MPQ2249

MPQ2249 MPS | Alldatasheet

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Technical content

6V, 3A, 1MHz, Low-Voltage Synchronous Step-Down Converter MPQ2249 Rev.1.01 www.MonolithicPower.com 1 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. The Future of Analog IC Technology

DESCRIPTION

The MPQ2249 is a 1MHz constant frequency, current mode, PWM step-down converter. The device integrates a main switch and a synchronous rectifier for high efficiency and eliminates the need for an external Schottky diode. It is ideal for powering portable equipment that runs from a single cell Lithium- Ion (Li+) battery. The MPQ2249 can supply 3A of load current from a 2.5V to 6V input voltage. It can run at 100% duty cycle for low dropout applications. The MPQ2249 provides internal soft-start control to reduce rush current and output discharge function to control discharging of the output capacitor. The MPQ2249 is available in small SOIC8E package.

FEATURES

• High Efficiency: Up to 90%
• Power Save Mode at Light Load
• 1MHz Constant Switching Frequency
• Up to 4.5A PeakCurrent
• 2.5V to 6V Input Voltage Range
• Output Adjustable from 0.6V to VIN
• 100% Duty Cycle in Dropout
• Output Discharge Function
• Internal Soft-Start Control
• Power Good Indicator
• Short Circuit Protection
• Thermal Fault Protection
• Available in SOIC8E Package

APPLICATIONS

• Cellular and Smart Phones
• Microprocessors and DSP Core Supplies
• PDAs
• MP3 Players
• Digital Still and Video Cameras
• Portable Instruments All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Quality Assurance. “MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithi c Power Systems, Inc. TYPICAL APPLICATION EN GND MPQ2249 PVIN FB SW 2. 2 H R2ON OFF VIN / 5V VOUT/ 1.8V PG PVIN PG C3 C4

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 2 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved.

ORDERING INFORMATION

Part Number Package Top Marking MPQ2249DN SOIC8E MP2249 For Tape and Reel, add suffix -Z (e.g. MPQ2249DN–Z). For RoHS Compliant Packaging, add suffix - LF (e.g. MPQ2249DN–LF–Z); PACKAGE REFERENCE SOIC8E ABSOLUTE MAXIMUM RATINGS (1) Continuous Power Dissipation (TA = +25°C) (2) Recommended Operating Conditions (3) Thermal Resistance (4) θJA θJC Notes: 1) Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the maximum junction temperature. T J(MAX) the junction-to- ambient thermal resistance θJA and the ambient temperature TA. The maximum allowable power dissipation at any ambien t temperature is calculated using: P D(MAX)=(TJ(MAX)-TA)/ θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB.

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 3 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved.

ELECTRICAL CHARACTERISTICS

VIN = VEN = 3.6V, TJ = -40°C to +125°C, typical values are at TJ=+25°C, unless otherwise noted. Parameter Symbol Condition Min Typ Max Units Supply Current I Q V EN = VIN, VFB = 0.51V 600 750 μA Shutdown Current V EN = 0V, TJ = 25°C 0.01 1 μA V EN = 0V 0.01 10 μA IN Under Voltage Lockout (UVLO) Threshold Rising Edge 2.15 2.3 2.45 V IN Under Voltage Lockout Hysteresis 210 mV Soft-Start Time 1 ms Discharge MOSFET On Resistance 100 Ω FB Input Bias Current V FB = 0.65V -50 0.5 +50 nA PFET On Resistance I SW = 100mA 92 m Ω NFET On Resistance I SW = -100mA 72 m Ω SW Leakage Current (5) VEN = 0V,VIN = 6V, VSW = 0V or 6V -1 +1 μA PFET Current Limit I LIMIT Duty Cycle = 100%, Current Pulse Width < 1ms 4.5 A Oscillator Frequency f SW 1 MHz Minimum On Time (5) t ON 100 ns Thermal Shutdown Trip Threshold (5) 145 °C EN Turn-on Trip Threshold -40°C ≤ TA ≤ +125°C 1.8 V EN Turn-off Trip Threshold -40°C ≤ TA ≤ +125°C 0.4 V EN-pull down resistor 25°C 340 400 540 kΩ -40°C = TA = +125°C 300 620 Latch Off Under Voltage (UV) Threshold (5) 67% V FB PG Upper Trip Threshold 90% V FB PG Lower Trip Threshold 85% V FB PG Output Low Voltage I SINK=1mA 0.3 V Notes: 5) Guarantee by design, no production test.

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 4 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS VIN = 5V, EN = 5V, VO = 1.8V, L1 = 2.2µH, and TA = +25°C, unless otherwise noted. LOAD CURRENT ( A )LOAD CURRENT ( A ) LOAD CURRENT ( A ) Line Efficiency VOUT=1.8V Line Regulation VOUT=1.8V Load Efficiency VOUT=3.3V Line Efficiency VOUT=3.3V Load Regulation VOUT=1.8V Load Regulation VOUT=3.3V Peak Current vs. Duty Cycle Line Regulation VOUT=3.3V LOAD CURRENT ( A ) LOAD CURRENT ( A ) LOAD CURRENT ( A )LOAD CURRENT ( A ) LOAD CURRENT ( A ) Load Efficiency VOUT=1.8V 100 VIN=6V VIN=5V VIN=4V VIN=3V 100 IOUT=2A IOUT=1A 1.70 1.74 1.78 1.82 1.86 1.90 IOUT=2A IOUT=1A 1.75 1.77 1.79 1.81 1.83 1.85 VIN=5V VIN=3V 100 VIN=6V VIN=5.5V VIN=5V VIN=4.5V 100 IOUT=2A IOUT=1A 3.20 3.24 3.28 3.32 3.36 3.40 IOUT=2A IOUT=1A 3.20 3.24 3.28 3.32 3.36 3.40 VIN=5.5V VIN=4.5V 4.0 4.3 4.6 4.9 5.2 5.5 20 30 40 50 60 70 80 90 PEAK CURRENT ( A )

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 5 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 5V, EN = 5V, VO = 1.8V, L1 = 2.2µH, and TA = +25°C, unless otherwise noted. FSW FREQUENCY ( MHz ) VOUT VOLTAGE ( V ) VOUT Voltage vs. TA IQ Current vs. TA FSW Frequency vs. TA VFB VOLTAGE ( mV ) VFB Voltage vs. TA 570 580 590 600 610 620 -40 -10 20 50 80 110 140 1.5 1.6 1.7 1.8 1.9 2.0 -40 -10 20 50 80 110 140 400 440 480 520 560 600 -40 -10 20 50 80 110 140 0.5 0.7 0.9 1.1 1.3 1.5 -40 -10 20 50 80 110 140

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 6 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 5V, EN = 5V, VO = 1.8V, L1 = 2.2µH, and TA = +25°C, unless otherwise noted. Steady State Operation IOUT=0A SW 2V/div VOUT/AC 50mV/div IL 500mA/div Steady State Operation IOUT=3A SW 2V/div VOUT/AC 50mV/div IL 5A/div PG 5V/div VOUT 1V/div EN 5V/div Start-up through EN IOUT=0A PG 5V/div VOUT 1V/div EN 5V/div PG 5V/div VOUT 1V/div EN 5V/div Shut-down through EN IOUT=0A Start-up through EN IOUT=3A SW 2V/div VOUT 1V/div IL 5A/div Short Circuit Protection IOUT=0A to short Shut-down through EN IOUT=3A PG 5V/div VOUT 1V/div EN 5V/div Load Transient IOUT=1.5A to 3A Short Circuit Protection IOUT=3A to short SW 2V/div VOUT 1V/div IL 5A/div SW 5V/div VOUT/AC 50mV/div IL 2A/div

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 7 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 5V, EN = 5V, VO = 1.8V, L1 = 2.2µH, and TA = +25°C, unless otherwise noted. VIN 2V/div. VSW 2V/div. VOUT 2V/div. IL 2A/div. VIN 2V/div. VSW 2V/div. VOUT 2V/div. IL 2A/div. Power Ramp Up VIN=2.5V, IOUT=3A Power Ramp Down VIN=2.5V, IOUT=3A

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 8 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. PIN FUNCTIONS Pin # SOIC8E Name Description 5, 6 SW Power Switch Output. Inductor connection to drains of the internal PFET and NFET switches. 7 PG Power-good indicator. PG is pulled low when output is outside the window of regulation or the device enters shutdown. 8 EN Regulator Enable Control Input. Drive EN above 1.8V to turn on the MPQ2249. Drive EN below 0.4V to turn it off. EN is pulled to GND with a 450kΩ internal resistor. 1 FB Feedback Input. Connect FB to the center point of the external resistor divider. The feedback threshold voltage is 0.6V. 2, 3 Exposed Pad GND Ground. Connect Exposed Pad to ground plane for optimal thermal performance. 4 PVIN Power Stage Supply Input. Bypass to GND with a 2.2 μF or bigger ceramic capacitor.

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 9 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. FUNCTION BLOCK DIAGRAM PVIN EN FB SW GND 0. 6V 1pF 34pF600k BIAS & VOLTAGE REFERENCE 0.6V 1MHz OSCILLATOR ISLOPE OSC CONTROL LOGIC MAIN SWITCH PCH R LOW SIDE GATE DRIVE SYNCHRONOUS RECTIFIER NCHOUTPUT DISCHARGE Internal SS PG 0.54V PWM PVIN COMP 0.4V 0.4V Figure 1—Function Block Diagram OPERATION The MPQ2249 is a constant frequency current mode PWM step-down converter. The MPQ2249 is optimized for low voltage, Li-Ion battery powered applications where high efficiency and small size are critical. The MPQ2249 uses an external resistor divider to set the output voltage from 0.6V to 6V. The device integrates both a main switch and synchronous rectifier, which provides high efficiency and eliminates an external Schottky diode. The MPQ2249 can achieve 100% duty cycle. The duty cycle D of a step-down converter is defined as: %100V V%100fTD IN OUT OSCON ×≈××= Where TON is the main switch on time, f OSC is the oscillator frequency (1MHz), V OUT is the output voltage and VIN is the input voltage Current Mode PWM Control Slope compensated current mode PWM control provides stable switching and cycle-by-cycle current limit for superior load and line response and protection of the internal main switch and synchronous rectifier. The MPQ2249 switches at a constant frequency (1MHz) and regulates the output voltage. During each cycle the PWM comparator modulates the power transferred to the load by changing the inductor peak current based on the feedback error voltage. During normal operation, the main switch is turned on for a certain time to ramp the inductor current at each rising edge of the internal oscillator, and switched off when the peak inductor current is above the error voltage. When the main switch is off, the synchronous rectifier will be turned on immediately.

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 10 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. Power Save Mode Operation The MPQ2249 enters asynchronous mode as soon as current of LS MOS goes below zero. When the load is light enough and comp voltage is lower than the set value, the part goes into power skipping mode. This mode improves efficiency at light load condition. Dropout Operation The MPQ2249 allows the main switch to remain on for more than one switching cycle and increases the duty cycle while the input voltage is dropping close to the output voltage. When the duty cycle reaches 100%, the main switch is held on continuously to deliver current to the output up to the switch’s current limit. The output voltage then is the input voltage minus the voltage drop across the main switch and the inductor. Over-Current-Protection and Latchoff The MPQ2249 provides cycle-by-cycle over current limit when inductor current peak value exceeds the current limit threshold. Meanwhile, output voltage starts to drop until FB is below the Under-Voltage (UV) threshold, typically 33% below the reference. Once the UV is triggered, the MPQ2249 enters latched off mode. This protection mode is especially useful when the output is dead-short to ground. The MPQ2249 exits the latch off mode once the EN or input power is recycled. This operation mode will be masked off for the soft start stage. Maximum Load current The MPQ2249 can operate down to 2.5V input voltage. However, the maximum load current decreases at lower input due to large IR drop across the main switch and synchronous rectifier. The slope compensation signal reduces the peak inductor current as a function of the duty cycle to prevent sub-harmonic oscillations at duty cycles greater than 50%. Conversely the current limit increases as the duty cycle decreases. Internal Soft-Start The soft-start is implemented to prevent the converter output voltage from overshooting during startup. When the chip starts, the internal circuitry generates a soft-start voltage (SS) ramping up from 0V to 1.2V. When it is lower than the internal reference (REF), SS overrides REF so the error amplifier uses SS as the reference. When SS is higher than REF, REF regains control. Output Discharge Function When the device is disabled, the part goes into output discharge mode automatically and its internal discharge MOSFET provides a resistive discharge path for the output capacitor. This function is only suitable for discharge output capacitor for the limited time. If the part is used in a pre-bias application, the external power supply providing the pre-bias should supply larger current than the discharge MOSFET sinks. PG Indicator MPQ2249 provides an open-drain PG output that goes high after output level reaches regulation after startup. PG is pulled low immediately if the output goes out of regulation level or when device enters shutdown.

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 11 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved.

APPLICATION INFORMATION

The external resistor divider sets the output voltage (see Page 1, Schematic Diagram). The feedback resistor R1 also set the feedback loop bandwidth with the internal compensation. The feedback loop bandwidth (f C) is no higher than 1/10 th of switching frequency of MPQ2249. In the case of output ceramic capacitor as C O, it is usually set in the range of 50kHz and 100kHz for optimal transient performance and good phase margin. If an electrolytic capacitor is used, the loop bandwidth is no higher than 1/4 of the ESR zero frequency (f ESR). fESR is given by: ESR ESR O 1f 2R C= π× × For example, choose f C=80kHz with a ceramic capacitor, CO=47μF, R1 is estimated to be 150kΩ. R2 is then given by: OUT R1R2 V 10.6V Table 1—Resistor Selection vs. Output Voltage Setting VOUT R1 R2 L C OUT (Ceramic) 1.2V 150k Ω 150k Ω 1.5 μH-2.2μH 22 μF x 2 1.5V 150k Ω 100k Ω 1.5 μH-2.2μH 22 μF x 2 1.8V 150k Ω 75k Ω 1.5 μH-2.2μH 22 μF x 2 2.5V 150k Ω 47.5k Ω 1.5 μH-2.2μH 22 μF x 2 3.3V 150k Ω 33.2k Ω 1.5 μH-2.2μH 22 μF x 2 Inductor Selection A 1.5µH to 2.2µH inductor with DC current rating at least 25% higher than the maximum load current is recommended for most applications. For best efficiency, the inductor DC resistance shall be <20m Ω. See Table 2 for recommended inductors and Vendors. For most designs, the inductance value can be derived from the following equation: OUT IN OUT IN L OSC Vx ( V - V)L= Vx ΔIx f where ∆IL is Inductor Ripple Current. Choose inductor ripple current approximately 30% of the maximum load current 3A. The maximum inductor peak current is: L L(MAX) LOAD ΔII= I + 2 Table 2—Suggested Surface Mount Inductors Vendor Part Number L (μH) DCR (mΩ) SC (A) L x W x H (mm3) WURTH 744777002 2.2 13 6 7.3×7.3×4.5 744310200 2 14.2 6.5 7×6.9×3 TDK RLF7030T- Input Capacitor Selection The input capacitor reduces the surge current drawn from the input and the switching noise from the device. The input capacitor impedance at the switching frequency shall be less than input source impedance to prevent high frequency switching current passing to the input source. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. For most applications, a 47µF capacitor is sufficient. Output Capacitor Selection The output capacitor keeps output voltage ripple small and ensures a stable regulation loop. The output capacitor impedance shall be low at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended. If an electrolytic capacitor is used, pay attention to output ripple voltage, extra heating, and the selection of feedback resistor R1 (refer to “Output Voltage Setting” section) due to the large ESR of electrolytic capacitor. The output ripple ∆V OUT is approximately: OUT IN OUT OUT IN OSC OSC O Vx ( V - V) 1V x(ESR + )Vx f x L 8 x f x CΔ≤

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER MPQ2249 Rev.1.01 www.MonolithicPower.com 13 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved. TYPICAL APPLICATION CIRCUIT PVIN 75k 2. 2 150k 0.1 GNDEN FB SW PG 0.1 100k 100k 0.1 GND VIN 5,6 PG 2,3 VOUT GND MPQ2249DN Figure 3—Typical application circuit of MPQ2249DN

MPQ2249 – INDUSTRIAL GRADE, 6V, 3A, 1MHZ, LOW-VOLTAGE SYNCHRONOUS STEP-DOWN CONVERTER NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon w hen integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MPQ2249 Rev.1.01 www.MonolithicPower.com 14 6/11/2014 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2014 MPS. All Rights Reserved.

PACKAGE INFORMATION

SOIC8E (exposed pad) SEE DETAIL "A" 0. 0075 (0.19 ) 0. 0098 (0.25 ) 0.050(1.27) BSC 0.013(0.33) 0.020(0.51) SEATING PLANE 0.000(0.00) 0.005(0.125) 0.051 (1.30 ) 0.067 (1.70 ) TOP VIEW FRONT VIEW SIDE VIEW BOTTOM VIEW NOTE : 1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN BRACKET IS IN MILLIMETERS. 2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. 4) LEAD COPLANARITY ( BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.004" INCHES MAX. 5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION BA. 6) DRAWING IS NOT TO SCALE. 0.089(2.26) 0.101(2.56) 0.124 (3.15 ) 0.136 (3.45 ) RECOMMENDED LAND PATTERN 0.213(5.40) 0.063 (1.60) 0. 10 3( 2.6 2) 0.138(3.51) 0.150 (3.80) 0.157 (4.00)PIN 1 ID 0.189(4.80) 0.197(5.00) 0.228(5.80) 0.244(6.20)14 0.016 (0.41) 0.050 (1.27)0o-8o DETAIL "A" 0.010(0.25) 0.020(0.50) x 45o 0.010(0.25) BSC GAUGE PLANE