ISL8010 ® Data Sheet September 27, 2005 Monolithic 600mA Step-Down Regulator with Low Quiescent Current The ISL8010 is a synchronous, integrated FET 600mA stepdown regulator with internal compensation. It operates with an input voltage range from 2.5V to 5.5V, which accommodates supplies of 3.3V, 5V, or a Li-Ion battery source. The output can be externally set from 0.8V to VIN with a resistive divider. The ISL8010 features automatic PFM/PWM mode control, or PWM mode only. The PWM frequency is typically 1.4MHz and can be synchronized up to 12MHz. The typical no load quiescent current is only 120µA. Additional features include a Power-Good output, <1µA shutdown current, short-circuit protection, and over-temperature protection. FN6191.0 Features • Less than 0.18in2 footprint for the complete 600mA converter • Components on one side of PCB • Max height 1.1mm MSOP10 • Power-Good (PG) output • Internally-compensated voltage mode controller • Up to 95% efficiency • <1µA shutdown current • 120µA quiescent current • Hiccup mode overcurrent and over-temperature protection The ISL8010 is available in the 10 Ld MSOP package, making the entire converter occupy less than 0.18in2 of PCB area with components on one side only. The 10 Ld MSOP package is specified for operation over the full -40°C to +85°C temperature range. • External synchronizable up to 12MHz Ordering Information • Bar code readers PART NUMBER PART TAPE & MARKING REEL PACKAGE PKG. DWG. # ISL8010IUZ (Note) 8010Z - 10 Ld MSOP MDP0043 (Pb-free) ISL8010IUZ-T7 (Note) 8010Z 7” 10 Ld MSOP MDP0043 (Pb-free) ISL8010IUZ-T13 8010Z (Note) 13” 10 Ld MSOP MDP0043 (Pb-free) • Pb-free plus anneal available (RoHS compliant) Applications • PDA and pocket PC computers • Cellular phones • Portable test equipment • Li-Ion battery powered devices • Small form factor (SFP) modules Pinout and Typical Application Diagram ISL8010 TOP VIEW NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are 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. C1 10µF VO (1.8V@600mA) VS (2.5V-6V) C2 10µF L1 1.8µH R3 100Ω C3 0.1µF R2* 100kΩ R1* 124kΩ 1 SGND FB 10 2 PGND VO 9 3 LX PG 8 PG 4 VIN EN 7 EN C4 470pF 5 VDD SYNC 6 R4 100kΩ R5 100kΩ SYNC R6 100kΩ * VO = 0.8V * (1 + R1 / R2) 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. 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL8010 Absolute Maximum Ratings (TA = 25°C) Thermal Information VIN, VDD, PG to SGND . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.5V LX to PGND . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to (VIN + +0.3V) SYNC, EN, VO, FB to SGND . . . . . . . . . . . . . -0.3V to (VIN + +0.3V) PGND to SGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +0.3V Peak Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800mA Thermal Resistance (Typical) θJA (°C/W) MSOP10 Package (Note 1) . . . . . . . . . . . . . . . . . . . 130 Operating Ambient Temperature . . . . . . . . . . . . . . . .-40°C to +85°C Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +125°C 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 NOTE: 1. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech Brief TB379. Electrical Specifications PARAMETER VDD = VIN = VEN = 3.3V, C1 = C2 = 10µF, L = 1.8µH, VO = 1.8V (as shown in Typical Application Diagram), TA = -40°C to 85°C unless otherwise specified. DESCRIPTION CONDITIONS MIN TYP MAX UNIT 790 800 810 mV 100 nA 2.5 5.5 V 2 2.2 V 2.2 2.4 V DC CHARACTERISTICS VFB Feedback Input Voltage IFB Feedback Input Current VIN, VDD Input Voltage TA = 25°C only VIN,OFF Minimum Voltage for Shutdown VIN falling, TA = 25°C only VIN,ON Maximum Voltage for Start-up VIN rising IS Input Supply Quiescent Current PWM Mode Active - PFM Mode VSYNC = 0V 120 145 µA Active - PWM Mode VSYNC = 3.3V 6.5 7.5 mA Supply Current PWM, VIN = VDD = 5V 400 500 µA EN = 0, VIN = VDD = 5V 0.1 3 µA PMOS FET Resistance VDD = 5V, TA = 25°C 70 100 mΩ RDS(ON)-NMOS NMOS FET Resistance VDD = 5V, TA = 25°C 45 75 mΩ IDD RDS(ON)-PMOS ILMAX Current Limit TOT,OFF Over-temperature Threshold TOT,ON 1.2 A T rising 145 °C Over-temperature Hysteresis T falling 130 °C IEN, ISYNC EN, SYNC Current VEN, VRSI = 0V and 3.3V VEN1, VSYNC1 EN, SYNC Rising Threshold VDD = 3.3V VEN2, VSYNC2 EN, SYNC Falling Threshold VDD = 3.3V VPG Minimum VFB for PG, WRT Targeted VFB VFB rising Value VFB falling VOLPG PG Voltage Drop -1 1 µA 2.4 V 0.8 V 95 86 ISINK = 3.3mA % % 35 70 mV 1.4 1.6 MHz AC CHARACTERISTICS FPWM PWM Switching Frequency tSS Soft-start Time 1.25 650 2 µs FN6191.0 September 27, 2005 ISL8010 Pin Descriptions PIN NUMBER PIN NAME PIN FUNCTION 1 SGND Negative supply for the controller stage 2 PGND Negative supply for the power stage 3 LX Inductor drive pin; high current digital output with average voltage equal to the regulator output voltage 4 VIN Positive supply for the power stage 5 VDD Power supply for the controller stage 6 SYNC 7 EN Enable 8 PG Power-Good open drain output 9 VO Output voltage sense 10 FB Voltage feedback input; connected to an external resistor divider between VO and SGND for variable output SYNC input pin; when connected to HI, regulator runs at forced PWM mode; when connected to Low, auto PFM/PWM mode; when connected to external sync signal, at external PWM frequency up to 12MHz Block Diagram 100Ω 0.1µF VDD INDUCTOR SHORT VO + CURRENT SENSE 10pF C4 124K 470pF FB 5M + PWM COMPENSATION 100K SYNC SYNC CLOCK RAMP GENERATOR EN EN SOFTSTART 10µF 5V + – BANDGAP REFERENCE + PWM COMPARATOR PFM ON-TIME CONTROL + PWM COMPARATOR UNDERVOLTAGE LOCKOUT P-DRIVER LX CONTROL LOGIC 1.8µH 1.8V 0 TO 600mA 10µF N-DRIVER PGND TEMPERATURE SENSE SGND VIN + SYNCHRONOUS RECTIFIER 100K PG PG POWER GOOD 3 FN6191.0 September 27, 2005 ISL8010 Performance Curves and Waveforms All waveforms are taken at VIN = 3.3V, VO = 1.8V, IO = 600mA with component values shown on page 1 at room ambient temperature, unless otherwise noted. 100 100 VO=3.3V 95 85 80 75 VO=1.8V VO=1.5V 70 VO=1.0V 65 VO=0.8V 60 VO=1.2V 55 45 VO=1.8V 60 VO=1.5V 50 VO=1.2V 40 VO=1.0V 30 VO=0.8V 10 VIN=5V 1 VO=2.5V 70 20 50 40 VO=3.3V 80 EFFICIENCY (%) EFFICIENCY (%) 90 VO=2.5V 90 10 100 VIN=5V 0 600 1 10 100 IO (mA) FIGURE 1. EFFICIENCY vs IO (PFM/PWM MODE) VO=2.5V VO=1.8V 95 90 VO=1.8V 80 85 80 VO=1.5V VO=1.2V VO=1.0V 75 70 65 VO=0.8V 60 VO=1.5V 70 VO=1.2V 60 VO=1.0V 50 40 30 55 20 50 VO=0.8V 10 45 VIN=3.3V 1 10 IO (mA) 100 1 600 1.4 VIN=3.3V IO=0A 1.38 1.36 1.34 1.32 -50 600 0.1 VIN=5V IO=0A 1.42 100 FIGURE 4. EFFICIENCY vs IO (PWM MODE) VIN=3.3V IO=600mA VIN=5V IO=600mA 10 IO (mA) VO CHANGES (%) 1.44 VIN=3.3V 0 FIGURE 3. EFFICIENCY vs IO (PFM/FWM MODE) FS (MHz) VO=2.5V 90 EFFICIENCY (%) EFFICIENCY (%) FIGURE 2. EFFICIENCY vs IO (PWM MODE) 100 100 40 600 IO (mA) 0.0 -0.1 VIN=3.3V -0.2 VIN=5V -0.3 -0.4 -0.5 0 50 100 150 TA (°C) FIGURE 5. FS vs JUNCTION TEMPERATURE (PWM MODE) 4 0 0.2 0.4 0.6 0.8 1 IO (A) FIGURE 6. LOAD REGULATIONS (PWM MODE) FN6191.0 September 27, 2005 ISL8010 Performance Curves and Waveforms (Continued) All waveforms are taken at VIN = 3.3V, VO = 1.8V, IO = 600mA with component values shown on page 1 at room ambient temperature, unless otherwise noted. 0.1 12 VIN=5V IO=0A 10 VIN=3.3V IO=0A -0.1 8 -0.2 IS (mA) VO CHANGES (%) 0.0 VIN=3.3V IO=600mA -0.3 -0.4 6 4 -0.5 -0.6 -0.7 2 VIN=5V IO=600mA -50 0 50 100 0 150 2.5 3.5 3 TJ (°C) 4 4.5 5 VS (V) FIGURE 7. PWM MODE LOAD/LINE REGULATIONS vs JUNCTION TEMPERATURE FIGURE 8. NO LOAD QUIESCENT CURRENT (PWM MODE) 140 130 VO=1.8V VO=3.3V 120 IS (µA) 110 100 90 VO=1.5V VO=1.2V VO=1.0V VO=0.8V 80 70 60 50 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VS (V) FIGURE 9. NO LOAD QUIESCENT CURRENT (PFM MODE) 2 1 VIN (2V/DIV) EN IIN (0.25A/DIV) IIN (0.25A/DIV) VO (2V/DIV) VO (2V/DIV) PG PG 200µs/DIV FIGURE 10. START-UP AT IO = 600mA 5 500µs/DIV FIGURE 11. ENABLE AND SHUTDOWN FN6191.0 September 27, 2005 ISL8010 Performance Curves and Waveforms (Continued) All waveforms are taken at VIN = 3.3V, VO = 1.8V, IO = 600mA with component values shown on page 1 at room ambient temperature, unless otherwise noted. LX (2V/DIV) LX (2V/DIV) IL (0.5A/DIV) IL (0.5A/DIV) ∆VO (10mV/DIV) ∆VO (50mV/DIV) 0.5µs/DIV 2µs/DIV FIGURE 12. PFM STEADY-STATE OPERATION WAVEFORM (IO = 100mA) FIGURE 13. PWM STEADY-STATE OPERATION (IO = 600mA) SYNC (2V/DIV) SYNC (2V/DIV) LX (2V/DIV) IL (0.5A/DIV) LX (2V/DIV) IL (0.5A/DIV) 20ns/DIV 0.2µs/DIV FIGURE 14. EXTERNAL SYNCHRONIZATION TO 2MHz FIGURE 15. EXTERNAL SYNCHRONIZATION TO 12MHz IO (200mA/DIV) IO (200mA/DIV) ∆VO (100mV/DIV) ∆VO (100mV/DIV) 100µs/DIV FIGURE 16. LOAD TRANSIENT RESPONSE (22mA TO 600mA) 6 50µs/DIV FIGURE 17. PWM LOAD TRANSIENT RESPONSE (30mA TO 600mA) FN6191.0 September 27, 2005 ISL8010 Performance Curves and Waveforms (Continued) All waveforms are taken at VIN = 3.3V, VO = 1.8V, IO = 600mA with component values shown on page 1 at room ambient temperature, unless otherwise noted. 100 1.4MHz IO (200mA/DIV) EFFICIENCY (%) 80 ∆VO (50mV/DIV) 5MHz 12MHz 60 40 20 0 0 200 400 50µs/DIV 600 800 1K 1.2K IO (mA) FIGURE 18. PWM LOAD TRANSIENT RESPONSE (100mA TO 500mA) FIGURE 19. EFFICIENCY vs IO (PWM MODE) 0.5 1 12MHz 0.3 VO CHANGES (%) VO CHANGES (%) 0.6 1.4MHz 0.2 5MHz 0 12MHz 0.1 1.4MHz -0.1 5MHz -0.3 -0.2 -0.5 -0.6 0 200 400 600 800 1K 1.2K 0 200 400 600 800 1K 1.2K VIN (V) IO (mA) FIGURE 20. LOAD REGULATION (PWM MODE) FIGURE 21. LINE REGULATION @ 500mA (PWM MODE) IO=50mA IO=150mA 2µs/DIV FIGURE 22. PFM-PWM TRANSITION TIME 7 SYNC (2V/DIV) SYNC (2V/DIV) LX (2V/DIV) LX (2V/DIV) 2µs/DIV FIGURE 23. PFM-PWM TRANSITION TIME FN6191.0 September 27, 2005 ISL8010 Performance Curves and Waveforms (Continued) All waveforms are taken at VIN = 3.3V, VO = 1.8V, IO = 600mA with component values shown on page 1 at room ambient temperature, unless otherwise noted. 3 PG VO CHANGES (%) 2 1 IO 0 -1 PFM PWM -2 VO -3 0 200 400 600 800 1000 1200 IOUT (mA) FIGURE 24. PFM-PWM TRANSITION FIGURE 25. PFM-PWM LOAD TRANSIENT PG PG IO IO VO VO FIGURE 26. PFM TO PWM TRANSITION FIGURE 27. PWM TO PFM TRANSITION PG PG IL IL VO VO FIGURE 28. OVERCURRENT SHUTDOWN 8 FIGURE 29. OVERCURRENT HICCUP MODE FN6191.0 September 27, 2005 ISL8010 Performance Curves and Waveforms (Continued) All waveforms are taken at VIN = 3.3V, VO = 1.8V, IO = 600mA with component values shown on page 1 at room ambient temperature, unless otherwise noted. 1 JEDEC JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 870mW 0.9 486mW 0.5 0.4 θ M JA = 0.3 POWER DISSIPATION (W) POWER DISSIPATION (W) 0.6 JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD SO P8 /1 20 0 6° C/ W 0.2 0.1 0.8 0.7 θ M SO P8 /1 11 0 5° C/ W JA = 0.6 0.5 0.4 0.3 0.2 0.1 0 0 25 75 85 50 100 125 AMBIENT TEMPERATURE (°C) FIGURE 30. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE 9 0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) FIGURE 31. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE FN6191.0 September 27, 2005 ISL8010 Applications Information Product Description The ISL8010 is a synchronous, integrated FET 600mA stepdown regulator which operates from an input of 2.5V to 5.5V. The output voltage is user-adjustable with a pair of external resistors. When the load is very light, the regulator automatically operates in the PFM mode, thus achieving high efficiency at light load (>70% for 1mA load). When the load increases, the regulator automatically switches over to a voltage-mode PWM operating at nominal 1.4MHz switching frequency. The efficiency is up to 95%. It can also operate in a fixed PWM mode or be synchronized to an external clock up to 12MHz for improved EMI performance. PFM Operation The heart of the ISL8010 regulator is the automatic PFM/PWM controller. If the SYNC pin is connected to ground, the regulator operates automatically in either the PFM or PWM mode, depending on load. When the SYNC pin is connected to VIN, the regulator operates in the fixed PWM mode. When the pin is connected to an external clock ranging from 1.6MHz to 12MHz, the regulator is in the fixed PWM mode and synchronized to the external clock frequency. In the automatic PFM/PWM operation, when the load is light, the regulator operates in the PFM mode to achieve high efficiency. The top P-channel MOSFET is turned on first. The inductor current increases linearly to a preset value before it is turned off. Then the bottom N-channel MOSFET turns on, and the inductor current linearly decreases to zero current. The N-channel MOSFET is then turned off, and an antiringing MOSFET is turned on to clamp the LX pin to VO. Both MOSFETs remain off until VFB drops below the internal reference voltage of 0.8V. The inductor current looks like triangular pulses. The frequency of the pulses is mainly a function of output current. The higher the load, the higher the frequency of the pulses until the inductor current becomes continuous. At this point, the controller automatically changes to PWM operation. PWM Operation The regulator operates the same way in the forced PWM or synchronized PWM mode. In this mode, the inductor current is always continuous and does not stay at zero. In this mode, the P-channel MOSFET and N-channel MOSFET always operate complementary. When the P-channel MOSFET is on and the N-channel MOSFET off, the inductor current increases linearly. The input energy is transferred to the output and also stored in the inductor. When the P-channel MOSFET is off and the N-channel MOSFET on, the inductor current decreases linearly, and 10 energy is transferred from the inductor to the output. Hence, the average current through the inductor is the output current. Since the inductor and the output capacitor act as a low pass filter, the duty cycle ratio is approximately equal to VO divided by VIN. The output LC filter has a second order effect. To maintain the stability of the converter, the overall controller must be compensated. This is done with the fixed internally compensated error amplifier and the PWM compensator. Because the compensations are fixed, the values of input and output capacitors are 10µF to 22µF ceramic and inductor is 1.5µH to 2.2µH. Forced PWM Mode/SYNC Input Pulling the SYNC pin HI (>2.5V) forces the converter into PWM mode in the next switching cycle regardless of output current. The duration of the transition varies depending on the output current. Figures 22 and 23 (under two different loading conditions) show the device goes from PFM to PWM mode. Start-Up and Shutdown When the EN pin is tied to VIN, and VIN reaches approximately 2.4V, the regulator begins to switch. The inductor current limit is gradually increased to ensure proper soft-start operation. When the EN pin is connected to a logic low, the ISL8010 is in the shutdown mode. All the control circuitry and both MOSFETs are off, and VOUT falls to zero. In this mode, the total input current is less than 1µA. When the EN reaches logic HI, the regulator repeats the start-up procedure, including the soft-start function. Current Limit and Short-Circuit Protection The current limit is set at about 1.2A for the PMOS. When a short-circuit occurs in the load, the preset current limit restricts the amount of current available to the output, which causes the output voltage to drop as load demand increases. When the output voltage drops 30mV below the reference voltage, the converter will shutdown for a period of time, approximated by Equation 1, and then restart. If the overcurrent condition still exists, it will repeat the shutdownwait-restart event. This is called a “hiccup” event. The average power dissipation is reduced, thereby reducing the likelihood of damage current and thermal conditions in the IC. 700u ⋅ VIN tHICCUP ≈ ----------------------------- + 216u 3 (EQ. 1) Thermal Shutdown Once the junction reaches about 145°C, the regulator shuts down. Both the P-channel and the N-channel MOSFETs turn off. The output voltage will drop to zero. With the output MOSFETs turned off, the regulator will cool down. Once the junction temperature drops to about 130°C, the regulator will perform a normal restart. FN6191.0 September 27, 2005 ISL8010 Thermal Performance Layout Considerations The ISL8010 is available in a fused-lead MSOP10. Compared with regular MSOP10 package, the fused-lead package provides lower thermal resistance. The θJA is 100°C/W on a 4-layer board and 125°C/W on 2-layer board. Maximizing the copper area around the pins will further improve the thermal performance. The layout is very important for the converter to function properly. The following PC layout guidelines should be followed: Output Voltage Selection Users can set the output voltage of the variable version with a resister divider, which can be chosen based on the following formula: 1. Separate the Power Ground ( ) and Signal Ground ( ); connect them only at one point right at the pins 2. Place the input capacitor as close to VIN and PGND pins as possible 3. Make the following PC traces as small as possible: 4. from LX pin to L 5. from CO to PGND 6. If used, connect the trace from the FB pin to R1 and R2 as close as possible R V O = 0.8 × 1 + ------2- R 1 7. Maximize the copper area around the PGND pin Component Selection Because of the fixed internal compensation, the component choice is relatively narrow. For a regulator with fixed output voltage, only two capacitors and one inductor are required. It is recommended to use between 10µF and 22µF multilayer ceramic capacitors with X5R or X7R rating for both the input and output capacitors, and 1.5µH to 2.2µH for the inductor. 8. Place several via holes under the chip to additional ground plane to improve heat dissipation The demo board is a good example of layout based on this outline. Please refer to the ISL8010 Application Brief. The RMS current present at the input capacitor is decided by the following formula: V O × ( V IN – V O ) I INRMS = ----------------------------------------------- × I O V IN This is about half of the output current IO for all the VO. This input capacitor must be able to handle this current. The inductor peak-to-peak ripple current is given as: ( V IN – V O ) × V O ∆I IL = ------------------------------------------L × V IN × f S L is the inductance fS the switching frequency (nominally 1.4MHz) The inductor must be able to handle IO for the RMS load current, and to assure that the inductor is reliable, it must handle the 2A surge current that can occur during a current limit condition. 11 FN6191.0 September 27, 2005 ISL8010 MSOP 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 http://www.intersil.com/design/packages/index.asp 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/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. For information regarding Intersil Corporation and its products, see www.intersil.com 12 FN6191.0 September 27, 2005