TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 D D D D D D D D D 50-mA Low-Dropout Regulator Available in 1.5-V, 1.8-V, 2.5-V, 2.8-V, 3.0-V Output Noise Typically 56 µVRMS (TPS79030) Only 17 µA Quiescent Current at 50 mA 1 µA Quiescent Current in Standby Mode Dropout Voltage Typically 57 mV at 50 mA (TPS79030) Over Current Limitation –40°C to 125°C Operating Junction Temperature Range 5-Pin SOT-23 (DBV) Package DBV PACKAGE (TOP VIEW) IN 1 GND 2 EN 3 5 OUT 4 BYPASS TPS79030 GROUND CURRENT vs JUNCTION TEMPERATURE 22 VI = 4 V Co = 4.7 µF 21 The usual PNP pass transistor has been replaced by a PMOS pass element. Because the PMOS pass element behaves as a low-value resistor, the dropout voltage is very low, typically 57 mV at 50 mA of load current (TPS79030), and is directly proportional to the load current. The quiescent current is ultralow (17 µA typically) and is stable over the entire range of output load current (0 mA to 50 mA). Intended for use in portable systems such as laptops and cellular phones, the ultralow-dropout voltage feature and ultralowpower operation result in a significant increase in system battery operating life. 20 IO = 50 mA 19 IO = 1 mA 18 17 16 15 –40 –25 –10 5 20 35 50 65 80 95 110 125 TJ – Junction Temperature – °C TPS78930 OUTPUT SPECTRAL NOISE DENSITY vs FREQUENCY 1200 Output Spectral Noise Density µ–V/ Hz The TPS790xx family of low-dropout (LDO) voltage regulators offers the benefits of low-dropout voltage, ultralow-power operation, low-output noise, and miniaturized packaging. These regulators feature low-dropout voltages and ultralow quiescent current compared to conventional LDO regulators. An internal resistor, in conjunction with an external bypass capacitor, creates a low-pass filter to reduce the noise. The TPS79030 exhibits only 56 µVRMS of output voltage noise using 0.01 µF bypass and 10 µF output capacitors. Offered in a 5-terminal small outline integrated-circuit SOT-23 package, the TPS790xx series devices are ideal for micropower operations, low output noise, and where board space is limited. Ground Current – µ A description VI = 4 V Co = 4.7 µF C(byp) = 0.1 µF 1000 800 600 IO = 50 mA IO = 1 mA 400 200 0 100 1k 10k f – Frequency – Hz 100k 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. Copyright 2000, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 description (continued) The TPS790xx also features a logic-enabled sleep mode to shut down the regulator, reducing quiescent current to 1 µA typical at TJ = 25°C. The TPS790xx is offered in 1.5-V, 1.8-V, 2.5-V, 2.8-V, 3.0-V. AVAILABLE OPTIONS VOLTAGE TJ PACKAGE PART NUMBER TPS79015DBVT† TPS79015DBVR‡ TPS79018DBVT† TPS79018DBVR‡ TPS79025DBVT† TPS79025DBVR‡ 1.5 V 1.8 V –40°C to 125°C 2.5 V SOT-23 SOT 23 (DBV) TPS79028DBVT† TPS79030DBVT† 2.8 V 3.0 V TPS79028DBVR‡ TPS79030DBVR‡ † The DBVT indicates tape and reel of 250 parts. ‡ The DBVR indicates tape and reel of 3000 parts. functional block diagram TPS79015/18/25/28/30 OUT IN EN 150 kΩ Current Limit / Thermal Protection Vref GND Bypass Terminal Functions TERMINAL I/O DESCRIPTION NAME NO. BYPASS 4 I Bypass EN 3 I Enable input GND 2 IN 1 I Input supply voltage OUT 5 O Regulated output voltage 2 Ground POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 SYMBOL PEBI PECI PEDI PEEI PEFI TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 detail description The TPS790xx uses a PMOS pass element to dramatically reduce both dropout voltage and supply current over more conventional PNP-pass-element LDO designs. The PMOS pass element is a voltage-controlled device and, unlike a PNP transistor, it does not require increased drive current as output current increases. Supply current in the TPS790xx is essentially constant from no load to maximum load. The TPS790xx family of low-dropout (LDO) regulators have been optimized for use in battery-operated equipment. They feature extremely low dropout voltages, low output noise, low quiescent current (17 µA typically), and enable inputs to reduce supply currents to 1 µA when the regulators are turned off. The internal voltage reference is a key source of noise in a LDO regulator. The TPS790xx has a BYPASS pin which is connected to the voltage reference through a 150-kΩ internal resistor. The 150-kΩ internal resistor, in conjunction with an external bypass capacitor connected to the BYPASS pin, creates a low pass filter to reduce the voltage reference noise and, therefore, the noise at the regulator output. Note that the output will start up slower as the bypass capacitance increases due to the RC time constant at the bypass pin that is created by the internal 150-kΩ resistor and external capacitor. Current limiting and thermal protection prevent damage by excessive output current and/or power dissipation. The device switches into a constant-current mode at approximately 350 mA; further load reduces the output voltage instead of increasing the output current. The thermal protection shuts the regulator off if the junction temperature rises above approximately 165°C. Recovery is automatic when the junction temperature drops approximately 25°C below the high temperature trip point. The PMOS pass element includes a back gate diode that conducts reverse current when the input voltage level drops below the output voltage level. A voltage of 1.7 V or greater on the EN input will disable the TPS790xx internal circuitry, reducing the supply current to 1 µA. A voltage of less than 0.9 V on the EN input will enable the TPS790xx and will enable normal operation to resume. The EN input does not include any deliberate hysteresis, and it exhibits an actual switching threshold of approximately 1.5 V. absolute maximum ratings over operating free-air temperature range (unless otherwise noted)Ĕ Input voltage range (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to 13.5 V Voltage range at EN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to VI + 0.3 V Voltage on OUT, FB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Peak output current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Internally limited ESD rating, HBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 kV Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table Operating virtual junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 150°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C † 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. NOTE 1: All voltage values are with respect to network ground terminal. DISSIPATION RATING TABLE PACKAGE TA ≤ 25°C POWER RATING DERATING FACTOR ABOVE TA = 25°C TA = 70°C POWER RATING TA = 85°C POWER RATING Recommended DBV 350 mW 3.5 mW/°C 192 mW 140 mW Absolute maximum DBV 437 mW 3.5 mW/°C 280 mW 227 mW POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 recommended operating conditions MIN Input voltage, VI (see Note 2) NOM 2.7 Continuous output current, IO (see Note 3) Operating junction temperature, TJ MAX UNIT 10 V 0 50 mA –40 125 °C NOTES: 2. To calculate the minimum input voltage for your maximum output current, use the following formula: VI(min) = VO(max) + VDO (max load) 3. Continuous output current and operating junction temperature are limited by internal protection circuitry, but it is not recommended that the device operate under conditions beyond those specified in this table for extended periods of time. electrical characteristics over recommended operating free–air temperature range, VI = VO(typ) + 1 V, IO = 1 mA, EN = 0V, CO = 4.7 µF (unless otherwise noted) PARAMETER TEST CONDITIONS Output voltage g ((10 µA µ to 50 mA Load)) (see Note 4) TPS79015 TJ = 25°C, TJ = –40°C to 125°C, 2.7 V < VI < 10 V TPS79018 TJ = 25°C, TJ = –40°C to 125°C, 2.8 V < VI < 10 V TPS79025 TJ = 25°C, TJ = –40°C to 125°C, 3.5 V < VI < 10 V TPS79028 TJ = 25°C, TJ = –40°C to 125°C, 3.8 V < VI < 10 V TPS79030 TJ = 25°C, TJ = –40°C to 125°C, 2.7 V < VI < 10 V 2.8 V < VI < 10 V 3.5 V < VI < 10 V Load regulation EN = 0 V, TJ = 25°C IO = 10 µA to 50 mA, Output voltage line regulation (∆VO/VO) (see Notes 4 and 5) VO + 1 V < VI ≤ 10 V, TJ = 25°C VO + 1 V < VI ≤ 10 V, TJ = –40°C to 125°C Output noise voltage (TPS79030) BW = 300 Hz to 50 kHz, C(byp) = 0.01 µF, Co = 10 µF, IO = 50 mA, TJ = 25°C VO = 0 V, EN = VI , See Note 4 UNIT 1.8 1.854 2.5 2.425 2.575 V 2.8 2.910 IO = 50 mA, MAX 1.545 1.746 4.0 V < VI < 10 V EN = 0 V, TJ = –40°C to 125°C Output current limit 1.455 2.716 10 µA < IO < 50 mA, TYP 1.5 3.8 V < VI < 10 V 4.0 V < VI < 10 V EN = 0 V, TJ = 25°C Quiescent current (GND current) (see Note 4) MIN 2.884 3 3.090 17 µA 28 8 mV 0.04 0.1 µVrms 56 350 %/V 750 mA 2.7 < VI < 10 V 1 µA TJ = –40°C to 125°C 2 µA NOTES: 4. The minimum IN operating voltage is 2.7 V or VO (typ) + 1 V, whichever is greater. The maximum IN voltage is 10 V. The minimum output current is 10 µA and the maximum output current is 50 mA. 5. If VO ≤ 1.8 V then VImin = 2.7 V, VImax = 10 V: Standby current Line Reg. (mV) + ǒ%ńVǓ V O ǒ ǒ V Imax Ǔ * 2.7 V 100 If VO ≥ 2.5 V then VImin = VO + 1 V, VImax = 10 V: Line Reg. (mV) 4 + ǒ%ńVǓ V O V Imax * ǒ V 100 O 1000 ǓǓ )1 V POST OFFICE BOX 655303 1000 • DALLAS, TEXAS 75265 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 electrical characteristics over recommended operating free–air temperature range, VI = VO(typ) + 1 V, IO = 1 mA, EN = 0V, CO = 4.7 µF (unless otherwise noted) (continued) PARAMETER TEST CONDITIONS High level enable input voltage 2.7 V < VI < 10 V Low level enable input voltage 2.7 V < VI < 10 V Power supply ripple rejection (TPS79030) f = 1 kHz, TJ = 25°C, Input current (EN) Dropout voltage (see Note 6) Dropout voltage (see Note 6) MIN TYP MAX UNIT 1.7 V 0.9 Co = 10 µF, C(byp) = 0.01 µF, V 85 EN = 0 V –1 EN = VI –1 0 TPS79028 IO = 50 mA, IO = 50 mA, TJ = 25°C TJ = –40°C to 125°C 60 TPS79030 IO = 50 mA, IO = 50 mA, TJ = 25°C TJ = –40°C to 125°C 57 dB 1 µA 1 µA 125 mV 115 6. IN voltage equals VO(typ) –100 mV; The TPS79030 output voltage is set to 2.9 V. The TPS79015, TPS79018, and TPS79025 dropout voltage is limited by input voltage range limitations. TYPICAL CHARACTERISTICS Table of Graphs FIGURE VO Zo VDO VO Output voltage vs Output current 1, 2, 3 vs Junction temperature 4, 5, 6 Ground current vs Junction temperature Output spectral noise density vs Frequency Root mean squared output noise vs Bypass capacitance 11 Output impedance vs Frequency 12 Dropout voltage vs Junction temperature 13 Ripple rejection vs Frequency 14 – 16 Output voltage, enable voltage vs Time (start-up) 17 – 19 Line transient response 7 8 – 10 20, 22 Load transient response 21, 23 Equivalent series resistance (ESR) POST OFFICE BOX 655303 vs Output current • DALLAS, TEXAS 75265 24, 25 5 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 TYPICAL CHARACTERISTICS TPS79015 TPS79025 OUTPUT VOLTAGE vs OUTPUT CURRENT OUTPUT VOLTAGE vs OUTPUT CURRENT 1.515 2.545 VI = 3.5 V Co = 4.7 µF TJ = 25°C 1.510 VO – Output Voltage – V VO – Output Voltage – V 2.510 VI = 2.7 V Co = 4.7 µF TJ = 25°C 2.505 2.500 2.495 1.505 1.500 1.495 1.490 2.490 1.485 2.485 0 20 10 40 30 0 50 10 20 Figure 1 TPS79030 TPS79015 OUTPUT VOLTAGE vs OUTPUT CURRENT OUTPUT VOLTAGE vs JUNCTION TEMPERATURE 50 1.515 VI = 2.7 V Co = 4.7 µF VI = 4 V Co = 4.7 µF TJ = 25°C 1.510 VO – Output Voltage – V 3.010 VO – Output Voltage – V 40 Figure 2 3.015 3.005 3.000 2.995 2.990 1.505 IO = 1 mA 1.500 IO = 50 mA 1.495 1.490 2.985 0 10 20 30 40 IO – Output Current – mA 50 1.485 –40 –25 –10 5 20 35 50 Figure 4 POST OFFICE BOX 655303 65 80 95 110 125 TJ – Junction Temperature – °C Figure 3 6 30 IO – Output Current – mA IO – Output Current – mA • DALLAS, TEXAS 75265 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 TYPICAL CHARACTERISTICS TPS79025 TPS79030 OUTPUT VOLTAGE vs JUNCTION TEMPERATURE OUTPUT VOLTAGE vs JUNCTION TEMPERATURE 2.515 3.015 VI = 3.5 V Co = 4.7 µF VI = 4 V Co = 4.7 µF 3.010 IO = 1 mA 2.505 VO – Output Voltage – V VO – Output Voltage – V 2.510 2.500 IO = 50 mA 2.495 2.490 3.005 IO = 1 mA 3.000 2.995 IO = 50 mA 2.990 2.485 –40 –25 –10 5 20 35 50 65 80 2.985 –40 –25 –10 5 95 110 125 20 TPS79030 65 80 95 110 125 TPS79030 GROUND CURRENT vs JUNCTION TEMPERATURE OUTPUT SPECTRAL NOISE DENSITY vs FREQUENCY 22 1200 VI = 4 V Co = 4.7 µF Output Spectral Noise Density – nV/ Hz Ground Current – µ A 50 Figure 6 Figure 5 21 35 TJ – Junction Temperature – °C TJ – Junction Temperature – °C 20 IO = 50 mA 19 IO = 1 mA 18 17 16 15 –40 –25 –10 5 20 35 50 65 80 95 110 125 VI = 4 V Co = 4.7 µF C(byp) = 0.1 µF 1000 800 600 IO = 50 mA IO = 1 mA 400 200 0 100 TJ – Junction Temperature – °C 1k 10k 100k f – Frequency – Hz Figure 8 Figure 7 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 TYPICAL CHARACTERISTICS TPS79030 TPS79030 OUTPUT SPECTRAL NOISE DENSITY vs FREQUENCY OUTPUT SPECTRAL NOISE DENSITY vs FREQUENCY 1800 VI = 4 V Co = 10 µF C(byp) = 0.1 µF 600 Output Spectral Noise Density – nV/ Hz Output Spectral Noise Density – nV/ Hz 700 500 400 IO = 1 mA 300 IO = 50 mA 200 100 1400 C(byp) = 0.01 µF 1200 C(byp) = 0.1 µF 1000 800 600 400 200 0 100 1k 10k 0 100 100k 1k 10k f – Frequency – Hz f – Frequency – Hz Figure 9 OUTPUT IMPEDANCE vs FREQUENCY 300 2 Co = 10 µF 1.8 250 VI = 4 V Co = 10 µF TJ = 25°C 1.6 Zo – Output Impedance – Ω RMS – Root Mean Squared Output Noise – µ V(RMS) 100k Figure 10 ROOT MEAN SQUARED OUTPUT NOISE vs BYPASS CAPACITANCE 200 150 100 VO = 3 V 1.2 1 0.8 IO = 1 mA 0.6 0.4 50 IO = 50 mA 0.2 VO = 1.5 V 0 0.00001 1.4 0.1 0.0001 0.001 0.01 C(bypass) – Bypass Capacitance – µF 1 0 10 100 1k 10k f – Frequency – Hz Figure 11 8 VI = 4 V IO = 50 mA Co = 10 µF C(byp) = 0.001 µF 1600 Figure 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 100k 1M TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 TYPICAL CHARACTERISTICS TPS79030 TPS79030 DROPOUT VOLTAGE vs JUNCTION TEMPERATURE RIPPLE REJECTION vs FREQUENCY 110 75 100 IO = 50 mA IO = 1 mA 90 Ripple Rejection –dB VDO – Dropout Voltage – mV 65 VI = 2.9 V Co = 4.7 µF 55 45 35 80 70 IO = 50 mA 60 50 25 40 IO = 1 mA 15 5 –40 –25 –10 VI = 4 V Co = 4.7 µF C(byp) = 0.1 µF 30 20 5 20 35 50 65 80 95 110 125 10 100 TA – Junction Temperature – °C 1k 100k 1M 100k 1M Figure 14 Figure 13 TPS79030 TPS79030 RIPPLE REJECTION vs FREQUENCY RIPPLE REJECTION vs FREQUENCY 100 100 90 90 IO = 1 mA 80 Ripple Rejection –dB Ripple Rejection –dB 10k f – Frequency – Hz 70 IO = 50 mA 60 50 40 IO = 1 mA 80 70 IO = 50 mA 60 50 40 VI = 4 V Co = 4.7 µF C(byp) = 0.01 µF 30 VI = 4 V Co = 4.7 µF C(byp) = 0.001 µF 30 20 20 10 100 1k 10k f – Frequency – Hz 100k 1M 10 100 1k 10k f – Frequency – Hz Figure 15 Figure 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 TYPICAL CHARACTERISTICS TPS79030 Enable Voltage – V OUTPUT VOLTAGE, ENABLE VOLTAGE vs TIME (START-UP) 5 0 VO – Output Voltage – V 3 2 VI = 4 V VO = 3 V IO = 50 mA C(byp) = 0.01 µF VI = 4 V Co = 4.7 µF C = 4.7 µF TJ = 25°CO 1 0 0 1 2 3 4 5 6 t – Time – ms 7 8 9 10 TPS79030 OUTPUT VOLTAGE, ENABLE VOLTAGE vs TIME (START-UP) Enable Voltage – V TPS79030 OUTPUT VOLTAGE, ENABLE VOLTAGE vs TIME (START-UP) 5 0 3 VO – Output Voltage – V VO – Output Voltage – V Enable Voltage – V Figure 17 2 VI = 4 V VO = 3 V IO = 50 mA C(byp) = 0.001 µF Co = 4.7 µF TJ = 25°C 1 0 0 0.2 0.4 0.6 0.8 1 1.2 t – Time – ms 1.4 1.6 1.8 2 5 0 C(byp) = 0.001 µF C(byp) = 0.01 µF 2 VI = 4 V VO = 3 V IO = 50 mA Co = 4.7 µF TJ = 25°C 1 0 0 10 Figure 18 10 C(byp) = 0.1 µF 3 20 30 40 50 60 t – Time – ms Figure 19 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 70 80 90 100 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 TPS79015 LOAD TRANSIENT RESPONSE Current Load – mA TPS79015 LINE TRANSIENT RESPONSE 20 0 –20 50 0 3.7 ∆ VO – Change In Output Voltage – mV VI – Input Voltage – V VO – Output Voltage – mV TYPICAL CHARACTERISTICS 2.7 IO = 10 mA Co = 4.7 µF 0 20 40 60 0 –50 VI = 2.7 V Co = 10 µF –100 0 80 100 120 140 160 180 200 t – Time – µs 20 40 TPS79030 LOAD TRANSIENT RESPONSE I O – Output Current – mA TPS79030 LINE TRANSIENT RESPONSE IO = 10 mA Co = 4.7 µF 5 4.5 4 50 0 50 ∆ VO – Change In Output Voltage – mV VI – Input Voltage – V 80 100 120 140 160 180 200 t – Time – µs Figure 21 Figure 20 VO – Output Voltage – mV 60 20 0 –20 0 20 40 60 80 100 120 140 160 180 200 t – Time – µs 0 –50 VI = 4 V Co = 4.7 µF –100 0 20 40 60 80 100 120 140 160 180 200 t – Time – µs Figure 23 Figure 22 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 TYPICAL CHARACTERISTICS TPS79030 TYPICAL REGIONS OF STABILITY TPS79030 TYPICAL REGIONS OF STABILITY EQUIVALENT SERIES RESISTANCE (ESR) vs OUTPUT CURRENT EQUIVALENT SERIES RESISTANCE (ESR) vs OUTPUT CURRENT 100 VI = 4 V Co = 4.7 µF VO = 3 V ESR – Equivalent Series Resistance – Ω ESR – Equivalent Series Resistance – Ω 100 Region of Instability 10 1 Region of Stability 0.1 VI = 4 V Co = 10 µF VO = 3 V Region of Instability 10 Region of Stability 1 0 5 10 15 20 25 30 35 40 45 50 0 5 15 20 25 Figure 25 Figure 24 POST OFFICE BOX 655303 30 35 IO – Output Current – mA IO – Output Current – mA 12 10 • DALLAS, TEXAS 75265 40 45 50 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 APPLICATION INFORMATION The TPS790xx family of low-dropout (LDO) regulators have been optimized for use in battery-operated equipment. They feature extremely low dropout voltages, low quiescent current (17 µA typically), and enable inputs to reduce supply currents to less than 1 µA when the regulators are turned off. A typical application circuit is shown in Figure 21. TPS790xx† 1 VI IN BYPASS 4 OUT C1 1 µF 5 VO 3 EN + GND 0.01 µF 4.7 µF ESR = 0.2 Ω 2 Figure 26. Typical Application Circuit external capacitor requirements Although not required, a 0.047-µF or larger ceramic input bypass capacitor, connected between IN and GND and located close to the TPS790xx, is recommended to improve transient response and noise rejection. A higher-value electrolytic input capacitor may be necessary if large, fast-rise-time load transients are anticipated and the device is located several inches from the power source. Like all low dropout regulators, the TPS790xx requires an output capacitor connected between OUT and GND to stabilize the internal control loop. The minimum recommended capacitance is 4.7 µF. The ESR (equivalent series resistance) of the capacitor should be between 0.2 Ω and 10 Ω. to ensure stability. Capacitor values larger than 4.7 µF are acceptable, and allow the use of smaller ESR values. Capacitances less than 4.7 µF are not recommended because they require careful selection of ESR to ensure stability. Solid tantalum electrolytic, aluminum electrolytic, and multilayer ceramic capacitors are all suitable, provided they meet the requirements described above. Most of the commercially available 4.7 µF surface-mount solid tantalum capacitors, including devices from Sprague, Kemet, and Nichico, meet the ESR requirements stated above. Multilayer ceramic capacitors may have very small equivalent series resistances and may thus require the addition of a low value series resistor to ensure stability. CAPACITOR SELECTION PART NO. MAX ESR† SIZE (H × L × W)† MFR. VALUE T494B475K016AS KEMET 4.7 µF 1.5 Ω 1.9 × 3.5 × 2.8 195D106x0016x2T SPRAGUE 10 µF 1.5 Ω 1.3 × 7.0 × 2.7 695D106x003562T SPRAGUE 10 µF 1.3 Ω 2.5 × 7.6 × 2.5 TPSC475K035R0600 AVX 4.7 µF 0.6 Ω 2.6 × 6.0 × 3.2 † Size is in mm. The ESR maximum resistance is in Ohms at 100 kHz and TA = 25°C. Contact the manufacturer for the minimum ESR values. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 APPLICATION INFORMATION external capacitor requirements (continued) The external bypass capacitor, used in conjunction with an internal resistor to form a low-pass filter, should be a low ESR ceramic capacitor. For example, the TPS79030 exhibits only 56 µVRMS of output voltage noise using a 0.01 µF ceramic bypass capacitor and a10 µF ceramic output capacitors. Note that the output will start up slower as the bypass capacitance increases due to the RC time constant at the bypass pin that is created by the internal 150 kΩ resistor and external capacitor. power dissipation and junction temperature Specified regulator operation is assured to a junction temperature of 125°C; the maximum junction temperature should be restricted to 125°C under normal operating conditions. This restriction limits the power dissipation the regulator can handle in any given application. To ensure the junction temperature is within acceptable limits, calculate the maximum allowable dissipation, PD(max), and the actual dissipation, PD, which must be less than or equal to PD(max). The maximum-power-dissipation limit is determined using the following equation: P D(max) * TA + TJmax R qJA Where: TJmax is the maximum allowable junction temperature. RθJA is the thermal resistance junction-to-ambient for the package, i.e., 285°C/W for the 5-terminal SOT23. TA is the ambient temperature. ǒ Ǔ The regulator dissipation is calculated using: P D + VI * VO I O Power dissipation resulting from quiescent current is negligible. Excessive power dissipation will trigger the thermal protection circuit. regulator protection The TPS790xx PMOS-pass transistor has a built-in back diode that conducts reverse current when the input voltage drops below the output voltage (e.g., during power down). Current is conducted from the output to the input and is not internally limited. If extended reverse voltage operation is anticipated, external limiting might be appropriate. The TPS790xx features internal current limiting and thermal protection. During normal operation, the TPS790xx limits output current to approximately 350 mA. When current limiting engages, the output voltage scales back linearly until the overcurrent condition ends. While current limiting is designed to prevent gross device failure, care should be taken not to exceed the power dissipation ratings of the package. If the temperature of the device exceeds approximately 165°C, thermal-protection circuitry shuts it down. Once the device has cooled down to below approximately 140°C, regulator operation resumes. 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TPS79015, TPS79018, TPS79025, TPS79028, TPS79030 ULTRALOW-POWER LOW-NOISE 50 mA LOW-DROPOUT LINEAR REGULATORS SLVS299A – SEPTEMBER 2000 – REVISED SEPTEMBER 2000 MECHANICAL DATA DBV (R-PDSO-G5) PLASTIC SMALL-OUTLINE 0,50 0,30 0,95 5 0,20 M 4 1,70 1,50 1 0,15 NOM 3,00 2,60 3 Gage Plane 3,00 2,80 0,25 0°–8° 0,55 0,35 Seating Plane 1,45 0,95 0,05 MIN 0,10 4073253-4/F 10/00 NOTES: A. B. C. D. All linear dimensions are in millimeters. This drawing is subject to change without notice. Body dimensions do not include mold flash or protrusion. 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