MP2130 The Future of Analog IC Technology High Efficiency, 3.5A, 6V, 1.2MHz Synchronous Step-Down Converter in an Ultra–Small QFN12 (2x2mm) Package DESCRIPTION FEATURES The MP2130 is a monolithic step-down switch mode converter with built-in internal power MOSFETs. It achieves 3.5A continuous output current from a 2.7V to 6V input voltage with excellent load and line regulation. The MP2130 is ideal for powering portable equipment that runs from a single cell Lithium-Ion (Li+) Battery. The output voltage can be regulated as low as 0.6V. • • • • • • • • • • • • • • The Constant-On-time (COT) control scheme provides fast transient response high light-load efficiency and easy loop stabilization. Fault condition protection includes cycle-by-cycle current limit and thermal shutdown. The MP2130 requires a minimum number of readily available standard external components and is available in an ultra-small QFN12 (2x2mm) package. The MP2130 is ideal for a wide range of applications including PDAs, portable instruments, DVD drives, small handhold and battery–powered devices. • Above 95% Peak Efficiency Above 80% Light Load Efficiency. Wide 2.7V to 6V Operating Input Range Output Voltage as Low as 0.6V 100% Duty Cycle in Dropout 3.5A Output Current 50mΩ and 40mΩ Internal Power MOSFET 1.2MHz Frequency EN and Power Good for Power Sequencing Cycle-by-Cycle Over Current Protection Auto Discharge at Power-off Short Circuit Protection with Hiccup Mode Thermal Shutdown Stable with Low ESR Output Ceramic Capacitors Available in a QFN12 (2x2mm) Package APPLICATIONS • • • • Storage Drives Portable/Handheld Devices Wireless/Networking Cards Low Voltage I/O System Power 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 Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION Efficiency VIN=5V L 1 C1 22 10 SW PVIN VIN OUT 2,11 PG 8 9 EN FB PG NC AGND PGND 4 3,12 VOUT 1.2V 6 MP2130 EN 1 7 5 C2 10 R1 200k R2 200k VO=3.3V 95 EFFICIENCY (%) VIN 5V 100 VO=2.4V 90 85 VO=1.8V 80 75 VO=1.2V 70 0.01 MP2130 Rev. 1.23 11/22/2013 0.1 1 LOAD CURRENT (A) www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 10 1 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER ORDERING INFORMATION Part Number MP2130DG Package QFN12 (2x2mm) Top Marking AB Free Air Temperature -40°C to +85°C * For Tape & Reel, add suffix –Z (e.g. MP2130DG–Z); For RoHS Compliant Packaging, add suffix –LF (e.g. MP2130DG–LF–Z) PACKAGE REFERENCE TOP VIEW VIN PVIN 1 SW 2 PGND 3 AGND 4 10 11 SW 12 PGND 5 9 PG 8 EN 7 FB 6 OUT NC ABSOLUTE MAXIMUM RATINGS (1) Supply Voltage VIN ...................................... 6.5V VSW ........................ (-3V for <8ns) to (VIN + 0.3V) All Other Pins ...............................-0.3V to +6.5V Continuous Power Dissipation (TA = +25°C) (2) ............................................................. 1.6W Junction Temperature ...............................150°C Lead Temperature ....................................260°C Storage Temperature............... -65°C to +150°C Recommended Operating Conditions (3) Supply Voltage VIN .............................2.7V to 6V Output Voltage VOUT ........................0.6V to 5.5V Maximum Junction Temp. (TJ) .............. +125°C MP2130 Rev. 1.23 11/22/2013 Thermal Resistance (4) θJA θJC QFN12 (2x2mm) .....................80 ...... 16 ... °C/W Notes: 1) 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 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. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 2 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS VIN = 3.6V, TA = +25°C, unless otherwise noted. Parameters Symbol Feedback Voltage VFB Feedback Current PFET Switch On Resistance (5) NFET Switch On Resistance (5) IFB RDSON_P RDSON_N Switch Leakage PFET Current Limit NFET Switch Sinking Current On Time On Time Minimum Off Time Soft-Start Time Soft-Stop Time EN Input Current Supply Current (Shutdown) Supply Current (Quiescent) Thermal Shutdown Thermal Hysteresis(5) 2.7V ≤ VIN ≤ 6V VFB = 0.6V VIN=3.6V VIN=3.6V VEN = 0V, VIN=6V, VSW = 0V and 6V Min Typ Max Units 0.591 0.600 0.609 V 10 50 40 3.6 INSW TON VOUT=1.2V, VFB=0.7V VIN = 5V, VOUT=1.2V VIN=3.6V, VOUT=1.2V TOFF TSS-ON TSS-OFF FB with respect to the Regulation Power Good Upper Trip Threshold Power Good Lower Trip Threshold Power Good Delay Power Good Sink Current Capability Power Good Logic High Voltage Power Good Internal Pull Up Resistor Under Voltage Lockout Threshold Rising Under Voltage Lockout Threshold Hysteresis EN Input Logic Low Voltage EN Input Logic High Voltage Condition VPG_LO VPG_HI Sink 1mA VIN=5V, VFB=0.6V nA mΩ mΩ 0 2 μA 4.5 100 200 277 30 1 1 6 A μA ns ns ns ms ms +10 % -10 90 % μs V V 0.4 4.9 RPG 500 2.35 2.5 kΩ 2.65 400 mV 0.4 1.2 VEN = 2V VEN = 0V VEN = 0V VEN = 2V, VFB = 0.63V, VIN=3.6V 2 0 0 V V V μA μA 40 μA 150 30 °C °C Note: 5) Guaranteed by design. MP2130 Rev. 1.23 11/22/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 3 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER PIN FUNCTIONS Pin # Name Description 1 2, 11 3, 12 4 5 6 PVIN SW PGND AGND NC OUT 7 FB 8 EN 9 PG 10 VIN Supply Voltage to power FETs. PVIN is connected to VIN internally. Switch Output. Pin 2 and 11 can be connected together. Power Ground. Pin 3 and 12 can be connected together. Quiet ground for controller circuits Leave this pin open. Do not connect it to ground. Input sense pin for output voltage Feedback. An external resistor divider from the output to GND, tapped to the FB pin, sets the output voltage. On/Off Control. Power Good Indicator. The output of this pin is an open drain with internal pull up resistor to IN. PG is pulled up to IN when the FB voltage is within 10% of the regulation level, otherwise it is LOW. Supply Voltage to internal control circuitry. VIN is connected to PVIN internally. MP2130 Rev. 1.23 11/22/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 4 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS VIN=5V, VOUT=1.2V, L=1µH, COUT=10µF, TA = +25°C, unless otherwise noted Quiescent Current vs. Input Voltage Shutdown Current vs. Input Voltage Load Regulation 0.5 100 0.6 0.45 0.4 60 40 0.35 ERROR (%) CURRENT (µA) CURRENT (µA) 80 0.3 0.25 0.2 0.15 0.1 20 3 3.5 4 4.5 5 INPUT VOLTAGE (V) 0 2.5 5.5 0 3 3.5 4 4.5 5 5.5 INPUT VOLTAGE (V) -0.6 6 6.5 Case Temp Rise 100 1 30 95 0 IO=1.5A -0.5 IO=3A -1 -1.5 2.5 3 3.5 4 4.5 5 5.5 6 6.5 INPUT VOLTAGE (V) 25 EFFICIENCY (%) IO=0.3A 20 15 10 0 0.5 1 1.5 2 2.5 3 LOAD CURRENT (A) 0 0.5 1 1.5 2 2.5 3 LOAD CURRENT (A) 3.5 3.5 VO=3.3V VO=2.4V 90 85 VO=1.8V 80 75 5 0 VIN=4V Efficiency 35 0.5 VIN=5V -0.2 1.5 CASE TEMP RISE (oC) REGULATION ERROR (%) Line Regulation 0.2 -0.4 0.05 0 2.5 VIN=3V 0.4 VO=1.2V 70 0.01 0.1 1 LOAD CURRENT (A) 10 Efficiency VIN=3.3V 100 EFFICIENCY (%) 95 90 VO=1.8V 85 VO=1.2V 80 75 70 0.010 0.100 1.000 10.000 OUTPUT CURRENT (A) MP2130 Rev. 1.23 11/22/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 5 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN=5V, VOUT=1.2V, L=1µH, COUT=10µF, TA = +25°C, unless otherwise noted. Input and Output Ripple Input and Output Ripple Input and Output Ripple IOUT = 0A IOUT = 1.5A IOUT = 3A VOUT/AC 20mV/div. VOUT/AC 100mV/div. VOUT/AC 20mV/div. VIN/AC 100mV/div. VIN/AC 100mV/div. SW 2V/div. SW 2V/div. SW 2V/div. IL 2A/div. IL 2A/div. IL 2A/div. VIN Power Up without Load VIN/AC 100mV/div. VIN Power Up with 3A Load VIN Shut down without Load VOUT 1V/div. VOUT 1V/div. VOUT 1V/div. VIN 2V/div. SW 2V/div. VIN 2V/div. SW 2V/div. VIN 2V/div. SW 2V/div. IL 2A/div. IL 2A/div. IL 2A/div. VIN Shut down with 3A Load VOUT 1V/div. VIN 2V/div. SW 2V/div. IL 2A/div. MP2130 Rev. 1.23 11/22/2013 EN Start Up without Load EN Shut Down without Load VOUT 1V/div. VOUT 1V/div. EN 5V/div. EN 5V/div. SW 5V/div. SW 5V/div. IL 2A/div. IL 2A/div. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 6 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN=5V, VOUT=1.2V, L=1µH, COUT=10µF, TA = +25°C, unless otherwise noted. EN Start Up with 3A Load EN Shut Down with 3A Load VOUT 1V/div. VOUT 1V/div. EN 5V/div. EN 5V/div. SW 5V/div. SW 5V/div. IL 2A/div. IL 2A/div. Power Good Through EN Shut Down EN 5V/div. Power Good Through EN Start Up EN 5V/div. VOUT 0.5V/div. PG 5V/div. Load Transient Response Short Circuit Entry IOUT = 1.5A to 3A VOUT/AC 50mV/div. VOUT 1V/div. SW 5V/div. VOUT 0.5V/div. VIN 2V/div. PG 5V/div. IOUT 1A/div. Short Circuit Short Circuit Recovery VOUT 1V/div. SW 5V/div. VOUT 1V/div. SW 5V/div. VIN 2V/div. VIN 2V/div. IL 5A/div. IL 5A/div. MP2130 Rev. 1.23 11/22/2013 IL 5A/div. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 7 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER FUNCTIONAL BLOCKDIAGRAM VIN PVIN Bias & Voltage Reference EN Soft start /off + COMP VTH Lo-Iq 0.6V RST + + E.A. - Constant On-Time Pulse Main Switch (PCH) PDRV PWM PWM + Lo-Iq + FB SW EN FBCOMP Driver VOUT Lo-Iq Ramp generator Synchronous Rectifier (NCH) SW Lo-Iq Hi-Z NDRV OUT PGND IN FB for fixed output 0.66V + + COMP COMP - Lo-Iq + AGND COMP 0.54V PG - Figure 1—Functional Block Diagram MP2130 Rev. 1.23 11/22/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 8 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER OPERATION MP2130 uses constant on-time control with input voltage feed forward to stabilize the switching frequency over full input range. At light load, MP2130 employs a proprietary control of low side switch and inductor current to eliminate ringing on switching node and improve efficiency. Constant On-time Control Compare to fixed frequency PWM control, constant on-time control offers the advantage of simpler control loop and faster transient response. By using input voltage feed forward, MP2130 maintains a nearly constant switching frequency across input and output voltage range. The ontime of the switching pulse can be estimated as: TON = VOUT ⋅ 0.833μs VIN To prevent inductor current run away during load transient, MP2130 fixes the minimum off time to be 30ns. However, this minimum off time limit will not affect operation of MP2130 in steady state in any way. Light Load Operation In light load condition, MP2130 uses a proprietary control scheme to save power and improve efficiency. Instead of turning off the low side switch immediately when inductor current start to reverse, MP2130 gradually ramp down and regulates the low side switch current to a minimal level, thus avoids the ringing at switching node that always occurs in discontinuous conduction mode (DCM) operation Enable When input voltage is greater than the undervoltage lockout threshold (UVLO), typically 2.5V, MP2130 can be enabled by pulling EN pin to higher than 1.2V. Leaving EN pin float or pull down to ground will disable MP2130. There is MP2130 Rev. 1.23 11/22/2013 an internal 1Meg Ohm resistor from EN pin to ground. Soft Start/Stop MP2130 has built-in soft start that ramps up the output voltage in a controlled slew rate, avoiding overshoot at startup. The soft start time is about 1ms typical. At disable, MP2130 ramps down the internal reference thus allow the load to linearly discharge the output. Power Good Indicator MP2130 has an open drain with 500kΩ pull-up resistor pin for power good indicator PG. When FB pin is within +/-10% of regulation voltage, i.e. 0.6V, PG pin is pulled up to IN by the internal resistor. If FB pin voltage is out of the +/-10% window, PG pin is pulled down to ground by an internal MOS FET. The MOS FET has a maximum Rdson of less than 100Ω. Current limit MP2130 has a typical 4.5A current limit for the high side switch. When the high side switch hits current limit, MP2130 will touch the hiccup threshold until the current lower down. This will prevent inductor current from continuing to build up which will result in damage of the components. Short Circuit and Recovery MP2130 enters short circuit protection mode when the inductor current hits the current limit, and tries to recover from short circuit with hiccup mode. In short circuit protection, MP2130 will disable output power stage, discharge soft-start cap and then automatically try to soft-start again. If the short circuit condition still holds after soft-start ends, MP2130 repeats this operation cycle till short circuit disappears and output rises back to regulation level. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 9 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER APPLICATION INFORMATION COMPONENT SELECTION Setting the Output Voltage The external resistor divider is used to set the output voltage (see Typical Application on page 1). The feedback resistor R1 can not be too large neither too small considering the trade-off for stability and dynamic. Choose R1 to be around 120kΩ to 200kΩ. R2 is then given by: R2 = R1 Vout −1 0.6 The feedback circuit is shown as Figure 2. Vout MP2130 R1 FB Figure 2— Feedback Network Table 1 lists the recommended resistors value for common output voltages. Table 1—Resistor Selection for Common Output Voltages R1 (kΩ) 200(1%) 200(1%) 200(1%) 200(1%) 200(1%) R2 (kΩ) 300(1%) 200(1%) 100(1%) 63.2(1%) 44.2(1%) Selecting the Inductor A 0.82µH to 4.7µH inductor is recommended for most applications. For highest efficiency, the inductor DC resistance should be less than 15mΩ. For most designs, the inductance value can be derived from the following equation. L1 = IL(MAX ) = ILOAD + ΔI L 2 Selecting the Input Capacitor The input current to the step-down converter is discontinuous, therefore a capacitor is required to supply the AC current to the step-down converter while maintaining the DC input voltage. Use low ESR capacitors for the best performance. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. For most applications, a 10µF capacitor is sufficient. For higher output voltage, 47µF may be needed for more stable system. Since the input capacitor absorbs the input switching current it requires an adequate ripple current rating. The RMS current in the input capacitor can be estimated by: R2 VOUT (V) 1.0 1.2 1.8 2.5 3.3 Choose inductor current to be approximately 30% of the maximum load current. The maximum inductor peak current is: I C1 = ILOAD × VOUT ⎛⎜ VOUT × 1− VIN ⎜⎝ VIN ⎞ ⎟ ⎟ ⎠ The worse case condition occurs at VIN = 2VOUT, where: IC1 = ILOAD 2 For simplification, choose the input capacitor whose RMS current rating greater than half of the maximum load current. The input capacitor can be electrolytic, tantalum or ceramic. When using electrolytic or tantalum capacitors, a small and high quality ceramic capacitor, i.e. 0.1μF, should be placed as close to the IC as possible. When using ceramic capacitors, make sure that they have enough VOUT × (VIN − VOUT ) VIN × ΔIL × fOSC Where ΔIL is the inductor ripple current. MP2130 Rev. 1.23 11/22/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 10 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER capacitance to provide sufficient charge to prevent excessive voltage ripple at input. The input voltage ripple caused by capacitance can be estimated by: ⎛ ⎞ I V V ΔVIN = LOAD × OUT × ⎜ 1 − OUT ⎟ fS × C1 VIN ⎝ VIN ⎠ Selecting the Output Capacitor The output capacitor (C2) is required to maintain the DC output voltage. Low ESR ceramic capacitors can be used with MP2130 to keep the output ripple low. Generally, 10μF output ceramic capacitor is enough for most of the cases. In higher output voltage condition, 22μF might be needed for a stable system. Layout Recommendation of MP2130 Proper layout of the switching power supplies is very important, and sometimes critical to make it work properly. Especially, for the high switching converter, if the layout is not carefully done, the regulator could show poor line or load regulation, stability issues. For MP2130, the high speed step-down regulator, the input capacitor should be placed as close as possible to the IC pins. As shown in Figure 6, the 0805 size ceramic capacitor is used, please make sure the two ends of the ceramic capacitor be directly connected to PIN1 (the Power Input Pin) and PIN 3 (the Power GND Pin). Using ceramic capacitors, the impedance at the switching frequency is dominated by the capacitance. The output voltage ripple is mainly caused by the capacitance. For simplification, the output voltage ripple can be estimated by: ΔVOUT = ⎛ V ⎞ VOUT × ⎜ 1 − OUT ⎟ VIN ⎠ 8 × fS 2 × L1 × C2 ⎝ In the case of tantalum or electrolytic capacitors, the ESR dominates the impedance at the switching frequency. For simplification, the output ripple can be approximated to: ΔVOUT = VOUT ⎛ V × 1 − OUT fS × L1 ⎜⎝ VIN ⎞ ⎟ × RESR ⎠ The characteristics of the output capacitor also affect the stability of the regulation system. Figure 5—Two Ends off Input Decoupling Capacitor Close to Pin 1 and Pin 3 MP2130 Rev. 1.23 11/22/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 11 MP2130 – HIGH EFFICIENCY, 3.5A, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER PACKAGE INFORMATION QFN12 (2x2mm) 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 when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MP2130 Rev. 1.22 11/22/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 12