Dual Switch-Mode DDR Power Supply

Freescale Semiconductor Advance Information Document Number: MC34716 Rev. 3.0, 5/2007 1.0 MHz Dual Switch-Mode DDR Power Supply The 34716 is a highly integrated, space-efficient, low cost, dual synchronous buck switching regulator with integrated N-channel power MOSFETs. It is a high performance point-of-load (PoL) power supply with its second output having the ability to track an external reference voltage. it provides a full power supply solution for DoubleData-Rate (DDR) Memories. Channel one provides a source only 5.0 A drive capability, while channel two can sink and source up to 3.0 A. Both channels are highly efficient with tight output regulation. With its high current drive capability, channel one can be used to supply the VDDQ to the memory chipset. The second channel’s ability to track a reference voltage makes it ideal to provide the termination voltage (VTT) for modern data buses. The 34716 also provides a buffered output reference voltage (VREFOUT) to the memory chipset The 34716 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 Tracks 1/2 an External Reference Voltage • ±1 % Accurate Buffered Reference Output Voltage www.DataSheet4U.com • Programmable Switching Frequency Range from 200 kHz to 1.0 MHz • Programmable Soft Start Timing for Channel One • Over Current Limit and Short Circuit Protection on Both Channels • Thermal Shutdown • Output Overvoltage and Undervoltage Detection • Active Low Power Good Output Signal • Active Low Standby and Shutdown Inputs • Pb-Free Packaging Designated by Suffix Code EP. 34716 3.0V to 6.0V VIN 34716 DUAL SWITCH-MODE DDR POWER SUPPLY EP SUFFIX 98ASA10728D 26-PIN QFN ORDERING INFORMATION Device MC34716EP/R2 Temperature Range (TA) -40 to 85°C Package 26 QFN VIN VDDQ PVIN1 BOOT1 SW1 VOUT1 INV1 COMP1 PGND1 VDDI FREQ ILIM1 GND PVIN2 VREFIN BOOT2 SW2 VOUT2 INV2 COMP2 VREFOUT PGND2 PG STBY SD VIN VDDQ VTT VDDQ Termination Resistors DDR Memory Controller DDR Memory Chipset VREF Memory Bus MCU Figure 1. 34716 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 STBY PG M1 System Reset SD Thermal Monitoring System Control Discharge VBG ILIM2 Bandgap Regulator VDDI Internal Voltage Regulator VIN FREQ Oscillator Buck Control Logic ISENSE2 ISENSE1 Current Monitoring ILIM1 ILIM1 BOOT1 PVIN1 M4 SW1 M5 PGND1 COMP1 ISENSE M2 VIN M3 VIN M6 BOOT2 PVIN2 Gate Driver FSW FSW Gate I Driver SENSE M7 SW2 INV1 VOUT1 M8 VBG M9 Discharge Discharge CHANNEL 1 M10 Discharge CHANNEL 2 + VREFIN GND VREFOUT Figure 2. 34716 Simplified Internal Block Diagram 34716 – 2 – – + Error Amplifier – Error Amplifier PWM Comparator Ramp Generator PWM Comparator Ramp Generator + PGND2 COMP2 – + + INV2 VOUT2 Analog Integrated Circuit Device Data Freescale Semiconductor PIN CONNECTIONS PIN CONNECTIONS FREQ STBY 26 25 24 23 22 21 20 19 BOOT1 1 PVIN1 2 PVIN1 SW1 3 SW1 PGND1 4 PGND1 VOUT1 5 6 INV1 7 COMP1 8 VREFIN 9 VREFOUT 10 PG 11 12 13 COMP2 INV2 SD 15 PGND2 14 VOUT2 Transparent Top View 16 SW2 PGND2 17 PVIN2 SW2 18 BOOT2 PVIN2 Figure 3. 34716 Pin Connections Table 1. 34716 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 10 11 12 13 Pin Name BOOT1 PVIN1 SW1 PGND1 VOUT1 INV1 COMP1 VREFIN VREFOUT PG SD COMP2 INV2 Pin Function Passive Supply Input/Output Ground Input Input Input Input Output 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 Reference Voltage Output Power Good Output Signal Shutdown Input Buck Convertor Compensation Input Error Amplifier Inverting Input 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 This is a buffered reference voltage output 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 ILIM1 VDDI GND VIN VIN NC 34716 Analog Integrated Circuit Device Data Freescale Semiconductor 3 PIN CONNECTIONS Table 1. 34716 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 26 Pin Name VOUT2 PGND2 SW2 PVIN2 BOOT2 ILIM1 NC FREQ VIN GND VDDI STBY Pin Function Output Ground Input/Output Power Input Input None Input Power Ground Output Input Formal Name Output Voltage Discharge Path Power Ground Switching Node Power Input Voltage Bootstrap Input Soft Start Adjustment Input No Connect Frequency Adjustment Input Input Supply Voltage Signal Ground Internal Supply Voltage Standby Input 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 No internal connections to this pin The buck converters switching frequency adjustment input Power supply voltage of the IC Analog ground of the IC Internal Supply Voltage Output Standby mode input control pin 34716 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, SD, and STBY Pins VDDI, FREQ, ILIM1, INV1, INV2, COMP1, COMP2, VREFIN, and VREFOUT 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 (5), (6) Maximum Junction Temperature Power Dissipation (TA = 85 °C) (7) 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. TA TSTG TPPRT TJ(MAX) PD -40 to 85 -65 to +150 Note 6 +150 2.03 °C °C °C °C W VESD1 VESD3 ±2000 ±750 VIN PVIN VSW VBOOT - VSW - Symbol Value Unit -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 ±3.0 V V V V V V A A V IOUT1 IOUT2 7. 34716 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 RθJMA 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. 34716 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 param