L6714TR STMicroelectronics, L6714TR Datasheet
L6714TR
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... Workstation and server CPU power supply ■ VRM modules Order codes Part number L6714 L6714TR November 2006 4 phase controller with embedded drivers for Intel VR10, VR11 and AMD 6Bit CPUs TQFP64 (Exposed Pad) Description L6714 implements a four phase step-down controller with 90º phase-shift between each ...
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Contents Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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L6714 12 Voltage positioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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Contents 23 Tolerance band (TOB) definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 23.1 Controller tolerance ...
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L6714 1 Block diagram Figure 1. L6714 block diagram SS_END / PGOOD OSC / FAULT SS_OSC / REF DIGITAL SOFT START VID0 VID1 VID2 VID3 VID4 VID5 VID6 VID7 / D-VID VID_SEL OUTEN OUTEN HS1 HS1 HS2 LS2 HS3 LOGIC ...
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Pin settings 2 Pin settings 2.1 Connections Figure 2. Pin connection (Through top view) TM SGND VCCDR4 LGATE4 PGND4 PGND2 LGATE2 VCCDR2 VCCDR3 LGATE3 PGND3 PGND1 LGATE1 VCCDR1 PHASE1 N.C. 6/ ...
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L6714 2.2 Functions Table 1. Pin functions N° Pin 1 UGATE1 2 BOOT1 3 N.C. 4 PHASE3 5 UGATE3 6 BOOT3 7 N.C. 8 PHASE2 9 UGATE2 10 BOOT2 11 N.C. 12 PHASE4 13 UGATE4 14 BOOT4 Channel 1 HS ...
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Pin settings Table 1. Pin functions N° Pin 15 VCC DAC/ 16 CS_SEL 17 OUTEN SSOSC/ 18 REF 19 SGND 20 VSEN 21 DROOP COMP 24 CS4+ 8/70 Device supply voltage. The operative voltage is 12V ±15%. ...
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L6714 Table 1. Pin functions N° Pin 25 CS4- 26 CS2+ 27 CS2- 28 CS3+ 29 CS3- 30 CS1+ 31 CS1- 32 OFFSET Channel 4 Current Sense Negative Input. LS Mosfet Sense: connect through a resistor Rg to the LS ...
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Pin settings Table 1. Pin functions N° Pin 33 OVP 34 VID_SEL 35 FBR 36 FBG OSC/ 37 FAULT VID7/ 38 DVID 39 VID6 40 to VID5 to 45 VID0 10/70 Over Voltage Programming Pin. Internally pulled up by 12.5µA(typ) ...
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L6714 Table 1. Pin functions N° Pin SS_END/ 46 PGOOD 47 VR_HOT 48 VR_FAN SGND 51 VCCDR4 52 LGATE4 53 PGND4 54 PGND2 55 LGATE2 56 VCCDR2 57 VCCDR3 58 LGATE3 59 PGND3 SSEND - Intel Mode. ...
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Pin settings Table 1. Pin functions N° Pin 60 PGND1 61 LGATE1 62 VCCDR1 63 PHASE1 64 N.C. THERMAL PAD PAD 12/70 Channel 1 LS Driver return path. Connect to Power ground Plane. Channel 1 LS Driver Output.A small series ...
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L6714 3 Electrical data 3.1 Maximum rating Table 2. Absolute maximum ratings Symbol PGNDx CC CCDRx V - BOOTx Boot voltage V PHASEx V - UGATEx V PHASEx BOOTx LGATEx, PHASEx, to ...
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Electrical characteristics 4 Electrical characteristics V = 12V ± 15 Table 4. Electrical characteristics Symbol Parameter Supply Current I VCC supply current CC I VCCDRx supply current CCDRx I BOOTx supply current BOOTx Power-ON VCC turn-ON UVLO VCC ...
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L6714 Table 4. Electrical characteristics Symbol Parameter Reference and DAC k Output voltage accuracy VID REF Reference accuracy V Boot voltage BOOT VID Pull-up current I VID VID Pull-down current VID IL VID thresholds VID IH VID_SEL threshold VID_SEL (Intel ...
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Electrical characteristics Table 4. Electrical characteristics Symbol Parameter Gate drivers t HS rise time RISE_UGATEx I HS source current UGATEx R HS sink resistance UGATEx t LS rise time RISE_LGATEx I LS source current LGATEx R LS sink resistance LGATEx ...
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L6714 5 VID Tables 5.1 Mapping for the Intel VR11 mode Table 5. Voltage Identification (VID) Mapping for Intel VR11 Mode VID7 VID6 800mV 400mV 5.2 Voltage Identification (VID) for Intel VR11 mode Table 6. Voltage Identification (VID) for Intel ...
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VID Tables Table 6. Voltage Identification (VID) for Intel VR11 mode Output HEX Code voltage ( 1.46875 1 8 1.46250 1 9 1.45625 1 A 1.45000 1 B 1.44375 1 C 1.43750 1 D 1.43125 1 E 1.42500 ...
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L6714 Table 6. Voltage Identification (VID) for Intel VR11 mode Output HEX Code voltage ( 1.26250 3 9 1.25625 3 A 1.25000 3 B 1.24375 3 C 1.23750 3 D 1.23125 3 E 1.22500 3 F 1.21875 1. ...
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VID Tables Table 7. Voltage identifications (VID) for Intel VR10 mode + 6.25mV VID VID VID VID ...
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L6714 Table 7. Voltage identifications (VID) for Intel VR10 mode + 6.25mV VID VID VID VID ...
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VID Tables Table 9. Voltage identifications (VID) codes for AMD 6BIT mode VID VID VID ...
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L6714 6 Reference schematic Figure 3. Reference schematic - Intel VR10.x, VR11 inductor sense V IN GND IN VID_SEL OUTEN +5V NTC L6714 REF. SCH. (INDUCTOR - Intel Mode VCCDR1 ...
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Reference schematic Figure 4. Reference schematic - Intel VR10.x, VR11 LS MOSFET sense V IN GND IN 170k VID_SEL OUTEN +5V NTC L6714 REF. SCH. (MOSFET - Intel Mode) 24/ ...
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L6714 Figure 5. Reference schematic - AMD 6BIT inductor sense V IN GND IN OUTEN +5V L6714 REF. SCH. (INDUCTOR - AMD 6BIT Mode VCCDR1 BOOT1 56 VCCDR2 57 1 VCCDR3 UGATE1 63,64 ...
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Reference schematic Figure 6. Reference schematic - AMD 6BIT LS MOSFET sense V IN GND IN OUTEN +5V NTC L6714 REF. SCH. (MOSFET - AMD 6BIT Mode) 26/ VCCDR1 BOOT1 ...
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L6714 7 Device description L6714 is four-phase PWM controller with embedded high current drivers that provides complete control logic and protections for a high performance step-down DC-DC voltage regulator optimized for advanced microprocessor power supply. Multi phase buck is the ...
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Configuring the device 8 Configuring the device Multiple DACs and different current reading methodologies need to be configured before the system starts-up by programming the apposite pin DAC/CS_SEL. The configuration of this pin identifies two main working areas between compliancy ...
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L6714 Table 11. Intel mode configuration Pin It allows selecting the Intel Mode and, furthermore, between Inductor or LS MOSFET DAC / CS_SEL current reading. Static info, no dynamic changes allowed. It allows programming the soft-start time T SSOSC / ...
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Power dissipation 9 Power dissipation L6714 embeds high current MOSFET drivers for both high side and low side MOSFET then important to consider the power the device is going to dissipate in driving them in order to avoid ...
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L6714 Figure 7. L6714 dissipated power (Quiescent + switching). 5000 4500 4000 3500 3000 2500 2000 1500 1000 500 0 50 7000 6000 5000 4000 3000 2000 1000 0 50 L6714; Rgate=0; Rmosfet=0 HS=1xSTD38NH02L; LS=1xSTD90NH02L HS=2xSTD38NH02L; LS=2xSTD90NH02L HS=1xSTD55NH22L; LS=1xSTD95NH02L HS=2xSTD55NH22L; ...
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Current reading and current sharing loop 10 Current reading and current sharing loop L6714 embeds a flexible, fully-differential current sense circuitry that is able to read across both low side or inductor parasitic resistance or across a sense resistor placed ...
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L6714 10.1 Low side current reading When reading current across LS, the current flowing trough each phase is read using the voltage drop across the low side MOSFET internally converted into a current. The trans-conductance ratio is ...
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Current reading and current sharing loop Figure 9. Current reading connections. LGATEx CSx- I CSx CSx+ LS Mosfet R Considering now to match the time constant between the inductor and the R-C filter applied (Time constant mismatches cause ...
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L6714 11 Remote voltage sense The device embeds a Remote Sense Buffer to sense remotely the regulated voltage without any additional external components. In this way, the output voltage programmed is regulated between the remote buffer inputs compensating motherboard or ...
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Voltage positioning 12 Voltage positioning Output voltage positioning is performed by selecting the reference DAC and by programming the Droop Function and Offset to the reference sourced from DROOP and FB pins cause the output voltage to vary according to ...
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L6714 12.1 Droop function (Optional) This method "recovers" part of the drop due to the output capacitor ESR in the load transient, introducing a dependence of the output voltage on the load current: a static error proportional to the output ...
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Voltage positioning 12.2 Offset (Optional) The OFFSET pin allows programming a positive offset (V connecting a resistor R one already introduced during the production stage for the Intel VR10,VR11 Mode. The OFFSET pin is internally fixed at 1.240V connecting the ...
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L6714 13 Dynamic VID transitions The device is able to manage Dynamic VID Code changes that allow Output Voltage modification during normal device operation. OVP and UVP signals (and PGOOD in case of AMD Mode) are masked during every VID ...
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Dynamic VID transitions Figure 13. Dynamic VID transitions VID Clock VID [0,7] Int. Reference T DVID out x 4 Step VID Transition Vout Slope Controlled by internal DVID-Clock Oscillator 40/70 T VID Step VID ...
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L6714 14 Enable and disable L6714 has three different supplies: VCC pin to supply the internal control logic, VCCDRx to supply the low side drivers and BOOTx to supply the high side drivers. If the voltage at pins VCC and ...
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Soft start 15 Soft start L6714 implements a soft-start to smoothly charge the output filter avoiding high in-rush currents to be required to the input power supply. The device increases the reference from zero up to the programmed value in ...
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L6714 15.1 Intel mode Once L6714 receives all the correct supplies and enables, and Intel Mode has been selected, it initiates the Soft-Start phase with a T ramps BOOT waits for sec 3 then ...
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Soft start Figure 15. Soft-start time for Intel mode 15.2 AMD mode Once L6714 receives all the correct supplies and enables, and AMD Mode has been selected, it initiates the ...
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L6714 Figure 16. Soft-start time for AMD mode 4 3.5 3 2.5 2 1.5 Time to 1.6000V Time to 1.1000V 1 Switching Frequency per phase 0 200 400 Rosc [kOhms] to SGND 4 3.5 3 2.5 2 1.5 ...
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Soft start 15.3 Low-Side-Less startup In order to avoid any kind of negative undershoot on the load side during start-up, L6714 performs a special sequence in enabling LS driver to switch: during the soft-start phase, the LS driver results disabled ...
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L6714 16 Output voltage monitor and protections L6714 monitors through pin VSEN the regulated voltage in order to manage the OVP, UVP and PGOOD (when applicable) conditions. The device shows different thresholds when programming different operation mode (Intel or AMD, ...
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Output voltage monitor and protections 16.3 Over voltage and programmable OVP Once VCC crosses the turn-ON threshold and the device is enabled (OUTEN = 1), L6714 provides an Over Voltage Protection: when the voltage sensed by VSEN overcomes the OVP ...
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L6714 17 Maximum Duty-cycle limitation The device limits the maximum duty cycle and this value is not fixed but it depends on the delivered current given by the following relationship: D max From the previous relationships the maximum duty cycle ...
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Over current protection 18 Over current protection Depending on the current reading method selected, the device limits the peak or the bottom of the inductor current entering in constant current until setting UVP as below explained. The Over Current threshold ...
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L6714 18.1 Low side MOSFET sense over current The device detects an Over Current condition for each phase when the current information I overcomes the fixed threshold of I INFOx keeps the relative LS MOSFET on, also skipping clock cycles, ...
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Over current protection in this particular situation, the switching frequency for each phase results reduced. The ON time is the maximum allowed T Figure 20. Constant current I PEAK I MAX I OCPx Skipping ON(max) Clock Cycles ...
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L6714 18.2 Inductor sense over current The device detects an over current when the II Since the device always senses the current across the inductor, the I happen during the HS conduction time consequence of OCP detection, the ...
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Oscillator 19 Oscillator L6714 embeds four phase oscillator with optimized phase-shift (90º phase-shift) in order to reduce the input rms current and optimize the output filter definition. The internal oscillator generates the triangular waveform for the PWM charging and discharging ...
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L6714 Figure 21. R OSC 7000 6000 5000 4000 3000 2000 1000 550 500 450 400 350 300 250 200 150 100 50 0 vs. switching frequency Fsw [kHz] Selected 150 250 350 450 550 Fsw ...
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Driver section 20 Driver section The integrated high-current drivers allow using different types of power MOS (also multiple MOS to reduce the equivalent R The drivers for the high-side MOSFETs use BOOTx pins for supply and PHASEx pins for return. ...
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L6714 21 System control loop compensation The control loop is composed by the Current Sharing control loop Average Current Mode control loop. Each loop gives, with a proper gain, the correction to the PWM in order to minimize the error ...
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System control loop compensation Where: ● the MOSFET R SENSE selected; R ● --------------------- R = DROOP function; ● Z (s) is the impedance resulting by the parallel of the output capacitor (and its ESR) P and the ...
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L6714 Compensation network can be simply designed placing frequency as desired obtaining (always considering that T 1/10th of the switching frequency F 21.1 Compensation network guidelines The Compensation Network design assures to having system response according to the cross-over frequency ...
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Thermal monitor 22 Thermal monitor L6714 continuously senses the system temperature through TM pin: depending on the voltage sensed by this pin, the device sets free the VR_FAN pin as a warning and, after further temperature increase, also the VR_HOT ...
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L6714 23 Tolerance band (TOB) definition Output voltage load-line varies considering component process variation, system temperature extremes, and age degradation limits. Moreover, individual tolerance of the components also varies among designs then possible to define a Manufacturing Tolerance ...
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Tolerance band (TOB) definition 23.2 Ext. current sense circuit tolerance (TOB CurrSense - Inductor Sense) It can be further sliced as follow: ● Inductor DCR Tolerance (k voltage since the device reads a current that is different from the real ...
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L6714 23.3 Time constant matching error tolerance (TOB TCMatching) ● Inductance and capacitance Tolerance (k in the value of the capacitor used for the Time Constant Matching causes over/under shoots after a load transient appliance. This impacts the output voltage ...
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Layout guidelines 24 Layout guidelines Since the device manages control functions and high-current drivers, layout is one of the most important things to consider when designing such high current applications. A good layout solution can generate a benefit in lowering ...
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L6714 24.2 Small signal components and connections These are small signal components and connections to critical nodes of the application as well as bypass capacitors for the device supply capacitor (VCC, VCCDRx and Bootstrap capacitor) close to the device and ...
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Embedding L6714 - Based VR 25 Embedding L6714 - Based VR When embedding the VRD into the application, additional care must be taken since the whole VRD is a switching DC/DC regulator and the most common system in which it ...
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L6714 26 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a Lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the ...
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Package mechanical data Table 13. TQFP64 mechanical data Dim 11. 11. ccc Figure 27. Package dimensions 68/70 mm. Min Typ Max 1.20 0.05 ...
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L6714 27 Revision history Table 14. Revision history Date 16-Mar-2006 02-Aug-2006 07-Nov-2006 Revision 1 Initial release. Updated IDROOP 2 characteristics on page Updated D2 and E2 exposed tab measures in 3 TQFP64 mechanical Revision history Changes values ...
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... Revision history Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...