MP2162A 2A, 6V, 1.5MHz, 17μA IQ, COT Synchronous Step-Down Converter The Future of Analog IC Technology DESCRIPTION FEATURES The MP2162A is a monolithic step-down, switch-mode converter with built-in internal power MOSFETs. It achieves 2A of continuous output current from a 2.5V to 6V input voltage with excellent load and line regulation. The output voltage can be regulated as low as 0.6V. The constant-on-time control scheme provides fast transient response and eases loop stabilization. Fault condition protection includes cycle-by-cycle current limiting and thermal shutdown. The MP2162A is available in small QFN-8 (2.0x1.5mm), TQFN-8 (2.0x1.5mmx0.75mm) and UTQFN-8 (2.0mmx1.5mmx0.55mm) packages and requires only a minimal number of readily available, standard, external components. The MP2162A is ideal for a wide range of applications, including high performance DSPs, FPGAs, PDAs, and portable instruments. Very Low IQ of 17μA Default 1.5MHz Switching Frequency 1.5% VFB Accuracy EN and Power Good for Power Sequencing Wide 2.5V to 6V Operating Input Range Output Adjustable from 0.6V Up to 2A of Output Current 100% Duty Cycle in Dropout 110mΩ and 60mΩ Internal Power MOSFET Switches Cycle-by-Cycle Over-Current Protection Short-Circuit Protection with Hiccup Mode Stable with Low ESR Output Ceramic Capacitors Available in QFN-8 (2.0x1.5mm), TQFN-8 (2.0x1.5mmx0.75mm) and UTQFN-8 (2.0mmx1.5mmx0.55mm) Packages APPLICATIONS Wireless/Networking Cards Portable Instruments Battery-Powered Devices Low Voltage I/O System Power 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. TYPICAL APPLICATION L1 1 H VIN 2.5V to 6V VOUT 1.2V/2A SW VIN C1 10 F OUT MP2162A EN EN PG PG PGND R1 200k C2 10 F FB AGND R2 200k MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 1 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER ORDERING INFORMATION Part Number Package Top Marking MP2162AGQH* QFN-8 (2.0mmx1.5mm) See Below MP2162AGQHT** TQFN-8 (2.0mmx1.5mmx0.75mm) See Below MP2162AGQHU*** UTQFN-8 (2.0mmx1.5mmx0.55mm) See Below *For Tape & Reel, add suffix –Z (e.g. MP2162AGQH-Z) **For Tape & Reel, add suffix –Z (e.g. MP2162AGQHT-Z) ***For Tape & Reel, add suffix –Z (e.g. MP2162AGQHU-Z) TOP MARKING EB: Product code of MP2162AGQH and MP2162AGQHU LL: Lot number TOP MARKING EQ: Product code of MP2162AGQHT LL: Lot number MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 2 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER PACKAGE REFERENCE EN 1 8 PG EN 1 8 PG FB 2 7 VIN FB 2 7 VIN AGND 3 6 SW AGND 3 6 SW OUT 4 5 PGND OUT 4 5 PGND TQFN-8 (2.0mmx1.5mmx0.75mm) UTQFN-8 (2.0mmx1.5mmx0.55mm) QFN-8 (2.0mmx1.5mm) ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply voltage (VIN) .................................... 6.5V VSW.…..-0.3V (-1.5V for <20ns and -4V for <8ns) to 6.5V (10V for <10ns) All other pins .................................-0.3V to 6.5 V Junction temperature ................................150C Lead temperature .....................................260C (2) Continuous power dissipation (TA = +25°C) ……….….. ............................................... 1.14W Storage temperature ................ -65C to +150C QFN-8 (2.0mmx1.5mm) ......... ......110 .. 55... C/W TQFN-8 (2.0mmx1.5mmx0.75mm).110.. 55... C/W UTQFN-8 (2.0mmx1.5mmx0.55mm).110 55... C/W Recommended Operating Conditions (3) Supply voltage (VIN) ...........................2.5V to 6V Operating junction temp. (TJ). .. -40°C to +125°C (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 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) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 3 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS VIN = 5V, TA = +25C, unless otherwise noted. Parameter Feedback voltage Symbol VFB Condition Min Typ Max 2.5V ≤ VIN ≤ 6V, TA = 25oC -1.5 0.600 +1.5 o o TA = -40 C to +85 C Feedback current PFET switch-on resistance NFET switch-on resistance IFB RDSON_P RDSON_N (6) VFB = 0.6V VEN = 0V, VIN = 6V VSW = 0V and 6V Switch leakage PFET current limit On time 2.6 TON Switching frequency Fs Minimum off time (6) Soft-start time TMIN-OFF TSS-ON Power good upper trip threshold PGH 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 PGL PGD VPG-L VPG-H EN input current Supply current (shutdown) Supply current (quiescent) -2.5 VIN = 5V, VOUT = 1.2V VIN = 3.6V, VOUT = 1.2V VOUT = 1.2V, TA = 25oC TA = -40oC to +85oC (6) VOUT from 10% to 90% FB voltage with respect to the regulation Sink 1mA VIN = 5V, VFB = 0.6V -20 -25 0.6 10 110 60 50 nA mΩ mΩ 0 1 μA 3.2 166 220 1500 1500 60 1.15 4.0 A ns +20 +25 1.7 % -10 50 % μs V V 550 2.3 kΩ 2.45 260 V mV 0.4 1.5 0 20 100 V V μA μA nA 17 20 μA 1.2 VEN = 2V VEN = 0V VEN = 0V, VIN = 3V VEN = 2V, VFB = 0.63V, VIN = 5V kHz/% kHz/% ns ms +10 0.4 2.15 V/% +2.5 4.9 RPG Units Thermal shutdown (5) 150 C Thermal hysteresis (5) 30 C NOTES: 5) Guaranteed by design. 6) Guaranteed by characterization test. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 4 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS VIN = 5V, VOUT = 1.2V, L = 1.0µH, TA = +25ºC, unless otherwise noted. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 5 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 5V, VOUT = 1.2V, L = 1.0µH, TA = +25ºC, unless otherwise noted. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 6 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 5V, VOUT = 1.2V, L = 1.0µH, TA = +25ºC, unless otherwise noted. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 7 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 5V, VOUT = 1.2V, L = 1.0µH, TA = +25ºC, unless otherwise noted. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 8 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER PIN FUNCTIONS Pin # (QFN-8) 1 Pin # (TQFN-8) (UTQFN-8) 1 2 2 FB 3 4 5 6 3 4 5 6 AGND OUT PGND SW 7 7 VIN 8 8 PG Name EN Description On/off control. Feedback. An external resistor divider from the output to AGND (tapped to FB) sets the output voltage. Analog ground for the internal control circuit. Input sense for output voltage. Power ground. Switch output. Supply voltage. The MP2162A operates from a +2.5V to +6V unregulated input. C1 is needed to prevent large voltage spikes from appearing at the input. Power good indicator. The output of PG is an open drain with an internal pull-up resistor to VIN. PG is pulled up to VIN when the FB voltage is within ±10% of the regulation level. If the FB voltage is out of that regulation range, it is low. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 9 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER FUNCTIONAL BLOCK DIAGRAM VIN Bias & Voltage Reference EN Soft start + COMP VTH Lo-Iq 0.6V RST + + E.A. - Constant On -Time Pulse PDRV PWM Main Switch (PCH) PWM + Lo-Iq + FB SW EN FBCOMP Driver VOUT Lo-Iq Ramp Generator Synchronous Rectifier ( NCH) SW Lo-Iq Hi-Z NDRV OUT PGND VIN FB for Fixed Output 0.66V + + COMP COMP - Lo-Iq + COMP 0.54V AGND PG - Figure 1: The MP2162A Block Diagram MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 10 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER OPERATION The MP2162A uses constant-on-time control with an input voltage feed-forward to stabilize the switching frequency over a full input voltage range. During light loads, the MP2162A employs proprietary control of the low-side switches and inductor currents to eliminate ringing on the switching node and improve efficiency. Constant-On-Time Control Compared to the fixed frequency PWM control, the constant-on-time control offers the advantage of a simpler control loop and a faster transient response. By using input voltage feed-forward, the MP2162A maintains a near constant switching frequency across the input and output voltage ranges. The on time of the switching pulse can be estimated with Equation (1): TON VOUT 0.667s VIN (1) To prevent inductor current runaway during the load transient, the MP2162A has a fixed minimum off time of 60ns. However, this minimum off time limit does not affect the operation of the MP2162A in its steady state in any way. Light-Load Operation In light-load conditions, the MP2162A uses a proprietary control scheme to save power and improve efficiency. The MP2162A uses a zero current cross circuit to detect if the inductor current is starting to reverse. The low-side switch turns off when the inductor current starts to reverse and then begins working in discontinuous conduction mode (DCM). The delay for the internal circuit propagation time is typically 50ns. This means that the inductor current continues falling after the ZCD is triggered in this delay. If the inductor current falling slew rate is fast (VOUT is high or close to VIN), then the low-side MOSFET turns off, the inductor current may be negative, and the MP2162A will not be able to enter DCM operation. If DCM mode is required, the off time of the low-side MOSFET in CCM should be longer than 100ns (2x the propagation delay). For example, if VIN is 3.6V and Vo is 3.3V, the off time in CCM is 55ns. It is difficult to enter DCM at a light load. Using a smaller inductor can help the MP2162A enter DCM more easily. Enable (EN) When the input voltage is greater than the undervoltage lockout (UVLO) threshold (typically 2.3V), the MP2162A is enabled by pulling EN higher than 1.2V. Leaving EN floating or grounded disables the MP2162A. There is an internal 1MΩ resistor from EN to ground. Soft Start The MP2162A has a built-in soft start that ramps up the output voltage at a controlled slew rate to avoid overshooting at start-up. The soft-start time is typically about 1.15ms. Power Good Indicator The MP2162A uses an open drain with a 550kΩ pull-up resistor as a power good indicator (PG). When the FB voltage is within +/-10% of the regulation voltage (i.e. 0.6V), PG is pulled up to VIN by an internal resistor. If the FB voltage is out of the +/-10% window, PG is pulled down to ground by an internal MOSFET. The MOSFET has a maximum Rds(on) of less than 400Ω. Current Limit The MP2162A has a typical 3.2A current limit for the high-side switch. When the high-side switch hits its current limit, the MP2162A enters hiccup mode until the current drops. This prevents the inductor current from rising and possibly damaging the components. Short Circuit and Recovery The MP2162A enters short-circuit protection mode when the current limit is hit; it tries to recover from the short circuit by entering hiccup mode. In short-circuit protection, the MP2162A disables the output power stage, discharges a soft-start capacitor, and automatically tries to soft start. If the short-circuit condition still holds after the soft start ends, the MP2162A repeats this operation until the short circuit disappears, and the output rises back to regulation levels. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 11 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER APPLICATION INFORMATION COMPONENT SELECTION Setting the Output Voltage The external resistor divider sets the output voltage (see Typical Application on page 1). The feedback resistor R1 cannot be too large or too small, considering the trade-off between a dynamic circuit and stability in the circuit. Set R1 to around 120kΩ to 200kΩ. R2 is then given by Equation (2): R2 R1 Vout 1 0.6 (2) The feedback circuit is shown in Figure 2. Vout MP2162A R1 FB R2 Table 1 lists the recommended resistor values 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%) VOUT (VIN VOUT ) VIN IL fOSC I L 2 (4) Selecting the Input Capacitor The input current to the step-down converter is discontinuous and requires a capacitor 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 values and small temperature coefficients. For most applications, a 10µF capacitor is sufficient. For a higher output voltage, a 47µF capacitor may be needed to improve system stability. I C1 ILOAD VOUT VOUT 1 VIN VIN (5) The worse case condition occurs at VIN = 2VOUT, shown in Equation (6): IC1 ILOAD 2 (6) For simplification, choose an input capacitor with an RMS current rating greater than half of the maximum load current. Selecting the Inductor A 0.68µH to 2.2µH inductor is recommended for most applications. For the highest efficiency, choose an inductor with a DC resistance of less than 15mΩ. For most designs, the inductance value can be derived from Equation (3): L1 IL(MAX ) ILOAD 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 with Equation (5): Figure 2: Feedback Network VOUT (V) 1.0 1.2 1.8 2.5 3.3 Set the inductor current to be approximately 30% of the maximum load current. The maximum inductor peak current is calculated in Equation (4): (3) The input capacitor can be electrolytic, tantalum, or ceramic. When using electrolytic or tantalum capacitors, use a small, high-quality ceramic capacitor (i.e. 0.1μF) and place it as close to the IC as possible. When using ceramic capacitors, make sure that they have enough capacitance to provide a sufficient enough charge to prevent an excessive voltage ripple at the input. The input voltage ripple caused by capacitance can be estimated with Equation (7): Where ΔIL is the inductor ripple current. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 12 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER VIN ILOAD V V OUT 1 OUT fS C1 VIN VIN (7) Selecting the Output Capacitor The output capacitor (C2) is required to maintain the DC output voltage. Ceramic, low ESR capacitors are recommended to keep the output voltage ripple low. The output voltage ripple can be estimated by Equation (8): VOUT 3. Place the external feedback resistors next to FB. 4. Keep the switching node (SW) short and away from the feedback network. EN PG GND R2 R1 VOUT V 1 1 OUT RESR fS L1 VIN 8 fS C2 (8) Where L1 is the inductor value and RESR is the equivalent series resistance (ESR) value of the output capacitor. When using ceramic capacitors, the impedance at the switching frequency is dominated by the capacitance, which mainly causes output voltage ripples. For simplification, the output voltage ripple can be estimated with Equation (9): ΔVOUT V VOUT 1 OUT 2 VIN 8 fS L1 C2 When using tantalum the ESR dominates switching frequency. output ripple can Equation (10): ΔVOUT RESR 8 2 7 3 6 4 5 C1 C2 SW OUT VIN Figure 3: PCB Layout Recommendation Design Example Below is a design example following the application guidelines for the specifications below: Table 2: Design Example (9) or electrolytic capacitors, the impedance at the For simplification, the be approximated with VOUT V 1 OUT fS L1 VIN 1 (10) VIN VOUT fSW 5V 1.2V 1500kHz The detailed application schematic is shown in Figure 4. The typical performance and circuit waveforms are shown in the Typical Performance Characteristics section on page 5. For more device applications, please refer to the related evaluation board datasheets. The characteristics of the output capacitor affect the stability of the regulation system. PCB Layout Guidelines Efficient PCB layout is critical for achieving stable operation. A poor layout design can result in poor line or load regulation and stability issues. For best results, refer to Figure 3 and follow the guidelines below: 1. Place the high-current paths (GND, VIN, and SW) as close to the device as possible with short, direct, and wide traces. 2. Place the input capacitor as close to VIN and GND as possible. MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 13 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL APPLICATION CIRCUITS L1 1 H VIN 2.5V to 6V VOUT 1.2V/2A SW VIN C1 10 F OUT MP2162A EN EN PG PG PGND R1 200k C2 10 F FB AGND R2 200k Figure 4: Typical Application Circuit MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 14 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER PACKAGE INFORMATION QFN-8 (2.0mmx1.5mm) PIN 1 ID PIN 1 ID MARKING PIN 1 ID INDEX AREA BOTTOM VIEW TOP VIEW SIDE VIEW NOTE: 0.125 X 45 1) ALL DIMENSIONS ARE IN MILLIMETERS. 2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH. 3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETERS MAX. 4) JEDEC REFERENCE IS MO-220. 5) DRAWING IS NOT TO SCALE. RECOMMENDED LAND PATTERN MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 15 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER TQFN-8 (2.0mmx1.5mmx0.75mm) PIN 1 ID PIN 1 ID MARKING PIN 1 ID INDEX AREA BOTTOM VIEW TOP VIEW SIDE VIEW 0.125 X 45° NOTE: 1) ALL DIMENSIONS ARE IN MILLIMETERS. 2) LEAD COPLANARITY SHALL BE 0.10 MILLIMETERS MAX. 3) JEDEC REFERENCE IS MO-220. 4) DRAWING IS NOT TO SCALE. RECOMMENDED LAND PATTERN MP2162A Rev. 1.03 www.MonolihicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 16 MP2162A – 2A, 6V, 1.5MHz SYNCHRONOUS STEP-DOWN CONVERTER UTQFN-8 (2.0mmx1.5mmx0.55mm) NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications. 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. MP2162A Rev. 1.03 www.MonolithicPower.com 6/30/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 17