MP9840GL-P

MP9840 36V, 3.5A, Low IQ, Synchronous Step-Down Converter DESCRIPTION FEATURES The MP9840 is a high-frequency, synchronous, rectified, step-down, switch-mode converter with built-in power MOSFETs. It offers a very compact solution that achieves 3.5A of continuous output current with excellent load and line regulation over a wide 3.3V to 36V input supply range. The switching frequency can be programmed or synchronized to an external clock in the range of 350kHz to 2.5MHz. The synchronous operation and ultralow 14μA sleep mode quiescent current provide high efficiency over the output current load range, allowing the MP9840 to be used in a variety of step-down applications in automotive input environments and battery-powered applications. • • • Peak-current-mode operation provides fast transient response and eases loop stabilization. The excellent low dropout performance allows the MP9840 to be used in high duty cycle applications. • • • • • • • 2μA Low Shutdown Supply Current 14μA No-Load Quiescent Current Internal 125mΩ High-Side and 55mΩ LowSide MOSFET 350kHz to 2.5MHz Programmable Switching Frequency Power Good (PG) Output External Soft Start (SS) 80ns Minimum On Time Selectable Forced CCM and AAM Hiccup Over-Current Protection (OCP) Available in a QFN-16 (3mmx4mm) Package APPLICATIONS • • Automotive Systems Industrial Power Systems All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. For MPS green status, please visit the MPS website under Quality Assurance. “MPS” and “The Future of Analog IC Technology” are registered trademarks of Monolithic Power Systems, Inc. Full protection features include over-current protection (OCP), short-circuit protection (SCP), and thermal shutdown. An open-drain power good (PG) signal indicates when the output is within 10% of its nominal voltage. The MP9840 is available in a space-saving QFN-16 (3mmx4mm) package. TYPICAL APPLICATION VIN VIN VOUT BST SW GND MP9840 OFF ON FB EN SYNC BIAS PG PHASE VCC FREQ MP9840 Rev. 1.01 1/23/2018 AGND PGND SS www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 1 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER ORDERING INFORMATION Part Number* Package Top Marking MP9840GL QFN-16 (3mmx4mm) See Below * For Tape & Reel, add suffix –Z (e.g. MP9840GL–Z) TOP MARKING MP: MPS prefix Y: Year code W: Week code 9840: First four digits of the part number LLL: Lot number PACKAGE REFERENCE TOP VIEW FREQ 16 FB SS AGND 15 14 13 PHASE 1 12 VCC VIN 2 11 BST SW 3 10 SW PGND 4 9 5 EN 6 SYNC 7 PG PGND 8 BIAS QFN-16 (3mmx4mm) MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 2 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance (3) Supply voltage (VINx) ..................... -0.3V to 40V Switch voltage (VSWx) ... -0.3V to VIN (MAX) + 0.3V BST voltage (VBSTx) ....................VSW (MAX) + 6.5V EN voltage (VENx) ........................... -0.3V to 40V PG voltage ..................................... -0.3V to 40V BIAS voltage .................................. -0.3V to 20V All other pins .................................... -0.3V to 6V Continuous power dissipation (TA = +25°C) (2) QFN-16 (3mmx4mm) .................................2.6W Junction temperature ............................... 150°C Lead temperature .................................... 260°C Storage temperature .................. -65°C to 150°C QFN-16 (3mmx4mm) ............ 48 ....... 11 ... °C/W θJA θJC NOTES: 1) Absolute maximum ratings are rated under room temperature unless otherwise noted. Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the maximum junction temperature TJ(MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD(MAX)=(TJ(MAX)TA)/ θJA. Exceeding the maximum allowable power dissipation produces an excessive die temperature, causing the regulator to go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) Measured on JESD51-7, 4-layer PCB. Recommended Operating Conditions Supply voltage (VIN) ....................... 3.3V to 36V Operating junction temp. (TJ) ...-40°C to +125°C MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 3 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS VIN = 12V, VEN = 2V, TJ = -40°C to +125°C +25°C. Parameter Symbol VIN quiescent current IQ VIN shutdown current ISHDN (4) , unless otherwise noted. Typical values are at TJ = Condition Min VFB = 0.85V, no load, no switching, TJ = +25°C Typ Max 14 21 VFB = 0.85V, no load, no switching VIN under-voltage lockout threshold rising VIN under-voltage lockout threshold hysteresis 0.9 VEN_HYS Feedback reference voltage VREF HS switch on resistance RON_HS LS switch on resistance RON_LS Switching frequency FSW (5) VSYNC_LOW SYNC input high voltage VSYNC_HIGH 6 µA 2.8 3.2 V 1.05 mV 1.2 120 TJ = 25°C V mV 784 800 816 mV 792 800 808 mV 125 165 mΩ 55 85 mΩ VBST - VSW = 5V RFREQ = 180kΩ or from sync clock RFREQ = 82kΩ or from sync clock 400 850 475 1000 550 1150 kHz kHz RFREQ = 27kΩ or from sync clock 2250 2500 2750 kHz TON_MIN SYNC input low voltage 2 150 VEN_RISING EN threshold hysteresis Minimum on time 2.4 INUVHYS EN rising threshold µA 29 VEN = 0V INUVRISING Units 80 ns 0.4 1.8 V V Current limit ILIMIT_HS Duty cycle = 40% 4.6 5.6 7.4 A Low-side valley current limit ILIMIT_LS VOUT = 3.3V, L = 4.7µH 3.1 4.4 5.7 A ZCD current Reverse current limit Switch leakage current IZCD 0.1 A ILIMIT_REVERSE 3 A ISW_LKG Soft-start current ISS VCC regulator VCC VCC load regulation Thermal shutdown VSS = 0.8V 5 0.01 1 µA 10 15 µA 5 ICC = 5mA (5) Thermal shutdown hysteresis (5) % 170 °C TSD_HYS 20 °C PGRISING PG falling threshold (VFB/VREF) PGFALLING TPG_DEGLITCH PG output voltage low 3.5 TSD PG rising threshold (VFB/VREF) PG deglitch timer V VPG_LOW VFB rising 85 90 95 VFB falling 105 110 115 VFB falling 79 84 89 VFB rising % % 113.5 118.5 123.5 % PG from low to high 30 µs PG from high to low 50 µs ISINK = 2mA 0.2 0.4 V NOTE: 4) Not tested in production and guaranteed by over-temperature correlation. 5) Not tested in production and guaranteed by design and characterization. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 4 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL CHARACTERISTICS VIN = 12V, TJ = -40°C to +125°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 5 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL CHARACTERISTICS (continued) VIN = 12V, TJ = -40°C to +125°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 6 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 7 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 8 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 9 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 10 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 11 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 12 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 13 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 3.3V, L = 10μH, FSW = 500kHz, AAM, TA = +25°C, unless otherwise noted. MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 14 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER PIN FUNCTIONS Pin # QFN-16 (3mmx4mm) Name 1 PHASE 2 VIN 3, 10 SW 4, 9 PGND 5 EN 6 SYNC 7 PG 8 BIAS 11 BST 12 VCC 13 AGND 14 SS 15 FB 16 FREQ MP9840 Rev. 1.01 1/23/2018 Description Selectable in-phase or 180° out-of-phase of SYNC input. Pull PHASE high to be in-phase. Pull PHASE low to be 180° out-of-phase. Input supply. VIN supplies power to all of the internal control circuitries and the power switch connected to SW. Place a decoupling capacitor to ground close to VIN to minimize switching spikes. Switch node. SW is the output of the internal power switch. Power ground. PGND is the reference ground of the power device and requires careful consideration during PCB layout. For best results, connect PGND with copper pours and vias. Enable. Pull EN below the specified threshold to shut the chip down. Pull EN above the specified threshold to enable the chip. Synchronize. Apply a 350kHz to 2.5MHz clock signal to SYNC to synchronize the internal oscillator frequency to the external clock. The external clock should be at least 250kHz larger than the RFREQ set frequency. SYNC can also be used to select forced CCM or AAM. Drive SYNC high before the chip starts up to choose forced CCM; drive SYNC low or leave SYNC floating to choose AAM. Power good output. The output of PG is an open drain. Bias input. Connect BIAS to an external power supply (5V ≤ VBIAS ≤ 18V) to reduce power dissipation and increase efficiency. If not in use, float BIAS or connect BIAS to ground. Bootstrap. BST is the positive power supply for the high-side MOSFET driver connected to SW. Connect a bypass capacitor between BST and SW. Bias supply. VCC supplies power to the internal control circuit and gate drivers. A decoupling capacitor (≥1µF) to ground is required close to VCC. Analog ground. AGND is the reference ground of the logic circuit. Soft-start input. Place a capacitor from SS to AGND to set the soft-start period. The MP9840 sources 10µA from SS to the soft-start capacitor during start-up. As the SS voltage rises, the feedback threshold voltage increases to limit inrush current during start-up. Feedback input. Connect FB to the center point of the external resistor divider. The feedback threshold voltage is 0.8V. Place the resistor divider as close to FB as possible. Avoid placing vias on the FB traces. Switching frequency program. Connect a resistor from FREQ to ground to set the switching frequency. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 15 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER BLOCK DIAGRAM BIAS VCC VCC VCC Regulator VIN VCC EN Vref Reference FREQ BST Oscillator PLL SYNC ISW PHASE PG Logic VREF SS FB + - VFB 110%xVREF + - 90%xVREF VFB Error Amplifier VFB + + - Control Logic, OCP, OTP, BST Refresh SW VCC VC R1 460kΩ C1 52pF C2 0.2pF Ireverse PGND AGND Figure 1: Functional Block Diagram MP9840 Rev. 1.01 1/23/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 16 MP9840 – 36V, 3.5A, LOW IQ, SYNC STEP-DOWN CONVERTER OPERATION The MP9840 is a synchronous, step-down, switching regulator with integrated, internal, high-side and low-side power MOSFETs. The MP9840 provides 3.5A of highly efficient output current with current mode control. The MP9840 features a wide input voltage range, switching frequency programmable from 350kHz to 2.5MHz, external soft start, and precision current limit. Its very low operational quiescent current makes it suitable for batterypowered applications. Pulse-Width Modulation (PWM) Control At moderate-to-high output currents, the MP9840 operates in a fixed-frequency, peakcurrent-control mode to regulate the output voltage. A pulse-width modulation (PWM) cycle is initiated by the internal clock. At the rising edge of the clock, the high-side power MOSFET (HS-FET) is turned on and remains on until its current reaches the value set by the COMP voltage (VCOMP). If the current in the HSFET does not reach VCOMP in one PWM period, the HS-FET remains on, saving a turn-off operation. When the high-side power switch is off, the lowside MOSFET (LS-FET) is turned on immediately and remains on until the next cycle begins. For each turn-on and -off in a switching cycle, the HS-FET turns on and off with a minimum on and off time limit. Advanced Asynchronous Mode (AAM) The MP9840 employs advanced asynchronous mode (AAM) functionality to optimize efficiency during light-load or no-load conditions. AAM can be enabled by connecting SYNC to a low level (