MPQ2456GJ-P

MPQ2456 0.5A, 50V, 1.2MHz Step-Down Converter in a TSOT23-6 The Future of Analog IC Technology DESCRIPTION FEATURES The MPQ2456 is a monolithic, step-down, switch-mode converter with a built-in power MOSFET. It achieves 0.5A of peak output current over a wide input supply range with excellent load and line regulation. • • • • Current-mode operation provides fast transient response and eases loop stabilization. Full protection features include cycle-by-cycle current limiting and thermal shutdown. • • • • • The MPQ2456 requires a minimal number of readily available, external components and is available in a TSOT23-6 package. • • • 0.5A Peak Output Current 1Ω Internal Power MOSFET Capable of Starting Up with a Large Output Capacitor Stable with Low ESR Ceramic Output Capacitors Up to 90% Efficiency 0.1μA Shutdown Mode Fixed 1.2MHz Frequency Thermal Shutdown Cycle-by-Cycle Over-Current Protection (OCP) Wide 4.5V to 50V Operating Input Range Output Adjustable from 0.81V to 0.9 x VIN Available in a TSOT23-6 Package APPLICATIONS • • • • • Power Meters Distributed Power Systems Battery Chargers Pre-Regulator for Linear Regulators WLED Drivers 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 5 V IN BST 1 IN C2 100n F M P Q2456 C1 4 .7 µF GND U1 SW L1 10 µH 6 D1 EN MPQ2456 Rev.1.0 2/16/2016 4 EN GND 2 FB 3 R1 2 3 .7 k R2 124k 5V C3 1 0 µF VOUT GND www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 1 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 ORDERING INFORMATION Part Number* Package Top Marking MPQ2456GJ TSOT23-6 See Below * For Tape & Reel, add suffix –Z (e.g. MPQ2456GJ–Z) TOP MARKING AGV: Product code of MPQ2456GJ Y: Year code PACKAGE REFERENCE TOP VIEW BST 1 6 SW GND 2 5 IN FB 3 4 EN TSOT23-6 ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply voltage (VIN) .................... …-0.3V to 52V VSW ....................................... −0.3V to VIN + 0.3V VBS ....................................................... VSW + 6V All other pins ...................................-0.3V to +6V EN sink current ........................................ 100μA (2) Continuous power dissipation (TA = +25°C) TSOT23-6 .............................................. 0.568W Junction temperature ................................150°C Lead temperature .....................................260°C Storage temperature ................ -65°C to +150°C TSOT23-6..............................220.....110....°C/W Recommended Operating Conditions (3) Supply voltage (VIN) .........................4.5V to 50V Output voltage (VOUT)..............0.81V to 0.9 x VIN Operating junction temp........... -40°C to +125°C MPQ2456 Rev.1.0 2/16/2016 (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 function is not guaranteed outside of the recommended operating conditions. 4) Measured on JESD51-7, 4-layer PCB. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 2 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 ELECTRICAL CHARACTERISTICS VIN = 12V, TJ = -40°C to +125°C, unless otherwise noted. Typical values are TJ = +25°C. Parameters Symbol Condition Feedback voltage VFB Feedback current IFB Switch-on resistance RDS(ON) Switch leakage ISW_LKG TJ = +25°C 0.792 0.812 0.832 TJ = -40°C to +125°C 0.787 0.837 0.1 VEN = 0V, VSW = 0V Oscillator frequency fSW Foldback frequency fSW_F VFB = 0V Maximum duty cycle DMAX VFB = 0.4V Under-voltage lockout threshold rising Under-voltage lockout threshold falling Under-voltage lockout threshold hysteresis Max 1 ILIM Minimum on time Typ VFB = 0.85V Current limit (5) Min VFB = 0.6V 1.0 TJ = -40°C to +125°C 0.9 TJ = +25°C 0.95 TJ = -40°C to +125°C 0.85 89 τON 1.25 1.5 1.7 1.2 V μA Ω 1 TJ = +25°C Units 1.45 1.45 μA A MHz 200 kHz 91 % 50 ns VUVLO_R 2.9 3.3 3.7 V VUVLO_F 2.65 3.05 3.45 V 250 VUVLO_HYS mV EN threshold rising VEN_R 1.2 1.35 1.5 V EN threshold falling VEN_F 1 1.17 1.35 V EN threshold hysteresis VEN_HYS 3.1 VEN = 0V 0.1 IS VEN = 0V 0.1 1.0 IQ VEN = 2V, VFB = 1V 0.73 0.85 IEN Supply current (shutdown) Supply current (quiescent) Thermal shutdown hysteresis(5) mV VEN = 2V EN input current Thermal shutdown(5) 180 TJ = +25°C TJ = -40°C to +125°C μA 1.0 μA mA TSD 165 °C TSD_HYS 20 °C NOTE: 5) Derived from bench characterization. Not tested in production. MPQ2456 Rev.1.0 2/16/2016 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 3 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 TYPICAL CHARACTERISTICS VIN = 12V, unless otherwise noted. MPQ2456 Rev.1.0 2/16/2016 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 4 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 12V, VOUT = 5V, L = 10μH, TA = 25°C, unless otherwise noted. Efficiency vs. Load Line Regulation VOUT=12V, L=33μH LOAD CURRENT ( mA ) 100 90 80 70 60 50 40 30 20 10 0 0.06 VIN=16V VIN=50V VIN=36V VIN=24V 1 10 100 LOAD CURRENT ( mA ) 1000 LINE REGULATION ( % ) 100 VIN=8V 90 80 VIN=12V 70 VIN=50V 60 V =36V 50 IN 40 VIN=24V 30 20 10 0 1 10 100 1000 EFFICIENCY (%) EFFICIENCY (%) Efficiency vs. Load IOUT=500mA 0.04 0.02 0 -0.02 -0.04 -0.06 0 10 20 30 40 50 INPUT VOLTAGE ( V ) Load Regulation LOAD REGULATION ( % ) 0.3 0.2 VIN=50V 0.1 VIN=36V VIN=8V 0 VIN=12V -0.1 VIN=24V -0.2 -0.3 0 100 200 300 400 500 LOAD CURRENT ( mA ) MPQ2456 Rev.1.0 2/16/2016 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 5 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 5V, L = 10μH, TA = 25°C, unless otherwise noted. MPQ2456 Rev.1.0 2/16/2016 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 6 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VOUT = 5V, L = 10μH, TA = 25°C, unless otherwise noted. - MPQ2456 Rev.1.0 2/16/2016 - www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 7 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 PIN FUNCTIONS Pin # Name Description 1 BST 2 GND 3 FB 4 EN 5 IN 6 SW MPQ2456 Rev.1.0 2/16/2016 Bootstrap. Connect a capacitor between SW and BS to form a floating supply across the power switch driver. This capacitor drives the power switch’s gate above the supply voltage. Ground. GND is the voltage reference for the regulated output voltage. GND requires special consideration during layout. Isolate GND from the D1 to C1 ground path to prevent inducing switching current spikes. Feedback. FB sets the output voltage. Connect FB to the tap of an external resistor divider from output to GND. The frequency foldback comparator lowers the oscillator frequency when the FB voltage is below 250mV to prevent current-limit runaway during a short-circuit fault. On/off. Pull EN above 1.35V to turn the device on. For automatic enable, connect EN to VIN using a resistor. Ensure that the sink current of EN does not exceed 100μA. Supply voltage. The MPQ2456 operates from a 4.5V to 50V unregulated input. Requires C1 to prevent large voltage spikes from appearing at the input. Switch output. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 8 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 OPERATION The MPQ2456 is a current mode buck regulator, meaning the EA output voltage is proportional to the peak inductor current. At the beginning of a cycle, M1 is off. The EA output voltage is higher than the current sense amplifier output, and the current comparator’s output is low. The rising edge of the 1.2MHz CLK signal sets the RS flip-flop. Its output turns on M1, connecting SW and the inductor to the input supply. The increasing inductor current is sensed and amplified by the current sense amplifier. Ramp compensation is summed to the current sense amplifier output and compared to the error amplifier output by the PWM comparator. When the sum of the current sense amplifier output and the slope compensation signal exceed the EA output voltage, the RS flip-flop is reset and M1 is turned off. The external Schottky rectifier diode (D1) conducts the inductor current. If the sum of the current sense amplifier output and the slope compensation signal do not exceed the EA output for an entire cycle, then the falling edge of the CLK resets the flip-flop. MPQ2456 Rev.1.0 2/16/2016 The output of the error amplifier integrates the voltage difference between the feedback and the 0.81V bandgap reference. The polarity is such that a FB voltage lower than 0.81V increases the EA output voltage. Since the EA output voltage is proportional to the peak inductor current, an increase in its voltage also increases the current delivered to the output. The MPQ2456 has a 0.6ms internal soft start. The soft start prevents the converter output voltage from overshooting during start-up. When the chip starts up, the internal circuit generates a soft-start voltage (SS) that ramps up with a fixed rising rate. When the SS voltage is below the internal reference (REF), SS overrides REF, so the error amplifier uses SS as the reference. When SS exceeds REF, REF regains control. When there is an extremely large capacitor at the output (e.g. 2200µF or larger), the output voltage rises slower than SS because the current needed to charge up the large output capacitor is higher than the chip's max output current ability. The current limit is kicked during the entire start-up period until VOUT rises to its regulated value. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 9 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 Figure 1: Functional Block Diagram MPQ2456 Rev.1.0 2/16/2016 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 10 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 APPLICATION INFORMATION Setting the Output Voltage The external resistor divider sets the output voltage (see the Typical Application schematic). Table 1 lists resistors for common output voltages. The feedback resistor (R2) sets the feedback loop bandwidth with the internal compensation capacitor (see Figure 1). R1 can be calculated with Equation (1): R1 = R2 (1) VOUT −1 0.812V Table 1: Resistor Selection for Common Output Voltages VOUT (V) R1 (kΩ) R2 (kΩ) 1.8 2.5 3.3 5 12 102 (1%) 59 (1%) 40.2 (1%) 23.7 (1%) 8.2 (1%) 124 (1%) 124 (1%) 124 (1%) 124 (1%) 113 (1%) Selecting the Input Capacitor The input capacitor reduces the surge current drawn from the input supply and the switching noise from the device. The input capacitor impedance at the switching frequency should be less than the input source impedance to prevent high-frequency switching current from passing through the input. Ceramic capacitors with X5R or X7R dielectrics are recommended for their low ESR and small temperature coefficients. For most applications, a 4.7µF capacitor is sufficient. Selecting the Output Capacitor The output capacitor keeps the output voltage ripple small and ensures feedback loop stability. The output capacitor impedance should be low at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended for their low ESR characteristics. For most applications, a 22µF ceramic capacitor is sufficient. Selecting the Inductor For most applications, use an inductor with a DC current rating at least 25% higher than the maximum load current. For best efficiency, the inductor’s DC resistance should be less than 200mΩ. For most designs, the required inductance value can be derived from Equation (2): L= VOUT × ( VIN − VOUT ) VIN × ΔIL × f SW (2) Where ΔIL is the inductor ripple current. Choose the inductor ripple current to be 30% of the maximum load current. The maximum inductor peak current can be calculated with Equation (3): IL(MAX ) = ILOAD + ΔI L 2 (3) Under light-load conditions (below 100mA), use a larger inductance to improve efficiency. MPQ2456 Rev.1.0 2/16/2016 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 11 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 PCB Layout Guide Efficient PCB layout is critical for stable operation. For best results, refer to Figure 2 and follow the guidelines below. 1) Keep the path of the switching current short and minimize the loop area formed by the input capacitor, high-side MOSFET, and Schottky diode. 2) Keep the connection from the power ground to the Schottky diode to SW as short and wide as possible. 3) Ensure that all feedback connections are short and direct. 4) Place the feedback resistors and compensation components as close to the chip as possible. 5) Route SW away from sensitive analog areas, such as FB. 6) Connect IN, SW, and especially GND to large copper areas to cool the chip for improved thermal performance and longterm reliability. For single layer PCBs, avoid soldering the exposed pad. R2 External Bootstrap Diode An external bootstrap diode may enhance regulator efficiency under the following conditions: z VOUT = 5V or 3.3V z High duty cycle: D = VOUT > 65% VIN In these cases, add an external BST diode from the output of the voltage regulator to BST (see Figure 3). MPQ2456 Figure 3: Optional Bootstrap Diode for Enhanced Efficiency The recommended external BST diode is IN4148, and the recommended BST capacitor is 0.1µF - 1µF. R1 SGND C3 1 BST SW 6 EN 4 2 GND IN 5 3 FB R3 C1 L1 D1 C2 PGND Figure 2: PCB Layout MPQ2456 Rev. 1.0 www.MonolithicPower.com 2/16/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 12 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 TYPICAL APPLICATION CIRCUIT U1 V IN C1 4.7µF 50V 5 C2 0.1µF 50 V BST IN M P Q24 56 GND SW R5 500 k 4 EN EN FB GND R4 NS D2 NS 1 R6 0 L1 10 µH C3 100 nF 6 D1 D F LS 160 3 R2 124 k VOUT GND R1 23 .7 k 2 5V C5 10 µF 16 V R3 C4 0 47pF Figure 4: 5V Output Typical Application Circuit U1 V IN C1 4 .7 µF 50 V 5 C2 0.1µF 50 V BST IN M P Q2456 GND SW R5 500 k 4 EN R4 NS EN GND 2 FB 1 R6 0 L1 33 µH C3 100 nF 6 D1 D F LS 160 3 R1 8.2k 12V C5 22 µF 16 V R2 113 k VOUT GND R3 C4 0 47 pF Figure 5: 12V Output Typical Application Circuit MPQ2456 Rev.1.0 2/16/2016 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 13 MPQ2456 – 0.5A, 50V, 1.2MHz, STEP-DOWN CONVERTER IN A TSOT23-6 PACKAGE INFORMATION TSOT23-6 See note 7 EXAMPLE TOP MARK PIN 1 ID IAAAA RECOMMENDED LAND PATTERN TOP VIEW SEATING PLANE SEE DETAIL''A'' FRONT VIEW SIDE VIEW NOTE: DETAIL "A" 1) ALL DIMENSIONS ARE IN MILLIMETERS . 2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH , PROTRUSION OR GATE BURR. 3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSION 4) LEAD COPLANARITY(BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.10 MILLIMETERS MAX. 5) DRAWING CONFORMS TO JEDEC MO-193, VARIATION AB. 6) DRAWING IS NOT TO SCALE. 7) PIN 1 IS LOWER LEFT PIN WHEN READING TOP MARK FROM LEFT TO RIGHT (SEE EXAMPLE TOP MARK) 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. MPQ2456 Rev. 1.0 www.MonolithicPower.com 2/16/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 14