Dual Switch-Mode Power Supply

Freescale Semiconductor Advance Information Document Number: MC34717 Rev. 3.0, 5/2007 5.0 A 1.0 MHz Fully Integrated Dual Switch-Mode Power Supply The 34717 is a highly integrated, space-efficient, low cost, dual synchronous buck switching regulator with integrated N-channel power MOSFETs. It is a high performance dual point-of-load (PoL) power supply with many desired features for the 3.3 V and 5.0 V environments. Both channels can provide up to 5.0 A of continuous output current capability with high efficiency and tight output regulation. The second channel has the ability to track an external reference voltage in different configurations. The 34717 offers the designer the flexibility of many control, supervisory, and protection functions to allow for easy implementation of complex designs. It is housed in a Pb-Free, thermally enhanced, and space efficient 26-Pin Exposed Pad QFN. Features • 50 mΩ Integrated N-Channel Power MOSFETs • Input Voltage Operating Range from 3.0 V to 6.0 V • ±1 % Accurate Output Voltages, Ranging from 0.7 V to 3.6 V • The Second Output Has Voltage Tracking Capability in Different Configurations • Programmable Switching Frequency Range from 200 kHz to 1.0 MHz • Programmable Soft Start Timing www.DataSheet4U.com • Over Current Limit and Short Circuit Protection • Thermal Shutdown • Output Overvoltage and Undervoltage Detection • Active Low Power Good Output Signal • Active Low Shutdown Input • Pb-Free Packaging Designated by Suffix Code EP. 3.0 V TO 6.0 V VIN 34717 DUAL SWITCH-MODE POWER SUPPLY EP SUFFIX (PB_FREE) 98ASA10728D 26-PIN QFN ORDERING INFORMATION Device MC34717EP/R2 Temperature Range (TA) -40 to 85°C Package 26 QFN 34717 VIN PVIN1 BOOT1 PVIN2 BOOT2 SW2 VOUT2 INV2 VIN VOUT1 VOUT2 VOUT1 SW1 VOUT1 INV1 MCU COMP1 COMP2 PGND1 PGND2 VDDI PG FREQ SD ILIM1 ILIM2 GND VREFIN VMASTER Optional Figure 1. 34717 Simplified Application Diagram * This document contains certain information on a new product. Specifications and information herein are subject to change without notice. © Freescale Semiconductor, Inc., 2007. All rights reserved. INTERNAL BLOCK DIAGRAM INTERNAL BLOCK DIAGRAM SD PG M1 System Reset System Control Buck Control Logic ILIM2 Current Monitoring ILIM1 Thermal Monitoring VBG Bandgap Regulator VDDI FREQ Oscillator FSW ISENSE2 ISENSE1 ILIM1 BOOT1 PVIN1 M4 SW1 M5 PGND1 COMP1 ISENSE Discharge Internal Voltage Regulator VIN ILIM2 M3 VIN M6 BOOT2 PVIN2 M2 VIN Gate Driver FSW FSW Gate I Driver SENSE M7 SW2 INV1 VOUT1 M8 VBG Discharge Reference Selection VBG M9 Discharge GND CHANNEL 1 CHANNEL 2 Figure 2. 34717 Simplified Internal Block Diagram 34717 2 – – + Error Amplifier – Error Amplifier PWM Comparator Ramp Generator PWM Comparator Ramp Generator + PGND2 COMP2 – + + INV2 VOUT2 VREFIN Analog Integrated Circuit Device Data Freescale Semiconductor PIN CONNECTIONS PIN CONNECTIONS FREQ ILIM2 26 25 24 23 22 21 20 19 BOOT1 PVIN1 2 PVIN1 SW1 3 SW1 PGND1 4 PGND1 VOUT1 5 6 INV1 7 COMP1 8 VREFIN 9 NC 10 PG 11 12 13 COMP2 INV2 SD 15 PGND2 14 VOUT2 Transparent Top View 16 SW2 PGND2 17 PVIN2 SW2 1 18 BOOT2 PVIN2 Figure 3. 34717 Pin Connections Table 1. 34717 Pin Definitions A functional description of each pin can be found in the Functional Pin Description section beginning on page 11. Pin Number 1 2 3 4 5 6 7 8 9, 26 10 11 12 13 Pin Name BOOT1 PVIN1 SW1 PGND1 VOUT1 INV1 COMP1 Pin Function Passive Supply Input/Output Ground Input Input Input Input None Output Input Input Input Formal Name Bootstrap Power Input Voltage Switching Node Power Ground Output Voltage Discharge Path Error Amplifier Inverting Input Buck Convertor Compensation Input Reference Voltage Input No Connect Power Good Output Signal Shutdown Input Buck Convertor Compensation Input Error Amplifier Inverting Input ILIM1 VDDI GND VIN VIN NC Definition Channel 1 Bootstrap capacitor input pin Channel 1 Buck converter power input Channel 1 Buck converter switching node Channel 1 Buck converter and discharge MOSFETs power ground Channel 1 Buck converter output voltage discharge pin Channel 1 Buck converter error amplifier inverting input Channel 1 Buck converter external compensation network input Voltage tracking reference voltage input No internal connections to this pin. Recommend attaching a 0.1 µF capacitor to GND. It is an active low open drain power good status reporting output Shutdown mode input control pin Channel 2 Buck converter external compensation network input Channel 2 Buck converter error amplifier inverting input VREFIN NC PG SD COMP2 INV2 34717 Analog Integrated Circuit Device Data Freescale Semiconductor 3 PIN CONNECTIONS Table 1. 34717 Pin Definitions (continued) A functional description of each pin can be found in the Functional Pin Description section beginning on page 11. Pin Number 14 15 16 17 18 19 20 21 22,23 24 25 Pin Name VOUT2 PGND2 SW2 PVIN2 BOOT2 ILIM1 ILIM2 FREQ VIN Pin Function Output Ground Input/Output Power Input Input Input Input Power Ground Output Formal Name Output Voltage Discharge Path Power Ground Switching Node Power Input Voltage Bootstrap Input Soft Start Adjustment Input CH 1 Soft Start Adjustment Input CH 2 Frequency Adjustment Input Input Supply Voltage Signal Ground Internal Supply Voltage Definition Channel 2 Buck converter output voltage discharge pin Channel 2 Buck converter and discharge MOSFETs power ground Channel 2 Buck converter switching node Channel 2 Buck converter power input Channel 2 Bootstrap capacitor input pin Channel 1 soft start adjustment Channel 2 soft start adjustment The buck converters switching frequency adjustment input Power supply voltage of the IC Analog ground of the IC Internal Supply Voltage Output GND VDDI 34717 4 Analog Integrated Circuit Device Data Freescale Semiconductor ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS Table 2. Maximum Ratings All voltages are with respect to ground unless otherwise noted. Exceeding these ratings may cause a malfunction or permanent damage to the device. Ratings ELECTRICAL RATINGS Input Supply Voltage (VIN) Pin High-Side MOSFET Drain Voltage (PVIN1, PVIN2) Pins Switching Node (SW1, SW2) Pins BOOT1, BOOT2 Pins (Referenced to SW1, SW2 Pins Respectively) PG, VOUT1, VOUT2, and SD Pins VDDI, FREQ, ILIM1, ILIM2, INV1, INV2, COMP1, COMP2, and VREFIN Pins Channel 1 Continuous Output Current (1) Channel 2 Continuous Output Current (1) ESD Voltage (2) Human Body Model (3) Charge Device Model THERMAL RATINGS Operating Ambient Temperature (4) Storage Temperature Peak Package Reflow Temperature During Reflow Maximum Junction Temperature Power Dissipation (TA = 85 °C) (7) (5) (6) Symbol Value Unit VIN PVIN VSW VBOOT - VSW IOUT1 IOUT2 -0.3 to 7.0 -0.3 to 7.0 -0.3 to 7.5 -0.3 to 7.5 -0.3 to 7.0 -0.3 to 3.0 +5.0 +5.0 V V V V V V A A VESD1 VESD3 ±2000 ±750 V TA TSTG , TPPRT TJ(MAX) PD -40 to 85 -65 to +150 Note 6 +150 2.03 °C °C °C °C W Notes 1. Continuous output current capability so long as TJ is ≤ TJ(MAX). 2. 3. 4. 5. 6. ESD testing is performed in accordance with the Human Body Model (HBM) (CZAP = 100 pF, RZAP = 1500 Ω) and the Charge Device Model (CDM). SW1 pin complies with ±1000V Human Body Model. The limiting factor is junction temperature, taking into account power dissipation, thermal resistance, and heatsinking. Pin soldering temperature limit is for 10 seconds maximum duration. Not designed for immersion soldering. Exceeding these limits may cause malfunction or permanent damage to the device. Freescale’s Package Reflow capability meets Pb-free requirements for JEDEC standard J-STD-020C. For Peak Package Reflow Temperature and Moisture Sensitivity Levels (MSL), Go to www.freescale.com, search by part number [e.g. remove prefixes/suffixes and enter the core ID to view all orderable parts. (i.e. MC33xxxD enter 33xxx), and review parametrics. Maximum power dissipation at indicated ambient temperature. 7. 34717 Analog Integrated Circuit Device Data Freescale Semiconductor 5 ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS Table 2. Maximum Ratings (continued) All voltages are with respect to ground unless otherwise noted. Exceeding these ratings may cause a malfunction or permanent damage to the device. Ratings THERMAL RESISTANCE (8) Thermal Resistance, Junction to Ambient, Single-Layer Board (1s) (9) Thermal Resistance, Junction to Ambient, Four-Layer Board (2s2p) Thermal Resistance, Junction to Board (11) (10) Symbol Value Unit RθJA RqJMA RqJB 93 32 13.6 °C/W °C/W °C/W Notes 8. The PVIN, SW, and PGND pins comprise the main heat conduction paths. 9. Per SEMI G38-87 and JEDEC JESD51-2 with the single-layer board (JESD51-3) horizontal. 10. Per JEDEC JESD51-6 with the board (JESD51-7) horizontal. There are thermal vias connecting the package to the two planes in the board. (per JESD51-5) 11. Thermal resistance between the device and the printed circuit board per JEDEC JESD51-8. Board temperature is measured on the top surface of the board near the package. 34717 6 Analog Integrated Circuit Device Data Freescale Semiconductor ELECTRICAL CHARACTERISTICS STATIC ELECTRICAL CHARACTERISTICS STATIC ELECTRICAL CHARACTERISTICS Table 3. Static Electrical Characteristics Characteristics noted under conditions 3.0 V ≤ VIN ≤ 6.0 V, - 40°C ≤ TA ≤ 85°C, GND = 0 V unless otherwise noted. Typical values noted reflect the approximate parameter means at TA = 25°C under nominal conditions unless otherwise noted. Characteristic IC INPUT SUPPLY VOLTAGE (VIN) Input Supply Voltage Operating Range Input DC Supply Current (12) (Normal Mode: SD = 1, Unloaded Outputs) Input DC Supply Current (12) (Shutdown Mode, SD = 0) INTERNAL SUPPLY VOLTAGE OUTPUT (VDDI) Internal Supply Voltage Range VDDI 2.35 2.5 2.65 V IINOFF 100 µA IIN 35 mA VIN 3.0 6.0 V Symbol Min Typ Max Unit CHANNEL 1 BUCK CONVERTER (PVIN1, SW1, PGND1, BOOT1, INV1, COMP1, ILIM1)