TinyBuck 6A 24V Input Integrated Synchronous Buck Regulator

FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator April 2007 FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator Features Over 95% efficiency Internal power MOSFETs: High-side RDS(ON) = 30mΩ Low-side RDS(ON) = 14mΩ Integrated low-side Schottky diode Programmable frequency operation Power-good signal Wide input range: 3.0V to 24V Output voltage range: 0.8V to 90%VIN Input under-voltage lockout (UVLO) Programmable over-current protection Selectable light-load power-saving mode 5x6mm, 25-pin, 3-pad MLP Description The FAN2106 TinyBuckTM is an easy-to-use, cost and space-efficient, synchronous buck solution. It enables designers to solve high current requirements in a small area with minimal external components. External programming of clock frequency, current limit, and loop response allows for optimization and flexibility selecting output filter components and transient response. The summing current mode modulator uses lossless current sensing for current feedback and over-current, and includes voltage feedforward. Fairchild’s advanced BiCMOS power process, combined with a thermally efficient MLP package, provides lowRDS(ON) internal MOSFETs and the ability to dissipate www.DataSheet4U.com high power in a small package. Under-voltage, thermal shutdown, and power-good are blanked at start-up, but protect the device from damage during fault conditions. Under-voltage, over-voltage, and thermal protection Applications Thin and light Notebook PCs Graphics cards Battery-powered equipment Set-top box Point-of-load regulation Ordering Information Operating Part Number Temperature Range Pb-Free FAN2106MPX FAN2106EMPX -10°C to 85°C -40°C to 85°C Yes Yes Package Molded Leadless Package (MLP) 5x6mm Molded Leadless Package (MLP) 5x6mm Packing Method Tape and Reel Tape and Reel © 2006 Fairchild Semiconductor Corporation FAN2106 Rev. 1.0.1 www.fairchildsemi.com FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator Typical Application Diagram Figure 1. Typical Application Block Diagram Figure 2. Block Diagram © 2006 Fairchild Semiconductor Corporation FAN2106 Rev. 1.0.1 www.fairchildsemi.com 2 FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator Pin Assignments Figure 3. MLP 5x6mm Pin Configuration (PCB Layout View) Pin Definitions Pin P1, 6-12 P2, 2-5 P3, 21-23 1 Name SW PVIN PGND BOOT Description Switching Node. Power Input Voltage. Connect to the main input power source. Power Ground. Power return and Q2 source. High-Side Drive BOOT Voltage. Connect through capacitor (CBOOT) to SW. The IC includes an internal synchronous bootstrap diode to recharge the capacitor on this pin to VCC when SW is LOW. Power-Good Flag. An open-drain output that pulls LOW when FB is outside a ±10% range of the reference when EN is HIGH. PGOOD does not assert HIGH until the fault latch is enabled. ENABLE. Enables operation when pulled to logic HIGH or left open. Toggling EN resets the regulator after a latched fault condition. This input has an internal pull-up when the IC is functioning normally. When a latched fault occurs, EN is discharged by a current sink. Input Bias Supply for IC. The IC’s logic and analog circuitry are powered from this pin. 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. Current Limit. A resistor (RILIM) from this pin to AGND can be used to program the currentlimit trip threshold lower than the default setting. Oscillator Frequency. A resistor (RT) from this pin to AGND sets the PWM switching frequency. Output Voltage Feedback. Connect through a resistor divider to the output voltage. Compensation. Error amplifier output. Connect the external compensation network between this pin and FB. Forced PWM / VOUT. Connect to VOUT to enable light-load, power-saving mode of operation. Connect to GND or leave open for PWM mode. Ramp Amplitude. A resistor (RRAMP) connected from this pin to PVIN sets the ramp amplitude and provides voltage feedforward functionality. 13 PGOOD 14 15 16 17 18 19 20 24 25 EN VCC AGND ILIM R(T) FB COMP PWM# / VOUT RAMP © 2006 Fairchild Semiconductor Corporation FAN2106 Rev. 1.0.1 www.fairchildsemi.com 3 FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator Absolute Maximum Ratings Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Parameter PVIN to PGND VCC to AGND BOOT to PGND BOOT to SW SW to PGND All other pins Continuous AGND = PGND Conditions Min. Max. 28 6 35 Unit V V V V V V V -0.3 -0.5 -5 -0.3 Transient (t < 20nsec, F < 600KHz) 6 24 30 VCC+0.3 Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to absolute maximum ratings. Symbol VCC VIN TA TJ Parameter Bias Voltage Supply Voltage Ambient Temperature Junction Temperature Conditions VCC to AGND PVIN to PGND FAN2106M FAN2106EM Min. 4.5 3 -10 -40 Typ. 5.0 Max. 5.5 24 85 85 125 Unit V V °C °C °C Thermal Information Symbol TSTG TL TVP TI θJC θJ-PCB PD Storage Temperature Lead Soldering Temperature, 10 seconds Vapor Phase, 60 seconds Infrared, 15 seconds Thermal Resistance: Junction-to-Case P1 (Q2) P2 (Q1) P3 Thermal Resistance: Junction-to-Mounting Surface Power Dissipation, TA = 25°C 4 7 4 35(1) 2.8 (1) Parameter Min. -65 Typ. Max. 150 300 215 220 Unit °C °C °C °C °C/W °C/W °C/W °C/W W Note: 1. Typical thermal resistance when mounted on a four-layer, two-ounce PCB, as shown in Figure 25. Actual results are dependent on mounting method and surface related to the design. © 2006 Fairchild Semiconductor Corporation FAN2106 Rev. 1.0.1 www.fairchildsemi.com 4 FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator Electrical Specifications Recommended operating conditions are the result of using the circuit shown in Figure 1 unless otherwise noted. Parameter Power Supplies Conditions SW = Open, FB = 0.7V, VCC = 5V, FSW = 600KHz Shutdown: EN=0, VCC = 5V Power Saving Mode, VCC = 5V, FMIN Rising VCC Hysteresis VCC = 5V, 25°C VCC = 5V, 25°C RT = 50KΩ RT = 24KΩ Min. Typ. 8 7 2.2 Max. 12 10 4.5 4.5 Unit mA µA mA V mV VCC Current VCC UVLO Threshold Power Output Section N-Channel (Q1) RDS(ON) N-Channel (Q2) RDS(ON) Oscillator Frequency Minimum On-Time (2) 4.1 4.3 300 30 14 35 16 345 660 65 mΩ mΩ KHz KHz nsec V 255 540 300 600 50 Ramp Amplitude, pk–pk Minimum Off-Time(2) Reference Reference Voltage (VFB) Error Amplifier DC Gain(2) Gain Bandwidth Product(2) Output Voltage (VCOMP) Output Current, Sourcing Output Current, Sinking FB Bias Current Protection and Shutdown Current Limit ILIM Current Over-Temperature Shutdown Over-Temperature Hysteresis Over-Voltage Threshold Under-Voltage Shutdown Fault Discharge Threshold Fault Discharge Hysteresis 16VIN, 1.8VOUT, RT = 30KΩ, RRAMP = 200KΩ 0.53 100 150 806 805 nsec mV mV dB MHz FAN2106M, 25°C FAN2106EM, 25°C VCC = 5V VCC = 5V VCC = 5V VCC = 5V, VCOMP = 2.2V VCC = 5V, VCOMP = 1.2V VFB = 0.8V, 25°C RILIM open Die temperature Die temperature 2 consecutive clock cycles 16 consecutive clock cycles Measured at FB pin Measured at FB pin (VFB ~500mV) 794 795 80 12 0.4 1.5 0.8 -850 6 -11 800 800 85 15 3.2 2.2 1.2 -650 8 -10 150 25 -450 10 -9 V mA mA nA A µA °C °C 110 68 115 73 250 250 120 78 %VOUT %VOUT mV mV Note: 2. Specifications guaranteed by design and characterization; not production tested. © 2006 Fairchild Semiconductor Corporation FAN2106 Rev. 1.0.1 www.fairchildsemi.com 5 FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator Electrical Specifications (Continued) Recommended operating conditions are the result of using the circuit shown in Figure 1 unless otherwise noted. Parameter Soft-Start EN to VOUT Regulation (T0.8) EN to Fault Enable/SSOK (T1.0) Control Functions EN Threshold, Rising EN Hysteresis EN Pull-Up Resistance EN Discharge Current FB OK Drive Resistance PGOOD Threshold PGOOD Output Low PGOOD Output High PWM# Threshold PWM# Input Current FB < VREF FB > VREF IOUT < 2mA VPGOOD = 5V Conditions Frequency = 600KHz Frequency = 600KHz Min. Typ. 3.0 3.3 1.35 250 800 Max. Unit msec msec 2.0 V mV KΩ µA Auto-restart mode -14 107 1 800 -11 110 -8 113 0.4 1 0.6 0.8 1.2 1.0 Ω %VFB %VFB V µA V µA VPWM# = 0.4V © 2006 Fairchild Semiconductor Corporation FAN2106 Rev. 1.0.1 www.fairchildsemi.com 6 FAN2106 — TinyBuck™ 6A, 24V Input Integrated Synchronous Buck Regulator Typical Characteristics 1.010 1.005 V FB 1.000 0.995 0.990 -50 0 50 Temperature (oC) 100 150 1.20 1.10 I FB 1.00 0.90 0.80 -50 0 50 Temperature (oC) 100 150 Figure 4. Reference Voltage (VFB) vs. Temperature, Normalized Figure 5. Reference Bias Current (IFB) vs. Temperature, Normalized 1500 1200 900 600 300 0 0 20 40 60 80 100 120 140 RT (KΩ) 1.02 1.01 Frequency Frequency (KHz) 600KHz 1.00 300KHz 0.99 0.98 -50 0 50 Temperature ( C) o 100 150 Figure 6. Frequency vs. RT Figure 7. Frequency vs. Temperature, Normalized 1.60 1.40 I ILIM o Q1 ~0.32 %/ C 1.04 1.02 1.00 0.98 0.96 RDS 1.20 1.00 0.80 0.60 -50 0 50 Temperature ( C) o Q2 ~0.35 %/oC 100 150 -50 0 50 Temperature ( C) o 100 150 Figure 8. RDS vs. Temperature, Normalized (VCC = VGS = 5V) Figure 9. ILIM Current (IILIM) vs. Temperature, Normalized © 2006 Fairchild Semiconductor C