TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com –36V, –200mA, Ultralow-Noise, Negative LINEAR REGULATOR FEATURES DESCRIPTION • • The TPS7A30xx series of devices are negative, high-voltage (–36V), ultralow-noise (15.1μVRMS, 72dB PSRR) linear regulators capable of sourcing a maximum load of 200mA. 1 23 • • • • • • • • • Input Voltage Range: –3V to –36V Noise: – 14μVRMS (20Hz to 20kHz) – 15.1μVRMS (10Hz to 100kHz) Power-Supply Ripple Rejection: – 72dB (120Hz) – ≥ 55dB (10Hz to 700kHz) Adjustable Output: –1.18V to –33V Maximum Output Current: 200mA Dropout Voltage: 216mV at 100mA Stable with Ceramic Capacitors ≥ 2.2μF CMOS Logic-Level-Compatible Enable Pin Built-In, Fixed, Current-Limit and Thermal Shutdown Protection Available in High Thermal Performance MSOP-8 PowerPAD™ Package Operating Tempature Range: –40°C to +125°C APPLICATIONS • • • • • • • • Supply Rails for Op Amps, DACs, ADCs, and Other High-Precision Analog Circuitry Audio Post DC/DC Converter Regulation and Ripple Filtering Test and Measurement RX, TX, and PA Circuitry Industrial Instrumention Base Stations and Telecom Infrastrucure –12V and –24V Industrial Buses DGN PACKAGE 3mm ´ 5mm MSOP-8 PowerPAD (TOP VIEW) OUT FB NC GND 1 2 3 4 8 7 6 5 IN DNC NR/SS EN These linear regulators include a CMOS logic-level-compatible enable pin and capacitor-programmable soft-start function that allows for customized power-management schemes. Other features available include built-in current limit and thermal shutdown protection to safeguard the device and system during fault conditions. The TPS7A30xx family is designed using bipolar technology, and is ideal for high-accuracy, high-precision instrumentation applications where clean voltage rails are critical to maximize system performance. This design makes it an excellent choice to power operational amplifiers, analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and other high-performance analog circuitry. In addition, the TPS7A30xx family of linear regulators is suitable for post dc/dc converter regulation. By filtering out the output voltage ripple inherent to dc/dc switching conversion, maximum system performance is provided in sensitive instrumentation, test and measurement, audio, and RF applications. For applications where positive and negative high-performance rails are required, consider TI’s TPS7A49xx family of positive high-voltage, ultralow-noise linear regulators. Typical Application +18V IN OUT +15V TPS7A49 -18V EN GND IN OUT -15V TPS7A30 EN GND EVM Post DC/DC Converter Regulation for High-Performace Analog Circuitry 1 2 3 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. PowerPAD is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 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 © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 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) PRODUCT VOUT XX is nominal output voltage (01 = Adjustable). (2) YYY is package designator. Z is package quantity. TPS7A30xx yyy z (1) For the most current package and ordering information see the Package Option Addendum at the end of this document, or visit the device product folder on www.ti.com. For fixed -1.2V operation, tie FB to OUT. (2) ABSOLUTE MAXIMUM RATINGS (1) Over operating free-air temperature range (unless otherwise noted). VALUE MIN MAX UNIT IN pin to GND pin –36 +0.3 V OUT pin to GND pin –33 +0.3 V OUT pin to IN pin –0.3 +36 V –2 +0.3 V FB pin to IN pin –0.3 +36 V EN pin to IN pin –0.3 +36 V EN pin to GND pin –36 +36 V NR/SS pin to IN pin –0.3 +36 V –2 +0.3 V FB pin to GND pin Voltage NR/SS pin to GND pin Current Peak output Temperature Operating virtual junction, TJ –40 +125 °C Storage, Tstg –65 +150 °C 1500 V 500 V Human body model (HBM) Electrostatic discharge rating (1) Internally limited Charged device model (CDM) 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 is not implied. Exposure to absolute-maximum rated conditions for extended periods may affect device reliability. THERMAL INFORMATION TPS7A30xx THERMAL METRIC (1) DGN UNITS 8 PINS θJA Junction-to-ambient thermal resistance 55.09 θJC(top) Junction-to-case(top) thermal resistance 8.47 θJB Junction-to-board thermal resistance ψJT Junction-to-top characterization parameter 0.36 ψJB Junction-to-board characterization parameter 14.6 θJC(bottom) Junction-to-case(bottom) thermal resistance — (1) — °C/W For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. DISSIPATION RATINGS (1) 2 BOARD PACKAGE RθJA RθJC DERATING FACTOR ABOVE TA = +25°C TA ≤ +25°C POWER RATING TA = +70°C POWER RATING TA = +85°C POWER RATING High-K (1) DGN 55.09°C/W 8.47°C/W 16.6mW/°C 1.83W 1.08W 0.833W The JEDEC High-K (2s2p) board design used to derive this data was a 3-inch x 3-inch multilayer board with 2-ounce internal power and ground planes and 2-ounce copper traces on top and bottom of the board. Submit Documentation Feedback Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com ELECTRICAL CHARACTERISTICS (1) At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2µF, COUT = 2.2µF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted. TPS7A30xx PARAMETER VIN Input voltage range VREF Internal reference TEST CONDITIONS MIN TYP –35.0 (2) TJ = +25°C, VNR/SS = VREF –1.202 |VIN| ≥ |VOUT(NOM)| + 1.0V –1.184 MAX UNIT –3.0 V –1.166 V –33.0 VREF V Nominal accuracy TJ = +25°C, |VIN| = |VOUT(NOM)| + 0.5V –1.5 +1.5 %VOUT Overall accuracy |VOUT(NOM)| + 1.0V ≤ |VIN| ≤ 35V 1mA ≤ IOUT ≤ 200mA –2.5 +2.5 %VOUT DVOUT(DVIN) VOUT(NOM) Line regulation TJ = +25°C, |VOUT(NOM)| + 1.0V ≤ |VIN| ≤ 35V 0.14 %VOUT DVOUT(DIOUT) VOUT(NOM) Load regulation TJ = +25°C, 1mA ≤ IOUT ≤ 200mA 0.04 %VOUT VIN = 95% VOUT(NOM), IOUT = 100mA 216 mV Output voltage range VOUT |VDO| Dropout voltage ILIM Current limit IGND Ground current |ISHDN| Shutdown supply current I FB Feedback current (3) |IEN| Enable current V+EN_HI Positive enable high-level voltage V+EN_LO Positive enable low- level voltage V–EN_HI Negative enable high-level voltage V–EN_LO Negative enable low- level voltage VNOISE Output noise voltage PSRR Power-supply rejection ratio TSD Thermal shutdown temperature TJ Operating junction temperature range (1) (2) (3) (4) VIN = 95% VOUT(NOM), IOUT = 200mA VOUT = 90% VOUT(NOM) 220 IOUT = 0mA 325 600 mV 330 500 mA 55 100 μA μA IOUT = 100mA 950 VEN = +0.4V 1.0 3.0 μA VEN = –0.4V 1.0 3.0 μA 14 100 nA VEN = |VIN| = |VOUT(NOM)| + 1.0V 0.48 1.0 μA VIN = VEN = –35V 0.51 1.0 μA VIN = –35V, VEN = +15V 0.50 1.0 μA V TJ = –40°C to +125°C +2.0 +15 TJ = –40°C to +85°C +1.8 +15 0 +0.4 V VIN –2.0 V –0.4 0 V VIN = –3V, VOUT(NOM) = VREF, COUT = 10μF, CNR/SS = 10nF, BW = 10Hz to 100kHz 15.1 μVRMS VIN = –6.2V, VOUT(NOM) = –5V, COUT = 10μF, CNR/SS = CBYP (4) = 10nF, BW = 10Hz to 100kHz 17.5 μVRMS VIN = –6.2V, VOUT(NOM) = –5V, COUT = 10μF, CNR/SS = CBYP (4) = 10nF, f = 120Hz 72 dB Shutdown, temperature increasing +170 °C Reset, temperature decreasing +150 °C –40 +125 °C At operating conditions, VIN ≤ 0V, VOUT(NOM) ≤ VREF ≤ 0V. At regulation, VIN ≤ VOUT(NOM) – |VDO|. IOUT > 0 flows from OUT to IN. To ensure stability at no load conditions, a current from the feedback resistive network equal to or greater than 5μA is required. IFB > 0 flows into the device. CBYP refers to a bypass capacitor connected to the FB and OUT pins. Copyright © 2010–2011, Texas Instruments Incorporated Submit Documentation Feedback 3 TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com DEVICE INFORMATION FUNCTIONAL BLOCK DIAGRAM GND EN Enable FB Bandgap NR/SS Antisaturation OUT Error Amp Pass Device Thermal Shutdown Current Limit IN TYPICAL APPLICATION CIRCUIT VIN EN VOUT OUT IN CIN 10mF CBYP 10nF TPS7A3001 R1 FB R2 CNR/SS 10nF NR/SS GND Where: COUT 10mF VOUT ³ 5mA, and R1 + R2 R1 = R2 VOUT -1 VREF Maximize PSRR Performance and Minimize RMS Noise 4 Submit Documentation Feedback Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com PIN CONFIGURATION DGN PACKAGE MSOP-8 (TOP VIEW) OUT FB NC GND 1 2 3 4 8 7 6 5 IN DNC NR/SS EN PIN DESCRIPTIONS TPS7A30xx NAME NO. OUT 1 Regulator output. A capacitor ≥ 2.2µF must be tied from this pin to ground to assure stability. DESCRIPTION FB 2 This pin is the input to the control-loop error amplifier. It is used to set the output voltage of the device. NC 3 Not internally connected. This pin must either be left open or tied to GND. GND 4 Ground EN 5 This pin turns the regulator on or off. If VEN ≥ V+EN_HI or VEN ≤ V–EN_HI, the regulator is enabled. If V+EN_LO ≥ VEN ≥ V–EN_LO, the regulator is disabled. The EN pin can be connected to IN, if not used. |VEN| ≤ |VIN|. NR/SS 6 Noise reduction pin. Connecting an external capacitor to this pin bypasses noise generated by the internal bandgap. This capacitor allows RMS noise to be reduced to very low levels and also controls the soft-start function. DNC 7 DO NOT CONNECT. Do not route this pin to any electrical net, not even GND or IN. IN 8 Input supply PowerPAD Must either be left open or tied to GND. Solder to printed circuit board (PCB) plane to enhance thermal performance. Copyright © 2010–2011, Texas Instruments Incorporated Submit Documentation Feedback 5 TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com TYPICAL CHARACTERISTICS At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2μF, COUT = 2.2μF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted. FEEDBACK VOLTAGE vs INPUT VOLTAGE FEEDBACK CURRENT vs TEMPERATURE 100 -1.165 90 80 70 IFB (nA) VFB (V) -1.17 -1.175 +125°C +105°C +85°C +25°C -40°C -1.18 60 50 40 30 20 10 0 -1.185 -40 -35 -30 -25 -20 VIN (V) -15 -10 -5 0 -40 -25 -10 5 Figure 1. 80 95 110 125 Figure 2. GROUND CURRENT vs INPUT VOLTAGE GROUND CURRENT vs INPUT VOLTAGE 2500 1200 0mA 10mA 50mA 100mA 200mA 2000 TJ = +25°C 1000 800 1500 IGND (mA) IGND (mA) 20 35 50 65 Temperature (°C) 1000 600 +125°C +105°C +85°C +25°C -40°C 400 500 200 IOUT = 100mA 0 0 -40 -35 -30 -25 -20 VIN (V) -15 -10 -5 0 -40 -35 -30 Figure 3. -25 -20 VIN (V) -15 -10 -5 0 Figure 4. GROUND CURRENT vs OUTPUT CURRENT ENABLE CURRENT vs ENABLE VOLTAGE 2500 1000 +125°C +25°C -40°C 800 2000 600 IEN (nA) IGND (mA) 400 1500 1000 +125°C +105°C +85°C +25°C -40°C 500 0 0 -200 -400 -600 -800 -1000 0 20 40 60 80 100 120 140 160 180 200 IOUT (mA) Figure 5. 6 200 Submit Documentation Feedback -35 -25 -15 5 -5 VEN (V) 15 25 35 Figure 6. Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2μF, COUT = 2.2μF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted. QUIESCENT CURRENT vs INPUT VOLTAGE SHUTDOWN CURRENT vs INPUT VOLTAGE 100 3.5 90 +125°C +105°C +85°C +25°C -40°C 3 80 2.5 ISHDN (mA) IQ (mA) 70 60 50 40 +125°C +105°C +85°C +25°C -40°C 30 20 IOUT = 0mA 10 1.5 1 0.5 VEN = -0.4V 0 0 -40 -35 -30 -25 -20 VIN (V) -15 -10 -5 0 -40 -35 -30 -25 -20 VIN (V) -15 -10 -5 Figure 7. Figure 8. DROPOUT VOLTAGE vs OUTPUT CURRENT DROPOUT VOLTAGE vs TEMPERATURE 450 500 400 450 350 400 350 VDO (mV) 300 VDO (mV) 2 250 200 +125°C +105°C +85°C +25°C -40°C 150 100 50 0 10mA 50mA 100mA 200mA 300 250 200 150 100 50 0 0 0 20 40 60 80 100 120 140 160 180 200 IOUT (mA) -40 -25 -10 5 Figure 9. 20 35 50 65 Temperature (°C) 80 95 110 125 Figure 10. CURRENT LIMIT vs INPUT VOLTAGE CURRENT LIMIT vs TEMPERATURE 450 500 VOUT = 90% VOUT(NOM) 400 450 350 400 ILIM (mA) ILIM (mA) 300 250 200 +125°C +105°C +85°C +25°C -40°C 150 100 50 350 300 250 0 200 -10 -9 -8 -7 -6 VIN (V) -5 Figure 11. Copyright © 2010–2011, Texas Instruments Incorporated -4 -3 -40 -25 -10 5 20 35 50 65 Temperature (°C) 80 95 110 125 Figure 12. Submit Documentation Feedback 7 TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2μF, COUT = 2.2μF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted. ENABLE THRESHOLD VOLTAGE vs TEMPERATURE POWER-SUPPLY REJECTION RATIO vs COUT 90 2 ON 80 1 70 0.5 60 0 PSRR (dB) VEN (V) 1.5 OFF -0.5 50 40 30 -1 -1.5 20 ON COUT = 10mF VOUT = -5V VIN = -6.2V IOUT = 200mA CNR/SS = 10nF CBYP = 0mF COUT = 2.2mF 10 -2 -40 -25 -10 5 20 35 50 65 Temperature (°C) 80 95 10 110 125 100 1k Figure 13. LINE REGULATION POWER-SUPPLY REJECTION RATIO vs CNR/SS +125°C +105°C +85°C +25°C -40°C 0.4 80 CNR/SS = 10nF 70 PSRR (dB) 0.6 VOUT(NOM) (%) 10M 90 0.8 0.2 0 -0.2 -0.4 60 50 40 30 -0.6 20 -0.8 -1 VOUT = -5V VIN = -6.2V IOUT = 200mA COUT = 10mF CBYP = 0mF CNR/SS = 0nF 10 -40 -35 -30 -25 -20 VIN (V) -15 -10 -5 0 10 100 1k Figure 15. 10k 100k Frequency (Hz) 1M 10M Figure 16. LOAD REGULATION POWER-SUPPLY REJECTION RATIO vs CBYP 1 90 0.6 0.4 0.2 0 -0.2 -0.4 80 CBYP = 10nF 70 PSRR (dB) +125°C +105°C +85°C +25°C -40°C 0.8 VOUT(NOM) (%) 1M Figure 14. 1 60 50 40 30 -0.6 20 -0.8 -1 VOUT = -5V VIN = -6.2V IOUT = 200mA CNR/SS = 10nF COUT = 10mF CBYP = 0nF 10 0 20 40 60 80 100 120 140 160 180 200 IOUT (mA) Figure 17. 8 10k 100k Frequency (Hz) Submit Documentation Feedback 10 100 1k 100k 10k Frequency (Hz) 1M 10M Figure 18. Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2μF, COUT = 2.2μF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted. Output Spectral Noise Density (mV/ÖHz) OUTPUT SPECTRAL NOISE DENSITY vs OUTPUT CURRENT 10 VOUT = -1.2V VIN = -3V CNR/SS = 10nF COUT = 10mF 1 RMS NOISE IOUT 10Hz to 100kHz 100Hz to 100kHz 1mA 15.13 14.73 200mA 17.13 16.71 IOUT = 200mA 0.1 IOUT = 1mA 0.01 10 100 1k Frequency (Hz) 10k 100k Figure 19. Output Spectral Noise Density (mV/ÖHz) OUTPUT SPECTRAL NOISE DENSITY vs CNR/SS 10 VOUT = -1.2V VIN = -3V IOUT = 200mA COUT = 10mF CNR/SS = 0nF 1 RMS NOISE CNR/SS 10Hz to 100kHz 100Hz to 100kHz 0nF 80.00 79.83 10nF 17.29 16.81 0.1 CNR/SS = 10nF 0.01 10 100 1k Frequency (Hz) 10k 100k Figure 20. Output Spectral Noise Density (mV/ÖHz) OUTPUT SPECTRAL NOISE DENSITY vs VOUT(NOM) 10 VOUT(NOM) = -5V 1 IOUT = 1mA CNR/SS = 10nF CBYP = 10nF COUT = 10mF RMS NOISE VOUT(NOM) 10Hz to 100kHz 100Hz to 100kHz -5V 17.50 15.04 -1.2V 15.13 14.73 0.1 VOUT(NOM) = -1.2V 0.01 10 100 1k Frequency (Hz) 10k 100k Figure 21. Copyright © 2010–2011, Texas Instruments Incorporated Submit Documentation Feedback 9 TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2μF, COUT = 2.2μF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted. CAPACITOR-PROGRAMMABLE SOFT START VOUT = -1.2V VIN = -3V IOUT = 1mA CIN = COUT = 2.2mF CNR/SS = 0pF VOUT 1V/div 1V/div CAPACITOR-PROGRAMMABLE SOFT START VEN VOUT = -1.2V VIN = -3V IOUT = 1mA CIN = COUT = 2.2mF CNR/SS = 100pF VOUT VEN Time (20ms/div) Figure 22. Figure 23. CAPACITOR-PROGRAMMABLE SOFT START CAPACITOR-PROGRAMMABLE SOFT START VOUT = -1.2V VIN = -3V IOUT = 1mA CIN = COUT = 2.2mF CNR/SS = 1nF VOUT VEN VEN Time (100ms/div) Time (1ms/div) Figure 24. Figure 25. LINE TRANSIENT RESPONSE LINE TRANSIENT RESPONSE VIN VIN = -20V to -4.3V IOUT = 200mA COUT = 2.2mF VIN = -4.3V to -20V IOUT = 200mA COUT = 2.2mF 5V/div 5V/div VOUT = -1.2V VIN = -3V IOUT = 1mA CIN = COUT = 2.2mF CNR/SS = 10nF VOUT 1V/div 1V/div Time (10ms/div) 20mV/div 20mV/div VIN VOUT Time (10ms/div) Figure 26. 10 Submit Documentation Feedback VOUT Time (10ms/div) Figure 27. Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com TYPICAL CHARACTERISTICS (continued) At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2μF, COUT = 2.2μF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted. 50mV/div 200mA/div LOAD TRANSIENT RESPONSE IOUT VOUT VIN = -3.0V IOUT = 1mA to 200mA COUT = 2.2mF Time (100ms/div) Figure 28. Copyright © 2010–2011, Texas Instruments Incorporated Submit Documentation Feedback 11 TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com THEORY OF OPERATION GENERAL DESCRIPTION The TPS7A30xx belongs to a family of new generation linear regulators that use an innovative bipolar process to achieve ultralow-noise and very high PSRR levels at a wide input voltage range. These features, combined with a high thermal performance MSOP-8 with PowerPAD package make this device ideal for high-performance analog applications. ADJUSTABLE OPERATION VEN VIN The TPS7A3001 has an output voltage range of –1.174 to –33V. The nominal output voltage of the device is set by two external resistors, as shown in Figure 29. Time (20ms/div) Figure 30. Enable Pin Positive/Negative Threshold VOUT VIN OUT IN CIN 10mF EN CBYP 10nF TPS7A3001 R1 FB R2 CNR/SS 10nF NR/SS CAPACITOR RECOMMENDATIONS COUT 10mF GND Figure 29. Adjustable Operation for Maximum AC Performance R1 and R2 can be calculated for any output voltage range using the formula shown in Equation 1. To ensure stability under no load conditions, this resistive network must provide a current equal to or greater than 5μA. VOUT VOUT ³ 5mA R1 = R2 - 1 , where R1 + R2 VREF (1) If greater voltage accuracy is required, take into account the output voltage offset contributions because of the feedback pin current and use 0.1% tolerance resistors. ENABLE PIN OPERATION The TPS7A30xx provides a dual polarity enable pin (EN) that turns on the regulator when |VEN| > 2.0V, whether the voltage is positive or negative, as shown in Figure 30. This functionality allows for different system power management topologies: • Connecting the EN pin directly to a negative voltage, such as VIN, or • Connecting the EN pin directly to a positive voltage, such as the output of digital logic circuitry. 12 VOUT Submit Documentation Feedback Low ESR capacitors should be used for the input, output, noise reduction, and bypass capacitors. Ceramic capacitors with X7R and X5R dielectrics are preferred. These dielectrics offer more stable characteristics. Ceramic X7R capacitors offer improved over-temperature performance, while ceramic X5R capacitors are the most cost-effective and are available in higher values. Note that high ESR capacitors may degrade PSRR. INPUT AND OUTPUT CAPACITOR REQUIREMENTS The TPS7A30xx family of negative, high-voltage linear regulators achieve stability with a minimum input and output capacitance of 2.2μF; however, it is highly recommended to use a 10μF capacitor to maximize ac performance. NOISE REDUCTION AND BYPASS CAPACITOR REQUIREMENTS Although noise reduction and bypass capacitors (CNR/SS and CBYP, respectively) are not needed to achieve stability, it is highly recommended to use 0.01μF capacitors to minimize noise and maximize ac performance. MAXIMUM AC PERFORMANCE In order to maximize noise and PSRR performance, it is recommended to include 10μF or higher input and output capacitors, and 0.01μF noise reduction and bypass capacitors, as shown in Figure 29. The solution shown delivers minimum noise levels of 15.1μVRMS and power-supply rejection levels above 55dB from 10Hz to 700kHz; see Figure 18 and Figure 19. Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx www.ti.com OUTPUT NOISE The TPS7A30xx provides low output noise when a noise reduction capacitor (CNR/SS) is used. The noise reduction capacitor serves as a filter for the internal reference. By using a 0.01μF noise reduction capacitor, the output noise is reduced by almost 80% (from 80μVRMS to 17μVRMS); see Figure 20. SBVS125A – AUGUST 2010 – REVISED MARCH 2011 Additionally, ac performance can be maximized by adding a 0.01μF bypass capacitor (CBYP) from the FB pin to the OUT pin. This capacitor greatly improves power-supply rejection at lower frequencies, for the band from 10Hz to 200kHz; see Figure 18. TPS7A30xx low output voltage noise makes it an ideal solution for powering noise-sensitive circuitry. The very high power-supply rejection of the TPS7A30xx makes it a good choice for powering high-performance analog circuitry, such as operational amplifiers, ADCs, DACS, and audio amplifiers. POWER-SUPPLY REJECTION TRANSIENT RESPONSE The 0.01μF noise reduction capacitor greatly improves TPS7A30xx power-supply rejection, achieving up to 20dB of additional power-supply rejection for frequencies between 110Hz and 400KHz. As with any regulator, increasing the size of the output capacitor reduces over/undershoot magnitude but increases duration of the transient response. Copyright © 2010–2011, Texas Instruments Incorporated Submit Documentation Feedback 13 TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com APPLICATION INFORMATION POWER FOR PRECISION ANALOG One of the primary TPS7A30xx applications is to provide ultralow noise voltage rails to high-performance analog circuitry in order to maximize system accuracy and precision. In conjunction with its positive counterpart, the TPS7A49xx family of positive high-voltage linear regulators, the TPS7A30xx family of negative high voltage linear regulators provides ultralow noise positive and negative voltage rails to high-performance analog circuitry, such as operational amplifiers, ADCs, DACs, and audio amplifiers. Because of the ultralow noise levels at high voltages, analog circuitry with high-voltage input supplies can be used. This characteristic allows for high-performance analog solutions to optimize the voltage range, maximizing system accuracy. The TPS7A30xx offers a wide-bandwidth, very-high power-supply rejection ratio. This specification makes it ideal for post dc/dc converter filtering, as shown in Figure 31. It is highly recommended to use the maximum performance schematic shown in Figure 29. Also, verify that the fundamental frequency (and its first harmonic, if possible) is within the bandwidth of the regulator PSRR, shown in Figure 18. +18V DC/DC converters are the preferred solution to step up or down a voltage rail when current consumption is not negligible. They offer high efficiency with minimum heat generation, but they have one primary disadvantage: they introduce a high-frequency component, and the associated harmonics, on top of the dc output signal. This high-frequency component, if not filtered properly, degrades analog circuitry performance, reducing overall system accuracy and precision. OUT +15V TPS7A49 POST DC/DC CONVERTER FILTERING Most of the time, the voltage rails available in a system do not match the voltage specifications demanded by one or more of its circuits; these rails must be stepped up or down, depending on specific voltage requirements. IN -18V EN GND IN OUT -15V TPS7A30 EN GND EVM Figure 31. Post DC/DC Converter Regulation to High-Performance Analog Circuitry AUDIO APPLICATIONS Audio applications are extremely sensitive to any distortion and noise in the audio band from 20Hz to 20kHz. This stringent requirement demands clean voltage rails to power critical high-performance audio systems. The very-high power-supply rejection ratio (> 55dB) and low noise at the audio band of the TPS7A30xx maximize performance for audio applications; see Figure 18. 14 Submit Documentation Feedback Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com LAYOUT PACKAGE MOUNTING Solder pad footprint recommendations for the TPS7A30xx are available at the end of this product datasheet and at www.ti.com. BOARD LAYOUT RECOMMENDATIONS TO IMPROVE PSRR AND NOISE PERFORMANCE To improve ac performance such as PSRR, output noise, and transient response, it is recommended that the board be designed with separate ground planes for IN and OUT, with each ground plane connected only at the GND pin of the device. In addition, the ground connection for the output capacitor should connect directly to the GND pin of the device. Equivalent series inductance (ESL) and equivalent series resistance (ESR) must be minimized in order to maximize performance and ensure stability. Every capacitor (CIN, COUT, CNR/SS, CBYP) must be placed as close as possible to the device and on the same side of the printed circuit board (PCB) as the regulator itself. Do not place any of the capacitors on the opposite side of the PCB from where the regulator is installed. The use of vias and long traces is strongly discouraged because they may impact system performance negatively and even cause instability. If possible, and to ensure the maximum performance denoted in this product datasheet, use the same layout pattern used for TPS7A30 evaluation board, available at www.ti.com. THERMAL PROTECTION Thermal protection disables the output when the junction temperature rises to approximately +170°C, allowing the device to cool. When the junction temperature cools to approximately +150°C, the output circuitry is enabled. Depending on power dissipation, thermal resistance, and ambient temperature, the thermal protection circuit may cycle on and off. This cycling limits the dissipation of the regulator, protecting it from damage as a result of overheating. Any tendency to activate the thermal protection circuit indicates excessive power dissipation or an inadequate heatsink. For reliable operation, junction temperature should be limited to a maximum of +125°C. To estimate the margin of safety in a complete design (including heatsink), increase the ambient temperature until the thermal protection is triggered; use worst-case loads and signal conditions. For good reliability, thermal protection should trigger Copyright © 2010–2011, Texas Instruments Incorporated at least +35°C above the maximum expected ambient condition of your particular application. This configuration produces a worst-case junction temperature of +125°C at the highest expected ambient temperature and worst-case load. The internal protection circuitry of the TPS7A30xx has been designed to protect against overload conditions. It was not intended to replace proper heatsinking. Continuously running the TPS7A30xx into thermal shutdown degrades device reliability. POWER DISSIPATION The ability to remove heat from the die is different for each package type, presenting different considerations in the PCB layout. The PCB area around the device that is free of other components moves the heat from the device to the ambient air. Performance data or JEDEC low- and high-K boards are given in the Dissipation Ratings Table. Using heavier copper increases the effectiveness in removing heat from the device. The addition of plated through-holes to heat dissipating layers also improves the heatsink effectiveness. Power dissipation depends on input voltage and load conditions. Power dissipation (PD) is equal to the product of the output current times the voltage drop across the output pass element, as shown in Equation 2: PD = (VIN - VOUT) IOUT (2) SUGGESTED LAYOUT AND SCHEMATIC Layout is a critical part of good power-supply design. There are several signal paths that conduct fast-changing currents or voltages that can interact with stray inductance or parasitic capacitance to generate noise or degrade the power-supply performance. To help eliminate these problems, the IN pin should be bypassed to ground with a low ESR ceramic bypass capacitor with a X5R or X7R dielectric. The GND pin should be tied directly to the PowerPAD under the IC. The PowerPAD should be connected to any internal PCB ground planes using multiple vias directly under the IC. It may be possible to obtain acceptable performance with alternate PCB layouts; however, the layout shown in Figure 32 and the schematic shown in Figure 33 have been shown to produce good results and are meant as a guideline. Submit Documentation Feedback 15 TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com Figure 32. PCB Layout Example U1 TPS7A30XXDGN 5 6 C4 7 8 Vin J1 4 GND EN 3 NR/SS NC DNC FB 2 IN PwPd J1 1 OUT C1 J7 GND R1 9 J4 C2 C3 R3 Figure 33. Schematic for PCB Layout Example 16 Submit Documentation Feedback Copyright © 2010–2011, Texas Instruments Incorporated TPS7A30xx SBVS125A – AUGUST 2010 – REVISED MARCH 2011 www.ti.com REVISION HISTORY NOTE: Page numbers for previous revisions may differ from the page numbers in the current version. Changes from Original (August 2010) to Revision A • Page Switched colors for 10mA and 200mA curves in Figure 10 .................................................................................................. 7 Copyright © 2010–2011, Texas Instruments Incorporated Submit Documentation Feedback 17 PACKAGE OPTION ADDENDUM www.ti.com 28-Mar-2011 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) TPS7A3001DGNR ACTIVE MSOPPowerPAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS7A3001DGNT ACTIVE MSOPPowerPAD DGN 8 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Samples (Requires Login) (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) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 26-Mar-2011 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant TPS7A3001DGNR MSOPPower PAD DGN 8 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 TPS7A3001DGNT MSOPPower PAD DGN 8 250 180.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 26-Mar-2011 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS7A3001DGNR MSOP-PowerPAD DGN 8 2500 346.0 346.0 29.0 TPS7A3001DGNT MSOP-PowerPAD DGN 8 250 190.5 212.7 31.8 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Communications and Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP® Products www.dlp.com Energy and Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com Wireless www.ti.com/wireless-apps RF/IF and ZigBee® Solutions www.ti.com/lprf TI E2E Community Home Page e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2011, Texas Instruments Incorporated