EL7584 FN7317 24-PIN EL7584IR MDP0044 EL7584IR-T7 EL7584IR-T13 1-888-INTERSIL - Datasheet Archive

 

® Data Sheet PRELIMINARY August 29, 2003 4-Channel DC:DC Converter Features The EL7584 is a 4-channel DC:DC converter IC

 

EL7584 EL7584 ® Data Sheet PRELIMINARY August 29, 2003 4-Channel DC:DC Converter Features The EL7584 EL7584 is a 4-channel DC:DC converter IC which is designed primarily for use in TFT-LCD applications. The boost converter has 2V to 14V input capability and provides 5V to 17V output, which powers the column drivers and provides up to 370mA @ 15V. A pair of charge pump control circuits provide outputs to allow the external generation of VON and VOFF supplies at 5V to 40V and 0V to -40V, respectively, each at up to 60mA for VBOOST = 15V. The VCOM buffer provides up to 50mA continuous output current from 2V to 13V. · TFT/LCD display supply - Boost regulator - VCOM buffer - VON charge pump - VOFF charge pump The EL7584 EL7584 features adjustable switching frequency and onchip power sequence to simplify start-up operation. A separate input is available to externally increase the default delay of the positive charge pump. An over-temperature feature is provided to allow the IC to be automatically protected from excessive power dissipation. FN7317 FN7317.1 · -40V < VOFF < 0V The EL7584 EL7584 is available in a 24-pin TSSOP package and is specified for operation over the full -40°C to +85°C temperature range. · 2V to 14V VIN supply · 5V < VBOOST < 17V · 2V < VCOM < 13V · 5V < VON < 40V · VBOOST = 15V @ 370mA · High frequency, small inductor DC:DC boost circuit · Over 90% efficient DC:DC boost converter capability · Built-in power-up sequence with adjustable VON delay · Adjustable frequency · Adjustable soft-start · Adjustable outputs Pinout · Over-temperature protection EL7584 EL7584 (24-PIN 24-PIN TSSOP) TOP VIEW · Small parts count Applications SS 1 24 VSSB FBB 2 23 ROSC EN 3 22 VREF VDDB 4 21 PGND LX1 5 20 PGND LX2 6 19 VSSP EL7584IR EL7584IR 24-Pin TSSOP - MDP0044 MDP0044 VSSN 7 18 DRVP EL7584IR-T7 EL7584IR-T7 24-Pin TSSOP 7" MDP0044 MDP0044 DRVN 8 17 VDDP EL7584IR-T13 EL7584IR-T13 24-Pin TSSOP 13" MDP0044 MDP0044 VDDN 9 16 FBP FBN 10 Ordering Information PART NUMBER PACKAGE TAPE & REEL PKG. DWG. # 14 VCOM INC 12 · PDAs 15 VSSC DP 11 · TFT-LCD panels 13 VDDC 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL 1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2003. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc. All other trademarks mentioned are the property of their respective owners. EL7584 EL7584 Absolute Maximum Ratings (TA = 25°C) LX Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18V VDDB, VDDP, VDDN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18V VDDC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.5V Maximum Continuous VBOOST Output Current. . . . . . . . . . . 800mA Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Ambient Operating Temperature . . . . . . . . . . . . . . . .-40°C to +85°C Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. 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: TJ = TC = TA Electrical Specifications PARAMETER VIN = 3.3V, VBOOST = 12V, ROSC = 62k, TA = 25°C, Unless Otherwise Specified. DESCRIPTION CONDITIONS MIN TYP MAX UNIT DC:DC BOOST CONVERTER IQ1_B Quiescent Current - Shut-down EN = 0V 0.8 10 µA IQ2_B Quiescent Current - Switching EN = VDDB 4.8 8 mA V(FBB) Feedback Voltage 1.275 1.300 1.325 V VREF Reference Voltage 1.260 1.310 1.360 V VROSC Oscillator Set Voltage 1.260 1.325 1.390 V I(FBB) Feedback Input Bias Current VDDB Boost Converter Supply Range 2 DMAX Maximum Duty Cycle 85 I(LX)MAX Peak Internal FET Current RDS-ON Switch On Resistance at VBOOST = 10V, I(LX) total = 350mA ILEAK-SWITCH Switch Leakage Current I(LX) total VBOOST Output Range VBOOST > VIN + VDIODE VBOOST/VIN Line Regulation 2.7V < VIN < 13.2V, VBOOST = 15V 0.1 % VBOOST/IO1 Load Regulation 50mA < IO1 < 250mA 0.5 % FOSC-RANGE Frequency Range ROSC range = 240k to 60k 200 FOSC1 Switching Frequency ROSC = 62k 900 0.1 µA 17 V 92 % 1.75 A 0.22 1 17 5 µA V 1200 1100 kHz 15 1000 kHz V VCOM BUFFER VDDC Supply Voltage Range IQ1, VDDC VDDC Disable Current VDDC = 12V, EN = 0V 5.5 20 µA IQ2, VDDC VDDC Enable Current VDDC = 12V, VEN = VDDB, no load 1.7 5 mA VCOM-offset Accuracy of VCOM Output Voltage 2V < VCOM < (VDDC - 2V) -10 +10 mV I(INC) VCOM Input Bias Currents Current magnitude -0.1 0.1 µA RO(VCOM) VCOM Output Impedance VDDC = VBOOST = 12V, VCOM = 6V with -100mA < ILOAD < 100mA CLOAD for VCOM > 0.47µF, MLCC ICOM(max) Output Current Limit PSRR Supply Voltage Rejection VINC = VDDC/2, 9V < VDDC < 15V CMRR Common Mode Voltage Rejection VDDC = 12V, 2V < VINC < 10V 2 6 0.01 0.25 150 mA 60 102 dB 60 93 dB EL7584 EL7584 Electrical Specifications PARAMETER VIN = 3.3V, VBOOST = 12V, ROSC = 62k, TA = 25°C, Unless Otherwise Specified. (Continued) DESCRIPTION CONDITIONS MIN TYP MAX UNIT POSITIVE REGULATED CHARGE PUMP (VON) Most positive VON output depends on the magnitude of the VDDP input voltage (normally connected to VBOOST) and the external component configuration (doubler or tripler) VDDP Supply Input for Positive Charge Pump Usually connected to VBOOST output IQ1(VDDP) Quiescent Current - Shut-down EN = 0V IQ2(VDDP) Quiescent Current - Switching EN = VDDB IDP1 Disable Charge Current EN = 0V, DP = 0V IDP2 Enable Discharge Current EN = VDDB, DP = 5V V(FBP) Feedback Reference Voltage I(FBP) Feedback Input Bias Current I(DRVP) RMS DRVP Output Current 5 17 V 11.5 20 µA 2.3 5 mA 1.5 1.9 2.5 mA 100 200 300 nA 1.245 1.310 1.375 V 0.1 60 VDDP = 12V VDDP = 6V ILR_VON Load Regulation 5mA < IL < 15mA FPUMP Charge Pump Frequency µA mA 15 -0.5 Frequency set by ROSC - see boost section mA 0.03 0.5 %/mA 0.5*FOSC NEGATIVE REGULATED CHARGE PUMP (VOFF) Most negative VOFF output depends on the magnitude of the VDDN input voltage (normally connected to VBOOST) and the external component configuration (doubler or tripler) VDDN Supply Input for Negative Charge Pump Usually connected to VBOOST output 5 IQ1(VDDN) Quiescent Current - Shut-down ENBN = 0V IQ2(VDDN) Quiescent Current - Switching ENBN = VDDB V(FBN) Feedback Reference Voltage I(FBN) Feedback Input Bias Current Magnitude of input bias 0.1 µA I(DRVN) RMS DRVN Output Current VDDN = 12V 60 mA VDDN = 6V ILR_VOFF Load Regulation -15mA < IL < -5mA FPUMP Charge Pump Frequency V 4.5 20 µA 2.3 -80 17 5 mA 0 +80 mV 15 -0.5 Frequency set by ROSC - see boost section mA 0.03 0.5 %/mA 0.5*FOSC ENABLE CONTROL LOGIC VHI-EN Enable Input High Threshold VLO-EN Enable Input Low Threshold I(EN) Enable Input Bias Current 1.6 V 0.5 VEN = 5V 3.7 V 7.5 µA OVER-TEMPERATURE PROTECTION TOT Over-temperature Threshold 130 °C THYS Over-temperature Hysteresis 40 °C 3 EL7584 EL7584 Pin Descriptions I = Input, O = Output, S = Supply PIN NUMBER PIN NAME PIN TYPE PIN FUNCTION 1 SS I Soft-Start input: a capacitor determines the current limit ramp time. 2 FBB I Voltage feedback input determines the value of VBOOST. 3 EN I Starts internal power sequencing of VBOOST, VOFF, VCOM and VON outputs (See Applications Information) ; active HIGH input. 4 VDDB P Positive supply for VBOOST DC:DC controller. 5 LX1 O Boost inductor saturating MOSFET #1. 6 LX2 O Boost inductor saturating MOSFET #2. 7 VSSN* P Ground return for VOFF regulator. 8 DRVN O Pump capacitor driver for VOFF regulator. 9 VDDN P Positive supply for VOFF regulator. 10 FBN I Voltage feedback input determines the value of VOFF. 11 DP I An external capacitor increases VON power up delay time. 12 INC I VCOM Buffer input. 13 VDDC P Positive supply for VCOM Buffer. 14 VCOM O VCOM Buffer output. 15 VSSC* P Ground return for VCOM Buffer. 16 FBP I Voltage feedback input determines the value of VON. 17 VDDP P Positive supply for VON regulator. 18 DRVP O Pump capacitor driver for VON regulator. 19 VSSP* P Ground return for VON regulator. 20 PGND* P Ground return for MOSFET #1. 21 PGND* P Ground return for MOSFET #2. 22 VREF O Voltage reference for VOFF feedback . 23 ROSC I An external resistor sets the DC:DC switching frequency. 24 VSSB* P Ground return for VBOOST DC:DC controller. NOTE: *VSSB, VSSC, VSSN, VSSP, and PGND (2) are shorted internally to the device substrate. 4 EL7584 EL7584 Typical Performance Curves 95 95 90 15V EFFICIENCY (%) EFFICIENCY (%) 9V 80 9V 90 5V 85 12V 75 70 65 12V 85 15V 80 75 70 60 65 VIN=3.3V FREQ=1MHz 55 VIN=5V FREQ=1MHz 60 50 0 100 200 300 400 500 600 700 800 0 100 200 300 FIGURE 1. EFFICIENCY vs IOUT 600 700 800 FIGURE 2. EFFICIENCY vs IOUT 95 95 90 90 5V 85 9V 12V 15V 80 EFFICIENCY (%) EFFICIENCY (%) 500 IOUT (mA) IOUT (mA) 75 70 65 12V 15V 85 9V 80 75 70 65 VIN=3.3V FREQ=700kHz 60 VIN=5V FREQ=700kHz 60 0 100 200 300 400 500 600 700 800 0 100 200 IOUT (mA) 300 400 500 600 700 800 IOUT (mA) FIGURE 3. EFFICIENCY vs IOUT FIGURE 4. EFFICIENCY vs IOUT 1.27 970 ROSC = 61.9k 969 1.265 968 VOLTAGE (V) FREQUENCY (kHz) 400 967 966 965 1.26 1.255 964 963 962 3 3.5 4 4.5 5 VDDB (V) FIGURE 5. FS vs VDDB 5 5.5 6 1.25 -50 0 50 100 TEMPERATURE (°C) FIGURE 6. VREF vs TEMPERATURE 150 EL7584 EL7584 Typical Performance Curves (Continued) 1.5 f=675kHz, VIN=5.0V 1.5 1.0 LOAD REGULATION (%) LOAD REGULATION (%) 1.0 f=675kHz, VIN=3.3V 0.5 0.0 -0.5 -1.0 18V -1.5 0 100 200 300 15V 12V 0.0 -0.5 15V -1.0 18V 9V 12V 700 600 0 100 200 300 f=1MHz, VIN=5.0V 1.5 1.0 500 600 700 800 f=1MHz, VIN=3.3V 1.0 LOAD REGULATION (%) LOAD REGULATION (%) 400 FIGURE 8. LOAD REGULATION vs IOUT FIGURE 7. LOAD REGULATION vs IOUT 0.5 0.0 -0.5 -1.0 18V 9V 12V 0 100 200 300 500 400 0.5 0.0 -0.5 15V 12V -1.0 9V 18V 15V -1.5 600 5V -1.5 700 0 100 200 300 400 500 600 700 800 IOUT (mA) IOUT (mA) FIGURE 9. LOAD REGULATION vs IOUT FIGURE 10. LOAD REGULATION vs IOUT 6.5 20 19 VDDN = 15V 6 VDDP = 15V VDDN = 12V 5.5 18 VDDP = 12V VOFF (-V) VON (V) 5V IOUT (mA) IOUT (mA) 1.5 9V -1.5 500 400 0.5 17 5 16 4.5 15 4 3.5 14 0 10 20 30 40 50 ILOAD (mA) FIGURE 11. VON vs ION 6 60 70 80 0 10 20 30 40 50 ILOAD (mA) FIGURE 12. VOFF vs IOFF 60 70 80 EL7584 EL7584 Typical Performance Curves (Continued) 1400 f(MHz)=1/(0.0118 ROSC+0.378) 6 SWITCHING PERIOD (µs) FREQUENCY (kHz) 1200 1000 800 600 400 200 SWITCHING PERIOD(µs)=0.0118 ROSC+0.378) 5 4 3 2 1 0 0 0 50 100 150 200 250 300 350 400 450 0 50 100 150 200 250 300 ROSC (k) 100K & 0.1µF DELAY NETWORK ON ENP, CSS=0.1µF 5V/DIV VBOOST 5V/DIV 10V/DIV VON VON VOFF 200ms/DIV FIGURE 15. POWER-DOWN VIN=3.3V, VOUT=11.3V, IOUT=50mA FIGURE 17. LX WAVEFORM - DISCONTINUOUS MODE 7 450 100K & 0.1µF DELAY NETWORK ON ENP, CSS=0.1µF VBOOST 2V/DIV 400 FIGURE 14. FS vs ROSC FIGURE 13. FS vs ROSC 10V/DIV 350 ROSC (k) 2V/DIV VOFF 1ms/DIV FIGURE 16. POWER-UP VIN=3.3V, VOUT=11.3V, IOUT=250mA FIGURE 18. LX WAVEFORM - CONTINUOUS MODE EL7584 EL7584 Typical Performance Curves (Continued) JEDEC JESD51-7 JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD JEDEC JESD51-3 JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 0.9 0.8 1.2 POWER DISSIPATION (W) POWER DISSIPATION (W) 1.4 1.176W TS SO JA P2 =8 4 5° C/ W 1 0.8 0.6 0.4 0.2 781mW 0.7 0.6 JA = 0.5 0.4 TS SO P2 12 4 8° C/ W 0.3 0.2 0.1 0 0 0 25 75 85 50 100 125 0 25 AMBIENT TEMPERATURE (°C) 50 75 85 100 125 AMBIENT TEMPERATURE (°C) FIGURE 19. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE FIGURE 20. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE Functional Block Diagram VOUT 10µH R2 R1 13k VIN 110k 49 10µF 10µF 0.1µF FBB VDDB LX MAX_DUTY ROSC R3 62k REFERENCE GENERATOR VREF VRAMP PWM LOGIC PWM COMPARATOR 0.22 EN 12µA + START-UP OSCILLATOR ILOUT VSSB 7.2K 160m SS 0.1µF 8 PGND EL7584 EL7584 Applications Information Steady-State Operation The EL7584 EL7584 is high efficiency multiple output power solution designed specifically for thin-film transistor (TFT) liquid crystal display (LCD) applications. The device contains one high current boost converter and two low power charge pumps (VON and VOFF). When the output reaches the preset voltage, the regulator operates at steady state. Depending on the input/output condition and component, the inductor operates at either continuous-conduction mode or discontinuous-conduction mode. The boost converter contains an integrated N-channel MOSFET to minimize the number of external components. The converter output voltage can be set from 5V to 18V with external resistors. The VON and VOFF charge pumps are independently regulated to positive and negative voltages using external resistors. Output voltages as high as 40V can be achieved with additional capacitors and diodes. 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 forms a resonant circuit. Oscillation will occur in this period. This oscillation is normal and will not affect the regulation. Boost Converter The boost converter operates in constant frequency pulsewidth-modulation (PWM) mode. Quiescent current for the EL7584 EL7584 is only 5mA when enabled, and since only the low side MOSFET is used, switch drive current is minimized. 90% efficiency is achieved in most common application operating conditions. A functional block diagram with typical circuit configuration is shown on previous page. Regulation is performed by the PWM comparator which regulates the output voltage by comparing a divided output voltage with an internal reference voltage. The PWM comparator outputs its result to the PWM logic. The PWM logic switches the MOSFET on and off through the gate drive circuit. Its switching frequency is external adjustable with a resistor from timing control pin (ROSC) to ground. The boost converter has 200kHz to 1.2MHz operating frequency range. At very low load, the MOSFET will skip pulse sometimes. This is normal. Current Limit The MOSFET is current limited to 1.13V and VOFF first reaches its required regulation voltage, the VCOM regulator is enabled and VCOM rises at a rate determined by the VCOM load capacitor, the load on VCOM, and the current limit of the VCOM amplifier. 3. When VCOM rises to within 100mV of V(INC), an internal delay circuit triggers and, for VDDP = 12V, a default delay of approximately 3.5ms is introduced before the positive charge pump is then enabled. This delay can be increased externally by connecting a capacitor between DP and VSSP. A 1nF capacitor will typically increase the delay before VON becomes enabled to 80ms. The enabled states of the on-chip functions become independent of VBOOST, VOFF, VCOM, and VON once each is triggered. The chip may be reset by forcing EN to logic 0 and allowing sufficient time for the various supplies to discharge sufficiently before taking EN to 1 again. Over-Temperature Protection An internal temperature sensor continuously monitors the die temperature. In the event that die temperature exceeds the thermal trip point, the device will shut down and disable itself. The upper and lower trip points are typically set to 130°C and 90°C respectively. PCB Layout Guidelines Careful layout is critical in the successful operation of the application. The following layout guidelines are recommended to achieve optimum performance. 1. VREF and VDDB bypass capacitors should be placed next to the pins. 2. Place the boost converter diode and inductor close to the LX pins. 3. Place the boost converter output capacitor close to the PGND pins. 4. Locate feedback dividers close to their respected feedback pins to avoid switching noise coupling into the high impedance node. 5. Place the charge pump feedback resistor network after the diode and output capacitor node to avoid switching noise. 6. All low-side feedback resistors should be connected directly to VSSB. VSSB should be connected to the power ground at one point only. A demo board is available to illustrate the proper layout implementation. EL7584 EL7584 Typical Application Circuit C7 1 SS 3 EN + 22µF VIN GND 4 VDDB PGND 21 5 LX PGND 20 VSSP 19 7 VSSN DRVP 18 8 DRVN C6 0.1µF + VDDP 17 9 VDDN FBP 16 R3 61.9k C8 1nF *D1 L1 C1 10µF VREF 22 6 LX 49.9 C5 ROSC 23 0.1µF R4 VBOOST (12V@ 350mA) VSSB 24 2 FBB R2 110k R1 13k 10µH C12 0.1µF C11 0.1µF VOFF -6V C21 R21 154k C26 3.3µF 0.1µF *D21 *C20 1nF 10 FBN VCOM 14 12 INC VDDC 13 VCOM REFERENCE R22 33.2k 15 C31 1µF C32 0.1µF C33 * MBRM120LT3 MBRM120LT3 * BAT54S BAT54S * C20 is optional if extended VON delay is required 0.1µF VSSC 15 11 DP VON 18V *D11 C22 C13 2.2µF R12 51k R11 3.9k VCOM EL7584 EL7584 Package Outline Drawing NOTE: The package drawing shown here may not be the latest version. To check the latest revision, please refer to the Intersil website at All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 ISO9000 quality systems. Intersil Corporation's quality certifications can be viewed at www.intersil.com/design/quality 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. 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