIGURE 1 EFFICIENCY vs loUT FIGURE 2 EFFICIENCY vs loUT Vin 5V Vo 12V ae Vpp 10V Vo 12V TO 17V 92 21 90 2 z 88 19 gt 2 G 86 18 FaN a a L 84 17 m e u g2 6 oot WAY COMA i rs 78 1 4 0 100 200 300 400 50 600 650 750 9850 950 1050 1150 1250 lout mA Fs kHz FIGURE 3 EFFICIENCY vs louT FIGURE 4 Ipp vs Fs VDD 10V 1400 1400 Rq 51 1kQ 1200 es 1200 1000 Ry 71 5kQ 1000 Creer F 800 N 800 i 600 Ry 100k2 iY 600 400 mmea a 400 R 200kQ 200 200 0 0 5 6 7 8 9 10 11 12 50 100 150 200 Vpp V Rr kO FIGURE 5 Fs vs Vpp FIGURE 6 Fs vs RT 5 intersil FN7120 2 w August 10 2007 EL7515 Typical Performance Curves continued Vin 5V Vo 12V l 30MA AVIN ii Laelia ee 50mV DIV Vix MEI J y 10V DIV AVo cali kde nce aasi aan A ade ak Li saia
6. MARKING PACKAGE DWG EL75151Y e 10 Ld MSOP MDP0043 EL75151Y T7 e 10 Ld MSOP MDP0043 EL75151Y T13 je 10 Ld MSOP MDP0043 EL7515IYZ BAAAR 10 Ld MSOP MDP0043 Note Pb free EL7515IYZ T7 BAAAR 10 Ld MSOP MDP0043 Note Pb free EL7515IYZ T13 BAAAR 10 Ld MSOP MDP0043 Note Pb free Please refer to TB347 for details on reel specifications NOTE These Intersil Pb free plastic packaged products employ special Pb free material sets molding compounds die attach materials and 100 matte tin plate PLUS ANNEAL e3 termination finish which is ROHS compliant and compatible with both SnPb and Pb free soldering operations Intersil Pb free products are MSL classified at Pb free peak reflow temperatures that meet or exceed the Pb free requirements of IPC JEDEC J STD 020 1 CAUTION These devices are sensitive to electrostatic discharge follow proper IC Handling Procedures 1 888 INTERSIL or 1 888 468 3774 Intersil and design is a registered trademark of Intersil Americas Inc Copyright Intersil Americas Inc 2003 2005 2007 All Rights Reserved All other trademarks mentioned are the property of their respective owners EL7515 Typical Application Vour 1 8V TO a 2 12V UP TO ww BDTI C com ntersi 2 intersil FN7120 2 ws August 10 2007 EL7515 Absolute Maximum Ratings TA 25 C E EBI NSS aa dual u uuu quassy h magis 12V Oln adis saali e E ude 18V Thermal Information SAE va t ar
7. e 20mVIDIV L O 5AIDIV 0 5usIDIV FIGURE 7 STEADY STATE OPERATION INDUCTOR DISCONTINUOUS CONDUCTION Vin 5V Vo 12V lo 300mA 2VIDIV 5VIDIV 0 5ms DIV FIGURE 9 POWER UP Applications Information The EL7515 is a step up regulator operated at fixed frequency pulse width modulation PWM control The input voltage is 1 8V to 13 2V and output voltage is 4 5V to 17V The switching frequency up to 1 2MHz is decided by the resistor connected to Rr pin Start Up After Vpp reaches a threshold of about 1 7V the start up oscillator generates fixed duty ratio of 0 5 to 0 7 ata frequency of several hundred kilohertz This will boost the output voltage When Vpp reaches about 3 7V the PWM comparator takes over the control The duty ratio will be decided by the multiple input direct summing comparator Max Duty signal about 90 duty ratio and the Current Limit Comparator whichever is the smallest The soft start is provided by the current limit comparator As the internal 12A current source charges the external CSS the peak MOSFET current is limited by the voltage on the re CO Vin 5V Vo 12V lo 300mA AVIN bpm pm el pet 50mV DIV panhwsa aa aai E P E IN FSI 10VIDIV AA Ls site Peel 20mVIDIV IL Pl TOE T LL Ts 0 5AIDIV 0 5usIDIV
8. e output voltage ripple can be calculated as Equation 6 I xD 0 EO 6 AVo eet pk ESR EQ 6 sx o Where Co is the output capacitance The ESR is the output capacitor ESR value Ricapagi shoul to r inimize the output C l ri nef la m acilbrs X5R and X7R are preferred for the output capacitors since they have a low ESR and small packages Tantalum capacitors also can be used but they take more board space and have higher ESR A minimum of 22uF output capacitor is sufficient for high output current application For lower output current the output capacitor can be smaller like 4 74F The capacitor should always have enough voltage rating In addition to the voltage rating the output capacitor should also be able to handle the RMS current which is given by Equation 7 2 Al gi lcornms 1 D x D 2 IL AVG ILAVG EQ 7 Output Voltage An external resistor divider is reguired to divide the output voltage down to the nominal reference voltage The current drawn by the resistor network should be limited to maintain the overall converter efficiency The maximum value of the resistor network is limited by the feedback input bias current and the potential for noise being coupled into the feedback pin A resistor network less than 300kQ is recommended 7 intersil FN7120 2 August 10 2007 EL7515 The boost converter output voltage is determined by the relationship in Equation 8 N A i EQ
9. ia tee 65 C to 150 C Beat hua e me aitan Baye 40 C to 85 C Storage Temperature Operating Temperature Operating Junction Temperature 135 C Pb free reflow profile Saana yaya a n E e ee see link below http www intersil com pbfree Pb FreeReflow asp CAUTION Do not operate at or near the maximum ratings listed for extended periods of time Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty IMPORTANT NOTE All parameters having Min Max specifications are guaranteed Typ values are for information purposes only Unless otherwise noted all tests are at the specified temperature and are pulsed tests therefore T Tc TA Electrical Specifications Vis 5V Vour 12V L 104H lout OMA RrT 100kQ T4 25 C Unless Otherwise Specified PARAMETER DESCRIPTION CONDITIONS E TYP pe UNIT VIN Input Voltage Range 1 8 13 2 V VOUT Output Voltage Range 4 5 17 V 101 Quiescent Current Shut down Ven 0 feedback resistors disconnected 1 HA 102 Quiescent Current VEN 2V 1 4 2 mA VEB Feedback Voltage 1 29 1 33 1 37 V IB Feedback Input Bias Current 0 10 HA DMAX Maximum Duty Cycle 84 90 ILIM Current Limit Max Peak Input 1 1 4 A Current ISHDN Shut down Input Bias Current 1 HA VLBI LBI Threshold Vo 180 220 250 mV vou WAVE BDTL G eomtt ntet sft ILEAK LBO LBO Out
10. intersil Data Sheet High Freguency PWM Step Up Regulator The EL7515 is a high freguency high efficiency step up DC DC regulator operated at fixed freguency PWM mode With an integrated 1 4 A MOSFET it can deliver up to 600mA output current at up to 92 efficiency The adjustable switching freguency is up to 1 2MHz making it ideal for DSL applications When shut down it draws lt 1yA of current This feature along with the minimum starting voltage of 1 8V makes it suitable for portable eguipment powered by one Lithium lon 3 to 4 NIMH cells or 2 cells of alkaline battery The EL7515 is available in a 10 Ld MSOP package with maximum height of 1 1mm With proper external components the whole converter takes less than 0 25in2 PCB space This device is specified for operation over the full 40 C to 85 C temperature range Pinout EL7515 EL7515 FN7120 2 August 10 2007 Features Up to 92 efficiency e Up to 600mA lourT 4 5V lt Vout lt 17V 1 8V lt Viy lt 13 2V Up to 1 2MHz adjustable frequency e lt 1HA shutdown current Adjustable soft start e Low battery detection Internal thermal protection 1 1mm max height 10 Ld MSOP package Pb Free available ROHS compliant Applications e 3V to 5V and 12V converters e 5V to 12V converters omil ntersi l rtable equipment Desktop equipment Ordering Information PART PART PKG NUMBER
11. izing the copper area around it is preferable In addition a solid ground plane is always helpful for the EMI performance The demo board is a good example of layout based on these principles Please refer to the EL7515 Application Brief for the layout http www intersil com data tb tb429 pdf neces BDTI C com ntersi 8 intersil FN7120 2 August 10 2007 EL7515 Mini SO Package Family MSOP S lo25 c A B A MDP0043 5 MINI SO PACKAGE FAMILY N Niaje MILLIMETERS SYMBOL MSOP8 MSOP10 TOLERANCE NOTES A 1 10 1 10 Max A1 0 10 0 10 0 05 Nika PIN EI A2 0 86 0 86 0 09 b 0 33 0 23 0 07 0 08 0 18 0 18 0 05 Yo J D 3 00 3 00 0 10 1 3 B N2 E 4 90 4 90 0 15 E1 3 00 3 00 0 10 2 3 e 0 65 0 50 Basic e H c i L 0 55 0 55 0 15 i NV _ L1 0 95 0 95 Basic PLANE es N 8 10 Reference 010 10 C b gt 0 08 mW c A B NOTES 1 Plastic or metal protrusions of 0 15mm maximum per side are not u included L1 lt x 2 Plastic interlead protrusions of 0 25mm maximum per side are UAL Pot SEE DETAIL X zf indudBd i i ios DI a e Shi tum Plane H im nsioning and tolerancing per ASME Y14 5M 1994 0 25
12. put Leakage Current Vip 250mV Vi po 5V 0 02 2 HA DS ON Switch On Resistance at 12V output 220 mO ILEAK SWITCH Switch Leakage Current 1 HA AVouT AVin VoutT Line Regulation SV lt Vin lt 6V Vour 12V no load 0 4 WIN AVout VouT Load Regulation lout 50mA to 150mA 1 foSC MAX Maximum Switching Freguency RT 49 9kQ 1200 kHz fosc1 Switching Freguency 600 670 750 kHz VHI EN EN Input High Threshold 1 6 V VLO EN EN Input Low Threshold 0 5 V Pin Descriptions PIN NUMBER PIN NAME PIN FUNCTION 1 PGND Power ground connected to the source of internal N Channel power MOSFET 2 SGND Signal ground ground reference for all the control circuitry needs to have only a single connection to PGND 3 RT Timing resistor to adjust the oscillation frequency of the converter 4 EN Chip enable connects to logic HI gt 1 6V for chip to function 5 LBI Low battery input connects to a sensing voltage or left open if function is not used 6 LBO Low battery detection output connected to the open drain of a MOSFET able to sink 1MA current 7 ss Soft start connects to a capacitor to control the start up of the converter 8 FB Voltage feedback input needs to connect to resistor divider to decide Vo 9 VDD Control circuit positive supply 10 LX Inductor drive pin connected to the drain of internal N Channel power MOSFET 3 intersil FN7120 2 August 10 2007 EL7515 10k2 4 7nF Block Diagram R

intersil EL7515 Manual (1)

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