SS6580

SS6580 SSC | Alldatasheet

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www.SiliconStandard.com 1 of 8 SS6580/L Step-Down DC/DC Controller with Shutdown n FEATURES l Operating Voltage up to 15V. l Simple Voltage-Mode PWM Control. l Fast Transient Response. l 2V and 1.3V ± 2% Feedback Voltage Reference Options. l Adjustable Current Limit without External Sense Resistors. l 200 KHz Switching Oscillator. l Short-Circuit Protection with Low Short -Circuit Output Current. l Low Shutdown Current l Built-in Soft Start. n APPLICATIONS l Power Supply for Motherboard VGTL (1.5V Output) l Power Supply for Motherboard VI/O. l High-Power 5V to 3.xV DC/DC Regulators. l Low-Voltage Distributed Power Supplies. n DESCRIPTION The SS6580 is a high-power, high-efficiency voltage-mode switching regulator controller for motherboard VI/O power supply applications. Designed to drive an N-channel MOSFET in a standard buck topology, the SS6580 features a high voltage CMOS output driver with short-circuit protection in an 8-pin package. An external 4-bit Digital-to-Analog Converter (DAC) can be used along with the SS6580 to adjust the output voltage from 2.0V to 3.5V in 0.1V increments. Table 1 on the following page specifies the corresponding output voltage for 16 combinations of DAC inputs as shown in the typical application circuit. The 200 KHz switching frequency allows the use of small external components while maintaining high conversion efficiency. The 11MHz bandwidth and the 6V/ µS slew rate of the error amplifier ensure high converter bandwidth and fast transient response. The SS6580 provides both adjustable over-current and adjustable short-circuit protection by sensing the output current across the on - resistance of the external N-channel MOSFET, rather than an external low value sense resistor. The SS6580L provides a lower reference voltage (1.30V) than the default SS6580 (2.00V) for lower V OUT requirements. Rev.2.01 6/26/2003

www.SiliconStandard.com 2 of 8 SS6580/L n ORDERING INFORMATION PIN CONFIGURATION SO-8 TOP VIEW *SS6580: 2.00V SS6580L: 1.30V PHASE VCC SD COMP FB* UGATE GND OCSET PACKING TYPE TR: TAPE & REEL TB: TUBE PACKAGING TYPE N: PLASTIC DIP S: SMALL OUTLINE REFERENCE VOLTAGE DEFAULT: 2.00V L: 1.30V SS6580XCXXX Example: SS6580CSTR à 2.00V in SO-8 Package & Tape & Reel Packing Type (CN is not available in TR packing) n TYPICAL APPLICATION CIRCUIT 2K2 1nF 33P 1nF R6 90.9K 4K7 OCSET 1 SD 2 COMP 3 FB 4 GND 5 PHASE 6 UGATE 7 VCC 8 SS6580 CEB6030L 7µH 1.5µH SB1020 1000µF*6 VOUT VIN1 10 C1 1µF VIN2 12V 3.01K 6.04K 30.1k 15K 7.5K SW0 VID0 SW1 VID1 SW2 VID2 SW3 VID3 Optional Circuit 1000µF*2 *C1 must be very close to VCC pin Supply DC-DC Step Down Circuit Rev.2.01 6/26/2003

Table 1. Output Voltage Program Note 1: θ JA is measured with the component mounted on an evaluation PC board in free air.

www.SiliconStandard.com 4 of 8 SS6580/L n TEST CIRCUIT Refer to TYPICAL APPLICATION CIRCUIT. n ELECTRICAL CHARACTERISTICS (VCC=12V, TA=25°C, unless otherwise specified.) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT VCC Supply Current Nominal Supply UGATE Open IVCC 2 mA Power-On Reset VCC Threshold VOCSET=4.5V 9.5 V Oscillator Frequency 200 KHz Duty Cycle 88 % Internal Reference Voltage Reference Voltage SS6580 SS6580L 1.96 1.27 2.00 1.30 2.04 1.33 V Error Amplifier DC Gain 76 dB Gain-Bandwidth Product GBW 11 MHz Slew Rate Comp=10pF SR 6 V/µS Gate Driver Upper Gate Source RUGATE 7 Ω Upper Gate Sink RUGATE 5 Ω Protection OCSET Current Source VOCSET =4.5VDC IOCSET 200 µA SS Current ISS 10 µA Shutdown Shutdown Low Input VINL 0.35 V Shutdown High Input VINH 2 V Shutdown Mode Current 1 µA Rev.2.01 6/26/2003

www.SiliconStandard.com 5 of 8 SS6580/L n TYPICAL PERFORMANCE CHARACTERISTICS 1 2 3 4 5 6 7 8 9 10 11 100 Vo=1.3V Vo=2.0V Vo=3.5V Efficiency (%) IOUT (A) Fig. 1 Efficiency vs. Load Current OCSET (µA) Temperature (°C) Fig. 2 OCSET Current vs. Temperature -40 -20 0 20 40 60 80 100 120 140 160 192 194 196 198 200 Tc=134ppm/ C@ 0~100°C Fig. 3 Over-Current Operation Fig. 4 Output Clamped by Built-In Soft Start Fig. 5 Transient Response VOUT NOISE Rev.2.01 6/26/2003

www.SiliconStandard.com 6 of 8 SS6580/L n BLOCK DIAGRAM SD Oscillator PWM Comparator Error AMP COMP FB REF VCC PHASE OCSET UGATE GND 200µA Over Current Built-In Soft Start Gate Control Power-On Reset n PIN DESCRIPTIONS PIN 1: OCSET - Current limit sense pin. Connect a resistor ROCSET from this pin to the drain of the external MOSFET. ROCSET, an internal 200µA current source (IOCSET), and the external MOSFET on -resistance (RDS(ON)) jointly set the over-current trip point according to the following equation: I I R R PEAK OCSET OCSET DS(ON = × If the FB pin voltage is sensed to be below 50% of the internal voltage reference VDAC, the over-current comparator cycles the soft-start function. PIN 2:SD - Shutdown pin. Connect this pin to ground for shutdown. PIN 3:COMP - External compensation pin. This pin is connected to the error amplifier output and PWM comparator. An RC network is connected to the FB pin to compensate the voltage -control feedback loop of the converter. PIN 4: FB - The error amplifier inv erting input pin. The FB pin and COMP pin are used to compensate the voltage-control feedback loop. PIN 5: GND - Ground pin. PIN 6: PHASE - Over-current detection pin. Connect the PHASE pin to the source of the external N-MOSFET. This pin detects the volta ge drop across the MOSFET RDS(ON) for over-current protection. PIN 7: UGATE - External MOSFET gate drive pin. Connect this pin to the gate of the external MOSFET. PIN 8: VCC - The chip power supply pin. Recommended supply voltage is 12V. Rev.2.01 6/26/2003

www.SiliconStandard.com 7 of 8 SS6580/L n APPLICATION CIRCUIT SS6580L *C1 1µF C7 33P 1000P 1000P 1000µF*6 + C3 1000µF*3 13K 4K7 R6 90.9K R1 10 R2 2.2K 7µF 1.5µF SB1020 1.5V/10A *C1 must be very close to VCC PIN VOUT 12V OCSET VCC SD COMP FB UGATE PHASE GND *VOUT=1.3V(R5+R7)/R7 Fig. 6 DC/DC Step Down Circuit Rev.2.01 6/26/2003

www.SiliconStandard.com 8 of 8 SS6580/L Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no guarantee or warranty, express or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no responsibility for its use, or for infri ngement of any patent or other intellectual property rights of third parties that may result from its use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of Silicon Standard Corporation or any third parties. n PHYSICAL DIMENSIONS l 8 LEAD PLASTIC SO (unit: mm) SYMBOL MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 e 1.27(TYP) H 5.80 6.20 L 0.40 1.27 D H e A B C E L l 8 LEAD PLASTIC DIP (unit: mm) SYMBOL MIN MAX A1 0.381 — A2 2.92 4.96 b 0.35 0.56 C 0.20 0.36 D 9.01 10.16 E 7.62 8.26 E1 6.09 7.12 e 2.54 (TYP) eB — 10.92 b e L eB E C D L 2.92 3.81 Rev.2.01 6/26/2003