ISL97516IUZ-TK

NOT RECOMMENDED FOR NEW DESIGNS RECOMMENDED REPLACEMENT PART ISL97519A ISL97516 DATASHEET FN9261 Rev 6.00 March 28, 2014 600kHz/1.2MHz PWM Step-Up Regulator The ISL97516 is a high frequency, high efficiency step-up voltage regulator operated at constant frequency PWM mode. With a 2.0A typical switch current limit and 200m MOSFET, it can deliver over 90% efficiency. The selectable 600kHz and 1.2MHz allows smaller inductors and faster transient response. An external compensation pin gives the user greater flexibility in setting frequency compensation allowing for the use of low ESR Ceramic output capacitors. Features When shut down, it draws 90% Efficiency • 2.0A, 200m Power MOSFET • 2.3V to 5.5V Input • 1.1*VIN to 25V Output • 600kHz/1.2MHz Switching Frequency Selection • Internal Thermal Protection • 1.1mm Max Height 8 Ld MSOP Package Applications • TFT-LCD displays • DSL modems • PCMCIA cards • Digital cameras • GSM/CDMA phones • Portable equipment • Handheld devices EN FSEL VDD REFERENCE GENERATOR OSCILLATOR SS SHUTDOWN AND START-UP CONTROL LX PWM LOGIC CONTROLLER FET DRIVER COMPARATOR CURRENT SENSE GND FB GM AMPLIFIER COMP FIGURE 1. BLOCK DIAGRAM FN9261 Rev 6.00 March 28, 2014 Page 1 of 9 ISL97516 Pin Configuration ISL97516 (8 LD MSOP) TOP VIEW COMP 1 8 SS FB 2 7 FSEL EN 3 6 VDD GND 4 5 LX Pin Descriptions PIN NUMBER PIN NAME DESCRIPTION 1 COMP 2 FB Voltage feedback pin. Internal reference is 1.294V nominal. Connect a resistor divider from VOUT. VOUT = 1.294V (1 + R1/R2). See “Typical Application Circuit” on page 2. 3 EN Shutdown control pin. Pull EN low to turn off the device. 4 GND 5 LX 6 VDD Analog power supply input pin. 7 FSEL Frequency select pin. When FSEL is set low, switching frequency is set to 620kHz. When connected to high or VDD, switching frequency is set to 1.25MHz. 8 SS Compensation pin. Output of the internal error amplifier. Capacitor and resistor from COMP pin to ground. Analog and power ground. Power switch pin. Connected to the drain of the internal power MOSFET. Soft-start control pin. Connect a capacitor to control the converter start-up. Typical Application Circuit R3 3.9k C5 4.7nF 1 COMP R1 85.2k R2 10k SS 8 2 FB FSEL 7 3 EN VDD 6 4 GND LX 5 C3 27nF + C1 0.1µF 22µF 2.3V TO 5.5V C4 S1 10µH D1 + C2 22µF 12V Ordering Information PART NUMBER (Notes 2, 3) PART MARKING PACKAGE (Pb-free) PKG. DWG. # ISL97516IUZ 7516Z 8 Ld MSOP M8.118A ISL97516IUZ-T (Note 1) 7516Z 8 Ld MSOP M8.118A ISL97516IUZ-TK (Note 1) 7516Z 8 Ld MSOP M8.118A NOTES: 1. Please refer to TB347 for details on reel specifications. 2. 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. 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL97516. For more information on MSL please see techbrief TB363. FN9261 Rev 6.00 March 28, 2014 Page 2 of 9 ISL97516 Absolute Maximum Ratings (TA = +25°C) Thermal Information LX to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27V VDD to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.5V COMP, FB, EN, SS, FSEL to GND . . . . . . . . . . . . . . . . . . -0.3V to (VDD +0.3V) Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Operating Ambient Temperature . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . .+135°C Power Dissipation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves Pb-free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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. Typical 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 temperature range, -40°C to +85°C. PARAMETER VIN = 3.3V, VOUT = 12V, IOUT = 0mA, FSEL = GND, TA = -40°C to +85°C. Boldface limits apply over the operating DESCRIPTION CONDITIONS MIN (Note 4) TYP MAX (Note 4) UNIT 1 5 µA IQ1 Quiescent Current - Shutdown EN = 0V IQ2 Quiescent Current - Not Switching EN = VDD, FB = 1.3V 0.7 IQ3 Quiescent Current - Switching EN = VDD, FB = 1.0V 3 4 mA VFB Feedback Voltage 1.294 1.309 V IB-FB Feedback Input Bias Current 0.5 µA VDD Input Voltage Range 5.5 V 1.272 0.01 2.3 DMAX - 600kHz Maximum Duty Cycle FSEL = 0V DMAX - 1.2MHz Maximum Duty Cycle FSEL = VDD 85 mA 92 % 85 90 % 1.7 2.0 A ILIM Current Limit - Max Peak Input Current IEN Shutdown Input Bias Current EN = 0V rDS(ON) Switch ON-Resistance VDD = 2.7V, ILX = 1A 0.2 ILX-LEAK Switch Leakage Current VSW = 27V 0.01 VOUT/VIN Line Regulation 3V < VIN < 5.5V, VOUT = 12V 0.2 VOUT/IOUT 0.01 0.5 µA 3 µA  % Load Regulation VIN = 3.3V, VOUT = 12V, IO = 30mA to 200mA fOSC1 Switching Frequency Accuracy FSEL = 0V 500 620 740 kHz fOSC2 Switching Frequency Accuracy FSEL = VDD 1000 1250 1500 kHz VIL EN, FSEL Input Low Level VIH EN, FSEL Input High Level GM Error Amp Tranconductance VDD-ON VDD UVLO On Threshold HYS VDD UVLO Hysteresis ISS Soft-Start Charge Current OTP Over-Temperature Protection 0.3 % 0.5 V 1.5 I = 5µA 70 2.1 V 130 150 2.2 2.3 1µ/ 100 4 6 V mV 8 150 µA °C NOTE: 4. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested. FN9261 Rev 6.00 March 28, 2014 Page 3 of 9 ISL97516 95 92 90 90 VIN = 3.3V, VO = 9V, fs = 620kHz 88 85 EFFICIENCY (%) EFFICIENCY (%) Typical Performance Curves VIN = 5V, VO = 12V, fs = 1.25MHz 80 VIN = 5V, VO = 12V, fs = 620kHz 75 VIN = 5V, VO = 9V, fs = 620kHz 70 86 84 82 VIN = 3.3V, VO = 12V, fs = 620kHz VIN = 3.3V, VO = 12V, 80 78 65 60 VIN = 5V, VO = 9V, fs = 1.25MHz 0 200 400 600 800 fs = 1.25MHz VIN = 3.3V, VO = 9V, fs = 1.25MHz 76 74 1000 0 100 FIGURE 2. BOOST EFFICIENCY vs IOUT 0.7 VIN = 5V, VO = 12V, 0.8 VIN = 5V, VO = 9V, fs = 1.25MHz fs = 1.25MHz 0.6 0.7 0.6 LOAD REGULATION (%) LOAD REGULATION (%) 300 VIN = 5V, VO = 9V, fs = 620kHz 0.5 0.4 0.3 0.2 VIN = 5V, VO = 12V, fs = 620kHz 0.1 200 400 500 VIN = 3.3V, VO = 12V, VIN = 3.3V, VO = 9V, fs = 1.25MHz fs = 1.25MHz 0.5 VIN = 3.3, VO = 9V, fs = 1.25kHz 0.4 0.3 0.2 0.1 0 0 400 FIGURE 3. BOOST EFFICIENCY vs IOUT 0.9 0 200 IOUT (mA) IOUT (mA) 600 800 1000 VIN = 3.3, VO = 12V, fs = 620kHz 0 100 IOUT (mA) 200 300 400 500 IOUT (mA) FIGURE 4. LOAD REGULATION vs IOUT FIGURE 5. LOAD REGULATION vs IOUT 0.6 VO = 12V IO = 50mA TO 300mA LINE REGULATION (%) 0.5 0.4 VO = 9V, IO = 100mA fs = 620kHz 0.3 VIN = 3.3V VO = 12V, IO = 80mA fs = 600kHz fs = 1.25MHz 0.2 0.1 VO = 9V, IO = 80mA 0 -0.1 VO = 12V, IO = 80mA fs = 1.25MHz fs = 620kHz 3 2 4 5 FIGURE 6. LINE REGULATION vs VIN FN9261 Rev 6.00 March 28, 2014 6 FIGURE 7. TRANSIENT RESPONSE Page 4 of 9 ISL97516 Typical Performance Curves (Continued) IO = 50mA TO 300mA 1.0 VO = 12V JEDEC JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD VIN = 3.3V POWER DISSIPATION (W) 0.9 fs = 1.2MHz 870mW 0.8 0.7  JA = 0.6 0.5 0.4 M SO +1 P8 15 °C /W 0.3 0.2 0.1 0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) FIGURE 8. TRANSIENT RESPONSE FIGURE 9. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD POWER DISSIPATION (W) 0.6 0.5 486mW 0.4  JA = 0.3 M SO +2 P 8 06 °C /W 0.2 0.1 0.0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) FIGURE 10. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE Applications Information The ISL97516 is a high frequency, high efficiency boost regulator operated at constant frequency PWM mode. The boost converter stores energy from an input voltage source and deliver it to a higher output voltage. The input voltage range is 2.3V to 5.5V and output voltage range is 5V to 25V. The switching frequency is selectable between 600kHz and 1.2MHz allowing smaller inductors and faster transient response. An external compensation pin gives the user greater flexibility in setting output transient response and tighter load regulation. The converter soft-start characteristic can also be controlled by external CSS capacitor. The EN pin allows the user to completely shutdown the device. Boost Converter Operations Figure 11 shows a boost converter with all the key components. In steady state operating and continuous conduction mode where the inductor current is continuous, the boost converter operates in two cycles. During the first cycle, FN9261 Rev 6.00 March 28, 2014 as shown in Figure 12, the internal power FET turns on and the Schottky diode is reverse biased and cuts off the current flow to the output. The output current is supplied from the output capacitor. The voltage across the inductor is VIN and the inductor current ramps up in a rate of VIN/L, L is the inductance. The inductance is magnetized and energy is stored in the inductor. The change in inductor current is shown in Equation 1: V IN I L1 = t1  --------L D t1 = ---------f SW D = Duty Cycle I OUT V O = ----------------  t 1 C OUT (EQ. 1) Page 5 of 9 ISL97516 During the second cycle, the power FET turns off and the Schottky diode is forward biased, (Figure 13). The energy stored in the inductor is pumped to the output supplying output current and charging the output capacitor. The Schottky diode side of the inductor is clamp to a Schottky diode above the output voltage. So the voltage drop across the inductor is VIN - VOUT. The change in inductor current during the second cycle is: L D VOUT VIN COUT CIN ISL97516 IL IL2 V IN – V OUT I L = t2  -------------------------------L T2 VO 1–D t2 = ------------f SW (EQ. 2) For stable operation, the same amount of energy stored in the inductor must be taken out. The change in inductor current during the two cycles must be the same. I1 + I2 = 0 V IN 1 – D V IN – V OUT D ----------  --------+ -------------  -------------------------------- = 0 L f SW L f SW V OUT 1 ---------------- = ------------1–D V IN (EQ. 3) L FIGURE 13. BOOST CONVERTER - CYCLE 2, POWER SWITCH OPEN Output Voltage An external feedback resistor divider is required to divide the output voltage down to the nominal 1.294V 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 100k is recommended. The boost converter output voltage is determined by the relationship in Equation 4: R 1  V OUT = V FB   1 + ------- R 2  D VOUT VIN CIN COUT (EQ. 4) The nominal VFB voltage is 1.294V. Inductor Selection ISL97516 FIGURE 11. BOOST CONVERTER L VOUT VIN COUT CIN The inductor selection determines the output ripple voltage, transient response, output current capability, and efficiency. Its selection depends on the input voltage, output voltage, switching frequency, and maximum output current. For most applications, the inductance should be in the range of 2µH to 33µH. The inductor maximum DC current specification must be greater than the peak inductor current required by the regulator. The peak inductor current can be calculated using Equation 5: I OUT  V OUT V IN   V OUT – V IN  I L  PEAK  = ------------------------------------ + 1  2  ----------------------------------------------------V IN L  V OUT  FREQ (EQ. 5) ISL97516 Output Capacitor IL IL1 t1 VO FIGURE 12. BOOST CONVERTER - CYCLE 1, POWER SWITCH CLOSED Low ESR capacitors should be used to minimize the output voltage ripple. Multilayer ceramic capacitors (X5R and X7R) are preferred for the output capacitors because of their lower ESR and small packages. Tantalum capacitors with higher ESR can also be used. The output ripple can be calculated in Equation 6: I OUT  D V O = ------------------------- + I OUT  ESR f SW  C O (EQ. 6) For noise sensitive applications, a 0.1µF placed in parallel with the larger output capacitor is recommended to reduce the switching noise coupled from the LX switching node. FN9261 Rev 6.00 March 28, 2014 Page 6 of 9 ISL97516 Schottky Diode Maximum Output Current In selecting the Schottky diode, the reverse break down voltage, forward current and forward voltage drop must be considered for optimum converter performance. The diode must be rated to handle 2.0A, the current limit of the ISL97516. The breakdown voltage must exceed the maximum output voltage. Low forward voltage drop, low leakage current, and fast reverse recovery will help the converter to achieve the maximum efficiency. The MOSFET current limit is nominally 2.0A and guaranteed 1.7A. This restricts the maximum output current, IOMAX, based on Equation 7: Input Capacitor The value of the input capacitor depends upon the input and output voltages, the maximum output current, the inductor value and the noise allowed to put back on the input line. For most applications, a minimum 10µF is required. For applications that run close to the maximum output current limit, input capacitor in the range of 22µF to 47µF is recommended. The ISL97516 is powered from the VIN. A High frequency 0.1µF bypass capacitor is recommended to be close to the VIN pin to reduce supply line noise and ensure stable operation. Loop Compensation The ISL97516 incorporates a transconductance amplifier in its feedback path to allow the user some adjustment on the transient response and better regulation. The ISL97516 uses current mode control architecture, which has a fast current sense loop and a slow voltage feedback loop. The fast current feedback loop does not require any compensation. The slow voltage loop must be compensated for stable operation. The compensation network is a series RC network from COMP pin to ground. The resistor sets the high frequency integrator gain for fast transient response and the capacitor sets the integrator zero to ensure loop stability. For most applications, the compensation resistor in the range of 2k to 7.5k and the compensation capacitor in the range of 3nF to 10nF. Soft-Start The soft-start is provided by an internal 6µA current source which charges the external CSS; the peak MOSFET current is limited by the voltage on the 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 pin is pulled to HI. For most applications, the external CSS of 27nF is recommended. I L = I L-AVG +  1  2  I L  (EQ. 7) where: IL = MOSFET current limit IL-AVG = average inductor current IL = inductor ripple current V IN    V O + V DIODE  – V IN  I L = -----------------------------------------------------------------------------L   V O + V DIODE   f S (EQ. 8) VDIODE = Schottky diode forward voltage, typically, 0.6V fS = switching frequency, 600kHz or 1.2MHz I OUT I L-AVG = ------------1–D (EQ. 9) D = MOSFET turn-on ratio: V IN D = 1 – -------------------------------------------V OUT + V DIODE (EQ. 10) Table 1 gives typical maximum IOUT values for 1.2MHz switching frequency and 10µH inductor. TABLE 1. VIN (V) VOUT (V) IOMAX (mA) 2.5 5 870 2.5 9 500 2.5 12 380 3.3 5 1150 3.3 9 655 3.3 12 500 5 9 990 5 12 750 Frequency Selection Cascaded MOSFET Application The ISL97516 switching frequency can be user selected to operate at either constant 620kHz or 1.25MHz. Connecting FSEL pin to ground sets the PWM switching frequency to 620kHz. When connecting FSEL high or VDD, the switching frequency is set to 1.25MHz. An 25V N-Channel MOSFET is integrated in the boost regulator. For the applications where the output voltage is greater than 25V, an external cascaded MOSFET is needed as shown in Figure 13. The voltage rating of the external MOSFET should be greater than AVDD. Shutdown Control When the EN pin is pulled down, the ISL97516 is shutdown reducing the supply current to