MP9942GJ-Z

MP9942 The Future of Analog IC Technology High Efficiency 2A, 36V, 410kHz Synchronous Step-Down Converter with Power Good DESCRIPTION FEATURES The MP9942 is a high-frequency, synchronous, rectified, step-down, switch-mode converter with built-in power MOSFETs. It offers a very compact solution to achieve a 2A continuous output current with excellent load and line regulation over a wide input supply range. The MP9942 has synchronous mode operation for higher efficiency over the output current load range.  Current-mode operation provides fast transient response and eases loop stabilization.         Full protection features include over-current protection and thermal shutdown. The MP9942 requires a minimal number of readily-available standard external components, and is available in a space-saving 8-pin TSOT23 package.     Wide 4V to 36V Continuous Operating Input Range 90mΩ/55mΩ Low RDS(ON) Internal Power MOSFETs High-Efficiency Synchronous Mode Operation 410kHz Switching Frequency Synchronizes from 200kHz to 2.2MHz External Clock High Duty Cycle for Automotive Cold-crank Internal Power-Save Mode Internal Soft-Start Power Good Indicator Over-Current Protection with Hiccup Thermal Shutdown Output Adjustable from 0.8V Available in an 8-pin TSOT-23 package APPLICATIONS    Automotive Industrial Control System Distributed Power Systems 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 Registered Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION MP9942 Rev.1.1 8/7/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 1 MP9942 – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER ORDERING INFORMATION Part Number* MP9942GJ Package TSOT23-8 Top Marking See Below * For Tape & Reel, add suffix –Z (e.g. MP9942GJ–Z); TOP MARKING ALL: product code of MP9942GJ; Y: year code; PACKAGE REFERENCE TOP VIEW PG 1 8 FB IN 2 7 VCC SW 3 6 EN/SYNC GND 4 5 BST TSOT23-8 MP9942 Rev.1.1 8/7/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 2 MP9942 – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance VIN .................................................. -0.3V to 40V VSW .................................................. -0.3V to 41V VBS ......................................................... VSW+6V All Other Pins ................................ -0.3V to 6V (2) (3) Continuous Power Dissipation (TA = +25°C) TSOT23-8 ................................................ 1.25W Junction Temperature ...............................150°C Lead Temperature ....................................260°C Storage Temperature ................. -65°C to 150°C TSOT23-8 .............................. 100 ..... 55... °C/W Recommended Operating Conditions (4) Continuous Supply Voltage VIN ........... 4V to 36V Output Voltage VOUT ..................0.8V to VIN*DMAX Operating Junction Temp. (TJ). -40°C to +125°C MP9942 Rev.1.1 8/7/2017 (5) θJA θJC Notes: 1) Absolute maximum ratings are rated under room temperature unless otherwise noted. Exceeding these ratings may damage the device. 2) About the details of EN pin’s ABS MAX rating, please refer to page 14, Enable/SYNC control section. 3) 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. 4) The device is not guaranteed to function outside of its operating conditions. 5) Measured on JESD51-7, 4-layer PCB. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 3 MP9942 – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS VIN = 12V, TJ = +25°C, unless otherwise noted. Parameter Symbol Supply Current (Shutdown) ISHDN Supply Current (Quiescent) IQ HS Switch-ON Resistance Condition Min Typ VEN = 0V Max Units 8 μA VEN = 2V, VFB = 1V 0.5 0.7 mA RON_HS VBST-SW=5V 90 155 mΩ LS Switch-ON Resistance RON_LS VCC =5V 55 105 mΩ Switch Leakage ILKG_SW VEN = 0V, VSW =12V 1 μA Current Limit ILIMIT Oscillator Frequency Fold-Back Frequency fSW fFB Maximum Duty Cycle DMAX Minimum ON Time(6) tON_MIN Under 40% Duty Cycle 3 4.2 5.5 A VFB=750mV VFB65%) or VIN is below 5V, and also help to avoid BST voltage insufficient at light load PFM operation. A power supply between 3.3V and 5V can be used to power the external bootstrap diode and VCC or VOUT is the good choice of this power supply in the circuit as shown in Figure 7. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 17 MP9942 – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER C3 R1 GND C4 SW R5 PCB Layout (8) PCB layout, especially the input capacitor and VCC capacitor placement, is very important to achieve stable operation. For the best results, follow these guidelines: R9 6 5 4 7 3 2 R4 L1 C8 C1 Figure 7: Optional External Bootstrap Diode to Enhance Efficiency The recommended external BST diode is 1N4148, and the BST capacitor value is 0.1µF to 1μF. 8 R7 1 R2 C6 Vin C2 Vout GND Top Layer 1) Place the ceramics input capacitor as close to IN and GND pins as possible, especially the small package size (0603) input bypass capacitor. Keep the connection of input capacitor and IN pin as short and wide as possible. 2) Place the VCC capacitor to VCC pin and GND pin as close as possible. Make the trace length of VCC pin-VCC capacitor anode-VCC capacitor cathode-chip GND pin as short as possible. 3) Use large ground plane directly connect to GND pin. Add vias near the GND pin if bottom layer is ground plane. 4) Route SW, BST away from sensitive analog areas such as FB. 5) Place the T-type feedback resistor close to chip to ensure the trace which connects to FB pin as the short as possible. Notes: 8) The recommended layout is based on the typical application circuit in Page 20. MP9942 Rev.1.1 8/7/2017 Bottom Layer Figure 8: Recommended PCB Layout www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 18 MP9942 – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER Design Example Below is a design example following the application guidelines for the specifications: Table 2—Design Example VIN VOUT IO 12V 3.3V 2A The detailed application schematic is shown in Figure 9. The typical performance and circuit waveforms have been shown in the Typical Performance Characteristics section. For more device applications, please refer to the related Evaluation Board Datasheets. MP9942 Rev.1.1 8/7/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 19 MP9942 – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL APPLICATION CIRCUITS Figure 9: 12VIN, 3.3V/2A Output MP9942 Rev.1.1 8/7/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 20 MP9942 – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER PACKAGE INFORMATION TSOT23-8 See note 7 EXAMPLE TOP MARK PIN 1 ID 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) JEDEC REFERENCE IS MO-193, VARIATION BA. 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. MP9942 Rev.1.1 8/7/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 21