FAN5099MX

FAN5099MX Datasheet

FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller

Part	Datasheet
FAN5099MX	FAN5099MX (pdf)

Related Parts	Information
FAN5099MTCX	FAN5099MTCX
FAN5099M	FAN5099M

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FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller May 2008 FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller • General Purpose PWM Regulator and LDO Controller • Input Voltage Range 3V to 24V • Output Voltage Range 0.8V to 15V • VCC 5V Shunt Regulator for 12V Operation • Support for Ceramic Cap on PWM Output • Programmable Current Limit for PWM Output • Wide Programmable Switching Frequency Range 50kHz to 600kHz • RDS ON Current Sensing • Internal Synchronous Boot Diode • Soft-Start for both PWM and LDO • Multi-Fault Protection with Optional Auto-restart • 16-Pin TSSOP Package • High-Efficiency 80+ Computer Power Supplies • PC/Server Motherboard Peripherals VCC_MCH 1.5V , VDDQ 1.5V and VTT_GTL 1.25V • Power Supply for FPGA, DSP, Embedded Controllers, Graphic Card Processor, and Communication Processors • High-Power DC-to-DC Converters Related Application Notes • AN-6020 FAN5099 Component Calculation and Simulation Tools • AN-6005 Synchronous Buck MOSFET Loss Calculations with Excel Model The FAN5099 combines a high-efficiency pulse-width modulated PWM controller and an LDO low drop out linear regulator controller. The PWM controller is designed to operate over a wide frequency range 50kHz to 600kHz to accommodate a variety of applications. Synchronous rectification provides high efficiency over a wide range of load currents. Efficiency is further enhanced by using the low-side MOSFET’s RDS ON to sense current. In addition, the capability to operate at low switching frequencies provides opportunities to boost power supply efficiency by reducing switching losses and gain cost savings using low-cost materials, such as powdered iron cores, on the output inductor. Both the linear and PWM regulator soft-start are controlled by a single external capacitor, to limit in rush current from the supply when the regulators are first enabled. Current limit for PWM is also programmable. The FAN5099’s ability to handle wide input voltage ranges makes this controller suitable for power solutions in a wide range of applications involving conversion input voltages from Silver box, battery, and adapters. The PWM regulator employs a summing-current-mode control with external compensation to achieve fast load transient response and provide system design optimization. FAN5099 is offered in both industrial temperature grade -40°C to +85°C as well as commercial temperature grade -10°C to +85°C . Ordering Information Part Number Operating Temperature Range FAN5099MTCX -10°C to +85°C FAN5099EMTCX -40°C to +85°C FAN5099MX -10°C to +85°C FAN5099EMX -40°C to +85°C Package Packing Method 16-Lead TSSOP Tape and Reel 16-Lead TSSOP Tape and Reel 16-Lead SOIC Tape and Reel 16-Lead SOIC Tape and Reel Qty/Reel 2500 All standard Fairchild Semiconductor products are RoHS compliant and many are also “GREEN” or going green. For Fairchild’s definition of “green” please visit: Contact Fairchild sales for availability of other package options. FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller Figure Typical Application Diagram 2006 Fairchild Semiconductor Corporation FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller Pin Configuration Figure Pin Assignment Pin Description Pin No. Pin Name Pin Description FBLDO LDO Feedback. This node is regulated to VREF. Oscillator Set Resistor. This pin provides oscillator switching frequency adjustment. By placing a resistor RT from this pin to GND, the nominal 50kHz switching frequency is increased. ILIM Current Limit. A resistor from this pin to GND sets the current limit. Soft-Start. A capacitor from this pin to GND programs the slew rate of the converter and the LDO during initialization. It also sets the time by which the converter delays when restarting after a fault occurs. SS has to reach 1.2V before fault shutdown feature is enabled. The LDO is enabled when SS reaches 2.2V. COMP. The output of the error amplifier drives this pin. Feedback. This pin is the inverting input of the internal error amplifier. Use this pin, in combination with the COMP pin, to compensate the feedback loop of the converter. Enable. Enables operation when pulled to logic high. Toggling EN resets the regulator after a EN latched fault condition. This is a CMOS input whose state is indeterminate if left open and needs to be properly biased at all times. AGND Analog Ground. The signal ground for the IC. All internal control voltages are referred to this pin. Tie this pin to the ground island/plane through the lowest impedance connection available.

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FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller

May 2008

FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller
• General Purpose PWM Regulator and LDO Controller
• Input Voltage Range 3V to 24V
• Output Voltage Range 0.8V to 15V
• VCC
5V Shunt Regulator for 12V Operation
• Support for Ceramic Cap on PWM Output
• Programmable Current Limit for PWM Output
• Wide Programmable Switching Frequency Range 50kHz to 600kHz
• RDS ON Current Sensing
• Internal Synchronous Boot Diode
• Soft-Start for both PWM and LDO
• Multi-Fault Protection with Optional Auto-restart
• 16-Pin TSSOP Package
• High-Efficiency 80+ Computer Power Supplies
• PC/Server Motherboard Peripherals

VCC_MCH 1.5V , VDDQ 1.5V and VTT_GTL 1.25V
• Power Supply for FPGA, DSP, Embedded Controllers, Graphic Card Processor, and Communication Processors
• High-Power DC-to-DC Converters

Related Application Notes
• AN-6020 FAN5099 Component Calculation and Simulation Tools
• AN-6005 Synchronous Buck MOSFET Loss Calculations with Excel Model

The FAN5099 combines a high-efficiency pulse-width modulated PWM controller and an LDO low drop out linear regulator controller. The PWM controller is designed to operate over a wide frequency range 50kHz to 600kHz to accommodate a variety of applications. Synchronous rectification provides high efficiency over a wide range of load currents. Efficiency is further enhanced by using the low-side MOSFET’s RDS ON to sense current. In addition, the capability to operate at low switching frequencies provides opportunities to boost power supply efficiency by reducing switching losses and gain cost savings using low-cost materials, such as powdered iron cores, on the output inductor.

Both the linear and PWM regulator soft-start are controlled by a single external capacitor, to limit in rush current from the supply when the regulators are first enabled. Current limit for PWM is also programmable.

The FAN5099’s ability to handle wide input voltage ranges makes this controller suitable for power solutions in a wide range of applications involving conversion input voltages from Silver box, battery, and adapters. The PWM regulator employs a summing-current-mode control with external compensation to achieve fast load transient response and provide system design optimization.

FAN5099 is offered in both industrial temperature grade -40°C to +85°C as well as commercial temperature grade -10°C to +85°C .
Ordering Information

Part Number Operating Temperature Range

FAN5099MTCX
-10°C to +85°C

FAN5099EMTCX
-40°C to +85°C

FAN5099MX
-10°C to +85°C

FAN5099EMX
-40°C to +85°C

Package Packing Method
16-Lead TSSOP Tape and Reel
16-Lead TSSOP Tape and Reel
16-Lead SOIC

Tape and Reel
16-Lead SOIC Tape and Reel

Qty/Reel 2500

All standard Fairchild Semiconductor products are RoHS compliant and many are also “GREEN” or going green. For Fairchild’s definition of “green” please visit:

Contact Fairchild sales for availability of other package options.

FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller

Figure Typical Application Diagram
2006 Fairchild Semiconductor Corporation

FAN5099 Wide Frequency Synchronous Buck PWM & LDO Controller

Pin Configuration

Figure Pin Assignment

Pin Description

Pin No. Pin Name

Pin Description

FBLDO LDO Feedback. This node is regulated to VREF.

Oscillator Set Resistor. This pin provides oscillator switching frequency adjustment. By placing a resistor RT from this pin to GND, the nominal 50kHz switching frequency is increased.

ILIM Current Limit. A resistor from this pin to GND sets the current limit.

Soft-Start. A capacitor from this pin to GND programs the slew rate of the converter and the

LDO during initialization. It also sets the time by which the converter delays when restarting after a fault occurs. SS has to reach 1.2V before fault shutdown feature is enabled. The LDO
is enabled when SS reaches 2.2V.

COMP. The output of the error amplifier drives this pin.

Feedback. This pin is the inverting input of the internal error amplifier. Use this pin, in combination with the COMP pin, to compensate the feedback loop of the converter.

Enable. Enables operation when pulled to logic high. Toggling EN resets the regulator after a

EN latched fault condition. This is a CMOS input whose state is indeterminate if left open and
needs to be properly biased at all times.

AGND

Analog Ground. The signal ground for the IC. All internal control voltages are referred to this pin. Tie this pin to the ground island/plane through the lowest impedance connection available.

Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived FAN5099MX Datasheet file may be downloaded here without warranties.

Datasheet ID: FAN5099MX 513920