Multifunctional Voltage Regulator and Watchdog TLE 6711 Data Sheet 1 Overview 1.1 Features • • • • • • • • • • • • • Step up converter (Boost Voltage) Boost Over- and Under-Voltage-Lockout Step down converter (Logic Voltage) 2% output voltage tolerance Logic Over- and Under-Voltage-Lockout Overtemperature Shutdown Power ON/OFF reset generator Digital window watchdog System Enable Output Ambient operation temperature range – 40 °C to 125 °C Wide Supply voltage operation range Very low current consumption Very small P-DSO-14-3 SMD package Type Ordering Code Package TLE 6711 G Q67006-A9455-A201-A7 P-DSO-14-3 1.2 Functional Description The TLE 6711 G is a multifunctional power supply circuit especially designed for automotive applications. It delivers a programmable step up voltage (Boost) and a precise 5 V fully short circuit protected output voltage (Buck). The TLE 6711 G contains a power on reset feature to start up the system, an integrated digital window watchdog to monitor the connected microcontroller and a system enable output to indicate the microcontroller window watchdog faults. The device is based on Infineon’s power technology SPT® which allows bipolar and CMOS control circuitry to be integrated with DMOS power devices on the same monolithic circuitry. The very small P-DSO-14-3 SMD packages meet the application requirements. Furthermore, the build-in features like under- and overvoltage lockout for boost- and Data Sheet V 2.22 1 2001-04-23 TLE 6711 Overview buck-voltage and the overtemperature shutdown feature increase the reliability of the TLE 6711 G supply system. 1.3 Pin Definitions and Functions Pin No. SO-14 Symbol Function 1 R Reference Input; an external resistor from this pin to GND determines the reference current and the oscillator frequency 2 RO Reset Output; open drain output from reset comparator with an internal pull up resistor 3 WDI Watchdog Input; input for the watchdog control signal from the controller 4 GND Ground; analog signal ground 5 SEN System Enable Output; open drain output from Watchdog fail-circuit with an internal pull up resistor 6 BUC Buck-Converter Compensation Input; output of internal error amplifier; for loop-compensation connect an external R-C-series combination to GND 7 VCC Supply Voltage Output; buck converter output; external blocking capacitor necessary 8 BUO Buck Converter Output; source of the integrated power-DMOS 9 VBOOST Boost Converter Input; input supply voltage of the IC; coming from the boost converter output voltage; buck converter input voltage 10 BDS Buck Driver Supply Input; voltage to drive the buck converter powerstage 11 OVL Boost Status Output; open drain output from boost PWM comparator 12 BOFB Boost Converter Feedback Input; connect boost voltage divider to this pin; internal reference is the boost feedback threshold VBOFBTH 13 BOGND Boost-Ground; power signal ground; source of boost converter power-DMOS 14 BOI Data Sheet V 2.22 Boost Converter Input; drain of the integrated buck converter power-DMOS 2 2001-04-23 TLE 6711 Overview 1.4 Pin Configuration R RO WDI GND SEN BUC VCC 1 2 3 4 5 6 7 14 13 12 11 10 9 8 BOI BOGND BOFB OVL BDS VBoost BUO AEP02960 Figure 1 Pin Configuration (top view) Data Sheet V 2.22 3 2001-04-23 TLE 6711 Overview 1.5 Block Diagram BOFB 12 TLE 6711 G 14 Boost Converter Biasing 13 VBoost 10 VREF 9 BUC 6 Buck Converter 8 7 VInternal 5 R 1 Reset, Window Watchdog and System Enable Reference Current Generator and Oscillator 3 2 11 BOI BOGND BDS VBOOST BUO VCC SEN WDI RO OVL 4 GND Figure 2 AEB02949 Block Diagram Data Sheet V 2.22 4 2001-04-23 TLE 6711 Overview 1.6 Absolute Maximum Ratings Parameter Symbol Limit Values Unit Remarks min. max. VBOI VBOOST VBOFB VBUO VBDS VBUC – 0.3 46 V – – 0.3 46 V – – 0.3 46 V – –1 46 V – – 0.3 48 V – – 0.3 6.8 V – VCC VRO VSEN – 0.3 6.8 V – – 0.3 6.8 V – – 0.3 6.8 V – VR VWDI VOVL – 0.3 6.8 V – – 0.3 6.8 V – – 0.3 6.8 V – Voltages Boost input voltage Boost output voltage Boost feedback voltage Buck output voltage Buck driver supply voltage Buck compensation input voltage Logic supply voltage Reset output voltage System Enable output voltage Current reference voltage Watchdog input voltage OVL output voltage ESD-Protection (Human Body Model; R = 1.5 kΩ; C = 100 pF) All pins to GND VHBM –2 2 kV – Tj Tstg – 40 150 °C – – 50 150 °C – Temperatures Junction temperature Storage temperature Note: Stresses above those listed here may cause permanent damage to the device. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Data Sheet V 2.22 5 2001-04-23 TLE 6711 Overview 1.7 Operating Range Parameter Symbol Limit Values Unit Remarks min. max. VBOI VBOOST – 0.3 40 V – 5 35 V VBOOST increasing Boost input voltage; (normal operation) VBOOST 4.5 36 V VBOOST decreasing Boost input voltage VBOOST – 0.3 4.5 V Boost- and Buck-Converter OFF 0 3.0 V – – 0.6 40 V – – 0.3 48 V – 0 3.0 V – VCC VRO VSEN 4.00 6.25 V – – 0.3 – – 0.3 VCC + 0.3 V VCC + 0.3 V VWDI VR Tj 0 VCC + 0.3 V – 0 3.0 V – – 40 150 °C – Rthj-a – 120 K/W – Boost input voltage Boost input voltage; (normal operation) VBOFB Buck output voltage VBUO Buck driver supply voltage VBDS Buck compensation input VBUC Boost feedback voltage voltage Logic supply voltage Reset output voltage System Enable output voltage Watchdog input voltage Current reference voltage Junction temperature – Thermal Resistance Junction ambient Note: In the operating range, the functions given in the circuit description are fulfilled. Data Sheet V 2.22 6 2001-04-23 TLE 6711 Overview 1.8 Electrical Characteristics 8 V < VBoost < 35 V; 4.75 V < VCC < 5.25 V; – 40 °C < Tj < 150 °C; RR = 47 kΩ; all voltages with respect to ground; positive current defined flowing into pin; unless otherwise specified. Parameter Symbol Limit Values min. typ. max. Unit Test Conditions Current Consumption Current consumption; see application circuit IBoost – 1.5 4 Current consumption; see application circuit IBoost – 5 10 ICC = 0 mA; IBoLoad = 0 mA mA ICC = 200 mA; IBoLoad = 50 mA mA Under- and Over-Voltage Lockout at VBoost UV ON voltage; boost and buck conv. ON VBOUVON 4.0 4.5 5.0 V VBOOST increasing; UV OFF voltage; boost and buck conv. OFF VBOUVOFF 3.5 4.0 4.5 V VBOOST decreasing UV Hysteresis voltage VBOUVHY 0.2 VBOOVOFF 34 0.5 1.0 V HY = ON - OFF 37 40 V VBOOST increasing OV ON voltage; boost conv. ON VBOOVON 30 33 36 V VBOOST decreasing OV Hysteresis voltage VBOUVHY 4 10 V HY = OFF - ON OV OFF voltage; boost conv. OFF 1.5 Over-Voltage Lockout at VCC OV OFF voltage; buck conv. OFF VBUOVOFF 5.5 6.0 6.5 V VCC increasing OV ON voltage; buck conv. ON VBUOVON 5.25 5.75 6.25 V VCC decreasing OV Hysteresis voltage VBUOVHY 0.25 0.50 V HY = OFF - ON Data Sheet V 2.22 0.10 7 2001-04-23 TLE 6711 Overview 1.8 Electrical Characteristics (cont’d) 8 V < VBoost < 35 V; 4.75 V < VCC < 5.25 V; – 40 °C < Tj < 150 °C; RR = 47 kΩ; all voltages with respect to ground; positive current defined flowing into pin; unless otherwise specified. Parameter Symbol Limit Values min. typ. max. Unit Test Conditions Boost-Converter; BOI, BOFB and VBOOST Boost voltage; see application circuit VBOOST 24.0 27.5 31.0 V 5 mA < IBoost < 100 mA; Tj = 25 °C 8 V < VBatt < 16 V Boost Voltage; see application circuit VBOOST 23 – 32 V 5 mA < IBoost < 100 mA; 8 V < VBatt < 16 V – 80 – % Efficiency; see. appl. circuit η Power-Stage ON resistance RBOON – 0.6 0.75 Ω Power-Stage ON resistance RBOON – – 1.4 Ω IBoost = 100 mA Tj = 25 °C; IBOI = 1 A IBOI = 1 A Boost overcurrent threshold IBOOC 1.0 1.3 1.8 A – Feedback threshold voltage VBOFBTH 2.55 2.7 2.85 V –2 – 0.4 0 µA VBOI = 12 V IBoost = 25 mA 2 V < VBOFB< 4 V 4.9 – 5.1 V 1 mA < ICC < 250 mA; see. appl. circuit – 85 – % Feedback input current IFB Buck-Converter; BUO, BDS, BUC and VCC Logic supply voltage VCC Efficiency; see. appl. circuit η Power-Stage ON resistance RBUON – 0.38 0.5 Ω Power-Stage ON resistance RBUON – – 1.0 Ω ICC = 250 mA; VBoost = 25 V Tj = 25 °C; IBUO = 1 A IBUO = 1 A 0.7 0.95 1.2 A – Buck overcurrent threshold IBUOC Data Sheet V 2.22 8 2001-04-23 TLE 6711 Overview 1.8 Electrical Characteristics (cont’d) 8 V < VBoost < 35 V; 4.75 V < VCC < 5.25 V; – 40 °C < Tj < 150 °C; RR = 47 kΩ; all voltages with respect to ground; positive current defined flowing into pin; unless otherwise specified. Parameter Input current on pin VCC Buck Gate supply voltage; VBGS = VBDS – VBOOST Symbol ICC VBGS Limit Values Unit Test Conditions min. typ. max. – 0.2 0.5 mA VCC = 5 V 5 – 10 V – Reference Input; R (Oscillator; Timebase for Boost- and Buck-Converter, Reset and Watchdog) VR fOSC fOSC tCYL 1.3 1.4 1.5 V 85 95 105 kHz Tj = 25 °C 75 – 115 kHz – – 1.05 – ms tCYL = 100/fOSC Reset threshold; VCC decreasing/increasing VRT 4.50 4.65 4.75 V VRO H to L or L to H Reset low voltage VROL – 0.2 0.4 V Reset low voltage VROL – 0.2 0.4 V Reset high voltage VROH VCC – – VCC + V 0.1 0.1 Voltage on pin R Oscillator frequency Oscillator frequency Cycle time for watchdog and reset timing – Reset Generator; RO Reset pull up current Reset Reaction time Power-up reset delay time Data Sheet V 2.22 transition; VRO remains low down to VCC > 1 V IRO tRR tRD IROL = 2 mA; 2.5 V < VCC < VRT IROL = 0.2 mA; 1 V < VCC < VRT IROH = 0 mA – 240 – µA 0 V < VRO < 4 V 50 100 150 µs – 64 – tCYL VCC < VRT VCC ≥ 4.8 V 9 2001-04-23 TLE 6711 Overview 1.8 Electrical Characteristics (cont’d) 8 V < VBoost < 35 V; 4.75 V < VCC < 5.25 V; – 40 °C < Tj < 150 °C; RR = 47 kΩ; all voltages with respect to ground; positive current defined flowing into pin; unless otherwise specified. Parameter Symbol Limit Values Unit Test Conditions min. typ. max. – – 0.7 × V Watchdog Generator; WDI H-input voltage threshold VWDIH – VCC L-input voltage threshold VWDIL 0.3 × – – V – VCC TWD tSR – 128 – – 64 – tCYL VCC ≥ 4.8 V tCYL VCC ≥ 4.8 V Reset duration; after watchdog time-out tWDR – 64 – tCYL VCC ≥ 4.8 V Open window time tOW tCW tWD – 32 – – 32 – – 46.4 – tCYL VCC ≥ 4.8 V tCYL VCC ≥ 4.8 V tCYL VCC ≥ 4.8 V Watchdog period Start of reset; after watchdog time-out Closed window time Window watchdog trigger time System Enable Output; SEN Enable low voltage VSENL – 0.2 0.4 V Enable low voltage VSENL – 0.2 0.4 V Enable high voltage VSENH VCC – – VCC + V 0.1 0.1 Enable pull up current Data Sheet V 2.22 ISEN – 240 10 – µA ISENL = 2 mA; 2.5 V < VCC < VRT ISENL = 0.2 mA; 1 V < VCC < VRT ISENH = 0 mA 0 V < VSEN < 4 V 2001-04-23 TLE 6711 Overview 1.8 Electrical Characteristics (cont’d) 8 V < VBoost < 35 V; 4.75 V < VCC < 5.25 V; – 40 °C < Tj < 150 °C; RR = 47 kΩ; all voltages with respect to ground; positive current defined flowing into pin; unless otherwise specified. Parameter Symbol Limit Values min. typ. max. Unit Test Conditions Boost Status Output; OVL Enable low voltage VOVLL – 0.2 0.4 V IOVLL = 1 mA; 2.5 V < VCC < VRT Boost feedback threshold voltage; VOVLTH 2.3 2.45 2.6 V See application circuit Thermal Shutdown (Boost and Buck-Converter OFF) Thermal shutdown junction TjSD temperature 150 175 200 °C – Thermal switch-on junction TjSO temperature 120 – 170 °C – – 30 – K – Temperature hysteresis ∆T Note: The listed characteristics are ensured over the operating range of the integrated circuit. Typical characteristics specify mean values expected over the production spread. If not otherwise specified, typical characteristics apply at TA = 25 °C and the given supply voltage. Data Sheet V 2.22 11 2001-04-23 TLE 6711 Circuit Description 2 Circuit Description Below some important sections of the TLE 6711 are described in more detail. 2.1 Power On Reset In order to avoid any system failure, a sequence of several conditions has to be passed. In case of VCC power down (VCC < VRT for t > tRR) a logic LOW signal is generated at the pin RO to reset an external microcontroller. When the level of VCC reaches the reset threshold VRT, the signal at RO remains LOW for the Power-up reset delay time tRD before switching to HIGH. If VCC drops below the reset threshold VRT for a time extending the reset reaction time tRR, the reset circuit is activated and a power down sequence of period tRD is initiated. The reset reaction time tRR avoids wrong triggering caused by short “glitches” on the VCC-line. < t RR VCC VRT < t RD typ. 4.65 V 1V Start-Up RO H L ON Delay Invalid t RD Power Start-Up ON Delay Started ON Delay Stopped Invalid Invalid t RR Normal t t t RD Failed N Failed Normal AET02950 Figure 3 2.2 Reset Function Watchdog Operation The watchdog uses one hundred of the oscillator’s clock signal period as a timebase, defined as the watchdog cycle time tCYL. After power-on, the reset output signal at the RO pin (microcontroller reset) is kept LOW for the reset delay time tRD, i.e. 64 cycles. With the LOW to HIGH transition of the signal at RO the device starts the closed window time tCW = 32 cycles. A trigger signal within this window is interpreted as a pretrigger failure according to the figures shown below. After the closed window the open window with the duration tOW is started. The open Data Sheet V 2.22 12 2001-04-23 TLE 6711 Circuit Description window lasts at minimum until the trigger process has occurred, at maximum tOW is 32 cycles. A HIGH to LOW transition of the watchdog trigger signal on pin WDI is taken by a trigger. To avoid wrong triggering due to parasitic glitches two HIGH samples followed by two LOW samples (sample period tCYL) are decoded as a valid trigger. If a trigger signal appears at the watchdog input pin WDI during the open window or a power up/down occurs, the watchdog window signal is reset and a new closed window follows. A reset is generated (RO goes LOW) if there is no trigger pulse during the open window or if a pretrigger occurs during the closed window. This reset happens after 64 cycles after the latest valid closed window start time and lasts for further 64 cycles. The triggering is correct also, if the first three samples (two HIGH one LOW) of the trigger pulse at pin WDI are inside the closed window and only the fourth sample (the second LOW sample) is taken in the open window. In addition to the microcontroller reset signal RO the device generates a system enable signal at pin SEN. If RO is HIGH the system enable goes active HIGH with the first valid watchdog trigger pulse at pin WDI. The SEN output goes LOW immediately if a pretrigger, a missing trigger or a power down reset occurs. Data Sheet V 2.22 13 2001-04-23 TLE 6711 Circuit Description TWD = 256*tCYL tSR = 64*tCYL tWDR = 64*tCYL tCW=32*tCYL tOW=32*tCYL definition closed window open window definition reset start delay time after window watchdog timeout t EOW = end of open window tECW worst case reset duration time after window watchdog time-out Example with: t (CW+OW)min= ( tCW+ tOW ) (1 - ∆) ∆ fOSC=fOSCmax tCYL=1ms ∆=10% (oscillator deviation) t CWmax= tCW (1+∆ ∆) fOSC=fOSCmin t(CW+OW)min=(tCW+tOW)*(1-∆ ∆)= =(32+32)x0,9= 57,6ms t OWmin ∆)=32*1,1=35,2ms tCWmax= tCW(1+∆ t WD Closed window Open window Watchdog trigger signal WDI Valid WDI Indifferent WDI Not valid t ECW Closed window t EOW = Watchdog decoder sample point Figure 4 Open window AET02952 Window Watchdog Definitions Data Sheet V 2.22 14 2001-04-23 TLE 6711 Circuit Description a) Perfect Triggering after Power on Reset VCC VRT t tRD = 64 Cycles RO t 32 Cycles WDWI CW OW CW OW CW CW t 32 Cycles WDI xx xx xx xx t1 SEN t2 System Failed xx xx t3 t System Enable System Failed t b) Incorrect Triggering tWDR = 64 Cycles tSR = 64 Cycles tSR = 64 Cycles RO t TWD = 128 Cycles WDWI CW OW CW OW CW OW CW OW t 32 Cycles WDI xx x xx x xx x xx 1) 2) xx x xx 3) 4) SEN t 1) Pretrigger 2) Incorrect trigger duration within watchdog open window OW: tHIGH < 2 Cycles 3) Incorrect trigger duration within watchdog open window OW: tLOW < 2 Cycles 4) Missing trigger Figure 5 t Legend: WDWI = Internal Watchdog Window OW = Open Window (trigger signal at WDI) CW = Closed Window (trigger signal at WDI) x = Sample Point AED02945 Window Watchdog Function Data Sheet V 2.22 15 2001-04-23 TLE 6711 Circuit Description 2.3 Boost Converter The TLE 6711 contains a fully integrated boost converter (except the boost-diode), which provides a supply voltage for an energy reserve e.g. an airbag firing system. The regulated boost output voltage VBOOST is programmable by a divider network (external resistors) providing the feedback voltage for the boost feedback pin BOFB. The energy which is stored in the external electrolytic capacitor at VBOOST guarantees accurate airbag firing, even if the battery is disconnected by a car crash. The boost inductance LBO (typ. 100 µH) is PWM-switched by an integrated current limited power DMOS transistor with a programmable (external resistor RR) frequency. An internal bandgap reference provides a temperature independent, on chip trimmed reference voltage for the regulation loop. An error amplifier compares the reference voltage with the boost feedback signal VBOFB from the external divider network (determination of the output boost voltage VBOOST). Application note for programming the output voltage at pin VBOOST: ( R BO1 + R BO2 ) V BOOST = V BOF BTH × -----------------------------------R BO2 With a PWM (Pulse Width Modulation) comparator the output of the error amplifier is compared to a periodic linear ramp, provided by a sawtooth signal of the oscillator connected to pin R. A logic signal with variable pulse width is generated. It passes through the logic circuits (sets the output latch PWM-FF) and driver circuits to the power switching DMOS. The Schmitt-trigger output resets the output flip-flop PWM-FF by NOR 2. The PWM signal is gated by the NAND 2 to guarantee a dominant reset. Data Sheet V 2.22 16 2001-04-23 TLE 6711 Circuit Description OV COMP L when NAND 3 OV at VBoost & + - = VthOV 38 V H when Tj > 175 ˚C or OV at VBoost L when Tj > 175 ˚C GND UV COMP VBoost + - VthUV H when VBoost < 4 V 1 Error Gate BOI Pin 14 Error-FF L when H when NOR 2 R & Q Error Error 1 R H when Overcurrent = 4V NOR 1 PWM-FF INV H= & Q OFF 1 & Q = S PWM COMP Error-Ramp = + - Error-Signal + - H when Error-Signal < Error-Ramp GND Oscillator R Pin 1 Vmax Vmin Schmitt-trigger 1 Unlock Detector Ramp Vhigh tr tf tr Vlow t tr tf tr t OC COMP + - BOFB Pin 12 & & Error AMP 10 µA VREF NAND 2 Q S I Pullup 2.8 V & Power D-MOS Gate Driver NAND1 GND H= ON VthOC 18 mV R Sense 14.5 m Ω BOGND Pin 13 OVL Boost Status Pin 11 Low if Battery Disconnected Clock GND H when Outputcurrent > 1.2 A AEB02946 Figure 6 Boost Converter Block Diagram Figure 7 shows the most important waveforms during operation; for low, medium and high loads up to overload condition. The output transistor is switched off immediately if the overcurrent comparator detects an overcurrent level at the power DMOS or if the sense output switches to low induced by a VBOOST undervoltage command. The TLE 6711 is also protected against several boost loop errors: In case of a feedback interruption a pull up current source (IFB typ. 0.4 µA), integrated at pin BOFB pulls the voltage at the feedback pin BOFB above the reference voltage. The boost output is switched off by the high error voltage which controls the PWM-Comparator at a zero duty cycle. In the case of a resistive loop error caused by leakage currents to ground, the boost output voltage would increase to very high values. In order to protect the VBOOST input as well as the external load against catastrophic failures, an overvoltage protection is provided which switches the output transistor off as soon as the voltage at pin VBOOST exceeds the internal fixed overvoltage threshold VBOOVOFF = typ. 37 V. Data Sheet V 2.22 17 2001-04-23 TLE 6711 Circuit Description Application Note: A short circuit from VBOOST to ground will not destroy the IC, however, it may damage the external boost diode or the boost inductance if there is no overcurrent limitation in that path. VC Error Voltage and VError VCP VCV t OCLK H L PWM H L t I BOI I BOLI t I DBO t VBOI t VBOOST VS t Overcurrent Threshold Exceeded Load-Current Increasing with Time; Controlled by the Error Amp Controlled by the Overcurrent Comp AED02672 Figure 7 Most Important Waveforms of the Boost Converter Circuit Data Sheet V 2.22 18 2001-04-23 TLE 6711 Circuit Description 2.3.1 Boost Status Output OVL For supervision of the Boost output voltage an open drain DMOS output is used. The output is high impedance in normal operation and low during the warning. The OVL goes LOW if the PWM comparator output (see Boost Converter Block Diagram) remains HIGH for clock time period. This occurs when the Error-Signal falls below the minimum value of the Error-Ramp, this mean that Boost voltage falls below a certain threshold voltage. The OVL output used as a warning for insufficient Boost voltage. 2.4 Buck Converter A stabilized logic supply voltage (typ. 5 V) for general purpose is realized in the system by a buck converter. An external buck-inductance LBU is PWM switched by a high side DMOS power transistor with the programmed frequency (pin R). The buck regulator supply is given by the boost converter output VBOOST, in case of a battery power-down the stored energy of the boost converter capacitor is used. Like the boost converter, the buck converter uses the temperature compensated bandgap reference voltage (typ. 2.8 V) for its regulation loop. This reference voltage is connected to the non-inverting input of the error amplifier and an internal voltage divider supplies the inverting input. Therefore the output voltage VCC is fixed due to the internal resistor ratio to typ. 5.0 V. The output of the error amplifier goes to the inverting input of the PWM comparator as well as to the buck compensation output BUC. When the error amplifier output voltage exceeds the sawtooth voltage the output power MOS-transistor is switched on. So the duration of the output transistor conduction phase depends on the VCC level. A logic signal PWM with variable pulse width is generated. Data Sheet V 2.22 19 2001-04-23 TLE 6711 Circuit Description VCC UV COMP H when UV at VBoost OV COMP H when OV at VCC + + - 200 Ω 4V L when Overcurrent OC COMP VthOC 18 mV L when Overcurrent Boost Driver Supply VCC + - R VCC2 28kΩ PWM H when Error- COMP Error-Signal < Signal Error-Ramp ErrorRamp = VREF 2.8 V R Error-FF R & Vmax Vmin Figure 8 tr tf tr Schmitt-trigger 1 t Ramp Vhigh Vlow Pin 9 R Sense 18 mΩ BDS Pin 10 H= Q OFF Q INV 1 H= ON Power D-MOS Gate Driver & & S Q BUO Pin 8 & S tr tf tr & NAND 2 OFF when H Oscillator PWM-FF 1 Output Stage OFF when H L when Tj > 175 ˚C GND GND VBoost NOR 1 + - Error AMP R VCC1 22kΩ R Pin 1 VthUV GND VCC Pin 7 = GND GND R Prot1 BUC Pin 6 = VthOV 1.2 V = - R VCC4 10.3kΩ + - R VCC3 39.7kΩ t Q Clock AEB02947 Buck Converter Block Diagram External loop compensation is required for converter stability, and is formed by connecting a compensation resistor-capacitor series-network (RBUC, CBUC) between pin BUC and GND. In the case of overload or short-circuit at VCC (the output current exceeds the buck overcurrent threshold IBUOC) the DMOS output transistor is switched off by the overcurrent comparator immediately. The pulse width is then controlled by the overcurrent comparator as seen before in the boost description. In order to protect the VCC input as well as the external load against catastrophic failures, an overvoltage protection is provided which switches the output transistor off as soon as the voltage at pin VCC exceeds the internal fixed overvoltage threshold VBUOVOFF = typ. 6.0 V. Data Sheet V 2.22 20 2001-04-23 TLE 6711 Circuit Description VC Error Voltage and VError VCP VCV t OCLK H L PWM H L t I BUO I BULI t I DBU t VBUO t VBOOST VCC5 t Overcurrent Threshold Exceeded Load-Current Increasing with Time; Controlled by the Error Amp Controlled by the Overcurrent Comp AED02673 Figure 9 Most Important Waveforms of the Buck Converter Circuit Data Sheet V 2.22 21 2001-04-23 TLE 6711 Application Circuit 3 Application Circuit Figure 10 shows the application circuit of the TLE 6711 with the suggested external parts. D1 L BO D2 CL VBatt ZD1 36 V 10 µF DBO 100 µH I BOLoad CS 220 nF R BO1 CBO1 100 k Ω CBO1 CBO2 4700 µF 220 nF 10 nF BOFB 12 TLE 6711 G R BO2 Boost Converter Biasing 10 k Ω 14 BOI VBOOST 13 BOGND CBOT VBoost 10 BDS 10 nF VREF 9 VBOOST BUC 6 L BU Buck Converter 8 BUO R BUC 47 k Ω 7 VCC CBUC 220 µH DBU CBU1 CBU2 100 µF 220 nF VInternal 470 nF System Enable Output Watchdog Trigger Input 5 SEN R 1 RR 47 k Ω Reference Current Generator and Oscillator Reset Window Watchdog and System Enable 3 WDI 10 k Ω 2 RO Reset Output Boost Status Output 11 OVL 4 GND Figure 10 VCC Device Type Supplier Remarks D1 BAW78C Infineon 200 V; 1 A; SOT-89 D2 BAW78C Infineon 200 V; 1 A; SOT-89 D BO BAW78B Infineon 100 V; 1 A; SOT-89 D BO SS14 multiple Schottky; 40 V; 1 A D BU - - L BO B82442-A1104 EPCOS 100 µH; 0.25 A; 1.28 Ω L BO L BU Do3316P-104 Coilcraft 100 µH; 1.2 A; 0.28 Ω L BU Do3316P-224 Coilcraft 220 µH; 0.8 A; 0.61 Ω Schottky; 100 V; 1 A B82442-H2204 EPCOS 220 µH; 0.24 A; 2.72 Ω AEB02948 Application Circuit Data Sheet V 2.22 22 2001-04-23 TLE 6711 Diagrams: Oscillator and Boost/Buck-Converter Performance 4 Diagrams: Oscillator Performance and Boost/Buck-Converter In the following the behaviour of the Boost/Buck-converter and the oscillator is shown. Oscillator Frequency Deviation vs. Junction Temperature AED02938 10 kHz Boost Feedback Current vs. Junction Temperature ∆f OSC 5 -200 nA Referred to f OSC at Tj = 25 ˚C AED02939 I FB -300 0 -400 -5 -500 -10 -600 -15 -50 -25 0 25 50 75 100 ˚C 150 Tj -700 -50 -25 0 25 50 75 100 ˚C 150 Tj Data Sheet V 2.22 23 2001-04-23 TLE 6711 Diagrams: Oscillator and Boost/Buck-Converter Performance Current Consumption vs. Junction Temperature Efficiency Buck vs. Boost Voltage AED02940 3 mA AED02941 95 η % I Boost 90 2.5 Boost ON Buck ON I BO boost = 0 mA I CC = 0 mA 2 VCC = 5 V 85 I Load = 120 mA 80 1.5 80 mA 75 1 70 0.5 -50 -25 0 65 25 50 75 100 ˚C 150 40 mA 5 15 25 V 30 VBoost Tj Efficiency Buck vs. Load η AED02942 90 % 85 RT, HT CT 80 75 70 65 50 150 mA 250 I LOAD Data Sheet V 2.22 24 2001-04-23 TLE 6711 Diagrams: Oscillator and Boost/Buck-Converter Performance Efficiency Boost vs. Input Voltage AED02943 95 % η Boost Output Voltage vs. Load AED02944 31 V I Boost = 60 mA VBoost 30 90 HT 85 CT RT 80 28 75 27 70 10 8 12 14 RT HT CT 29 26 V 16 20 40 60 80 mA 100 VBatt I LOAD Oscillator Frequency vs. Resistor from R to GND Boost and Logic Output Voltage vs. Junction Temperature AED02982 1000 kHz fOSC VBoost 500 AED02983 30 V 29 28 I Boost = 50 mA 27 200 26 @ Tj = 25 ˚C 100 VCC 50 V 5.025 5.000 20 I CC = 250 mA 4.975 10 5 10 20 50 100 200 4.950 -50 -25 0 kΩ 1000 ˚C 150 Tj RR Data Sheet V 2.22 25 50 75 100 25 2001-04-23 TLE 6711 Diagrams: Oscillator and Boost/Buck-Converter Performance Boost and Buck ON Resistance vs. Junction Temperature Boost and Buck Overcurrent Threshold vs. Junction Temperature AED02984 1000 mΩ I OC R ON AED02985 1.4 A 1.3 800 R BOON @ I BOI = 1 A I BOOC (Boost-Converter) 700 1.2 600 1.1 500 400 R BUON @ I BUO = 1 A 1 300 200 I BUOC (Buck-Converter) 0.9 100 0 -50 -25 0 25 50 75 100 0.8 -50 -25 0 ˚C 150 ˚C 150 Tj Tj Data Sheet V 2.22 25 50 75 100 26 2001-04-23 TLE 6711 Package Outlines 5 Package Outlines GPS05474 P-DSO-14-3 (Plastic Dual Small Outline Package) Sorts of Packing Package outlines for tubes, trays etc. are contained in our Data Book “Package Information” SMD = Surface Mounted Device Data Sheet V 2.22 27 Dimensions in mm 2001-04-23 TLE 6711 Edition 2001-04-23 Published by Infineon Technologies AG, St.-Martin-Strasse 53, D-81541 München, Germany © Infineon Technologies AG 2001. 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Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. Data Sheet V 2.22 28 2001-04-23