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TPS51315RGFT

TPS51315RGFT

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    VFQFN40_EP

  • 描述:

    IC REG BUCK ADJ 10A SYNC 40QFN

  • 数据手册
  • 价格&库存
TPS51315RGFT 数据手册
TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 10-A STEP-DOWN SYNCHRONOUS SWITCHER WITH INTEGRATED MOSFETs Check for Samples: TPS51315 FEATURES APPLICATIONS • • • • • • 1 2 • • • • • • • • • • • • • • • Input Voltage Range: 3 V to 14 V Output Voltage Range: 0.75 V to 5.5 V Integrated Power MOSFETs with 10-A Continuous Current Output < 5-μA Shutdown Current D-CAP™ Mode with Fast Transient Response Programmable Switching Frequency with External Resistor From 100 kHz to 1 MHz Selectable Auto-Skip or PWM-Only Operation < 1% Initial Reference Accuracy Internal Soft-Start Control Integrated Boost Diode Power Good Signal Adjustable Overcurrent Limit via External Resistor OVP/UVP/UVLO Protection Integrated Selectable Output Discharge Prebias Output Voltage Start-Up with Disabled Output Discharge Thermal Shutdown 40-Pin QFN Package with Exposed Thermal Pad Supports All Ceramic Output Capacitors Portable Device Application Notebook Computers Server and Desktop DESCRIPTION The TPS51315 is a D-CAP™ Mode, 10-A, synchronous step-down converter with integrated MOSFETs. The combination of D-CAP™ mode and on-board MOSFETs provides fast transient response performance with ease of use, less external component count and small footprint. Externally adjustable switching frequency allows optimal design between component size and efficiency tradeoff. Ceramic output capacitors can be employed by adding a few extra components. The TPS51315 is available in the thermally-efficient 40-pin, 5 mm x 7 mm, QFN package and is specified from -40°C to 85°C ambient. R1 5V ENSW R3 R5 R7 29 28 27 26 25 24 23 22 21 V5IN VBST N/C LL LL LL LL LL LL LL LL L1 N/C 34 EN_PSV LL 19 35 TON LL 18 36 VOUT C1 LL 17 TPS51315 LL 16 37 VOUT_DS 38 V5FILT VIN 15 39 VFB VIN 14 40 PGOOD VIN 13 GND PGND PGND PGND PGND PGND PGND VIN VIN PGOOD R6 VOUT LL 20 33 PGND C4 30 GND C3 31 GND R4 32 TRIP R2 1 2 3 4 5 6 7 8 9 10 11 12 VIN 3 V to 14 V C2 UDG-08154 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. D-CAP is a trademark of Texas Instruments. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2009–2012, Texas Instruments Incorporated TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. ORDERING INFORMATION (1) TJ ORDERABLE PART NUMBER PACKAGE -40°C to 125°C Plastic QFN (RGF) (1) (2) TPS51315RGFT TPS51315RGFR PINS OUTPUT SUPPLY 40 Tape and Reel MINIMUM ORDER QUANTITY ECO PLAN (2) 250 Green (RoHS and no Pb/Br) 3000 For most current package and ordering information, see the Package Option Addendum at the end of this document, or see the web site at www.ti.com. These devices meet the following planned eco-friendly classification: Green (RoHS and No Sb/Br): Texas Instruments defines Green to mean Pb-free (RoHS compatible) and free of bromine (Br)- and antimony (Sb)-based flame retardants. Refer to the Quality and Lead-Free (Pb-Free) Data web site for more information. These devices have a Cu NiPdAu lead/ball finish. ABSOLUTE MAXIMUM RATINGS (1) TPS51315 Input voltage range Output voltage range VIN –0.3 to 20 VBST –0.3 to 26 VBST (with respect to LL) –0.3 to 6 EN_PSV, TRIP, V5IN, V5FILT –0.3 to 6 VOUT, VOUT_DS –0.3 to 6 TON –0.3 to 6 LL –1 to 20 PGOOD V –0.3 to 6 PGND Source/Sink current V –0.3 to 0.3 TON 1 VBST 50 mA Operating free-air temperature, TA –40 to 85 Storage temperature range, Tstg –55 to 150 Junction temperature range, TJ –40 to 125 Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds (1) UNIT °C 300 Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS MIN VIN Input voltage range VBST (with respect to LL) EN_PSV, V5IN, V5FILT, VOUT, VOUT_DS Output voltage range NOM MAX 3 14 4.5 5.5 –0.1 5.5 LL –0.8 15 PGOOD –0.1 5.5 –40 125 Junction temperature range, TJ UNIT V V °C PACKAGE DISSIPATION RATINGS 2 PACKAGE TA = 25°C POWER RATING DERATING FACTOR ABOVE TA = 25°C TA = 85°C POWER RATING 40-Pin Plastic QFN (RGF) 2.85 W 25 mW/°C 1.35 W Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 ELECTROSTATIC DISCHARGE (ESD) PROTECTION MIN Human Body Model (HBM) TYP MAX 2000 Charged Device Model (CDM) 500 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 UNIT V 3 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com ELECTRICAL CHARACTERISTICS over recommended free-air temperature range (unless otherwise noted) PARAMETER CONDITIONS MIN TYP MAX 0 1 UNIT SUPPLY CURRENT IV5IN V5IN supply current V5IN current, TA = 25°C, No Load, EN_PSV = 5V, VVFB = 0.75 V, VLL = 0.5 V IV5FILT V5FILT supply current V5FILT current, TA = 25°C, No Load, VEN_PSV = 5 V, VVFB = 0.75 V, LL = 0.5 V IV5INSDN V5IN shutdown current V5IN current, TA = 25°C, No Load, VEN_PSV = 0 V IV5FILTSDN V5FILT shutdown current V5FILT current, TA = 25°C, No Load, VEN_PSV = 0 V μA 400 1.5 μA 0 1 μA 4.5 7.5 μA 5.5 V VOUT AND VREF VOLTAGES VOUT Output voltage Adjustable output range VVFB VFB regulation voltage VFB voltage 0.75 751 mV TA = 25°C, bandgap initial accuracy –0.9% 0.9% 0°C ≤ TA ≤ 85°C –1.3% 1.3% –40°C ≤ TA ≤ 85°C –1.6% VVFB_TOL VFB regulation voltage tolerance IVFB VFB input current VVFB = 0.75 V, TA = 25°C RDischg VOUT_DS discharge resistance VEN_PSV = 0 V, VOUT_DS = 0.75 V 1.6% –0.025 μA 20 Ω HOUSEKEEPING CLOCK, ON-TIME TIMER, and INTERNAL SOFT START TONN Nominal on-time VIN = 10 V, VOUT = 2.5 V, RT(on) = 250 kΩ 1115 ns TONF Fast switch on-time VIN = 10 V, VOUT = 2.5 V, RT(on) = 100 kΩ 865 ns TONS Slow switch on-time VIN = 10 V, VOUT = 2.5 V, RT(on) = 400 kΩ 1515 ns TON (1) Minimum on-time VIN = 10 V, VOUT = 0.75 V, RT(on) = 100 kΩ TOFF(min) Minimum off-time TA = 25°C, VVFB = 0.75 V, VLL = –0.1V, VTRIP = OPEN 385 ns TSS Internal soft-start time TA = 25°C, VEN_PSV > 3 V 1.06 ms f CLK Clock frequency Soft-start, UVP, OVP, PGOOD (2) 170 200 ns 240 250 260 kHz 0.7 0.8 0.9 V 0.1 1 μA INTERNAL BST DIODE VFBST Forward voltage VV5IN-VBST, IF = 10 mA, TA = 25°C IVBSTLK VBST leakagecurrent VVBST = 26 V, LL = 20 V, TA = 25°C PROTECTIONS: OVERCURRENT LIMIT (OCL), UNDERCURRENT LIMIT (UCL) VOCL(off) Overcurrent limit comparator offset (VTRIP-GND– VPGND-LL) voltage VTRIP-GND = 60 mV –10 0 10 mV VUCL(off) Undercurrent limit comparator offset (VTRIP-GND– VLL-PGND) voltage VTRIP-GND = 60 mV, EN_PSV=FLOAT –9.5 0.5 10.5 mV VZC(off) Zero crossing comparator offset VPGND-LL voltage, V EN_PSV = 3.3V –9.5 0.5 10.5 mV 10 11 (2) VRTRIP Current limit threshold setting range VTRIP-GND voltage ITRIP TRIP source current VTRIP < 0.3 V, TA = 25°C TCITRIP Trip source current temperature coefficient TA = 25°C (2) (1) (2) 4 , TA = 25°C 30 9 mV 4500 μA ppm/°C Design constraint. Ensure actual on-time is greater than the maxiumum value (design RT(on) so that the minimum tolerance is 100 kΩ). Ensured by design. Not production tested. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 ELECTRICAL CHARACTERISTICS (continued) over recommended free-air temperature range (unless otherwise noted) PARAMETER CONDITIONS MIN TYP MAX UNIT PG in from lower (PGOOD goes high), TA = 25°C 92.5% 95% 97.5% PG Low hysteresis (PGOOD goes low) –4.5% –5.5% –6.5% PG in from higher (PGOOD goes high), TA = 25°C 102.5% 105% 107.5% PG High hysteresis (PGOOD goes low) 4.5% 5.5% 6.5% 2.5 7.5 mA 64 μs POWERGOOD COMPARATOR VTH(PG) Powergood threshold IPG(max) Powergood sink current VPGOOD = 0.5 V TPGDEL PGOOD delay Delay for PGOOD in UVLO / LOGIC THRESHOLD VUVLO VEN_PSV VEN_PSV V5FILT UVLO threshold EN_PSV connection EN_PSV logic input voltage Wake up (UVLO out) 3.4 Hysteresis 200 SKIP mode enabled 3.7 3.9 V 300 400 mV 3.3V PWM-Only mode enabled FLOAT EN_PSV low 0.7 1 1.3 V Hysteresis 130 160 220 mV EN_PSV float 1.70 1.95 2.25 V EN_PSV high 2.2 2.5 2.9 V Hysteresis 100 170 250 mV 110% 115% 120% 65% 70% PROTECTION: OVERVOLTAGE (OVP) AND UNDERVOLTAGE (UVP) VOVP VFB OVP trip threshold VUVP VFB UVP trip threshold TUVPDEL VFB UVP delay TUVPEN Output UVP enable delay OVP detect Hysteresis UVP detect 5% Hysteresis 75% 10% 32 μs 2 ms THERMAL SHUTDOWN TSDN Thermal SDN threshold Shutdown temperature (3) Hysteresis (3) 145 160 175 °C 10 12 14 °C INTEGRATED MOSFET RDS(on)upper RDS(on)lower (3) Upper MOSFET RDS(on) Lower MOSFET RDS(on) See (3) 19 mΩ See (3) 7 mΩ Ensured by design. Not production tested. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 5 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com PIN DESCRIPTIONS PIN NAME I/O DESCRIPTION NO. EN_PSV 34 I Enable/power-save pin. Connect to ground to disable switched-mode power supply (SMPS ). Connect to 3.3 V or 5 V to turn on SMPS and enable skip mode. Float to turn on SMPS but disable skip mode (forced continuous conduction mode). I Signal ground pin. 1 GND 2 4 16 17 18 19 20 21 LL 22 I/O Source node of the high-side power FET and drain node of the low-side power FET. Connect this pin to output inductor. — No connection inside. Leave open. I/O Power GND. Source node of the low-side power FET. 23 24 25 26 27 28 29 NC 33 3 5 6 PGND 7 8 9 10 PGOOD 40 O Power-good window comparator: open drain output. Pull up to 5-V rail with a pull-up resistor. Current capability is 7.5 mA. TON 35 I On-time / frequency adjustment pin. Connect to LL with proper resistor to program switching frequency. TRIP 32 I Overcurrent trip point set input. Connect resistor from this pin to signal ground to set threshold for both overcurrent and negative overcurrent limit. V5FILT 38 I 5-V power supply input for all control circuitry except gate drivers. Apply an R-C filter to reject high-frequency switching noise. V5IN 31 I 5-V Power supply input for FET gate drivers. Internally connected to VBST by a PN diode. Connect a cpacitor with a value of 1 μF or greater between this pin and PGND to support instantaneous current for gate drivers. VBST 30 I Supply input for high-side FET gate driver (boost terminal). Connect capacitor from this pin to LL-node. An internal PN diode is connected between V5IN to this pin. Add an external schottky diode if forward drop is critical to ensure efficient operation. VFB 39 I SMPS voltage feedback input. Connect the resistor divider here for adjustable output. I Input power source. Drain node of the high-side power FET. 11 12 VIN 13 14 15 VOUT 36 I Connect to SMPS output. This terminal serves as the output voltage monitor for on-time adjustment. VOUT_DS 37 O Prebias start-up and selectable output discharge. It is also the input for the output discharge switch. 6 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 TRIP V5IN VBST N/C LL LL LL LL LL LL LL LL 40-PIN RGY (QFN) PACKAGE (TOP VIEW) 32 31 30 29 28 27 26 25 24 23 22 21 N/C 33 20 LL EN_PSV 34 19 LL TON 35 18 LL VOUT 36 17 LL TPS51315 VIN PGOOD 40 13 VIN 2 3 4 5 6 7 8 9 10 11 12 VIN 1 VIN 14 PGND 39 PGND VFB PGND VIN PGND 15 PGND 38 PGND V5FILT GND LL PGND 16 GND 37 GND VOUT_DS Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 7 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com FUNCTIONAL BLOCK DIAGRAM +5/10% –30/20% + UV PGOOD + Delay Delay + –5/10% Control Logic + OV +15/10% 0.75 V SS VFB UVP/OVP Logic TON V5IN + + VBST PWM VIN 10uA GND ISHOT + OCP LL TRIP + LL PGND XCON V5IN + ZC/ + UCP UCP Buzz Logic PGND LL GND Ÿ Ÿ Ÿ Ÿ Ÿ 5V 2.9 V EN_PSV VOUT_DS + + 1V XPWMonly Enable VOUT On/Off time Minimum On/Off Light load OVP/UVP Discharge Fault Sdn V5FILT + V5OK THOK DISCHG + 160°C/148°C 3.9 V/3.6 V TPS51315 UDG-09048 8 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 DETAILED DESCRIPTION Dual PWM Operations The primary control loop of the switched-mode power supply (SMPS) functions as an adaptive on-time pulse width modulation (PWM) controller. It supports a proprietary D-CAP™ mode. D-CAP™ mode uses an internal compensation circuit and is suitable for a low external component count configuration with an appropriate amount of equivalent series resistance (ESR) at the output capacitor(s). The output voltage is monitored at a feedback point voltage. At the beginning of each cycle, the upper synchronous MOSFET is turned on, or enters the ON state. This MOSFET is turned off, or enters the OFF state, after an internal one-shot timer expires. This one shot is determined by the input voltage (VVIN) and the output volage (VOUT) to maintain a relatively constant frequency over the input voltage range. This is called adaptive on-time control (see PWM Frequency and Adaptive On-Time Control section). The MOSFET is turned on again when feedback indicates an insufficient output voltage and the inductor current falls below the overcurrent limit. By repeating the operation in this manner, the controller regulates the output voltage. The synchronous lower (rectifying) MOSFET is turned on at each OFF state in order to minimize the conduction losses. The TPS51315 supports both PWM-Only and Auto-Skip operating modes. When the EN_PSV pin is grounded, the switcher is disabled. When the EN_PSV pin is connected to a 3.3-V supply or a 5-V supply, Auto-Skip mode is enabled. The rectifying MOSFET is turned off when the inductor current is zero. This feature enables a seamless transition to the reduced-frequency operation at light load conditions so that high efficiency is maintained over a broad range of load currents. When the EN_PSV pin is floated, it is internally pulled up to 1.9 V, and PWM-Only mode is enabled. In this mode, the rectifying MOSFET is not turned off when the inductor current reaches zero, and so the switching frequency does not change at light load; however the efficiency is lower in PWM-Only mode than it is in Auto-Skip mode. The dc output voltage can be set by the external resistor divider as shown in Equation 1. æ ö R VOUT = ç 1 + UPPER ÷ ´ 0.75 V è RLOWER ø (1) Light Load Conditions When Auto-Skip mode is enabled, the TPS51315 automatically reduces the switching frequency under light load conditions to maintain high efficiency. As the output current decreases from a heavy load condition, the inductor current is also reduced and eventually its valley falls to zero current, which is the boundary between continuous conduction and discontinuous conduction modes. The rectifying MOSFET is turned off when zero inductor current is detected. As the load current continues to decrease, the converter runs in discontinuous conduction mode, taking longer to discharge the output capacitor toward the reference voltage. The on-time maintains the same as when under a heavy load condition. Alternatively, when the output current increase from light load to heavy load, switching frequency increases to the preset value as the inductor current reaches the continuous conduction threshold. The transition load point to the light load operation IOUT(LL) (that is, the threshold between continuous and discontinuous conduction mode) can be calculated using Equation 2. IOUT(LL) = (VIN - VOUT )´ VOUT 1 ´ 2´L ´f VIN where • f is the PWM switching frequency (2) Switching frequency versus output current under light load conditions is a function of L, ƒ, VIN and VOUT, but it decreases almost proportionally to the output current from IOUT(LL) as calculated in Equation 2. For example, it is approximately 60 kHz at IOUT(LL)/5 when the PWM frequency is 300 kHz. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 9 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com PWM Frequency and Adaptive On Time Control TPS51315 employs an adaptive on-time control scheme and does not include a dedicated oscillator on the device. However, the device runs with pseudo-constant frequency by feed-forwarding the input voltage and output voltage to the on-time, one-shot timer. The on-time control is inversely proportional to the input voltage and proportional to the output voltage, so that the duty ratio is maintained as VOUT/VIN with the same cycle time, as shown in Equation 3. æ (2 / 3)VOUT + 100mV ö TON = 19 ´ 10-12 ´ RT(on ) ç ÷ + 50ns VIN è ø where • RT(on)x is the external resistor connected from TON to LL (3) For the TPS51315, the input voltage is monitored at the LL pin during the ON state. An advantage of switchingnode monitoring is that any loss in the high-side n-channel FET becomes part of the on-time calculation, thereby making the frequency more stable with load. Another consideration regarding frequency is jitter. Jitter may have many causes, but the constant on-time DCAP mode scheme has some amount of inherent jitter. Because the output voltage ripple height is in the range of approximately 20 mV, on the order of a milli-volt of noise on the feedback signal can affect the frequency between approximately 3% and 10%. This is normal operation and risks only a small amount of influence to the power supply performance. Soft-Start The TPS51315 includes an independent, internal, 1.06-ms, voltage servo soft-start function with overcurrent limit. When the EN_PSV pin goes high, an internal digita-to-analog converter (DAC) begins ramping up the reference voltage to the error amplifier. Smooth control of the output voltage is maintained during start-up. Powergood The TPS51315 includes a powergood output function. The powergood function is activated after the soft-start function has completed. If the output voltage comes within ±5% of the target value, internal comparators detect a powergood state and the powergood signal becomes high after a 64-μs internal delay. If the output voltage rises above or falls below 10% of the target value, the powergood signal goes low immediately. Output Discharge Control The TPS51315 discharges output when EN_PSV is low or when the channel is in either a UVP or OVP fault condition. The TPS51315 discharges output using an internal 20-Ω MOSFET that is connected to VOUT_DS and PGND. The current capability of the MOSFET is limited to discharge slowly. An external resistor can be connected between VOUT_DS and VOUT to program discharge slow rate. In case the discharge function is not wanted, leave VOUT_DS open. 10 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 Overcurrent Limit The TPS51315 has cycle-by-cycle overcurrent limit function. The inductor current is monitored during the OFF state using the low-side FET RDS(on) which is 7 mΩ (typ). The controller maintains the OFF state and does not release next ON cycle until the detected current comes down to the overcurrent trip level set by the TRIP resister. Because of this scheme, RTRIP establishes the valley level of the inductor current. Note that the load current at the overcurrent threshold, IOCL, is higher than this value calculated in Equation 4. æ æI öö VTRIP = ç IOCL - ç RIPPLE ÷ ÷ ´ 7 m W 2 è øø è (4) RTRIP value can be calculated by Equation 5, but cannot exceed 12.1-kΩ to protect the internal FETs from overloading. RTRIP = VTRIP 10 mA (5) Undercurrent Limit The TPS51315 also supports a cycle-by-cycle undercurrent limit in PWM-Only mode. The undercurrent limit is the negative value of the overcurrent limit. If the output voltage continues to rise, the lower MOSFET is always on: thus, the inductor current reduces and reverses direction after it reaches zero (in PWM-Only mode). When there is too much negative current through the inductor, the lower MOSFET is turned off and the current flows to the VIN pin through the body diode of the upper MOSFET. Because there is less current with which to discharge the output capacitor, output voltage tends to rise, eventually reaching the overvoltage protection threshold and shutting down the TPS51315. In order to prevent triggering a false OVP shut down, the lower MOSFET is turned on 400-ns after it is turned off. If the device reaches an undercurrent threshold again before the output voltage is discharged to the target level, the lower MOSFET is turned off and the process repeats. This logic is called UCL Buzz. It ensures maximum allowable discharge capability when the output voltage continues to rise. Alternatively, if the output voltage is discharged to the target level before the UCL threshold is reached, the lower MOSFET is turned off, the upper MOSFET is then turned on, and the device resumes normal operation. Overvoltage Protection The TPS51315 monitors a resistor-divided feedback voltage to detect overvoltage and undervoltage conditions. When the feedback voltage becomes greater than 115% of the target value, the upper MOSFET is turned off and the lower MOSFET is turned on immediately. The output is also discharged by the internal 20-Ω transistor if it is connected to VOUT_DS. The, TPS51315 monitors the output voltage directly. If it becomes greater than 5.75 V, TPS51315 turns off the upper MOSFET driver. In no case should the device operate at more than 6 V, as damage would occur. Undervoltage Protection When the feedback voltage becomes lower than 70% of the target value, the undervoltage comparator output goes high and an internal UVP delay counter begins to increment. After 32 μs, TPS51315 latches off both the upper and lower MOSFETs and discharges the output with the internal 20-Ω transistor if it is connected to VOUT_DS. This function is enabled after 2ms from when EN_PSV is brought high, i.e., UVP is disabled during the start up. UVLO Protection The TPS51315 has V5FILT undervoltage lockout (UVLO) protection. When the V5FILT voltage is lower than UVLO threshold voltage, TPS51315 is shut off. This protection is not latched. Thermal Shutdown The TPS51315 includes a die-temperature monitor function. If the temperature exceeds the threshold value (typically 160°C), TPS51315 shutd off. This protection is not latched. The device recovers once the temperature has cooled to 148°C. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 11 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com TYPICAL CHARACTERISTICS At VIN = 12 V, VV5IN = 5 V, RT(on) = 237 kΩ, and TA = 25°C, unless otherwise noted. V5FILT SHUTDOWN CURRENT vs JUNCTION TEMPERATURE 800 8 700 7 IV5FILT_SHDN - Shutdown Current - mA IV5FILTPWM - Supply Current - mA PWM SUPPLY CURRENT vs JUNCTION TEMPERATURE 600 500 400 300 200 100 0 -50 0 50 100 TJ - Junction Temperature - ºC 4 3 2 1 Figure 2. TRIP CURRENT vs JUNCTION TEMPERATURE OVP/UVP THRESHOLD vs JUNCTION TEMPERATURE 150 130 14 12 10 8 6 0 50 100 TJ - Junction Temperature - º C 150 OVP 120 110 100 90 80 UVP 70 60 50 -50 Figure 3. 12 0 50 100 TJ - Junction Temperature - ºC Figure 1. VOVP, VUVP - OVP/UVP Threshold - % ITRIP - TRIP Source Current - mA 5 0 -50 150 16 4 -50 6 0 50 100 TJ - Junction Temperature - ºC 150 Figure 4. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 TYPICAL CHARACTERISTICS (continued) At VIN = 12 V, VV5IN = 5 V, RT(on) = 237 kΩ, and TA = 25°C, unless otherwise noted. SWITCHING FREQUENCY vs OUTPUT CURRENT SWITCHING FREQUENCY vs OUTPUT CURRENT 450 450 Mode Auto-Skip PWM Only 350 Mode Auto-Skip PWM Only 400 PWM Only fSW – Switching Frequency – kHz fSW – Switching Frequency – kHz 400 300 250 200 150 100 Auto-Skip 50 350 PWM Only 300 250 200 150 100 50 VOUT = 1.05 V 5 0.001 0.01 0.1 1 VOUT = 2.5 V 5 0.001 10 0.01 IOUT – Output Current – A 0.1 1 10 IOUT – Output Current – A Figure 5. Figure 6. OUTPUT VOLTAGE vs OUTPUT CURRENT OUTPUT VOLTAGE vs OUTPUT CURRENT 2.54 1.06 2.52 VOUT – Output Voltage – V VOUT – Output Voltage – V 1.07 1.05 2.50 1.04 2.48 Mode Auto-Skip PWM Only Mode Auto-Skip PWM Only VOUT = 1.05 V 1.03 0 1 2 3 4 5 6 7 8 9 10 2.46 0 1 IOUT – Output Current – A 2 3 4 VOUT = 2.5 V 5 6 7 8 9 10 IOUT – Output Current – A Figure 7. Figure 8. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 13 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com TYPICAL CHARACTERISTICS (continued) At VIN = 12 V, VV5IN = 5 V, RT(on) = 237 kΩ, and TA = 25°C, unless otherwise noted. OUTPUT VOLTAGE vs INPUT VOLTAGE OUTPUT VOLTAGE vs INPUT VOLTAGE 2.54 1.07 2.52 VOUT – Output Voltage – V VOUT – Output Voltage – V 1.06 2.50 2.48 1.05 2.46 2.44 1.04 ILOAD (A) ILOAD (A) 2.42 0 10 0 10 VOUT = 1.05 V 2.40 1.03 3 4 5 6 7 8 9 10 11 12 13 3 14 4 5 7 8 9 10 11 12 Figure 9. Figure 10. SWITCHING FREQUENCY vs INPUT VOLTAGE MEASURED SWITCHING FREQUENCY vs ON-TIME RESISTANCE 13 14 1000 400 PWM Mode IOUT = 2 A VOUT (V) 900 fSW – Switching Frequency – kHz 350 fSW – Switching Frequency – kHz 6 VIN – Input Voltage – V VIN – Input Voltage – V 300 250 200 150 100 VOUT (V) 1.05 2.50 50 1.05 2.50 800 700 600 500 400 300 200 100 0 0 3 4 5 6 7 8 9 10 11 12 13 14 0 100 200 300 400 500 600 700 TON – On-Time Resistance – kW VIN – Input Voltage – V Figure 11. 14 VOUT = 2.5 V Figure 12. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 TYPICAL CHARACTERISTICS (continued) At VIN = 12 V, VV5IN = 5 V, RT(on) = 237 kΩ, and TA = 25°C, unless otherwise noted. EFFICIENCY vs OUTPUT CURRENT EFFICIENCY vs OUTPUT CURRENT 100 100 VOUT = 2.5 V 90 90 80 80 h – Efficiency – % h – Efficiency – % VOUT = 1.05 V 70 60 70 60 VIN (V) VIN (V) 3.3 5.0 12.0 12.6 50 3.3 5.0 12.0 12.6 50 40 40 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 IOUT – Output Current – A 5 6 7 8 9 10 IOUT – Output Current – A Figure 13. Figure 14. EFFICIENCY vs OUTPUT CURRENT EFFICIENCY vs OUTPUT CURRENT 100 100 VIN = 5 V VIN = 5 V 90 90 80 80 h – Efficiency – % h – Efficiency – % 4 70 60 VOUT (V) 1.05 1.2 1.8 3.3 50 40 0.001 0.01 0.1 1 70 60 VOUT (V) 50 10 40 0.001 1.1 1.5 2.5 0.01 0.1 1 10 IOUT – Output Current – A IOUT – Output Current – A Figure 15. Figure 16. Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 15 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com TYPICAL CHARACTERISTICS (continued) At VIN = 12 V, VV5IN = 5 V, RT(on) = 237 kΩ, and TA = 25°C, unless otherwise noted. EFFICIENCY vs OUTPUT CURRENT EFFICIENCY vs OUTPUT CURRENT 100 100 VIN = 12 V 90 90 80 80 h – Efficiency – % h – Efficiency – % VIN = 12 V 70 60 70 60 VOUT (V) 1.05 1.2 1.8 3.3 50 40 0.001 0.01 0.1 1 VOUT (V) 1.1 1.5 2.5 5.0 50 10 40 0.001 IOUT – Output Current – A 0.01 0.1 1 10 IOUT – Output Current – A Figure 17. X X X Figure 18. X X X VOUT (500 mV/div) VOUT (500 mV/div) LL (10 V/div) LL (10 V/div) IOUT (10 A/div) IOUT (10 A/div) t – Time – 500 ms/div t – Time – 500 ms/div Figure 19. 1.05-V Start-Up Waveforms (Heavy Load) 16 Figure 20. 1.05-V Shut-Down Waveforms (Heavy Load) Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 TYPICAL CHARACTERISTICS (continued) At VIN = 12 V, VV5IN = 5 V, RT(on) = 237 kΩ, and TA = 25°C, unless otherwise noted. VOUT (500 mV/div) VOUT (500 mV/div) LL (10 V/div) LL (10 V/div) IOUT (10 A/div) IOUT (10 A/div) t – Time – 500 ms/div t – Time – 500 ms/div Figure 21. 1.05-V Start-Up Waveforms (Light Load)X X X VOUT (20 mV/div) Figure 22. 1.05-V Shut-Down Waveforms (Light Load)X X X VOUT (20 mV/div) LL (10 V/div) LL (10 V/div) IOUT (10 A/div) IOUT (10 A/div) t – Time – 50 ms/div t – Time – 50 ms/div Figure 23. 1.05-V Load Step-Up Waveforms Figure 24. 1.05-V Load Step-Down Waveforms Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 17 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com APPLICATION INFORMATION Loop Compensation and External Parts Selection Switching Modulator VIN R1 Lx VFB R2 PWM + + Control Logic and Divider IL IC IO 0.75 V ESR RL Voltage Divider VC CO Output Capacitor UDG-09062 Figure 25. Simplified Modulator Block Diagram The feedback voltage (VVFB) is compared to the internal reference voltage after the divider resistors. The PWM comparator determines when to turn on the upper MOSFET. The gain and speed of the comparator is high enough to maintain the voltage level relatively constant at the beginning of each on cycle, or at the end of each off cycle . The dc output voltage may have line regulation due to ripple amplitude that slightly increases as the input voltage increases. For loop stability, the 0 dB frequency, f0, defined in Equation 6 must be lower than 1/4 of the switching frequency. f0 = f 1 £ SW 2p ´ ESR ´ COUT 4 (6) Because f0 is determined solely by the output capacitor characteristics, the loop stability of the D-CAP™ Mode is determined by capacitor chemistry. For example, specialty polymer capacitors (SP-CAP) have and output capacitance on the order of several hundred micro-farads and and ESR of approximately 10 mΩ. These values make f0 on the order of 100 kHz or less and create a stable loop. However, ceramic capacitors have an f0 of more than 700 kHz, which is not suitable for this operating mode, although the D-CAP™ Mode provides many advantages such as ease-of-use, minimum external component configuration, and extremely short response time. These advantages are realized because there is no error amplifier in the loop, so a sufficient feedback signal is required from an external circuit to reduce the jitter level. The required signal level is approximately 15 mV at the comparing point. This generates output ripple at the output node that can be calculated in Equation 7. The output capacitor ESR should meet this requirement. V ö ´ 15 mV VRIPPLE = æç OUT ÷ 0.75 è ø (7) For applications with all ceramic output capacitors, a few external components need to be added to ensure the loop stability. Please refer to Figure 29. Since ceramics capacitors have low ESR, feedback ripple in phase with inductor current is recommended. R-C network across the output inductor can mimic inductor current when RC ≈ L / DCR, the ripple current can be coupled to the feedback through a 1-μF capacitor. 18 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 External Component Selection External component selection is a simple process in D-CAP™ Mode. 1. Determine the value of R1 and R2. The recommended R2 value is 10 kΩ to 100 kΩ. Calculate R1 by using Equation 8. R1 = VOUT - 0.75 ´ R2 0.75 (8) 2. Choose RT(on) The switching frequency is usually determined by overall view of the dc-dc converter designer in consideration of size, efficiency or cost, and mostly dictated by external component constraints such as the size of inductor and/or the output capacitor. If an extremely low or high duty factor is expected, the minimum on-time or off-time must also be considered to satisfy the required duty factor. Once the switching frequency is decided, RT(on) can be determined by Equation 9 and Equation 10. TON(max ) = RT(on ) = 1 VOUT ´ f VIN(min ) (9) ( ) VIN(min ) 3 TON(max) - 50ns ´ ´ (W ) 2 (VOUT + 150mV ) 19 ´ 10-12 (10) 3. Choose the inductor. To begin, choose an inductance value where the ripple current is approximately 1/4 to 1/2 of the maximum output current. LIND = 1 IIND(ripple )´f ´ (V IN(max ) - VOUT )´ V OUT VIN(max ) = 3 IOUT(max ) ´ f ´ (V IN(max ) - VOUT )´ V OUT VIN(max ) (11) For applications that require a fast transient response with a minimum of VOUT overshoot, consider a smaller inductance value than calculated in Equation 11. The cost of a small inductance value is higher steady-state ripple, larger line regulation, and higher switching loss. The inductor also needs to have low DCR to achieve good efficiency, as well as enough room above the peak inductor current before saturation. The peak inductor current can be estimated by Equation 12. IIND(peak ) = ) ( VIN(max ) - VOUT ´ VOUT VTRIP 1 + ´ RDS(on ) 2 ´ L ´ f VIN(max ) (12) 4. Choose output capacitor(s). Organic semiconductor capacitor(s) or specialty polymer capacitor(s) are recommended. Determine an ESR to meet the required ripple voltage. A quick approximation is shown in Equation 13. ESR = VOUT ´ 0.015 VOUT » ´ 60 (mW ) IRIPPLE ´ 0.75 IOUT(max ) (13) Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 19 TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com 5. Choose an RTRIP value. Select an appropriate RTRIP value with the considerations shown in Equation 14. Maximum RTRIP should be less than 12.1 kΩ. RTRIP = IOUT(max ) ´ 7mW ITRIP(min ) (14) 6. V5FILT input capacitor. In order to reject high-frequency noise possibly contained on +5-V supply and V5IN voltages, apply 1-μF of ceramic capacitor closely at the V5FILT pin with a 10-Ω resistor to create a low-pass filter between +5-V supply and the pin. 7. Applying the VBST capacitor and VBST diode. Apply 0.1-μF MLCC between VBST and the LL node as the flying capacitor for internal high-side FET driver. The TPS51315 has its own on-board boost diode between V5IN and VBST. This diode is a P-N junction diode and strong enough for most typical applications. However, if efficiency has priority over cost, the designer may add a Schottky diode externally to improve the gate drive voltage of the high-side FET. A Schottky diode has a higher leakage current, especially at high temperatures, than a P-N junction diode. A low-leakage diode should be selected in order to maintain VBST voltage during low-frequency operation in Auto-Skip mode. Layout Considerations Certain concepts must be considered before starting printed curcuit board (PCB) layout work using the TPS51315. • Connect the R-C low-pass filter from the 5-V supply to the V5FILT pin. A filter resistance of 10 Ω and a filter capacitance of 1 μF is recommended. Place the filter capacitor close to the device, within 12 mm (0.5 inches) if possible. • Connect the overcurrent setting resistors from TRIP to GND close to the device if possible. The trace from TRIP to the resistor and from the resistor to GND should avoid coupling to a high-voltage switching node. • The discharge path (VOUT_DS) should have a dedicated trace to the output capacitor(s); separate from the output voltage sensing trace, and use a 1,5 mm (60 mils) or wider trace with no loops. Make sure the feedback current setting resistor (the resistor between VFB to GND) is tied close to the device GND. The trace from this resistor to the VFB pin should be short and narrow. Place the trace on the component side and avoid vias between this resistor and the device. • All sensitive analog traces and components such as VOUT, VFB, GND, EN_PSV, PGOOD, TRIP, V5FILT, and TON should be placed away from high-voltage switching nodes such as LL or VBST to avoid coupling. Use internal layer(s) as ground plane(s) and shield the feedback traces from power traces and components. • Gather the ground terminals of the VIN capacitor(s), VOUT capacitor(s), and the PGND as close as possible. GND (signal ground) and PGND (power ground) should be connected strongly together near the device. The PCB trace defined as LL node, which connects to the source of the upper MOSFET, the drain of the lower MOSFET, and the high-voltage side of the inductor, should be as short and wide as possible. 20 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 Figure 26. Typical 1.05-V/10-A Application Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 21 Submit Documentation Feedback Product Folder Links: TPS51315 EN_VREG5 VRTC3 EN5 EN3 3 4 5 V3IN VREG3 VIN 6 7 8 C3 10 mF 1 mF VIN C4 ENSW R4 R7 4.5 V to 14 V PGOOD R3 R2 R5 R6 TON VOUT 35 36 1 PGOOD VFB 39 40 V5FILT 38 VOUT_DS EN_PSV 34 37 N/C 33 2 3 4 5 TPS51315 6 7 8 9 10 11 LL 16 LL 17 LL 18 LL 19 LL 20 12 C2 VIN 13 VIN 14 VIN 15 21 22 23 24 25 26 27 28 29 30 31 32 R1 GND 1 mF GND V5IN PGND 9 PGND V5IN 10 V5IN TRIP PGND VREG5 VBST PGND GND LL N/C PGND 2 LL LL VIN TPS51103 LL PGND VCLK LL LL PGND LL GND LL 22 VIN 1 L1 VIN UDG-08155 3 V to 14 V C1 VOUT TPS51315 SLUS881B – MAY 2009 – REVISED AUGUST 2012 www.ti.com Figure 27. 1.05-V/10-A Applications with TPS51103 Copyright © 2009–2012, Texas Instruments Incorporated TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 R1 301 kW ENSW R4 20 kW R3 8.06 kW D1 32 31 30 29 28 27 26 25 24 23 22 21 TRIP V5IN VBST N/C LL LL LL LL LL LL LL LL R2 12.1 kW L1 1 mF LL 20 33 N/C 34 EN_PSV LL 19 35 TON LL 18 36 VOUT LL 17 VOUT 1.8 V C1 330 mF LL 16 TPS51315 VOUT VFB 40 PGOOD VIN 14 PGND PGND VIN VIN VIN 13 PGND R6 100 kW VIN 12 V PGND C5 0.1 mF 39 VIN 15 PGND R7 27 kW V5FILT PGND C6 0.56 mF C4 PGOOD 1 mF 38 GND C3 1 mF VOUT_DS PGND Q1 MMBT3904 37 GND R6 120 kW R5 500 W GND V5IN R8 100 W 1 2 3 4 5 6 7 8 9 10 11 12 C2 47 mF UDG-09046 Figure 28. Typical 1.05-V/10-A Application with Hiccup Operation Mode Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 23 TPS51315 3 V to 14 V VIN C1 PGOOD C2 12 11 10 9 PGOOD 5V C3 R7 R4 C4 R3 ENSW C6 R2 R6 VFB 39 40 V5FILT 38 VOUT_DS GND 37 GND VOUT PGND 36 8 LL 16 LL 17 LL 18 LL 19 GND TON 7 TRIP PGND 35 6 V5IN TPS51315 PGND EN_PSV 5 VBST PGND 34 4 N/C PGND N/C 3 LL PGND 33 2 27 LL 28 1 26 LL 29 VIN 13 25 LL 30 VIN 14 24 LL 31 VIN 15 23 LL 32 LL 20 22 LL VIN PGND R8 L1 21 LL R1 VIN C5 UDG-08173 www.ti.com VOUT SLUS881B – MAY 2009 – REVISED AUGUST 2012 Figure 29. Typical Applications with All Ceramic Output 24 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 TPS51315 www.ti.com SLUS881B – MAY 2009 – REVISED AUGUST 2012 REVISION HISTORY Changes from Original (MAY 2009) to Revision A • Page Changed pinout to reflect correct placement of Pin 1 registration mark .............................................................................. 7 Changes from Revision A (MAY 2011) to Revision B • Page Changed ESD HBM rating from "1.5 kV" to "2.0 kV" (typographical error) .......................................................................... 3 Submit Documentation Feedback Copyright © 2009–2012, Texas Instruments Incorporated Product Folder Links: TPS51315 25 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) TPS51315RGFR ACTIVE VQFN RGF 40 3000 RoHS & Green NIPDAU Level-2-260C-1 YEAR -40 to 125 TPS 51315 TPS51315RGFT ACTIVE VQFN RGF 40 250 RoHS & Green NIPDAU Level-2-260C-1 YEAR -40 to 125 TPS 51315 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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