NCV896530 2.1 MHz Low Voltage Dual Output Buck Converter The NCV896530 dual step−down dc−dc converter is a monolithic integrated circuit dedicated to automotive driver information systems from a downstream voltage rail. Both channels are externally adjustable from 0.9 V to 3.3 V and can source totally up to 1600 mA. Converters are running at 2.1 MHz switching frequency above the sensitive AM band and operate 180° out of phase to reduce large amounts of current demand on the rail. Synchronous rectification offers improved system efficiency. The NCV896530 provides additional features expected in automotive power systems such as integrated soft−start, hiccup mode current limit and thermal shutdown protection. The device can also be synchronized to an external clock signal in the range of 2.1 MHz. The NCV896530 is available in a space saving, 3 x 3 mm 10−pin DFN package. www.onsemi.com MARKING DIAGRAM DFN10 CASE 485C A L Y W G Features • • • • • • • • • • Synchronous Rectification for Higher Efficiency 2.1 MHz Switching Frequency, 180° Out−of−Phase Sources up to 1600 mA Total and 1 A Per Channel Adjustable Output Voltage from 0.9 V to 3.3 V 2.7 V to 5.5 V Input Voltage Range Thermal Limit and Short Circuit Protection Auto Synchronizes with an External Clock Wettable Flanks – DFN NCV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC−Q100 Qualified and PPAP Capable This is a Pb−Free Device NCV89 6530 ALYWG G = Assembly Location = Wafer Lot = Year = Work Week = Pb−Free Device (Note: Microdot may be in either location) PIN CONNECTIONS FB1 1 10 FB2 EN1 2 9 EN2 SYNC 3 8 POR VIN 4 7 GND SW1 5 6 SW2 (Top View) Typical Applications • • • • ORDERING INFORMATION Audio Infotainment Vision System Instrumentation ÎÎ ÎÎ ÏÏ ÏÏ ÎÎ ÎÎ ÏÏ ÎÎ 4 VIN 7 GND OFF ON 2.1MHz 2 EN1 3 SYNC OFF ON 9 EN2 ÏÏ ÏÏ ÎÎ ÎÎ ÏÏ ÏÏ ÎÎ ÏÏ VOUT1 Shipping† NCV896530MWTXG DFN10 (Pb−Free) 3000 / Tape & Reel 10 mF FB1 1 POR POR 8 2.2 mH SW2 6 FB2 10 Package †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. 2.2 mH SW1 5 11 Device VOUT2 10 mF Figure 1. NCV896530 Typical Application © Semiconductor Components Industries, LLC, 2015 April, 2015 − Rev. 3 1 Publication Order Number: NCV896530/D NCV896530 BLOCK DIAGRAM EA1 FB1 EA2 UVLO 1 VREF Thermal shutdown EN 1 Oscillator EA1 AVIN VIN 4 SW 1 EA2 EN2 8 POR 7 GND 6 SW 2 VIN Ramp generator AVIN PVIN Q1 0° Q2 9 LOGIC CONTROL Voltage reference SYNC 3 FB 2 VIN 2 LOGIC CONTROL SYNC 10 VREF PWM PWM CONTROL CONTROL 5 ILIMIT Q3 PVIN 180° SYNC ILIMIT Figure 2. Simplified Block Diagram www.onsemi.com 2 Q4 NCV896530 PIN FUNCTION DESCRIPTION Pin Pin Name Type 1 FB1 Analog Input Feedback voltage from the output 1. This is the input to the error amplifier. Description 2 EN1 Digital Input Enable for converter 1. This pin is active HIGH (equal or lower Analog Input voltage) and is turned off by logic LOW. Do not let this pin float. 3 SYNC Digital Input Oscillator Synchronization. This pin can be synchronized to an external clock in the range of 2.1 MHz. If not used, the pin must to be connected to ground. 4 VIN Analog / Power Input Power supply input for the PFET power stage, analog and digital blocks. The pin must be decoupled to ground by a 10 mF ceramic capacitor. 5 SW1 Analog Output Connection from power MOSFETs of output 1 to the Inductor. 6 SW2 Analog Output Connection from power MOSFETs of output 2 to the Inductor. 7 GND Analog Ground This pin is the GROUND reference for the analog section of the IC. The pin must be connected to the system ground. 8 POR Digital Output 9 EN2 Digital Input Enable for converter 2. This pin is active HIGH (equal or lower Analog Input voltage) and is turned off by logic LOW. Do not let this pin float. 10 FB2 Analog Input Feedback voltage from the output 2. This is the input to the error amplifier. 11 Exposed Pad Power Ground Power On Reset. This is an open drain output. This output is shutting down when one of the output voltages are less than 90% (typ) of their nominal values. A pull−up resistor around 500 kW should be connected between POR and VIN, VOUT1 or VOUT2 depending on the supplied device. This pin is the GROUND reference for the NFET power stage of the IC. The pin must be connected to the system ground and to both input and output capacitors. MAXIMUM RATINGS Rating Symbol Value Unit Minimum Voltage All Pins Vmin −0.3 V Maximum Voltage All Pins Vmax 6.0 V Maximum Voltage ENx, SYNC, FBx, , SWx, POR Vmax VIN+0.3 V Thermal Resistance Junction−to−Ambient (3x3 DFN) (Note 1) RqJA 40 °C/W Storage Temperature Range Tstg −55 to 150 °C Junction Operating Temperature TJ −40 to 150 °C 2.0 200 kV V 3 per IPC ESD Withstand Voltage Human Body Model Machine Model Vesd Moisture Sensitivity Level MSL Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. 1. Mounted on 1 sq. in. of a 4−layer PCB with 1 oz. copper thickness. www.onsemi.com 3 NCV896530 ELECTRICAL CHARACTERISTICS (2.7 V < VIN < 5.5 V, Min and Max values are valid for the temperature range −40°C ≤ TJ ≤ +150°C unless noted otherwise, and are guaranteed by test design or statistical correlation, Typical values are referenced to TA = +25°C) Rating Conditions Symbol Min Typ Max Unit SYNC = GND, VFB = 0 V EN1 = EN2 = 2 V, No Switching IQ − 2.0 3.0 mA EN1 = EN2 = 0 V ISTBMAX − 4.0 10 mA INPUT VOLTAGE Quiescent Current Standby Current Under Voltage Lockout VIN falling VUVLO 2.2 2.4 2.6 V VUVLOH − 100 150 mV Logic high VIHSYNC 1.2 − − V Logic Low VILSYNC VSYNC = 5 V IILSYNC 2 External Synchronization FSYNC 1.8 SYNC Pulse Duty Ratio TSYNC Under Voltage Hysteresis SYNC SYNC Threshold Voltage SYNC Pin Bias Current 0.4 50 mA 2.7 MHz 50 % EN1, EN2 V ENx Threshold Voltage Logic high VIHENx Logic Low VILENx ENx Pin Bias Current VENx = 5 V IILENx 2 50 mA 1.2 − − 0.4 POWER ON RESET Power On Reset Threshold VOUT falling Power On Reset Hysteresis Sink Current VPOR = 0.4 V VPORT 87% 93% V VPORH − 3% V ISIPOR 2 − mA OUTPUT PERFORMANCES Feedback Voltage Threshold FB1, FB2 VFB Feedback Voltage Accuracy TA = 25C ΔVOUT Soft−Start Time Switching Frequency 0.6 − V ±1 − % −40°C < TA < 125°C ΔVOUT −2 − +2 Time from EN to 90% of output voltage tSTART 400 − 1000 ms EN1 = EN2 = 1, VIN = 5 V FSW 1.8 2.1 2.6 MHz D − − 100 % Duty Cycle POWER SWITCHES High−Side MOSFET On−resistance IRDS(on) = 600 mA, VIN = 5 V, TA = 25°C RONHS − 500 820 mW Low−Side MOSFET On−resistance IRDS(on) = 600 mA, VIN = 5 V, TA = 25°C RONLS − 450 820 mW High−Side MOSFET Leakage Current VIN = 5 V, VLX = 0 V, VENx = 0 V ILEAKHS − 5 mA Low−Side MOSFET Leakage Current VLX = 5 V, VENx = 0 V ILEAKLS − 5 mA TONMIN − 80 ns Minimum On Time PROTECTION Current Limit IPK 1.4 Thermal Shutdown Threshold TSD 150 Thermal Shutdown Hysteresis TSDH 5 Hiccup Time Peak inductor current % of Soft−Start Time thcp,dly 170 60 2.0 A 190 °C 20 °C % Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions. www.onsemi.com 4 NCV896530 TYPICAL CHARACTERISTICS CURVES 12 ISYNC, SYNC PULLDOWN CURRENT (mA) TJ = 25°C, EN1 = EN2 = 1 2.35 2.3 2.25 2.2 2.5 3 3.5 4 4.5 5 5.5 10 8 6 4 2 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 VIN, INPUT VOLTAGE (V) VSYNC, SYNC VOLTAGE (V) Figure 4. Sync Pulldown Current vs. Sync Voltage 12 5 14 TJ = 25°C 10 8 6 4 2 0 1 2 3 4 5 TJ = 25°C 12 10 8 6 4 2 0 2.5 0 6 3 3.5 4 4.5 5 VENX, ENABLE VOLTAGE (V) VIN, INPUT VOLTAGE (V) Figure 5. Enable Pulldown Current vs. Enable Voltage Figure 6. Standby Current vs. Input Voltage 2.00 VREF, REFERENCE VOLTAGE (mV) 600.0 1.95 IPK, CURRENT LIMIT (A) TJ = 25°C Figure 3. Switching Frequency vs. Input Voltage ISTBMAX, STANDBY CURRENT (mA) IENX, ENABLE PULLDOWN CURRENT (mA) FSW, SWITCHING FREQUENCY (MHz) 2.4 1.90 1.85 1.80 1.75 1.70 1.65 1.60 −40 10 60 599.5 599.0 598.5 598.0 597.5 597.0 596.5 596.0 −40 110 10 60 110 TJ, JUNCTION TEMPERATURE (°C) TJ, JUNCTION TEMPERATURE (°C) Figure 7. Current Limit vs. Temperature Figure 8. Reference Voltage vs. Temperature www.onsemi.com 5 5.5 NCV896530 TYPICAL CHARACTERISTICS CURVES 14 VENX = 5 V ISYNC, SYNC PULLDOWN CURRENT (mA) 12.0 11.0 10 10.5 10.0 9.5 9.0 8.5 8.0 −40 VSYNC = 5 V 12 −20 0 20 40 60 80 100 120 140 8 6 4 2 0 −50 0 50 100 TJ, JUNCTION TEMPERATURE (°C) TJ, JUNCTION TEMPERATURE (°C) Figure 9. Enable Pulldown Current vs. Temperature Figure 10. Sync Pulldown Current vs. Temperature 2.30 FSW, SWITCHING FREQUENCY (MHz) IENX, ENABLE PULLDOWN CURRENT (mA) 11.5 2.25 2.20 2.15 2.10 2.05 2.00 −40 VIN = 5 V, EN1 = EN2 = 1 10 60 110 TJ, JUNCTION TEMPERATURE (°C) Figure 11. Switching Frequency vs. Temperature www.onsemi.com 6 150 NCV896530 DC/DC OPERATION DESCRIPTION PWM Operating Mode When an over current event is detected the NCV896530 disables the outputs and attempts to re−enable the outputs after the hiccup time. The part remains off for the hiccup time and then goes through the power on reset procedure. If the excessive load has been removed then the output stage re−enables and operates normally; however, if the excessive load is still present the cycle begins again. Internal heat dissipation is kept to a minimum as current will only flow during the reset time of the protection circuitry. The hiccup mode is continuous until the excessive load is removed. The output voltage of the device is regulated by modulating the on−time pulse width of the main switch Q1 at a fixed 2.1 MHz frequency (Figure 12). The switching of the PMOS Q1 is controlled by a flip−flop driven by the internal oscillator and a comparator that compares the error signal from an error amplifier with the sum of the sensed current signal and compensation ramp. The driver switches ON and OFF the upper side transistor (Q1) and switches the lower side transistor in either ON state or in current source mode. At the beginning of each cycle, the main switch Q1 is turned ON by the rising edge of the internal oscillator clock. The inductor current ramps up until the sum of the current sense signal and compensation ramp becomes higher than the error amplifier’s voltage. Once this has occurred, the PWM comparator resets the flip−flop, Q1 is turned OFF while the synchronous switch Q2 is turned in its current source mode. Q2 replaces the external Schottky diode to reduce the conduction loss and improve the efficiency. To avoid overall power loss, a certain amount of dead time is introduced to ensure Q1 is completely turned OFF before Q2 is being turned ON. Low Dropout Operation The NCV896530 offers a low input−to−output voltage difference. The NCV896530 can operate at 100% duty cycle on both channels. In this mode the PMOS (Q1) remains completely ON. The minimum input voltage to maintain regulation can be calculated as: ǒ V IN(min) + V OUT(max) ) I OUT ǒRDS(on) ) RINDUCTOR)ǓǓ (eq. 1) VOUT: Output Voltage IOUT: Max Output Current RDS(ON): P−Channel Switch RDS(on) RINDUCTOR: Inductor Resistance (DCR) VOUT Power On Reset The Power On Reset (POR) is pulled low when one of the converter is out of 90% of the regulation. When both outputs are in the range of regulation. If only one channel is active, POR stays low. When the inactive regulator becomes enabled, POR is kept low until the output reaches its voltage range. A pull−up resistor is needed to this open drain output. The resistor may be connected to VIN or to an output voltage of one regulator if the device supplied can not accept VIN on the IO. POR is low when NCV896530 is off. Leave the POR pin unconnected when not used. ILX VLX Figure 12. PWM Switching Waveforms Frequency Synchronization (VIN = 3.6 V, VOUT = 1.2 V, IOUT = 600 mA, Temp = 25°C) The NCV896530 can be synchronized with an external clock signal by using the SYNC pin (1.8 MHz − 2.4 MHz). During synchronization, the outputs are in phase. Soft−Start The NCV896530 uses soft start to limit the inrush current when the device is initially powered up or enabled. Soft start is implemented by gradually increasing the reference voltage until it reaches the full reference voltage. During startup, a pulsed current source charges the internal soft start capacitor to provide gradually increasing reference voltage. When the voltage across the capacitor ramps up to the nominal reference voltage, the pulsed current source will be switched off and the reference voltage will switch to the regular reference voltage. Thermal Shutdown Internal Thermal Shutdown circuitry is provided to protect the integrated circuit in the event that the maximum junction temperature is exceeded. If the junction temperature exceeds TSD, the device shuts down. In this mode all power transistors and control circuits are turned off. The device restarts in soft start after the temperature drops below 130°C min. This feature is provided to prevent catastrophic failures from accidental device overheating. Over Current Hiccup Protection When the current through the inductor exceeds the current limit the NCV896530 enters over current hiccup mode. www.onsemi.com 7 NCV896530 effect on the control loop. If more than 100 mF is used on an output small signal analysis should be done to make sure that sufficient phase margin is maintained. The maximum allowable due to soft start current limit is given by the following equation: Switching Frequency When switcher 2 is enabled and switcher 1 is disabled, the switching frequency is approximately 120 kHz higher than when switcher 1 is enabled and switcher 2 is either enabled or disabled. Conversion Ratio C max + The minimum conversion ratio is dictated by switching frequency and the minimum on time. The minimum achievable output is: V OUT + 0.2 I OUT,startup t start V OUT Cmax: Maximum output capacitance (F) IOUT,startup: Output current during soft start (A) tstart: Soft-start time (s) Vout: Regulated output voltage (V) V IN Maximum Output Capacitance The maximum output capacitance is determined by the amount the capacitor can be charged during soft start and the www.onsemi.com 8 (eq. 2) NCV896530 PACKAGE DIMENSIONS DFN10, 3x3, 0.5P CASE 485C ISSUE C D PIN 1 REFERENCE EDGE OF PACKAGE A B L1 ÇÇÇ ÇÇÇ ÇÇÇ E DETAIL A Bottom View (Optional) 0.15 C 2X EXPOSED Cu TOP VIEW MOLD CMPD 0.15 C 2X (A3) DETAIL B 0.10 C A1 ÉÉÉ ÉÉÉ A 10X SIDE VIEW A1 D2 C DETAIL A SOLDERING FOOTPRINT* e L 1 A3 DETAIL B Side View (Optional) SEATING PLANE 0.08 C 10X NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M, 1994. 2. CONTROLLING DIMENSION: MILLIMETERS. 3. DIMENSION b APPLIES TO PLATED TERMINAL AND IS MEASURED BETWEEN 0.25 AND 0.30 MM FROM TERMINAL. 4. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. 5. TERMINAL b MAY HAVE MOLD COMPOUND MATERIAL ALONG SIDE EDGE. MOLD FLASHING MAY NOT EXCEED 30 MICRONS ONTO BOTTOM SURFACE OF TERMINAL b. 6. DETAILS A AND B SHOW OPTIONAL VIEWS FOR END OF TERMINAL LEAD AT EDGE OF PACKAGE. 7. FOR DEVICE OPN CONTAINING W OPTION, DETAIL B ALTERNATE CONSTRUCTION IS NOT APPLICABLE. 5 DIM A A1 A3 b D D2 E E2 e K L L1 MILLIMETERS MIN MAX 0.80 1.00 0.00 0.05 0.20 REF 0.18 0.30 3.00 BSC 2.40 2.60 3.00 BSC 1.70 1.90 0.50 BSC 0.19 TYP 0.35 0.45 0.00 0.03 2.6016 E2 10X K 10 10X 0.10 C A B 0.05 C 1.8508 2.1746 6 3.3048 b BOTTOM VIEW NOTE 3 10X 0.5651 10X 0.5000 PITCH 0.3008 DIMENSIONS: MILLIMETERS *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. 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