SC1153 Programmable Synchronous DC/DC Controller for Advanced Processors POWER MANAGEMENT Description Features u u u u u u The SC1153 is a low-cost, full featured, synchronous voltage-mode controller designed for use in single ended power supply applications where efficiency is of primary concern. Synchronous operation allows for the elimination of heat sinks in many applications. The SC1153 is ideal for implementing DC/DC converters needed to power advanced microprocessors such as Pentium(R) llI, in both single and multiple processor configurations. Internal level-shift, highside drive circuitry, and preset shoot-thru control, allows for use of inexpensive N-channel power switches. SC1153 features include an integrated 5-bit VID DAC, temperature compensated voltage reference, triangle wave oscillator, current limit comparator, frequency shift overcurrent protection, and an accessible, internally compensated error amplifier. Power good signaling, logic compatible shutdown, and over voltage protection are also provided. Low cost / full featured Synchronous operation 5 Bit VID programmable output On-chip power good and OVP functions Designed to meet Intel VRM8.4 (Pentium(R) III) 1.3V to 3.5V Range, 1% tolerance Applications u u u u u The SC1153 operates at a fixed 200KHz, providing an optimum compromise between efficiency, external component size, and cost. Pentium(R) III Core Supply Multiple Microprocessor Supplies Voltage Regulator Modules (VRM) Programmable Power Supplies High Efficiency DC/DC Conversion Typical Application Circuit +12V 4.7uF + +5V 0.1uF + 0.1uF 1500uF x2 10 2 OVP 3 VID0 20 VID1 19 VID2 18 17 VID3 16 VID4 14 EN 1 PWRGOOD 9 VCC CS+ OVP CS- VID0 VOSENSE VID1 PWRGOOD VID2 BSTH VID3 DH VID4 PGNDH EN GND NC BSTL DL PGNDL 6 5 15 4 2.32k 13 IRL3103S 8 1.00k 5mOhm 7 VCCP 4uH 12 IRL3103S 11 0.1uF 1500uF + x4 10 SC1153 0.1uF Pentium(R) llI Power Supply Revision 4/01 1 www.semtech.com SC1153 POWER MANAGEMENT Absolute Maximum Ratings Parameter VCC to GND Symbol Maximum Units VIN -0.3 to 7 V 1 V -0.3 to 15 V PGNDH(L) to GND BSTH(L) to PGNDH(L) Thermal Resistance Junction to Case JC 30 C/W Thermal Resistance Junction to Ambient JA 90 C/W Operating Junction Temperature Range TJ 0 to 70 C Storage Temperature Range TSTG -65 to +150 C Lead Temperature (Soldering) 10 Sec. TLEAD 300 C Electrical Characteristics Unless specified: VIN = 4.75V to 5.25V; GND = PGNDH = PGNDL = 0V; FB = VO; 0mV < (CS+ - CS-) < 60mV; TJ = 25oC Parameter Conditions Output Voltage IO = 2A Min Typ Max Units See Output Voltage Table Supply Voltage 4.2 7 V Supply Current VIN= 5.0V 5 mA Load Regulation IO = 0.3A to 15A 1 % Line Regulation All VID codes 0.5 % Gain (AOL) VOSENSE to VCCP 35 dB Current Limit Voltage 60 70 80 mV Oscillator Frequency 180 200 220 kHz Oscillator Max Duty Cycle 90 95 % DH Source/Sink Current BSTH - DH = 4.5V, DH - PGNDH = 2V 1 A DL Source/Sink Current BSTL - DL = 4.5V, DL - PGNDL = 2V 1 A OVP Threshold Voltage OVP Source Current 120 VOVP = 3V .% 10 Power Good Threshold Voltage 90 Dead Time 50 mA 110 100 % ns Note: (1) This device is ESD sensitive. Use of standard ESD handling precautions is required. 2000 Semtech Corp. 2 www.semtech.com SC1153 POWER MANAGEMENT Pin Configuration Ordering Information Device (1) Package Temp Range (T J) SC1153CSW.TR SO-20 0 to 125C TOP VIEW GND 1 20 VID0 VCC 2 19 VID1 OVP 3 18 VID2 PWRGOOD 4 17 VID3 CS- 5 16 VID4 CS+ 6 15 VOSENSE PGNDH 7 14 EN DH 8 13 BSTH NC 9 12 BSTL 10 11 DL PGNDL Note: (1) Only available in tape and reel packaging. A reel contains 1000 devices. (20 Pin SOIC) Pin Descriptions Pin # Pin Name Pin Function 1 GND Small Signal Analog and Digital Ground 2 VCC Chip Supply Voltage 3 OVP High Signal out if VO>setpoint + 20% 4 PWRGOOD (1) 5 CS- Current Sense Input (negative) 6 CS+ Current Sense Input (positive) 7 PGNDH 8 DH High Side Driver Output 9 NC Not Connected 10 PGNDL 11 DL 12 BSTL Supply for Low Side Driver (Boost) 13 BSTH Supply for High Side Driver (Boost) 14 EN (1) Enable, Logic low shuts down the converter 15 VOSENSE Open collector logic output, high if VO within 10% of setpoint Power Ground for High Side Switch Power Ground for Low Side Switch Low Side Driver Output Top end of internal feedback chain 16 VID4 (1) Programming Input (MSB) 17 VID3 (1) Programming Input 18 VID2 (1) Programming Input 19 VID1 (1) Programming Input 20 VID0 (1) Programming Input (LSB) NOTE: (1) All logic level inputs and outputs are open collector TTL compatible. 2000 Semtech Corp. 3 www.semtech.com SC1153 POWER MANAGEMENT Block Diagram VCC CS- CS+ EN CURRENT LIMIT 1.25V REF + 70mV BSTH - VID4 VID3 VID2 LEVEL SHIFT AND DRIVE R D/A DH Q OSCILLATOR VID1 VID0 S PGNDH VOSENSE + OPEN COLLECTORS PWRGOOD + + - - ERROR AMP SHOOT-THROUGH CONTROL BSTDL + VCC LOW SIDE DRIVE DL + - PGNDL OVP GND Applications Information - Theory of Operation The voltage at the VOSENSE pin is applied, through the internal precision resistor feedback chain, to the inverting input of the error amplifier. The non-inverting input of the error amplifier is supplied with a DC voltage derived by the DAC from the internal trimmed bandgap voltage reference. The output of the error amplifier is compared to the triangular output of the internal oscillator to generate a fixed frequency, variable duty cycle pulse train. The internal oscillator uses an on-chip capacitor and precision trimmed current sources to set the frequency to 200 kHz. signal for the upper FET. It is also inverted to produce a drive signal for the lower FET. These FET drive signals are modified by the shoot-through control circuitry so that the top FET turn-on is delayed until the bottom FET has turned off, and visa-versa. The current limit latch is set (ending the upper FET drive pulse early) if the current limit comparator indicates an overcurrent condition. The latch is reset at the start of each oscillator period. The PWRGOOD and OVP signals are derived from the voltage at the VOSENSE pin by comparators fed from the internal feedback chain. The generated pulse train is gated with the output of the current limit latch and the inhibit signal to produce a drive 2000 Semtech Corp. 4 www.semtech.com SC1153 POWER MANAGEMENT Output Voltage Table Unless specified: VIN = 4.75V to 5.25V; GND = PGNDH = PGNDL = 0V; FB = VO; 0mV < (CS+ - CS-) < 60mV; TJ = 25C Parameter Output Voltage (2) 2000 Semtech Corp. Conditions IO = 2A in Application circuit VID 43210 01111 01110 01101 01100 01011 01010 01001 01000 00111 00110 00101 00100 00011 00010 00001 00000 11111 11110 11101 11100 11011 11010 11001 11000 10111 10110 10101 10100 10011 10010 10001 10000 5 Min Typ Max Units 1.287 1.336 1.386 1.435 1.485 1.534 1.584 1.633 1.683 1.732 1.782 1.832 1.881 1.931 1.980 2.030 1.980 2.079 2.178 2.277 2.376 2.475 2.574 2.673 2.772 2.871 2.970 3.069 3.168 3.267 3.366 3.465 1.300 1.350 1.400 1.450 1.500 1.550 1.600 1.650 1.700 1.750 1.800 1.850 1.900 1.950 2.000 2.050 2.000 2.100 1.980 2.300 2.400 2.500 2.600 2.700 2.800 2.900 3.000 3.100 3.200 3.300 3.400 3.500 1.313 1.364 1.414 1.465 1.515 1.566 1.616 1.667 1.717 1.768 1.818 1.868 1.919 1.969 2.020 2.070 2.020 2.121 2.222 2.323 2.424 2.525 2.626 2.727 2.828 2.929 3.030 3.131 3.232 3.333 3.434 3.535 V www.semtech.com 2000 Semtech Corp. C11 0.1uF + 6 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15 B16 B17 B18 B19 B20 C2 1500uF VCCVID AMPMOD2_40 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 J1 5VIN C1 1500uF VID0 VID2 VID4 C3 0.1uF VID1 VID3 PWRGD VSS + R1 10k C9 0.1uF 3 2 9 1 14 16 17 18 19 20 R2 10 SC1153 NC GND EN VID4 VID3 VID2 VID1 VID0 OVP VCC U1 PGNDL DL BSTL PGNDH DH BSTH PWRGOOD VOSENSE CS- CS+ 10 11 12 7 8 13 4 15 5 6 C4 0.1uF Q2 Q1 L1 IRL3103S B17059A D1 SK13DICT IRL3103S R5 1.00k + + + + C6 1500uF C8 1500uF C5 1500uF C7 1500uF R6 5mOhm 2.32k R4 SC1153 POWER MANAGEMENT Evaluation Board Schematic (VRM) www.semtech.com SC1153 POWER MANAGEMENT Evaluation Board Bill of Materials Item Qty. Reference Value Notes 1 6 C1,C2,C5,C6,C7,C8 1500uF Low ESR Sanyo MV-GX or equivalent 2 4 C3,C4,C9,C11 0.1uF 3 1 D1 SK13DICT 4 1 J1 AMPMOD2_40 5 1 L1 4uH 6 2 Q1,Q2 IRL3103S 7 1 R1 10k 8 1 R2 10 9 1 R4 2.32k 1% 10 1 R5 1.00k 1% 11 1 R6 5mOhm IRC OAR1 12 1 U1 SC1153 SEMTECH 2000 Semtech Corp. 8 Turns 16AWG on MICROMETALS T50-52D core. 7 www.semtech.com SC1153 POWER MANAGEMENT Typical Characteristic Curves SC1153 Efficiency in Application Circuit 100% 95% Efficiency 90% 3.50V 3.00V 2.50V 2.00V 1.80V 85% 80% 75% 70% 0 2 4 6 8 10 12 14 16 Output Current (Amps) SC1153 Regulation in Application Circuit 0 Vout (mV) -5 -10 -15 -20 -25 0 2000 Semtech Corp. 2 4 6 8 Io (A) 8 10 12 14 16 www.semtech.com SC1153 POWER MANAGEMENT Outline Drawing - SO-20 Land Pattern - SO-20 Contact Information Semtech Corporation Power Management Products Division 652 Mitchell Rd., Newbury Park, CA 91320 Phone: (805)498-2111 FAX (805)498-3804 2000 Semtech Corp. 9 www.semtech.com