CM8500 3A BUS TERMINATOR GENERAL DESCRIPTION FEATURES The CM8500 is a switching regulator designed to provide a desired output voltage or termination voltage for various applications by converting voltage supplies ranging from 2.0V to 4.0V. The CM8500 can be implemented to produce regulated output voltages in two different modes. In the default mode, when the VIN/2 pin is open, the output voltage is 50% of the VCCQ. The CM8500 can also be used to produce various user-defined voltages by forcing a voltage on the VIN/2 pin. In this case, the output voltage follows the VIN/2 pin input voltage. The switching regulator is capable of sourcing or sinking up to 3A of current while regulating an output V TT voltage to within 3% or less. ! Patent Filed #6,452,366 ! 16 pin PTSSOP and PSOP package ! Source and sink up to 3A, no heat sink required ! Peak Current to 6A ! Integrated Power MOSFETs ! Output voltage can be programmed by external resistors ! Separate voltages for VCCQ and PVDD ! V OUT of 3% or less at 3A ! Minimum external components ! Shutdown for standby or suspend mode operation ! Thermal shutdown protection ! Soft start The CM8500, used in conjunction with series termination resistors, provides an excellent voltage source for active termination schemes of high speed transmission lines as those seen in high speed memory buses and distributed backplane designs. The voltage output of the regulator can be used as a termination voltage for other bus interface standards such as SSTL, CMOS, Rambus TM ,GTL+, VME, LV-CMOS, LV-TTL, and PECL. 24 Hours Technical Support---WebSIM Champion provides customers an online circuit simulation tool called WebSIM. You could simply logon our website at www.champion-micro.com for details. APPLICATIONS ! Mother Board ! IPC ! PCI / AGP Graphics ! SCSI-III Bus terminator ! Game / Play Station ! Buck Converter ! Set Top Box PIN CONFIGURATION PSOP-16 (PS16)/PTSSOP-16 (PT16) Top View 2002/09/30 Rev. 1.0 1 VC C 1 2 PV D D1 3 VL1 4 PG N D 1 PG N D 2 13 5 AG N D AG N D 12 6 SD VFB 11 7 VIN /2 VC C Q 10 8 AG SE N AG N D 9 VC C 2 16 PV D D2 15 VL2 14 Champion Microelectronic Corporation Page 1 CM8500 3A BUS TERMINATOR PIN DESCRIPTION Pin No. Symbol Description Operating Rating Typ. Max. Min. Unit 1,16 VCC1,VCC2 Voltage supply for internal circuits 2 2.5 4 V 2,15 PVDD1,PVDD2 Voltage supply for output power transistors 2 2.5 4 V 3,14 VL1,VL2 Output voltage/inductor connection -3 3 A 0.75 X VCC + V VCC 0.3V (IDD1+IDD2, Output RMS current) 4,13 PGND1,PGND2 Ground for output power transistors AGND Ground for internal reference voltage divider 8 AGSEN Ground for remote sensing 6 SD Shutdown active high. CMOS input level 5,9,12 7 VIN/2 Input for external reference voltage 10 VCCQ Voltage reference for external voltage divider 11 VFB Feedback node for the VTT VCCQ/2 V 2.5 V VCCQ/2 V BLOCK DIAGRAM VCCQ VCC1 10 1 PVDD2 15 PVDD1 2 SD 6 VCC2 16 OSCILLATOR/ RAMP GENERATOR 3 VL1 14 VL2 100K 7 AGND 5 Q R Q ERROR AMP VIN/2 S + + RAMP AMP COMPARATOR - 100K AGND 9 20PF AGND 12 AGND 13 4 11 8 PGND1 VFB PGND2 ORDERING INFORMATION Part Number Temperature Range CM8500IT -40 to 85 16-Pin PTSSOP (PT16) CM8500IS -40 to 85 16-Pin PSOP (PS16) CM8500TEVAL 2002/09/30 Rev. 1.0 Package Evaluation Board (T16) Champion Microelectronic Corporation Page 2 CM8500 3A BUS TERMINATOR ABSOLUTE MAXIMUM RATINGS Absolute maximum ratings are those values beyond which the Junction Temperature ........................... ............150C device could be permanently damaged. Storage Temperature PVDD/VCC/VCCQ ................................................-0.3V to 4.0V Lead Temperature (Soldering, 10 sec).................... 300C Thermal Resistance ( JA )..... ....................... .40C/W Voltage on Any Other Pin ............ GND - 0.3V to VCC + 0.3V ............................. -65C to 125C Output RMS Current, Source or Sink ...............................3.0A OPERATING CONDITIONS Temperature Range ............................. -40C to 85C PVDD Operating Range .........................2.0V to 4.0V ELECTRICAL CHARACTERISTICS (Unless otherwise stated, these specifications apply TA=25C; VCC=+3.3V and PVDD=+3.3V) maximum ratings are stress ratings only and functional device operation is not implied. (Note 1) Symbol Parameter Test Conditions CM8500 Min. Typ. Max. Unit SWITCHING REGULATOR IOUT = 0, VCCQ = 2.3V 1.12 1.15 1.18 V VCCQ = 2.5V 1.22 1.25 1.28 V VCCQ = 2.7V 1.32 1.35 1.38 IOUT = VCCQ = 2.3V 1.09 1.15 1.21 V 3A, VCCQ = 2.5V 1.19 1.25 1.31 V VCCQ = 2.7V 1.28 1.35 1.42 V VCCQ = 2.3V 1.139 1.15 1.162 V VCCQ = 2.5V 1.238 1.25 1.263 V VCCQ = 2.7V 1.337 1.35 1.364 V K 690 KHz VIN/2 = open Note 2 Output Voltage, SSTL_2 VL V VIN/2 = open Note 3 VIN/2 Internal Resistor Divider ZIN VIN/2 Reference Pin Input Impedance fsw Switching Frequency IOUT = 0 Note 2 Note 2 VCCQ = 0 CM8500 50 510 600 IOUT(RMS) Maximum Output RMS Current CM8500 3 A IOUT(PEAK) Maximum Output Peak Current CM8500 6 A Drain to Source on-State Resistance PVDD=5V 180 m MOSFETs RDS(ON) 150 SUPPLY IVCCA Quiescent Current IPVDD VFB = 1.4V LC unconnected VFB = 1.4V LC unconnected 200 A 500 A Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions Note 2: VCC, PVDD = 3.3V 10% Note 3: It's not 100% test 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 3 CM8500 3A BUS TERMINATOR FUNCTIONAL DESCRIPTION The CM8500 is a switching regulator that is capable of sinking INPUTS and sourcing 3A of current without an external heat sink. The input voltage pins (VCCQ or VIN/2) determine the output CM8500 uses a standard surface mount PTSSOP and PSOP voltages (VL1 or VL2). In the default mode, when the VIN/2 pin package with bottom metal exposed and the heat can be is open, the output voltage is 50% of the VCCQ input. piped through the bottom of the device and onto the PCB. If a specific voltage is forced at the VIN/2 pin, the output voltage follows the voltage at the VIN/2 pin. VCCQ suggested The CM8500 integrates power MOSFETs that are capable of connecting to VCCQ of memory module for better tracking with source and sink 3A of current while maintaining excellent memory VCCQ. voltage regulation. The output voltage can be regulated within 3% or less by using the external feedback. Separate voltage OTHER SUPPLY VOLTAGES supply inputs have been added to fit applications with various Several inputs are provided for the supply voltages: PVDD1, power supplies for the databus and power buses. PVDD2, VCC1, and VCC2. OUPUTS The PVDD1 and PVDD2 provide the power supply to the power The output voltage pins (VL1, VL2) are tied to the databus, MOSFETs. VCC1 and VCC2 provide the voltage supply to the address, or clock lines via an external inductor. Output voltage logic section and internal error amplifiers. is determined by the VCCQ or VIN/2 inputs. FEEDBACK The VFB pin is an input that can be used for closed loop compensation. This input is derived from the voltage output. AGSEN pin is a contact node of internal resistor divider for remote sense. APPLICATIONS USING THE CM8500 FOR SSTL BUS TERMINATION Figure 1 is the typical schematic of the CM8500TEVAL that shows the recommended approach for bus terminating solutions for SSTL-2 bus. This circuit can be used in PC memory and Graphics memory applications as shown in Figure 2 and Figure 3. Figure 4 shows the PCB layout of the CM8500TEVAL. Table 1details the key parameters of SSTL_2 specification. Figure 5 shows two different approach of SSTL_2 Terminated Output. (Refer to page 8 for detail description.) 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 4 CM8500 3A BUS TERMINATOR APPLICATION CIRCUIT NOTE: J3:referance output provided from Vtt J4:short :Demo kit on . open:off(into shutdown mode) J6:reference output provided from shunt regulator J5:pin1 ,pin2 short:Vtt = 1/2Vcc 1 2 C13 104 5 Vref-OUT J3 TP1 4 BNC 3 When external voltage applied ,pin1,2 should be open R8 100 and pin2:connect to external voltage (+) 1 2 pin3:connect to external voltage (-) 100uf/6.3V 100uf/6.3V 820uf/6.3V Vtt=1/2 external voltage D6 L1 3.3uH R6,R7(option circuit)forVttVOLTAGEADJUST SK12 Vtt=(Vcc*R6)/R6+R7 VTT J1 1 2 C12 C11 D5 SK12 C7 C3 104 C2 104 C15 10uf/6.3V VCC 1 VDD 2 1 2 C14 100uf/6.3V 3 C4 104 R5 100k 4 5 6 J4ON/OFF 2 7 2 R6 R7 C6 8 10k 10k 102 1 1 U1 CM8500 VCC1 VCC2 VDD1 VDD2 VL1 VL2 PGND1 PGND2 AGND1 AGND4 SD 2/VCC FB VCCQ G-sense AGND3 VCC 16 R1 5R1 J2 DC-INPUT VDD 1 2 VDD 15 14 C5 13 104 C1 104 C9 100uf/6.3V C10 10uf/6.3V C16 470uf/6.3V 12 11 10 9 J5 2 3 1 IN/EXT R3 200k 1 2 1 2 R4 1k C8 102 Figure 1. CM8500 Typical Application (Schematic of CM8500TEVAL) 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 5 CM8500 3A BUS TERMINATOR Figure 2. Termination Solution for PC Main Memory (Mother Boards) Figure 3. Termination Solution for Graphic Memory (AGP Graphics) 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 6 CM8500 3A BUS TERMINATOR CM8500TEVAL PART LIST Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Q'ty Description Resistors 0805, 5, 1/8W 1 0805, 100, 1/8W 1 0805, 470, 1/8W 1 0805, 1K, 1/8W 1 0805, 100K, 1/8W 2 Capacitors 1 0805, 1nF/ 16V (102) 6 0805, 0.1F/ 16V (104) 1 0805, 1F/ 16V (105) CE 10, 820uF/ 6.3V 1 Designator Manufacturer R1 R8 R9 (option) R4 R3, R5 2 B Size, Tant 10uF/ 6.3V 4 D Size, Tant 100uF/ 6.3V Magnetics 1 3.3uH 5A Inductor IC's 1 CM8500IT 1 CM431L Connectors 1 2-pin, 2.54mm 4 2-pin Jumper, 2.54mm 1 3-pin Jumper, 2.54mm PCBs 1 CM8500TEVAL PCB C6, C8 C1, C2, C3, C4, C5 C13 C7 C10, C15 C9, C11, C12, C14 Sanyo OSCON L1 Bipolar Electronic Corp. U1 U2 (option) Champion Microelectronic Corp. Champion Microelectronic Corp. J2 J1, J3, J4, J6 (option) J5 Champion Microelectronic Corp. Vendor Information Bipolar Electronic Corp. Sanyo 2002/09/30 Rev. 1.0 Phn: +886-3-360 8892 Champion Microelectronic Corporation Page 7 CM8500 3A BUS TERMINATOR CM8500TEVAL PCB LAYOUT Figure 4. CM8500EVAL PCB Layout SSTL-2 SPECIFICATIONS SYMBOL PARAMETER MIN TYP VDDQ MAX UNITS N/A V VDD Device Supply Voltage VDDQ Output Supply Voltage 2.3 2.5 2.7 V VREF Input Reference Voltage 1.15 1.25 1.35 V VTT Termination Voltage VREF - 0.04 VREF VREF + 0.04 V INPUT DC LOGIC LEVELS VIH (DC) DC Input Logic High VREF + 0.18 VDDQ + 0.3 V VIL (DC) DC Input Logic Low - 0.3 VREF - 0.18 V INPUT AC LOGIC LEVELS VIH (AC) AC Input Logic High VIL (AC) AC Input Logic Low VREF + 0.35 V VREF - 0.35 V OUTPUT DC CURRENT DRIVE IOH (DC) Output Minimum Source DC Current IOL (DC) Output Minimum Sink DC Current Notes: - 15.2 mA 15.2 mA VREF and VTT must track variations in VDDQ Peak-to-peak AC noise on VREF may not exceed 2% VREF (DC) VTT of transmitting device must track VREF of receiving device Table 1. Key Specifications for SSTL_2 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 8 CM8500 3A BUS TERMINATOR SSTL_2 TERMINATED OUTPUT Single Terminated Output Double Terminated Output Figure 5. SSTL_2 Terminated Output Note. The SSTL_2 specification requires adequate output current drive so that parallel termination schemes can be used. The use of parallel termination is important for high-speed signaling, since it allows proper termination of the bus transmission lines, which reduces signal reflections. The result will be improved settling, lower EMI emissions, and higher possible clock rates. A minimum termination resistance of 23 to VTT can be used and still comply with the minimum output voltages and output currents of the SSTL_2 specification. Two choices for implementing the parallel termination are shown in Figure 5. Double Terminated Output The bus is terminated at both ends with a 50 resistor, for a combined parallel resistance of 25. Single Terminated Output The bus is terminated at the far end from the controller with a single 25 resistor. It is strongly recommended that the single resistor termination scheme be used for best performance. The benefits of this approach include reduced cost, simpler signal routing, reduced reflections, and better signal bandwidth and settling. 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 9 CM8500 3A BUS TERMINATOR CM8500EVAL TESTING DIAGRAM Figure 6. CM8500EVAL Typical Testing Diagram TYPICAL CHARACTERISTICS CM8500 Temperature vs. VTT (VCC,VCCQ&VDD=3.3V) 1.350 VTT(V) 1.300 1A 2A 1.250 3A 1.200 1.150 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 85 T() Temperature vs. VTT VCC, VCCQ & VDD=3.3V 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 10 CM8500 3A BUS TERMINATOR CM8500 Temperature vs. VTT (VCC,VCCQ&VDD=2.5V) 1.350 VTT(V) 1.300 1A 2A 1.250 3A 1.200 1.150 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 85 T() Temperature vs. VTT VCC, VCCQ & VDD=2.5V 2V INPUT LOAD: 0A - 3A 2.5V INPUT LOAD: 0A - 3A 3.3V INPUT LOAD: 0A - 3A 2002/09/30 Rev. 1.0 2V INPUT 2.5V INPUT 3.3V INPUT Champion Microelectronic Corporation LOAD: 3A - 0A LOAD: 3A - 0A LOAD: 3A - 0A Page 11 CM8500 3A BUS TERMINATOR PACKAGE DIMENSION 16-PIN PTSSOP (PT16) 16-PIN PSOP (PS16) 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 12 CM8500 3A BUS TERMINATOR IMPORTANT NOTICE Champion Microelectronic Corporation (CMC) reserves the right to make changes to its products or to discontinue any integrated circuit product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before placing orders, that the information being relied on is current. A few applications using integrated circuit products may involve potential risks of death, personal injury, or severe property or environmental damage. CMC integrated circuit products are not designed, intended, authorized, or warranted to be suitable for use in life-support applications, devices or systems or other critical applications. CMC products in such applications is understood to be fully at the risk of the customer. Use of In order to minimize risks associated with the customer's applications, the customer should provide adequate design and operating safeguards. HsinChu Headquarter Sales & Marketing 5F, No. 11, Park Avenue II, Science-Based Industrial Park, HsinChu City, Taiwan 300 11F, No. 306-3, Sec. 1, Ta Tung Rd., Hsichih, Taipei Hsien Taiwan 221 T E L : +886-3-567 9979 F A X : +886-3-567 9909 http://www.champion-micro.com T E L : +886-2-8692 1591 F A X : +886-2-8692 1596 2002/09/30 Rev. 1.0 Champion Microelectronic Corporation Page 13