MP9942AGJ-Z

MP9942A The Future of Analog IC Technology High Efficiency 2A, 36V, 410kHz Synchronous Step-Down Converter with Power Good DESCRIPTION FEATURES The MP9942A 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 MP9942A 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 MP9942A requires a minimal number of readily-available standard external components, and is available in a space-saving 8-pin TSOT23 package. Wide 4V to 30V Continuous Operating Input Range 36V Input Transient Tolerance 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 Force CCM 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, halogen 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 VIN C1 22 F EN/SYNC BST IN R4 20 C4 100nF L1 MP9942A EN/SYNC SW PG C6 0.1 F VCC 10 H R9 51k GND R1 41.2k 3.3V/2A C2 47 F VOUT FB R2 13k MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 1 MP9942A – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER ORDERING INFORMATION Part Number* MP9942AGJ Package TSOT23-8 Top Marking See Below * For Tape & Reel, add suffix –Z (e.g. MP9942AGJ–Z). TOP MARKING AQW: product code of MP9942AGJ; 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 MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 2 MP9942A – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance VIN .................................................. -0.3V to 40V VSW .................................................. -0.3V to 41V VBST ........................................................ 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 30V Output Voltage VOUT ..................0.8V to VIN*DMAX Operating Junction Temp. (TJ). -40°C to +125°C (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 12, 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. MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 3 MP9942A – 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) Under 40% Duty Cycle 3.5 5 7 A VFB=750mV VFB65%) or VIN is below 5V, and also help to avoid BST voltage insufficient. 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 6. Selecting the Output Capacitor The output capacitor (C2) maintains the DC output voltage. Use ceramic, tantalum, or lowESR electrolytic capacitors. For best results, use low ESR capacitors to keep the output voltage ripple low. The output voltage ripple can be estimated by: VOUT   VOUT  VOUT   1  1      RESR  fS  L1  VIN   8  fS  C2  MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 17 MP9942A – 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 6: 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 18. Bottom Layer Figure 7: Recommended PCB Layout MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 18 MP9942A – 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 8. 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. MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 19 MP9942A – 36V, 2A SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL APPLICATION CIRCUITS Figure 8: 12VIN, 3.3V/2A Output MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 20 MP9942A – 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. MP9942A Rev. 1.0 www.MonolithicPower.com 10/14/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2016 MPS. All Rights Reserved. 21