MPQ2451-5-AEC1 MPS | Alldatasheet
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36V, 2.2MHz, 0.6A, Step-Down Converter AEC-Q100 Qualified MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 1 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved.
DESCRIPTION
The MPQ2451-5/33 is a high-frequency, step- down, switching regulator with an integrated, high-voltage, high-side power MOSFET . It efficiently outputs up to 0.6A, with current-mode control for fast loop response. The wide 3.3V-to-36V input range accommodates a variety of automotive step-down applications, and the 3μA shutdown-mode quiescent current allows use in battery-powered applications. The MPQ2451-5/33 achieves high power- conversion efficiency over a wide load range by scaling down the switching frequency under light-load conditions to reduce switching and gate driving losses. Frequency fold -back prevents inductor current runaway during start -up. Thermal shutdown provides reliable, fault-tolerant operation. The MPQ2451-5/33 is available in cost-effective SOT23-6L and QFN-6L packages.
FEATURES
Guaranteed Industrial/Automotive Temp. Ranges 130μA Operating Quiescent Current Wide 3.3V-to-36V Operating Input Range 500mΩ Internal Power MOSFET 2.2MHz Fixed Switching Frequency Internally Compensated Stable with Ceramic Output Capacitors Internal Soft-Start Precision Current Limit Without Current Sensing Resistor >90% Efficiency Fixed 5V & 3.3V Outputs 6-Lead SOT23 and QFN Packages Available in AEC-Q100 Grade 1
APPLICATIONS
High-Voltage Power Conversion, Including o Automotive Systems o Industrial Power Systems o Distributed Power Systems o Battery-Powered Systems All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Products, Quality Assurance page. “MPS” and “The Future of Analog IC Technology” are registered trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 2 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved.
ORDERING INFORMATION
Part Number Package Top Marking MPQ2451GT-5* SOT23-6L AGE MPQ2451GT-5-AEC1 MPQ2451GT-33** AGF MPQ2451GT-33-AEC1 MPQ2451GG-5 QFN-6L BP MPQ2451GG-5-AEC1 MPQ2451GG-33 BQ MPQ2451GG-33-AEC1 * For Tape & Reel, add suffix –Z (e.g. MPQ2451GT-5–AEC1-Z) ** For Tape & Reel, add suffix -Z (e.g. MPQ2451GT-33-Z) PACKAGE REFERENCE OUT OUT SOT23-6L QFN-6L ABSOLUTE MAXIMUM RATINGS (1) Continuous Power Dissipation (TA = 25°C) (2) Recommended Operating Conditions (3) Operating Junction Temp. (TJ).−40°C to +125°C 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 θ JA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient tem perature is calculated by P D (MAX) = (T J (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 pe rmanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB.
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 3 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved.
ELECTRICAL CHARACTERISTICS
VIN = 12V, VEN = 2V, TJ= −40°C to +125°C, unless otherwise noted. Typical values are at TJ = 25°C. Parameter Symbol Condition Min Typ Max Units Output Voltage MPQ2451-5 VOUT 6V < VIN < 36V 4.8 5 5.2 V 6V < VIN < 36V, TJ= 25°C 4.85 5 5.15 MPQ2451-33 3.3V < VIN < 36V 3.168 3.3 3.432 V 3.3V < VIN < 36V, TJ= 25°C 3.2 3.3 3.4 Upper Switch-On Resistance RDS(ON) VBST−VSW=5V TJ= 25°C 500 mΩ Upper Switch Leakage VEN = 0V, VSW = 0V 0.5 2 μA Current Limit ILIM TJ= 25°C 0.75
1 A TJ =-40°C to
+125°C 0.65 COMP to Current Sense Transconductance(5) GCS 3 A/V VIN UVLO, Upper Threshold 2.7 3.29 V VIN UVLO, Hysteresis 0.4 V Soft-Start Time 0.5 1 ms Oscillator Frequency fSW 1.8 2.2 2.6 MHz Minimum Switch-On Time(5) τON 80 ns Shutdown Supply Current IS VEN < 0.3V 1 μA Quiescent Supply Current IQ No load, no switching 130 170 µA Thermal Shutdown(5) 150 °C Enable Threshold, High VIH Low-to-High 1.35 1.5 1.8 V Enable Threshold, Hysteresis 400 mV Notes: 5) Derived from bench characterization, not tested in production.
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 4 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. PIN FUNCTIONS SOT23-6L Pin # QFN-6L Pin # Name Description 1 6 BST Bootstrap. Positive power supply for the internal , floating, high-side MOSFET driver. Connect a bypass capacitor between this pin and SW pin. 2 5 GND Ground. Connect the output capacitor as close to this pin as possible. Avoid routing near high-current switch paths. 3 4 OUT Output-Voltage Sense. Connected to the tap of an internal resistor divider to set the output voltage. 4 3 EN Enable. Pull this pin below the specified threshold to shut the chip down. Pull it above the specified threshold to enable th e chip. Float this pin to disable the chip. 5 2 VIN Input Supply. Supplies power to all internal control circuitry. Requires a decoupling capacitor to ground to reduce switching spikes. 6 1 SW Switch Node. Output of the high -side switch. Requires a low -VF Schottky diode connected to ground to reduce switching spikes.
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 5 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. TYPICAL CHARACTERISTICS
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 6 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS VIN = 12V, C1 = 10µF, C2 = 22µF, L = 3.3µH and TA= 25°C, unless otherwise noted. MPQ2451-5
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 7 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, C1 = 10µF, C2 = 22µF, L = 3.3µH and TA = 25°C, unless otherwise noted. MPQ2451-5
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 8 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, C1 = 10µF, C2 = 22µF, L = 3.3µH and TA= 25°C, unless otherwise noted. MPQ2451-33
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 9 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, C1 = 10µF, C2 = 22µF, L = 3.3µH and TA= 25°C, unless otherwise noted. MPQ2451-33
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 10 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. FUNCTIONAL BLOCK DIAGRAM OUT Figure 1: Functional Block Diagram
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 11 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. OPERATION The MPQ2451-5/33 is a 2 .2MHz, asynchronous, step-down, switching regulator with an integrated high-side, high-voltage, power MOSFET. It provides an internally-compensated, highly- efficient output of up to 0.6A with current -mode control. It also features a wide input voltage range, internal soft -start control, and a precise current limit. Its very -low, operational, quiescent current makes it suitable for battery-powered applications. PWM Control At moderate -to-high output current, the MPQ2451-5/33 operates in a fixed -frequency, peak-current-control mode to regulate the output voltage. A PWM cycle —initiated by the internal clock—turns the power MOSFET on , and the MOSFET remains on until its current reaches the value set by VCOMP. When the PWM signal goes low, the power switch turns off and remains off for at least 100ns before the next cycle starts. If the current in the power MOSFET does not reach the COMP-set current value within one PWM cycle, the power MOSFET remains ON to avoid a turn-off operation. Pulse-Skipping Mode Under light-load condition s, the MPQ2451-5/33 enters pulse-skipping mode to improve efficiency. Pulse-skipping occurs when VCOMP drops below the internal sleep threshold, which generates a PAUSE command to block the turn -on clock pulse so the power MOSFET does not turn ON; this procedure reduces gate driving and switching losses. This PAUSE command causes the whole chip to enter sleep mode, reducing the quiescent current to further improve light -load efficiency. When VCOMP exceeds the sleep threshold, the PAUSE signal reset s and the chip resumes normal PWM operation. Whenever the PAUSE changes state from LOW to HIGH, the PWM signal immediately goes HIGH and turns on the power MOSFET. Error Amplifier The error amplifier is composed of an internal op- amp with an RC feedback network connected between its output node (COMP) and its negative input node (FB). When VFB drops below the internal reference voltage ( VREF), the op-amp drives the COMP output high, driving the switch peak current to rise and deliver more energy to the output. Conversely, when VFB rises above VREF, the switch peak current output drops. Internal Regulator The 2.6V internal regulator powers most of the internal circuitry . This regulator takes the VIN input and operates in the full VIN range. When VIN exceeds 3.0V, the output of the regulator is in full regulation. When V IN drops below 3.0V , the output degrades. Enable Control The MPQ2451-5/33 has a dedicated enable control pin, EN. When VIN rises above threshold , the EN pin can enable or disable the chip for HIGH effective logic . Its falling threshold is 1.2V, and its rising threshold is about 1.6V. When left floating, the EN pin is internally pulled down to GND to disable the chip. When the EN voltage is pulled to 0V, the chip enters the lowest shutdown current mode. Between 0V and the rising threshold, the chip remains in shutdown mode with a slightly higher shutdown current. Under-Voltage Lockout (UVLO) VIN under-voltage lockout (UVLO) protect s the chip from operating at an insufficient supply voltage. The UVLO rising threshold is ~2.9V while its falling threshold is 2.6V. Internal Soft-Start A reference -type soft-start (SS) prevents the converter-output voltage from overshooting during startup. When the chip starts, the internal circuitry generates a soft-start voltage (VSS) that ramps up from 0V over the SS time. When VSS is less than VREF, VSS overrides VREF as the error amplifier reference. The maximum V SS is approximately the same as VFB; i.e. if VFB falls, the maximum of VSS falls. This accommodates short-circuit recovery ; when the short-circuit is removed, VSS ramps up to prevent output-voltage overshoot.
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 12 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. Thermal Shutdown Thermal shutdown prevent s thermal runaway. When the silicon die temperature exceeds its upper threshold, the entire chip shuts down. When the temperature drops below its lower threshold, the chip is enabled again. Floating Driver and Bootstrap Charging An external bootstrap capacitor powers the floating-power-MOSFET driver. This floating driver has its own UVLO protection with a rising threshold of about 2.4V and a falling threshold of about 300mV. During this UVLO, VSS resets to 0V. When the UVLO is removed, the controller enters soft-start. The dedicated intern al-bootstrap regulator charges and regulates the bootstrap capacitor to about 5V. When the voltage between the BST and SW nodes falls below its regulation, a PMOS pass transistor connected from V IN to BST turns on. The charging current path goes from V IN→ BST →SW. The external circuit must provide enough voltage headroom to facilitate charging. If VIN is sufficiently higher than VSW, the bootstrap capacitor will charge. When the power MOSFET is ON, V IN=VSW so the bootstrap capacitor does not charge. Optimal charging occurs when VIN−VSW reaches its apex when the external freewheeling diode is on. When there is no current in the inductor, VSW=VOUT so VIN−VOUT can charge the bootstrap capacitor. At a higher duty cycle, the bootstrap capacitor may not be charged sufficiently because of a shorter c harging period . If there is in sufficient voltage and time to charge the bootstrap capacitor, add an extra external circuit to ensure the bootstrap voltage in normal operation region. The floating driver’s UVLO is not communicated to the controller. Make s ure the bleed -through current at the SW node is at least higher than the floating driver’s DC quiescent current of about 20µA. Current Comparator and Current Limit A current -sense MOSFET senses the power MOSFET current. This value is the input to the high-speed-current comparator for current -mode control. When the power MOSFET turn s on, the comparator is first blanked to limit noise, and then compares the power switch current to the VCOMP. When the sensed value exceeds VCOMP, the comparator output goes LOW to turn off the power MOSFET. The maximum current of the internal power MOSFET is internally limited cycle-by-cycle. Startup and Shutdown If both V IN and VEN exceed their respective thresholds, the chip starts . The reference block starts first to generate a stable reference voltage and current , and then the internal regulator operates to provide a stable supply for the rest circuit. While the internal supply rail is up, an internal timer turns the power MOSFET off for about 50µs to blank startup noise. When the internal soft- start block is enabled, it first holds its SS output low to ensure the rest of the circuit is ready before ramping up. Three events shut down the chip: EN low, VIN low, thermal shutdown. During shutdown, the signaling path is blocked fir st to avoid any fault triggering. VCOMP and the internal supply rail are then pulled low. The floating driver is not subject to this shutdown command but its charging path is disabled.
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 13 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved.
APPLICATION INFORMATION
The inductor sup plies constant current to the output load while being driven by the switched input voltage. A larger -value inductor will result in less ripple current and lower output ripple voltage. However, the larger -value inductor is typically physically larger , has a higher series resistance, or has a lower saturation current. To determine the inductance, allow the peak-to- peak ripple current in the inductor to be approximately 30% of the maximum load current. Also, chose a peak inductor current below the maximum swi tch current limit. The inductance value can be calculated by: IN OUT LS OUT V V1ΔIf V1L Where VOUT is the output voltage, VIN is the input voltage, fS is the switching frequency, and ΔI L is the peak-to-peak inductor ripple current. Choose an inductor that will not saturate under the maximum inductor peak current. The peak inductor current can be calculated by: IN OUT S OUT LOADLP V V11Lf2 VII Where ILOAD is the load current. Table 2 lists a number of suitable inductors from various manufacturers. The choice of which style inductor to use mainly depends on the price vs. size requirements and any EMI requirement.
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 14 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. Table 1: Inductor Selection Guide Part Number Inductance (µH) Max DCR (Ω) Current Rating (A) Dimensions L × W × H (mm3) Wurth Electronics TOKO TDK COOPER BUSSMANN The input capacitor (C1) can be electrolytic, tantalum or ceramic. When using electrolytic or tantalum capacitors, add a small, high quality ceramic capacitor—for example, 0.1μF—as close to the IC as possible. When using ceramic capacitors, make sure that they have enough capacitance to provide sufficient charge to prevent excessive voltage ripple at input. The input voltage ripple caused by capacitance can be estimated by: IN OUT IN OUT S LOAD IN V V1V V 1Cf IV Output Capacitor The output capacitor (C2) maintain s the DC output voltage. Ceramic, tantalum, or low ESR electrolytic capacitors are recommended. Low ESR capacitors are preferred to keep the output voltage ripple low. The output vo ltage ripple can be estimated by: 1RV V1Lf VV S ESR IN OUT S OUT OUT Where L is the inductor value and R ESR is the equivalent series resistance (ESR) value of the output capacitor. For 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: IN OUT S OUT OUT V 2CLf8 VΔV For tantalum or electrolytic capacitors, the ESR dominates the impedance at the switchin g frequency. For simplification, the output ripple can be approximated to: ESRIN OUT S OUT OUT RV V1Lf VΔV The characteristics of the output capacitor also affect the stability of the regulation system.
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 16 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. Figure 4: 3.3V Output Typical Application Schematic
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 17 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved.
PACKAGE INFORMATION
MPQ2451-5/33―36V, 2.2MHz, 0.6A, STEP-DOWN CONVERTER, AEC-Q100 QUALIFIED NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third party Inte llectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MPQ2451-5/33 Rev 1.0 www.MonolithicPower.com 18 5/25/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. QFN6 (2mmx2mm) SIDE VIEW TOP VIEW 4 3 BOTTOM VIEW 1.90 2.10 0.65 0.85 1.90 2.10 1.25 1.45 0.65 BSC 0.20 0.30 0.80 1.00 0.00 0.05
0.20 REF
0.70 0.65 0.25 RECOMMENDED LAND PATTERN 1.90 PIN 1 ID SEE DETAIL A 1.40 0.70 PIN 1 ID OPTION A 0.30x45º TYP. PIN 1 ID OPTION B R0.20 TYP. DETAIL A 0.30 0.40 PIN 1 ID INDEX AREA