SC2646B Combi-Sense TM POWER MANAGEMENT Description Features The SC2646B controller provides a microprocessor core voltage regulation solution for up to 4 paralleled PWM channels. The solution can be configured in 2, 3, or 4phase form. This multi-phase buck regulator utilizes phase-shift timing control to allow interleaved switching of the power switches. The product’s architecture minimizes the core voltage ripple and the input current ripple, which leads to optimized voltage regulator design for power density, transient responses, and thermal performances. To satisfy the highly dynamic nature of the modern microprocessors, the SC2646B adopts peak current mode control topology which ensures wide control loop bandwidth and fast transient responses. The current mode control provides intrinsic phase current matching. The maximum ripple frequency is greater than 2MHz. One of the outstanding features of the SC2646B device is its voltage regulation accuracy. Not only does it provide 0.5% set point accuracy, but also the accuracy to be fully compliant with stringent load line slope specifications mandated by the modern microprocessors. Lossless output current sensing ensures the regulator output voltage is accurately positioned according to the load current condition. 2, 3 or 4 Phase PWM Controller VRD/VRM10.X compliant Core Voltage Set Point Accuracy 0.5% Combi-SenseTM Current Mode Control Intrinsic Phase Current Matching Fast Transient Responses Active Droop to Meet Load Line Slope Enable Function for Power Sequencing Cycle-by-Cycle Peak Current Limit Intelligent Over Current Shut Down Over Voltage Protection When Using Semtech Combi-SenseTM Driver SC1211 Under Voltage Protection Built in Externally Programmable Soft-Start Externally Programmable Switching Frequency 2, 3, or 4-Phase Configurations 24-Pin TSSOP Package Combi-SenseTM is a Trademark of Semtech Corporation Applications Voltage Regulator VRD/VRM10.X Voltage Regulation Modules High Current, Low Voltage Step Down DC/DC Converters Semtech’s patented Combi-SenseTM topology is employed by SC2646B controller. The MOSFET Rds(on) and the output inductor winding resistance is used to generate the phase current information. Semtech’s SC1211 CombiSenseTM MOSFET driver works with the SC2646B to enable a complete solution. The cycle-by-cycle current limit plus the intelligent over current shut down provide the maximum versatility of the system without false tripping under all possible changes of VID and load conditions. The differential voltage feedback sense eliminates the error caused by high load current on the ground plane. External offset is easy to achieve for the VID settings. The enable function is also provided to interface with the corresponding system signal for correct start up timing and shut down timing. Revision: Apr. 11, 2005 1 www.semtech.com SC2646B POWER MANAGEMENT Typical Application Circuit ATX12V ATX12V AUX1 R2 44.2K R9 54.9K 1 L1 640nH 2 R3 44.2K R10 54.9K AUX2 C8 6.8nF AUX3 C9 6.8nF 1 2 3 4 5 VIN R4 44.2K R11 54.9K PN2 R5 TBD C10 TBD 20 21 22 23 24 PN1 OS4 MSENSE OS3 OUTSEN U2 OS2 OUT3 OUT4 BGOUT OUT2 OS1 ERROUT 19 PN3 R6 TBD R13 TBD R7 TBD PN3 2R2 R1 AUX3 C6 1nF R14 100 C23 VOUT 1nF VCC PN2 R17 AUX2 320K 18 17 D1N4148 D1 1uF C3 C14 1uF D1N4148 D2 C28 1uF D1N4148 D3 1uF C16 4.7uF C15 PGND 1 C37 1uF PGND C29 4.7uF C30 1uF PGND C38 4.7uF U1 9 9 U3 9 U4 R8 1 R18 1 R28 1 M2 M5 M8 M4 M1 M3 VIN M6 VIN M7 M9 C2 4.7uF/1206 PN3 R12 IR0 C12 2.2nF PN2 C19 4.7uF/1206 R19 IR0 C26 2.2nF C33 4.7uF/1206 PN1 R29 IR0 C36 2.2nF 820nH L2 1800uF/16V C1 + 1 820nH L3 1800uF/16V C18 + 1 820nH L4 1800uF/16V C32 + 1 2 2 2 R32 0R0 C4 C5 + C11 + C13 + C17 + C21 + C24 + OUT1 AGND 16 DRN BG GNDSEN FB OSCREF 15 R21 100 BG 8 6 7 MSENSE PGOOD 14 8 1 C7 6.8nF VCC MSENSE VCC VID5 VID0 VID4 VID3 1 DRN VRM_EN C20 1uF 8 9 10 11 2 DRN VR EG (Open-Collector) R15 300 R16 20K C22 470pF R20 C25 13 TG 7 BG VID1 VR EG 2 8 VID2 PN1 7 TG VR EG 10 12 AUX1 C35 1nF R30 100 2 BST 7 4.7uF SC2646 DIFFERENTIAL PAIR FOR REMOTE SENSE 3 TG V IN BST ATX12V 3.3V R22 R23 R24 R25 R26 R27 1K 1K 1K 1K 1K 1K V_COREV_CORE+ BST 6 V IN VID0 VCC R31 2.9K R33 1.1K V IN 3 6 VID1 VID2 VID3 VID4 VID5 PGOOD (3V3 LOGIC) C39 10nF 4 6 4 4 C27 C31 C34 VOUT 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V 1800uF/6.3V PGND www.semtech.com 2 © 2005 Semtech Corp. CO 3 CO CO + SC1211 SC1211 SC 1211 + VPN VPN VPN + + 5 5 5 HIGH FREQUENCY DECOUPLING NOT SHOWN SC2646B POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Symbol Maximum Units VCC 20 V OS1, OS2, OS3, OS4, OUTSEN 5 V Ambient Temperature Range TA 0 to 85 o Junction Temperature Range TJ 0 to 125 o Storage Temperature Range TSTG -65 to +150 o Lead Temperature (Soldering) 10 Sec. TLEAD 260 o Supply Voltage Combi-Sense/Direct Output Voltage C C C C Electrical Characteristics o Unless specified: VCC = 12V, FOSC = 600kHz, 4 phase operation, V OUT = 1.28V, TA = 27 C. See Typical Application Circuit. Specifications subject to change without notice. Parameter Symbol Test Conditions Min Typ Max Units 10 12 14 V 5.4 8.0 mA 6.3 7.0 V Chip_Supply IC Supply Voltage VCC IC Supply Current ICC UVLO Ramp Up UVLO Hysteresis 700 890 mV 1.5 V Reference Section Bandgap Output VBGOUT CBGOUT = 4.7nF Source Current 55 Supply Rejection Temperature Stability (1) Voltage Accuracy 70 95 µA VCC = 10.0V ~ 14.0V 0.5 mV/V 0oC < TA < 85oC 0.5 % VOUT Internal offset is -20mV -0.5 Oscillator Frequency FOSC ROSC = 320K 540 Oscillator Frequency Range FOSC +0.5 % 660 kHz 3000 kHz Oscillator Section Temperature Stability (1) 600 500 0oC < TA < 85oC +/- 5 % 25 nA 80 dB Voltage Error Amplifier Input Bias Current (1) Open Loop Gain (1) 1V < VERROUT < 3.4V © 2005 Semtech Corp. 3 www.semtech.com SC2646B POWER MANAGEMENT Electrical Characteristics (Cont.) o Unless specified: VCC = 12V, FOSC = 600kHz, 4 phase operation, V OUT = 1.28V, TA = 27 C. See Typical Application Circuit. Specifications subject to change Parameter Unity Gain Bandwidth (1) Symbol Test Conditions GBW CERROUT = 10pF Source Current Sink Current Transconductance Gain Min Typ Max 5 Units MHz VBG > 1.8V, VFB = 0V, VERROUT = 0.8V 60 80 90 uA VBG > 1V, VFB = 2V, VERROUT = 2V -90 -80 -60 uA 0.62 0.82 1.03 mA/V GM Current Sense Amplifiers Input Offset Voltage VIO +/-3 mV Input Bias Current IM 50 nA Gca 12.45 V/V 80 dB Gain CMRR (1) 0 to 3V Input Common Mode Range -0.3 Gain Match 5 Bandwidth (1) 6 3 V 6 % MHz Droop Amplifier Gain ADRP VMSENSE-VOUTSEN = 20mV 11.1 11.7 12.3 V/V VIDs Logic High [VID0:5] 0.8 V Logi c Low [VID0:5] 0.4 V Internal Pull-up Impedance (1) [VID0:4] 26 Kohm Internal Pull-up Voltage (1) [VID0:4] 1.4 V 3-Phase Operation Output 4 pull up Threshold 3.88 4.0 4.5 V Pow er Good Threshold Rising VID - Power Good Threshold 100 mV Threshold Falling VID - Power Good Threshold 250 mV Power Good Delay (1) From Cross Rising Threshold Output High Leakage Pwrgood = VCC 60 Sink Current = 1mA 0.48 0.5 V 3.45 3.63 3.81 V 180 210 280 mV Output Voltage Low Level 4.0 5 6.5 mS nA Current Limit Section Max. Error Amp Voltage for Current Limit VOC Shutdown Voltage V SD VID - Shut Down Threshold Note: (1). Guaranteed by design, not tested in production. (2). This device is ESD sensitive. Use of standard ESD handling precautions is required. © 2005 Semtech Corp. 4 www.semtech.com SC2646B POWER MANAGEMENT Pin Configurations Ordering Information Top View 1 2 3 4 5 6 7 8 9 10 11 12 OS3 OS2 OS1 BGOUT ERROUT GSENSE FB MSENSE VCC VID4 VID3 VID2 24 23 22 21 20 19 18 17 16 15 14 13 OS4 OUTSEN OUT4 OUT3 OUT2 OUT1 AGND OSCREF PGOOD VID5 VID0 VID1 Part Number Package Temp. Range (T J) SC2646BTSTRT (1) (2) TSSOP-24 0 to 125 OC SC2646BEVB Embedded Evaluation Board Note: (1) Only available in tape and reel packaging. A reel contains 2500 devices for the TSSOP-24 package. (2) Lead free package.Device is fully WEEE and RoHS compliant. (24-Pin TSSOP) Pin Descriptions Pin# Pin Name 1 OS3 Current sense input 2 OS2 Current sense input. Connect to OUTSEN for 2 phase operation. 3 OS1 Current sense input 4 BGOUT Bandgap reference voltage. Connect soft start cap to AGND. 5 ERROUT Error-amplifier output. Connect compensation network to AGND. 6 GSENSE Remote sense for GND. 7 FB 8 MSENSE 9 VC C 10 VID[4:0] 15 VID5 16 PGOOD Power good. Open collector output. 17 OSCREF Oscillator frequency setting. Connect a resistor to AGND. 18 AGND Clean ground for analog signals. 19 OUT1 PWM output1. 20 OUT2 PWM output2. 21 OUT3 PWM output3. 22 OUT4 PWM output4. Connect to VCC for 3 phase operation. 23 OUTSEN 24 OS4 © 2005 Semtech Corp. Pin Function Feedback pin. Route FB and Gsense as differential pair to CPU sense point. Voltage regulator module output current sense. Power supply for chip. VID MSB to LSB. 12.5mV bit. Direct output sense. Current sense input. Connect to OUTSEN for 2 or 3 phase operation. 5 www.semtech.com SC2646B POWER MANAGEMENT Block Diagram C/A1 OS1 3 + + OUT OUT - C/A2 OS2 2 R - Q 19 OUT1 20 OUT2 21 OUT3 22 OUT4 S + + OUT OUT C/A3 1 DRV2 PWM2 - OS3 DRV1 PWM1 R - Q S + + OUT OUT - C/A4 OS4 24 DRV3 PWM3 R - Q S + + OUT OUTSEN DRV4 PWM4 OUT - R - Q S OUTSEN 23 OSCILLATOR ERROUT CLOCK DIVIDER Ramp ROSC OSCREF 17 OSC CLK SEL3 P1 P2 P3 P4 + OUT 14 VID1 13 VID2 12 VID3 11 VID4 10 VID5 15 DAC VID0 VID1 VID2 VID3 VID4 VID5 3 PHASE SELECT 11111 INHIBIT Shut Down VID0 - 4.2V I_DAC PWR_GOOD + OUTSEN OUT DROOP 0.8*VBG 16 PWRGD 5 ERROUT 9 VCC 18 AGND DELAY - OUT MSENSE FB 8 + - 7 R E/A ERROUT OUT + OCP & SHUTDOWM BGOUT BGOUT 4 VBG OUT BUFFER + VCC VCC VREF GSENSE UVLO & LATCH + BGOUT - 6 © 2005 Semtech Corp. 6 www.semtech.com SC2646B POWER MANAGEMENT Applications Information- Output Voltage VRD10 Output Voltage Unless specified: 0 = GND; 1 = High. TA = 25°C, VCC = 12V VID5 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 © 2005 Semtech Corp. VID4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 VID3 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 VID2 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 7 VID1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 VID0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 Vout (V) 0.8375 0.8500 0.8625 0.8750 0.8875 0.9000 0.9125 0.9250 0.9375 0.9500 0.9625 0.9750 0.9875 1.0000 1.0125 1.0250 1.0375 1.0500 1.0625 1.0750 1.0875 OFF OFF 1.1000 1.1125 1.1250 1.1375 1.1500 1.1625 1.1750 1.1875 1.2000 1.2125 1.2250 1.2375 1.2500 1.2625 1.2750 1.2875 1.3000 1.3125 1.3250 1.3375 1.3500 1.3625 1.3750 1.3875 1.4000 1.4125 1.4250 1.4375 1.4500 1.4625 1.4750 1.4875 1.5000 1.5125 1.5250 1.5375 1.5500 1.5625 1.5750 1.5875 1.6000 www.semtech.com SC2646B POWER MANAGEMENT Outline Drawing - TSSOP-24 DIMENSIONS MILLIMETERS INCHES DIM MIN NOM MAX MIN NOM MAX A D e A A1 A2 b c D E1 E e L L1 N 01 aaa bbb ccc N 2X E/2 E1 E PIN 1 INDICATOR ccc C 2X N/2 TIPS 1 2 3 e/2 B 1.20 0.15 0.05 1.05 0.80 0.19 0.30 0.20 0.09 7.70 7.80 7.90 4.30 4.40 4.50 6.40 BSC 0.65 BSC 0.45 0.60 0.75 (1.0) 24 0 8 0.10 0.10 0.20 D aaa C SEATING PLANE .047 .006 .002 .042 .031 .012 .007 .007 .003 .303 .307 .311 .169 .173 .177 .252 BSC .026 BSC .018 .024 .030 (.039) 24 0 8 .004 .004 .008 A2 A C H A1 bxN bbb c GAGE PLANE C A-B D 0.25 L (L1) SIDE VIEW SEE DETAIL A DETAIL 01 A NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H- 3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 4. REFERENCE JEDEC STD MO-153, VARIATION AD. © 2005 Semtech Corp. 8 www.semtech.com SC2646B POWER MANAGEMENT Land Pattern - TSSOP-24 X DIM (C) G C G P X Y Z Z Y DIMENSIONS INCHES MILLIMETERS (.222) .161 .026 .016 .061 .283 (5.65) 4.10 0.65 0.40 1.55 7.20 P NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Rd., Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804 © 2005 Semtech Corp. 9 www.semtech.com