L6706TR STMicroelectronics, L6706TR Datasheet

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... CPU power supply ■ High density DC/DC converters Table 1. Device summary Order codes L6706 L6706TR January 2010 VFQFPN- Description The device implements a single phase step-down controller with integrated high current driver in a compact 6x6 mm body package with exposed pad. The device embeds VR11.x DACs: the output voltage ranges ...

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Contents Contents 1 Principle application circuit and block diagram . . . . . . . . . . . . . . . . . . . 4 1.1 Principle application circuit . . . . . . . ...

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L6706 14.1 Low-side-less startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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Principle application circuit and block diagram 1 Principle application circuit and block diagram 1.1 Principle application circuit Figure 1. Principle application circuit V = 12V IN GND Optional:Pre-OVP V To Vcc R SSOSC Optional: D See DS ...

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L6706 1.2 Block diagram Figure 2. Block diagram OSC / FAULT SSOSC/ FLIMT DIGITAL SOFT START VID0 VID1 VID2 VID3 VID4 VID5 VID6 VID7 Principle application circuit and block diagram LOGIC PWM ADAPTIVE ANTI CROSS CONDUCTION PWM LTB SSOSC L6706 ...

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Pins description and connection diagrams 2 Pins description and connection diagrams Figure 3. Pins connection (top view) 2.1 Pin description Table 2. Pin description N° Name 1 DGND 2 SGND 3 VCC 4 COMP VSEN 7 FBG ...

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L6706 Table 2. Pin description (continued) N° Name 8 LTB 9 IMON 10 LTBGAIN 11 OFFSET 12 OVPSEL 13 OCSET OSC/ 14 FAULT SSOSC/ 15 FLIMIT Pins description and connection diagrams Load transient boost pin. Internally fixed ...

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Pins description and connection diagrams Table 2. Pin description (continued) N° Name 16 OUTEN 17 CS+ 18 CS- 19 INT1 VID0 VID7 28 INT2 29 SSEND 30 N.C. 31 INT3 32 N.C. 33 INT4 34 N.C. ...

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L6706 Table 2. Pin description (continued) N° Name 39 UGATE 40 BOOT Thermal PAD PAD 2.2 Thermal data Table 3. Thermal data Symbol Thermal resistance junction to ambient R thJA (Device soldered on 2s2p PC board) R Thermal resistance junction ...

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Electrical specifications 3 Electrical specifications 3.1 Absolute maximum ratings Table 4. Absolute maximum ratings Symbol PGND CC, CCDR V - BOOT Boot voltage V PHASE V - UGATE V PHASE LGATE to PGND All other pins to ...

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L6706 3.2 Electrical characteristics ± 15 Table 5. Electrical characteristics Symbol Parameter Supply current and power-on I VCC supply current CC I VCCDR supply current CCDR I BOOT supply current BOOT Power-on VCC turn-ON ...

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Electrical specifications Table 5. Electrical characteristics (continued) Symbol Parameter SR EA slew-rate Differential current sensing and offset V OCSET pin voltage OCSET Droop current deviation from K IDROOP nominal value K Offset current accuracy IOFFSET I OFFSET current range OFFSET ...

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L6706 4 Voltage identifications Table 6. Voltage Identification (VID) mapping Intel VR11.x VID7 VID6 800 mV 400 mV Table 7. Voltage Identification (VID) Intel VR11.x Output HEX code voltage 0 0 OFF 0 1 OFF 0 2 1.60000 0 3 ...

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Voltage identifications Table 7. Voltage Identification (VID) Intel VR11.x Output HEX code voltage 1 A 1.45000 1 B 1.44375 1 C 1.43750 1 D 1.43125 1 E 1.42500 1 F 1.41875 2 0 1.41250 2 1 1.40625 2 2 1.40000 ...

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L6706 Table 7. Voltage Identification (VID) Intel VR11.x Output HEX code voltage 3 C 1.23750 3 D 1.23125 3 E 1.22500 3 F 1.21875 1. According to INTEL specs, the device automatically regulates output voltage 19 mV lower to avoid ...

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Device description 5 Device description L6706 is single phase PWM controller with embedded high current drivers providing complete control logic and protections for a high performance step-down DC-DC voltage regulator optimized for advanced microprocessor power supply. L6706 is a dual-edge ...

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L6706 6 DAC and current reading L6706 embeds VRD11.x DAC (see tolerance of ±0.5% recovering from offsets and manufacturing variations. The device automatically introduces a -19 mV (both VRD11.x) offset to the regulated voltage in order to avoid any external ...

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DAC and current reading causing instability. In addition also important for the load transient response and to let the system show resistive equivalent output impedance), it results: L ------------ - = DCR Where I is the current information ...

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L6706 7 Differential remote voltage sensing The output voltage is sensed in fully-differential mode between the FB and FBG pin. The FB pin has to be connected through a resistor to the regulation point while the FBG pin has to ...

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Voltage positioning 8 Voltage positioning Output voltage positioning is performed by selecting the internal reference value through VID pins and by programming the droop function and offset to the reference (see on page 20). The currents sourced/sunk from FB pin ...

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L6706 where: Offset resistor can be designed by considering the following relationship (RFB is fixed by the Droop effect): Offset automatically given by the DAC selection differs from the offset implemented through the OFFSET pin: the built-in feature is trimmed ...

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Voltage positioning “real” voltage generator with an equivalent output resistance resistor can be also designed according to the R PROG FB 22/47 Rg ⋅ ------------ - = FB DROOP DCR Doc ID 15698 Rev ...

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L6706 9 Droop thermal compensation Current sense element (DCR inductor) has a non-negligible temperature variation consequence, the sensed current is subjected to a measurement error that causes the regulated output voltage to vary accordingly (when droop function is ...

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Output current monitoring (IMON) 10 Output current monitoring (IMON) The device sources from IMON pin a current proportional to the load current (the sourced current is a copy of droop current). Connect IMON pin through a R load indicator, as ...

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L6706 where T is the temperature. If the inductor temperature increases the DCR inductor increases and NTC resistor decreases consequence the equivalent R the monitoring voltage respect to temperature variation. NTC resistor must be placed as close as ...

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Load transient boost technology 11 Load transient boost technology LTB Technology™ further enhances the performances of dual-edge asynchronous systems by reducing the system latencies and immediately turning ON the phase to provide the correct amount of energy to the load. ...

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L6706 ● Gain design. Through the LTBGAIN pin it is possible to modify the slope of the LTB Ramp in order to modulate the entity of the LTB response once the LT has been detected. In fact, the response depends ...

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Dynamic VID transitions 12 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 are masked during every VID transition and they are re-activated ...

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L6706 Figure 12. Dynamic VID transitions VID Clock VID [0,7] Int. Reference T V out DVID Step VID Transition Vout Slope Controlled by internal DVID-Clock Oscillator Doc ID 15698 Rev 2 Dynamic VID transitions VID ...

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Enable and disable 13 Enable and disable L6706 has three different supplies: VCC pin to supply the internal control logic, VCCDR to supply the low side driver and BOOT to supply the high side driver. If the voltage at pin ...

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L6706 14 Soft-start L6706 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 and the output ...

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Soft-start Figure 14. SSOSC connection [ μs ] 200 μ where T is the time spent to reach the programmed voltage V SS connected between SSOSC and SSEND (through a signal diode) in kΩ. Figure 15. Soft-start ...

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L6706 Note: Connecting SSOSC pin to SGND through only the R Figure 14), the soft-start time depends on the F In this case use the following relationship to select F start time: Figure 16. Soft-start time (T 14.1 Low-side-less startup ...

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Output voltage monitor and protections 15 Output voltage monitor and protections L6706 monitors through pin VSEN the regulated voltage in order to manage the OVP and UVP conditions. Protections are active also during soft-start they are masked during D-VID transitions ...

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L6706 15.3 Over voltage and programmable OVP Once VCC crosses the turn-ON threshold and the device is enabled (OUTEN = 1), L6706 provides an over voltage protection: when the voltage sensed by VSEN overcomes the OVP threshold (OVP TH – ...

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Output voltage monitor and protections OCP during normal operation of the device. This value must take into consideration also the extra current needed during the dynamic VID transition I transitions for details): The device detects an over current when the ...

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L6706 15.5 Feedback disconnection L6706 allows to protect the load from dangerous over voltage also in case of feedback disconnection. The device is able to recognize both FB pin and FBG pin disconnections, as shown in the Figure When VSEN ...

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Oscillator 16 Oscillator The internal oscillator generates the triangular waveform for the PWM charging and discharging with a constant current an internal capacitor. The current delivered to the oscillator is typically 25 μA (corresponding to the free running frequency F ...

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L6706 17 Driver section The integrated high-current driver allow using different types of power MOS (also multiple MOS to reduce the equivalent R The driver for the high-side MOSFETs use BOOT pin for supply and PHASE pin for return. The ...

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System control loop compensation 18 System control loop compensation The control loop is an average current mode control loop (see is equal to the reference programmed by VID minus the droop function terms. The system control loop is reported in ...

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L6706 desired crossover frequency ω zero and two poles; both the poles are fixed once the output filter is designed (LC filter resonance ω ) and the zero (ω LC Figure 24. Equivalent control loop block diagram (left) and bode ...

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Power dissipation 19 Power dissipation L6706 embeds high current MOSFET drivers for both high side and low side MOSFETs then important to consider the power the device is going to dissipate in driving them in order to avoid ...

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L6706 20 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 power ...

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Layout guidelines points far from the load will cause a non-optimum load regulation, increasing output tolerance. Locate current reading components close to the device. The PCB traces connecting the reading point must use dedicated nets, routed as parallel traces in ...

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L6706 21 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ...

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Revision history 22 Revision history Table 10. Document revision history Date 26-May-2009 20-Jan-2010 46/47 Revision 1 First release Updated Table 2 on page 2 page 24, Figure 9 on page 24 Doc ID 15698 Rev 2 L6706 Changes 6, Table ...

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... L6706 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. ...