Product Presentation. Synchronous Buck H-Bridge H (Hi-Side) Driver MCP14628

Transcription

1 Product Presentation Synchronous Buck H-Bridge H (Hi-Side) Driver MCP14628 April Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 1 Hello and welcome to the Microchip Technology WebSeminar overview of the recently introduced MCP14628 Synchronous Buck H-Bridge MOSFET Driver. My name is Ray DiSilvestro and I am a Product Marketing Engineer within Microchip s Technology Analog division. 1

2 Analog & Interface Product Portfolio: THERMAL MANAGEMENT POWER MANAGEMENT MIXED SIGNAL INTERFACE Temperature Sensors Linear Regulators Delta-Sigma/SAR A/D Converters CAN Peripherals Brushless DC Fan Speed Controllers Fan Fault Detectors Switching Regulators/Controllers Energy Measurement ICs Infrared Peripherals LINEAR Single-Supply CMOS Op Amps Charge Pump DC/DC Converters Voltage References CPU/System Supervisors Dual Slope A/D Converters Display A/D Converters System D/A Converters LIN Transceivers Serial Peripherals Ethernet Controller Comparators Linear Integrated Devices Voltage Detectors Power MOSFET Drivers V/F and F/V Converters Digital Potentiometers Passive Access AFE Programmable-/ Selectable-Gain Amps Battery Management PWM Controller MCP14628 NEW 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 2 Shown here in Slide 1 is the Analog and Interface Product Portfolio. The MCP14628 is contained in the Power Management section within the MOSFET Driver Category. The MCP14628 is Microchip s first Hi-Side Synchronous Buck Driver. 2

3 MCP14628: 2A Synchronous Buck H-Bridge H driver What is it? The MCP14628 is a dual MOSFET gate Driver designed to optimally drive two N-channel MOSFETs arranged in a non-isolated synchronous buck converter topology. Buck Converters step down the Input voltage to the output Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 3 In Slide 2 - Sychronous Buck Drivers are used in DC to DC switching supplies to step down the input voltage to the output. The MCP14628 is a dual MOSFET gate driver designed to optimally drive two N-Channel MOSFETs arranged in a nonisolated synchronous buck converter topology. 3

4 Typical Application Circuit 5V 20V MCP14628 Drives Two External High Current N-Channel FETS BOOT VCC UG Q U V OUT PHASE Q L PWM LG MCP Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 4 Slide 3 - Shows the two external MOSFETs in a synchronous buck half bridge topology. With the capability to source 2A peaks typically from both the high-side and low-side drives, the MCP14628 is an ideal companion to buck controllers that lack integrated gate drivers. Additionally, greater design flexibility is offered by allowing the gate drivers to be placed close to the power MOSFETs. The UG pin (upper gate) provides the gate drive signal to control the highside power MOSFET. The gate of the high-side power MOSFET is connected to this pin. The LG pin (lower gate) provides the gate drive signal to control the low-side power MOSFET. The gate of the low-side power MOSFET is connected to this pin. The PWM control input signal is supplied to the PWM pin. This tri-state pin controls the state of the UG and LG pins. Placing a voltage equal to VCC/2 on this pin causes both the UG and LG to a low state. The BOOT pin is the floating bootstrap supply pin for the high-side gate drive. A capacitor is connected between this pin and the PHASE pin to provide the necessary charge to turn on the high-side power MOSFET. The PHASE pin provides the return path for the high side gate driver. The source of the high-side power MOSFET is connected to this pin. 4

5 Typical Application Schematic 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 5 Slide 4 - Shows a typical application schematic. Here the MCP1630 PWM controller is used to supply the PWM input to the MCP14628 Sychronous Buck Driver. 5

6 Where used? MCP14628: 2A Synchronous Buck Hi-Side driver Power conversion applications that require: High Output Current: High Current Low Output Voltage Synchronous DC/DC Buck Converters (>10Amps) High-voltage: High Input Voltage Synchronous Buck converters Application examples DC-to-DC converters Core Voltage Supplies for Microprocessors 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 6 Slide 5 - Describes where it is used? Sychronous Buck drivers are used in DC to DC switching supplies where high outputs current(>10a) are required. Synchronous Buck drivers are also used where high input voltage (typically 12 volts to 36 volts) needs to be stepped down to a lower output voltage also capable of having a high output current. Typical applications are DC to DC power converters that are used in laptops and servers. 6

7 MCP14628 Features Overview Synchronous buck topology (Drives both a high-side N-channel and a low-side N-channel MOSFET) Provides adaptive cross conduction protection Internal bootstrap blocking device Diode emulation mode to improve system light load efficiency 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 7 Slide 6 - Provides a Features overview of the MCP The Synchrous buck topology In a Half bridge configuration drives both a high-side N-channel and a low-side N-channel MOSFET. Internal adaptive cross conduction protection circuitry is also used to mitigate both external power MOSFETs from simultaneously conducting. Bootstrapping for the high-side drive is internally implemented which allows for a reduced system cost and design complexity. Light load system efficiency is improved by using the diode emulation feature of the MCP

8 Forced Continuous Conduction Mode Operation With FCCM pin grounded, Diode emulation is allowed. The zero crossing of the inductor is sensed. Lower MOSFET turned off until next switching cycle. Improved low load efficiency 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 8 In Slide 7 - Light load system efficiency is improved by using the diode emulation feature of the MCP When the FCCM pin is grounded, diode emulating mode is entered. In this mode, discontinuous conduction is allowed by sensing when the inductor current reach zero and turning off the low-side power MOSFET. The FCCM pin enables or disables the forced continuous conduction mode. With the FCCM pin connected to ground the MCP14628 enters a diode emulation mode to improve system efficiency at light loads. Continuous conduction is forced if the FCCM pin is connected to VCC. 8

9 MCP14628: Key Features Low output resistance allows quick transition of 3300 pf load in typically 8 ns and a propagation time of typically 20 ns Capable of sinking 3.5A peak for low-side gate drive - This allows holding off the low-side power MOSFET during rising edge of the Phase node Available in small 3X3 DFN and standard 8-lead SOIC packages Meets needs of both cutting-edge compact designs and traditional developments 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 9 Slide 8 - Outlines how the low resistance pull-up and pull-down drives allow the MCP14628 to quickly transition a 3300 pf load in typically 8 ns and with a propagation time of typically 20 ns. The MCP14628 features the capability to sink 3.5A peak typically for the low-side gate drive. This allows the MCP14628 the capability of holding off the low-side power MOSFET during the rising edge of the PHASE node. 9

10 MCP14628: Key Features PWM input to the MCP14628 can be tri-stated to force both drive outputs low for true power stage shutdown Light load system efficiency is improved by using the diode emulation feature of the MCP14628 Bootstrapping for the high-side drive is internally implemented which allows for a reduced system cost and design complexity 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 10 Slide 9 - The PWM input to the MCP14628 can be tri-stated to force both drive outputs low for true power stage shutdown. Light load system efficiency is improved by using the diode emulation feature of the MCP The BOOT pin is the floating bootstrap supply pin for the highside gate drive. A capacitor is connected between this pin and the PHASE pin to provide the necessary charge to turn on the highside power MOSFET. Bootstrapping for the high-side drive is internally implemented which allows for a reduced system cost and design complexity. 10

11 Unique Strengths MCP14628 Small, 3X3 DFN: Smaller board space Leadless packages have very low-profile and occupy smaller board space 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 11 Slide 10 - Shows that MCP14628 is also available in a 3X3 leadless DFN package, which has a very low profile and occupied smaller board space. 11

12 MCP14628 Typical Applications Core Voltage Supplies for Microprocessors DC/DC Converters High current, low output voltage High input voltage Motor Drive Applications 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 12 Slide 11- Shows typical applications. Applications include Power supplies for servers and laptop. DC to DC converter application where high current and high voltage is needed, and Motor Driver applications. 12

13 Part Type (MCP14628): MCP14628 Part Numbering MCP14628T-E/MF Packages: MF = 8-ld 8 3X3 DFN SN = 8-ld 8 SOIC T&R Temp: E = -40C to +85C 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 13 Slide 12 - Shows MCP part numbering. As shown a T after the part number implies tape and reel. After the dash an E defines the temperature range from -40 degree C to +85 degree C. The last to letters are used to define the package type. Both SOIC-8L and 3X3 DFN-8L are available. 13

14 Packages 8 Lead SOIC 8 Lead 3X3 DFN Package Options, Pricing & Availability Pricing - $ $1.33 each in 10,000-unit Samples available today at: Volume production available today at: Datasheet DS22083A 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 14 Slide 13 - The MCP14628 is available in both a SOIC 8 lead and a 3x3 DFN 8 lead package. Pricing in 10K quantity is $1.17 and $1.33 respectively. Sample are currently available at sample.microchip.com or at microchipdirect.com. The Datasheet can be downloaded for web page. 14

15 Thank You 2008 Microchip Technology Incorporated. All Rights Reserved. Synchronous Buck H-Bridge (Hi-Side) Driver Slide 15 Slide 14 - Thank You 15