MPM3506A MPS | Alldatasheet
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MPM3506A 36V/0.6A Module Synchronous Step-Down Converter with Integrated Inductor MPM3506A Rev. 1.0 www.MonolithicPower.com 1 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved.
DESCRIPTION
The MPM3506A is a synchronous , rectified, step-down converter with built -in power MOSFETs, inductor , and two capacitors. It offers a compact solution with only 4 external components to achieve a 0.6A continuous output current with excellent loa d and line regulation over a wide input supply range. The MPM3506A operates in a 1.15MHz switching frequency, which provides fast load transient response. Full protection features include over-current protection (OCP) and thermal shutdown (TSD). The MPM3506A eliminates design and manufacturing risks while dramatically improving time-to-market. The MPM3506A is available in a space -saving QFN-19 (3mmx5mmx1.6mm) package.
FEATURES
Complete Switch-Mode Power Supply 4.5V to 36V Wide Operating Input Range 0.6A Continuous Load Current 90mΩ/60mΩ Low RDS(ON) Internal Power MOSFETs Fixed 1.15MHz Switching Frequency 800kHz-2MHz Frequency Sync Power-Save Mode for Light Load Power Good Indicator OCP with Valley Current Detection and Hiccup Thermal Shutdown Output Adjustable from 0.8V Available in a QFN-19 (3mmx5mmx1.6mm) Package Total Solution Size 6.7mmx6.3mm
APPLICATIONS
Industrial Controls Automotive Medical and Imaging Equipment Telecom Applications LDO Replacement Space and Resource-Limited Applications Distributed Power Systems All MPS pa rts 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 MPM3506A IN EN/SYNC PGND FB VIN EN 75k 24k 47uF 4.7uF 3.3V/0.6A4.5V-36V VOUT AGND OUT
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 2 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved.
ORDERING INFORMATION
Part Number* Package Top Marking MPM3506AGQV QFN-19 (3mmx5mmx1.6mm) See Below * For Tape & Reel, add suffix –Z (eg. MPM3506AGQV –Z) TOP MARKING MP: MPS prefix Y: Year code W: Week code 3506A: First four digits of the part number LLL: Lot number M: Module PACKAGE REFERENCE VINPG SW VCC EN/ SYNC AGND SW BST SW OUT OUT OUT FB PGND NC NC NC NC PGND 6 7 1314151617 All “NC” pins must be left floating. TOP VIEW
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 3 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. ABSOLUTE MAXIMUM RATINGS (1) -0.3V (-5V for <10ns) to VIN + 0.3V (43V for <10ns) Continuous power dissipation (TA = +25°C) (3) Recommended Operating Conditions (4) Operating junction temp. (TJ). .. -40°C to +125°C Thermal Resistance (5) θJA θJC NOTES: 1) Absolute maximum ratings are rated under room temperature unless otherwise noted. Exceeding these ratings may damage the device. 2) Please refer to the “E NABLE/SYNC” section on page 12 for the absolute maximum rating of EN/SYNC. 3) The maximum allowable power dissipation is a function of the maximum junction temperature T J (MAX), the junction -to- ambient thermal resistance θ JA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by P D (MAX) = (T J (MAX)-TA)/θJA. Exceeding the maximum allowable power dissipation will produce an excessive die temperature, causing the regulator to go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 4) The device is not guaranteed to function outside of its operating conditions. 5) Measured on JESD51-7, 4-layer PCB.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 4 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved.
ELECTRICAL CHARACTERISTICS
VIN = 24V, TJ = -40°C to +125°C(6), unless otherwise noted. Typical values are at TJ = +25°C. Parameter Symbol Condition Min Typ Max Units Supply current (shutdown) IIN VEN = 0V 8 μA Supply current (quiescent) Iq VFB = 1V 0.58 0.8 mA HS switch-on resistance HSRDS-ON VBST-SW = 5V 90 165 mΩ LS switch-on resistance LSRDS-ON VCC = 5V 60 115 mΩ Inductor DC resistance LDCR 75 mΩ Switch leakage SWLKG VEN = 0V, VSW = 24V 1 μA High-side peak current limit IPEAK_LIMIT 20% duty cycle 2 4 A Low-side valley current limit IVALLEY_LIMIT Vout short to GND 1.3 A Oscillator frequency fSW VFB = 700mV 800 1150 1500 kHz Maximum duty cycle DMAX VFB = 700mV 89 92 % Minimum on time(7) τON_MIN 50 ns Feedback voltage VFB TJ = 25°C 798 810 822 mV TJ = -40°C to +125°C 790 830 mV Feedback current IFB VFB = 850mV 10 100 nA EN rising threshold VEN_RISING 1.1 1.45 1.8 V EN falling threshold VEN_FALLING 0.95 1.3 1.65 V EN input current IEN VEN = 2V 4 7 μA EN turn-off delay(7) ENTd-off 3 μs SYNC frequency range fSYNC 800 2000 kHz VIN under-voltage lockout threshold—rising INUVVth 3.75 4.05 4.35 V VIN under-voltage lockout threshold—hysteresis INUVHYS 400 mV PG rising threshold PGVth-Hi 84% 87.5% 91% VFB PG falling threshold PGVth-Lo 79% 82.5% 86% VFB PG rising delay PGTd_Rising 30 90 160 μs PG falling delay PGTd_Falling 25 55 95 μs PG sink current capability VPG Sink 4mA 0.4 V PG leakage current IPG-LEAK 100 nA VCC regulator VCC 4.6 4.9 5.2 V VCC load regulation ICC = 5mA 1.5 4 % Soft-start time tSS VOUT from 10% to 90% 0.5 1.45 2.5 ms Thermal shutdown (7) 165 °C Thermal hysteresis (7) 20 °C NOTES: 6) Not tested in production and guaranteed by over-temperature correlation. 7) Derived from characterization test. Not tested in production.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 5 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS Typical performance characteristic waveforms are captured from the evaluation board. VIN = 24V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 6 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) Typical performance characteristic waveforms are captured from the evaluation board. VIN = 24V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 7 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) Typical performance characteristic waveforms are captured from the evaluation board. VIN = 24V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 8 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) Typical performance characteristic waveforms are captured from the evaluation board. VIN = 24V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 9 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) Typical performance characteristic waveforms are captured from the evaluation board. VIN = 24V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 10 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. PIN FUNCTIONS Package Pin # Name Description 1 FB Feedback. Connect FB to the tap of an external resistor divider from the output to AGND to set the output voltage. The frequency foldback comparator lowers the oscillator frequency (when the FB voltage is below 400mV) to prevent current -limit runaway during a short -circuit fault. Place the resistor divider as close to FB as possible. Avoid placing vias on the FB traces. 2 VCC Internal 5V L DO output. The internal circuit integrates an LDO output capacitor, so an external capacitor is NOT necessary. 3 AGND Analog ground. AGND is the r eference ground of the logic circuit. AGND is connected internally to PGND. 4, 5, 6 SW Switch output. No connection is needed for the SW pins, but a large copper plane is recommended on pins 4, 5, and 6 for improved heat sink. 7, 8, 9 OUT Power output. Connect the load to OUT; an output capacitor is needed. 10, 14, 18, 19 NC No connection. Do NOT connect; NC must be left floating. 11 BST Bootstrap. A bootstrap capacitor is integrated internall y, so an external connection is NOT necessary. 12, 13, PGND Power ground. PGND is the r eference ground of the power device . PCB layout requires extra care (please see recommended “PCB Layout Guidelines” on page 16. For best results, connect to PGND with copper and vias.
15 VIN
Supply voltage. VIN supplies power for the internal MOSFET and regulator. The MPM3506A operates from a + 4.5V to + 36V input rail. VIN requires a low ESR and low inductance capacitor to decouple the input rail. Place the input capacitor very close to VIN and connect it with wide PCB traces and multiple vias.
16 EN/SYNC
Enable/Synchronize. EN/SYNC = high to enable the module. Float ing EN/SYNC or connecting it to ground will disable the converter. Apply an external clock to EN/SYNC to change the switching frequency. 17 PG Power good indicator. PG is an open-drain structure.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 11 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. FUNCTIONAL BLOCK DIAGRAM PG OUT AGND PGND EN/SYNC Comparator On-Time Control Logic Control Current-Sense Amplifier Current-Limit Comparator 10k VIN Figure 1: Functional Block Diagram
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 12 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. OPERATION The MPM3506A is a high -frequency, synchronous, rectified, step-down, switch-mode converter with built -in power MOSFETs , inductor, and two capacitors . It offers a very compact solution that achieves a 0.6A continuous output current with excellent load and line regulation over a 4.5V to 36V input supply range. The MPM3506A operates in a fixed -frequency, peak-current–control mode to regulate the output voltage. A n internal clock initiates a PWM cycle. The inte grated high -side power MOSFET (HS-FET) turns on and remains on until the current reaches the value set by the COMP voltage. When the power switch is off, it remains off until the next clock cycle starts. If the current in the HS -FET does not reach the value set by the COMP value within 92% of one PWM period, the HS-FET is forced off. Internal Regulator A 5V internal regulator powers most of the internal circuitries. This regulator takes V IN and operates in the full V IN range. When V IN exceeds 5.0V, the outp ut of the regulator is in full regulation. When V IN is less than 5.0V, the output will decrease. The part integrates an internal decoupling capacitor, so an external VCC output capacitor is NOT necessary. AAM Operation The MPM3506A has a dvanced asynchronous modulation (AAM) power -save mode for light load. AAM voltage (VAAM) is fixed internally. The internal 250mV AAM voltage sets the transition point from AAM to PWM. Under a heavy-load condition, the V COMP is higher than V AAM. When the clock goes high, the HS-FET turns on and remains on until V ILsense reaches the value set by the COMP voltage. The internal clock re-sets every time VCOMP is higher than VAAM. Under a light-load condition, the value of V COMP is low. When V COMP is less than V AAM and VFB is less than V REF, VCOMP ramps up until it exceeds VAAM. At this time, the internal clock is blocked, causing the MPM3506A to skip pulses for pulse frequency modulation (PFM) mode , achieving the light-load power save (see Figure 2). Figure 2: Simplified AAM Control Logic Error Amplifier (EA) The error amplifier compares the FB voltage to the internal 0.8 1V reference ( VREF) and outputs a current proportional to the difference between the two. This output curr ent then charge s or discharges the internal compensation network to form the COMP voltage (which controls the power MOSFET current ). The optimized internal compensation network minimizes the external component count and simplifies the control loop design. Under-Voltage Lockout (UVLO) Under-voltage lockout (UVLO) protects the chip from operating at an insufficient supply voltage. The MPM3506A UVLO comparator monitors the output voltage of the internal regulator (VCC). The UVLO rising threshold is about 4.05V while its falling threshold is 3.65V. EN/SYNC EN/SYNC is a digital control pin that turns the regulator on and off. Drive EN /SYNC high to turn on the regulator; drive EN/SYNC low to turn off the regulator. An internal 1MΩ resistor from EN/SYNC to GND allo ws EN/SYNC to be floated to shut down the chip. EN/SYNC is clamped internally using a 6.5V series Zener diode (see Figure 3). Connecting the EN/SYNC input through a pull-up resistor to the voltage on V IN limits the EN /SYNC input current to less than 100µA. For example, with 12V connected to V IN, RPULLUP ≥ (12V – 6.5V) ÷ 100µA = 55kΩ. Connecting EN /SYNC directly to a voltage source without a pul l-up resistor requires limiting the amplitude of the voltage source to ≤6V to prevent damage to the Zener diode.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 14 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. Start-Up and Shutdown If VIN exceeds its thresholds, the chip starts up. The reference block starts first, gener ating stable reference voltage and currents ; then the internal regulator is enabled. The regulato r provides a stable supply for the remaining circuitries. Three events can shut down the chip: V IN low, EN low , and thermal shutdown. During the shutdown proce dure, the signaling path is blocked first to avoid any fault triggering. The COMP voltage and the internal supply rail are then pulled down. The floating driver is not subject to this shutdown command.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 15 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved.
APPLICATION INFORMATION
Setting the Output Voltage The external resistor divider set s the output voltage (see “Typical Application ” on page 1). Also, t he feedback resistor (R1) sets the feedback loop bandwidth with the internal compensation capacitor (see “Typical Application” on page 1). Choose R1 around 75kΩ when VOUT 1V. R2 is then given using Equation (1): OUT V 0.81V (1) FB Vout Figure 5: Feedback Network See Figure 5 for the feedback network and Table 1 for a list of the recommended resistor values for common output voltages. Table 1: Resistor Selection for Common Output Voltages VOUT (V) R1 (kΩ) R2 (kΩ) C3(pF) 1.0 75 300 33 1.2 75 150 33 1.5 75 91 22 1.8 75 62 22 2.5 75 36 22 3.3 75 24 22 5 75 14.3 22 Selecting the Input Capacitor The input current to the step -down converter is discontinuous, therefore it requires a capacitor to supply the AC current while maintaining the DC input voltage. Use low ESR capacitors for the best performance. Use ceramic capacitors with X5R or X7R dielectrics for best results because of their low ESR and small temperature coefficients. For most applications, use a 4.7µF capacitor. Since C1 absorbs the input switching current, it requires an adequate ripple current rating. The RMS c urrent in the input capacitor can be estimated with Equation (2) and Equation (3): IN OUT IN OUTLOAD1C V V1V VII (2) The worse -case condition occurs at V IN = 2VOUT, where: II LOAD 1C (3) For simplification, choose an input capacitor with an 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, add a small, high -quality ceramic capacitor (e.g. 0.1μF) placed as close to the IC as possible. When using ceramic capacitors, ensure that they have enough capacitance to provide sufficient charge in order to prevent excessive voltage ripple at the input. The input voltage ripple caused by capacitance can be estimated with Equation (4): LOAD OUT OUT IN INS IN I V VV1 f C1 V V Selecting the Output Capacitor The output capacitor (C2) maintain s the DC output voltage. Use ceramic , tantalum, or low ESR electrolytic capacitors. For best results, use low ESR capacitors to keep the output voltage ripple low. The output voltage ripple can be estimated with Equation (5): OUT OUT OUT ESR S 1 IN S VV 1V 1 R f L V 8 f C2 Where L1 is the inductor value and R ESR is the equivalent series resistance (ESR) value of the output capacitor. For ceramic capacitors, the capacitance dominates the impedance at the switching frequency, and the capacitance causes the majority of the output voltage ripple. For
7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. Figure 8. The typical performance and circuit evaluation board datasheets.
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE CONVERTER MPM3506A Rev. 1.0 www.MonolithicPower.com 21 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. MPM3506AIN EN/ SYNC VCC PG PGND FB SW BST VIN EN 75k 300k 47µF 4.7µF 1V/0.6AContinuous: 4.5V-20V Transient: 36V VOUT AGND OUT 100k 33pF PG Figure 14: VOUT = 1V, IOUT = 0.6A
MPM3506A – SYNCHRONOUS STEP-DOWN MODULE 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 when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MPM3506A Rev. 1.0 www.MonolithicPower.com 22 7/21/2015 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved.
PACKAGE INFORMATION
QFN-19 (3mmx5mmx1.6mm) SIDE VIEW BOTTOM VIEW NOTE: 1) ALL DIMENSIONS ARE IN MILLIMETERS. 2) SHADED AREA IS THE KEEP-OUT ZONE. ANY PCB METAL TRACE AND VIA ARE NOT ALLOWED TO CONNECT TO THIS AREA ELECTRICALLY OR MECHANICALLY. 3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETERS MAX. 4) JEDEC REFERENCE IS MO-220. 5) DRAWING IS NOT TO SCALE. PIN 1 ID MARKING TOP VIEW PIN 1 ID INDEX AREA RECOMMENDED LAND PATTERN PIN 1 ID 0.15X45º TYP 0.15X45º NOTE 2 NOTE 2