Voltage Regulators AN78xx/AN78xxF Series 3-pin positive output voltage regulator (1 A type) ■ Overview AN78xx series Unit: mm (10.35) 10.0±0.3 The AN78xx series and the AN78xxF series are 3pin, fixed positive output type monolithic voltage regulators. Stabilized fixed output voltage is obtained from unstable DC input voltage without using any external components. 11 types of fixed output voltage are available; 5V, 6V, 7V, 8V, 9V, 10V, 12V, 15V, 18V, 20V, and 24V. They can be used widely in power circuits with current capacity of up to 1A. 4.5±0.2 1.4±0.1 1.4 +0.15 –0.05 12.5±0.2 17.0±0.2 26.1±0.2 29.0±0.3 15.4±0.2 (13.6) (4.5) 8.7±0.2 2.9±0.1 φ3.7±0.1 0.8 +0.15 –0.05 ■ Features 0.45 +0.2 –0.0 2.54 2.54 (2.0) (2.5) 1: Input 2: Common 3: Output 10.5±0.3 HSIP003-P-0000 AN78xxF series Unit: mm (1.73) 13.60±0.25 4.50±0.25 8.70±0.30 17.00±0.25 φ3.10±0.10 2.77±0.30 4.20±0.25 3.80±0.25 10.50±0.30 φ5.30 (4.30) 16.70±0.30 • No external components • Output voltage: 5V, 6V, 7V, 8V, 9V, 10V, 12V, 15V, 18V, 20V, 24V • Built-in overcurrent limit circuit • Built-in thermal overload protection circuit • Built-in ASO (area of safe operation) protection circuit (0.40) 0.80±0.20 2.00±0.25 1.40±0.20 4.50±0.30 2.54 1 2 0.40+0.10 −0.05 2.50±0.25 1: Input 2: Common 3: Output 3 HSIP003-P-0000A ■ Block Diagram 1 Input Pass Tr Q1 Current Source Current Limiter RSC 3 Starter Voltage Reference + Error Amp. Output R2 Thermal Protection − R1 2 Common 1 AN78xx/AN78xxF Series Voltage Regulators ■ Absolute Maximum Ratings at Ta = 25°C Parameter Symbol Input voltage Power dissipation VI AN78xx series PD AN78xxF series Rating 35 *1 Unit 40 *2 15 *3 V V W 10.25 *3 Operating ambient temperature Topr −30 to +80 °C Storage temperature Tstg −55 to +150 °C *1 AN7805/F, AN7806/F, AN7807/F, AN7808/F, AN7809/F, AN7810/F, AN7812/F, AN7815/F, AN7818/F *2 AN7820/F, AN7824/F *3 Follow the derating curve. When Tj exceeds 150°C, the internal circuit cuts off the output. ■ Electrical Characteristics at Ta = 25°C • AN7805, AN7805F (5V type) Parameter Symbol Output voltage VO Output voltage tolerance VO Line regulation REGIN Load regulation REGL Bias current Conditions Tj = 25°C VI = 8 to 20V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Min 4.8 Typ 5 4.75 Max Unit 5.2 V 5.25 V VI = 7.5 to 25 V, Tj = 25°C 3 100 mV VI = 8 to 12V, Tj = 25°C 1 50 mV IO = 5mA to 1.5A, Tj = 25°C 15 100 mV IO = 250 to 750mA, Tj = 25°C 5 50 mV Tj = 25°C 8 mA Bias current fluctuation to input ∆IBias(IN) VI = 7.5 to 25V, Tj = 25°C 1.3 mA Bias current fluctuation to load ∆IBias(L) IO = 5mA to 1A, Tj = 25°C 0.5 mA Output noise voltage Ripple rejection ratio Minimum input/output voltage difference Output impedance IBias Vno f = 10Hz to 100kHz RR VI = 8 to 18V, IO = 100mA, f = 120Hz VDIF(min) ZO IO = 1A, Tj = 25°C f = 1kHz IO(Short) VI = 25V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C Output short-circuit current 3.9 40 62 µV dB 2 V 17 mΩ 700 mA 2 A − 0.3 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 10V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W 2 Voltage Regulators AN78xx/AN78xxF Series ■ Electrical Characteristics at Ta = 25°C (continued) • AN7806, 7806F (6V type) Parameter Symbol Output voltage VO Output voltage tolerance VO Line regulation Load regulation Bias current REGIN REGL IBias Conditions Tj = 25°C VI = 9 to 21V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Min 5.75 Typ 6 5.7 VI = 8.5 to 25V, Tj = 25°C Max Unit 6.25 V 6.3 V 5 120 mV VI = 9 to 13V, Tj = 25°C 1.5 60 mV IO = 5mA to 1.5A, Tj = 25°C 14 120 mV IO = 250 to 750mA, Tj = 25°C 4 60 mV Tj = 25°C 8 mA Bias current fluctuation to input ∆IBias(IN) VI = 8.5 to 25V, Tj = 25°C 1.3 mA Bias current fluctuation to load ∆IBias(L) IO = 5mA to 1A, Tj = 25°C 0.5 mA Output noise voltage Ripple rejection ratio Minimum input/output voltage difference Output impedance Vno RR VDIF(min) ZO 3.9 f = 10Hz to 100kHz VI = 9 to 19V, IO = 100mA, f = 120Hz 59 IO = 1A, Tj = 25°C f = 1kHz IO(Short) VI = 25V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C Output short-circuit current µV 40 dB 2 V 17 mΩ 700 mA 2 A − 0.4 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 11V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W • AN7807, 7807F (7V type) Parameter Symbol Conditions Output voltage VO Output voltage tolerance VO Tj = 25°C VI = 10 to 22V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation Load regulation Bias current REGIN REGL IBias Min 6.7 Typ 7 6.6 Max Unit 7.3 V 7.4 V VI = 9.5 to 25V, Tj = 25°C 5 140 mV VI = 10 to 15V, Tj = 25°C 1.5 70 mV IO = 5mA to 1.5A, Tj = 25°C 14 140 mV 4 70 mV 3.9 8 mA IO = 250 to 750mA, Tj = 25°C Tj = 25°C Bias current fluctuation to input ∆IBias(IN) VI = 9.5 to 25V, Tj = 25°C 1 mA Bias current fluctuation to load ∆IBias(L) IO = 5mA to 1A, Tj = 25°C 0.5 mA Output noise voltage Vno f = 10Hz to 100kHz Ripple rejection ratio RR VI = 10 to 20V, IO = 100mA, f = 120Hz Minimum input/output voltage difference Output impedance VDIF(min) ZO IO = 1A, Tj = 25°C f = 1kHz Output short-circuit current IO(Short) VI = 25V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C 46 57 µV dB 2 V 16 mΩ 700 mA 2 A − 0.5 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 12V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W 3 AN78xx/AN78xxF Series Voltage Regulators ■ Electrical Characteristics at Ta = 25°C (continued) • AN7808, 7808F (8V type) Parameter Symbol Conditions Output voltage VO Output voltage tolerance VO Tj = 25°C VI = 11 to 23V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation Load regulation Bias current REGIN REGL IBias Output impedance ZO V mV mV IO = 5mA to 1.5A, Tj = 25°C 12 160 mV IO = 250 to 750mA, Tj = 25°C 4 80 mV 3.9 8 mA 1 mA 0.5 mA Tj = 25°C f = 10Hz to 100kHz VI = 11.5 to 21.5V, IO = 100mA, f = 120Hz Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C dB 56 f = 1kHz VI = 25V, Tj = 25°C µV 52 IO = 1A, Tj = 25°C IO(Short) Output short-circuit current 8.4 80 IO = 5mA to 1A, Tj = 25°C RR V 160 ∆IBias(L) VDIF(min) 8.3 2 Bias current fluctuation to load Minimum input/output voltage difference 7.6 Unit 6 VI = 10.5 to 25V, Tj = 25°C Ripple rejection ratio 8 Max VI = 11 to 17V, Tj = 25°C ∆IBias(IN) Vno 7.7 Typ VI = 10.5 to 25V, Tj = 25°C Bias current fluctuation to input Output noise voltage Min 2 V 16 mΩ 700 mA 2 A − 0.5 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 14V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W • AN7809, 7809F (9V type) Symbol Conditions Output voltage Parameter VO Output voltage tolerance VO Tj = 25°C VI = 12 to 24V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation REGIN Load regulation REGL Bias current IBias Bias current fluctuation to input ∆IBias(IN) Bias current fluctuation to load ∆IBias(L) 8.55 Max Unit 9.35 V 9.45 V 7 180 mV 90 mV IO = 5mA to 1.5A, Tj = 25°C 12 180 mV IO = 250 to 750mA, Tj = 25°C 4 90 mV 3.9 8 mA 1 mA 0.5 mA Tj = 25°C VI = 11.5 to 26V, Tj = 25°C IO = 5mA to 1A, Tj = 25°C Ripple rejection ratio RR VI = 12 to 22V, IO = 100mA, f = 120Hz ZO 9 2 f = 10Hz to 100kHz Output impedance Typ VI = 11.5 to 26V, Tj = 25°C Vno VDIF(min) 8.65 VI = 12 to 18V, Tj = 25°C Output noise voltage Minimum input/output voltage difference Min IO = 1A, Tj = 25°C f = 1kHz Output short-circuit current IO(Short) VI = 26V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C 57 56 µV dB 2 V 16 mΩ 700 mA 2 A − 0.5 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 15V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W 4 Voltage Regulators AN78xx/AN78xxF Series ■ Electrical Characteristics at Ta = 25°C (continued) • AN7810, 7810F (10V type) Parameter Symbol Conditions Output voltage VO Output voltage tolerance VO Tj = 25°C VI = 13 to 25V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation Load regulation Bias current REGIN REGL IBias Unit 10.4 V 10.5 V 8 200 mV 100 mV IO = 5mA to 1.5A, Tj = 25°C 12 200 mV 4 100 mV 3.9 8 mA 1 mA 0.5 mA IO = 250 to 750mA, Tj = 25°C Tj = 25°C Bias current fluctuation to load ∆IBias(L) IO = 5mA to 1A, Tj = 25°C Output noise voltage Vno f = 10Hz to 100kHz Ripple rejection ratio RR VI = 13 to 23V, IO = 100mA, f = 120Hz ZO Max 2.5 VI = 12.5 to 27V, Tj = 25°C Output impedance 10 9.5 VI = 12.5 to 27V, Tj = 25°C ∆IBias(IN) VDIF(min) 9.6 Typ VI = 13 to 19V, Tj = 25°C Bias current fluctuation to input Minimum input/output voltage difference Min IO = 1A, Tj = 25°C f = 1kHz Output short-circuit current IO(Short) VI = 27V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C µV 63 56 dB 2 V 16 mΩ 700 mA 2 A − 0.6 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 16V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W • AN7812, 7812F (12V type) Symbol Conditions Output voltage Parameter VO Output voltage tolerance VO Tj = 25°C VI = 15 to 27V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation Load regulation Bias current REGIN REGL IBias Max Unit 12.5 V 12.6 V 10 240 mV 3 120 mV 12 240 mV IO = 250 to 750mA, Tj = 25°C 4 120 mV Tj = 25°C 4 8 mA 1 mA 0.5 mA VI = 14.5 to 30V, Tj = 25°C ∆IBias(L) IO = 5mA to 1A, Tj = 25°C Output noise voltage Vno f = 10Hz to 100kHz Ripple rejection ratio RR VI = 15 to 25V, IO = 100mA, f = 120Hz ZO 12 11.4 VI = 16 to 22V, Tj = 25°C ∆IBias(IN) VDIF(min) Typ IO = 5mA to 1.5A, Tj = 25°C Bias current fluctuation to load Output impedance 11.5 VI = 14.5 to 30V, Tj = 25°C Bias current fluctuation to input Minimum input/output voltage difference Min IO = 1A, Tj = 25°C f = 1kHz Output short-circuit current IO(Short) VI = 30V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C 75 55 µV dB 2 V 18 mΩ 700 mA 2 A − 0.8 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 19V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W 5 AN78xx/AN78xxF Series Voltage Regulators ■ Electrical Characteristics at Ta = 25°C (continued) • AN7815, 7815F (15V type) Parameter Symbol Conditions Output voltage VO Output voltage tolerance VO Tj = 25°C VI = 18 to 30V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation Load regulation Bias current REGIN REGL IBias V 11 300 mV 3 150 mV 12 300 mV IO = 250 to 750mA, Tj = 25°C 4 150 mV Tj = 25°C 4 8 mA 1 mA 0.5 mA VI = 20 to 26V, Tj = 25°C IO = 5mA to 1.5A, Tj = 25°C Bias current fluctuation to load ∆IBias(L) IO = 5mA to 1A, Tj = 25°C Output noise voltage Vno f = 10Hz to 100kHz Ripple rejection ratio RR VI = 18.5 to 28.5V, f = 120Hz ZO 14.25 VI = 17.5 to 30V, Tj = 25°C VI = 17.5 to 30V, Tj = 25°C Output impedance Unit 15.75 14.4 f = 1kHz IO(Short) VI = 30V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C µV 90 54 IO = 1A, Tj = 25°C Output short-circuit current 15 Max V ∆IBias(IN) VDIF(min) Typ 15.6 Bias current fluctuation to input Minimum input/output voltage difference Min dB 2 V 19 mΩ 700 mA 2 A −1 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 23V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W • AN7818, 7818F (18V type) Symbol Conditions Output voltage Parameter VO Output voltage tolerance VO Tj = 25°C VI = 21 to 33V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation Load regulation Bias current REGIN REGL IBias Max Unit 18.7 V 18.9 V 14 360 mV 4 180 mV 12 360 mV IO = 250 to 750mA, Tj = 25°C 4 180 mV 4.1 8 mA 1 mA 0.5 mA Tj = 25°C VI = 21 to 33V, Tj = 25°C ∆IBias(L) IO = 5mA to 1A, Tj = 25°C Output noise voltage Vno f = 10Hz to 100kHz Ripple rejection ratio RR VI = 22 to 32V, IO = 100mA, f = 120Hz ZO 18 IO = 5mA to 1.5A, Tj = 25°C ∆IBias(IN) VDIF(min) Typ 17.1 VI = 24 to 30V, Tj = 25°C Bias current fluctuation to load Output impedance 17.3 VI = 21 to 33V, Tj = 25°C Bias current fluctuation to input Minimum input/output voltage difference Min IO = 1A, Tj = 25°C f = 1kHz Output short-circuit current IO(Short) VI = 35V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C 110 53 µV dB 2 V 16 mΩ 700 mA 2 A −1.1 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 27V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W 6 Voltage Regulators AN78xx/AN78xxF Series ■ Electrical Characteristics at Ta = 25°C (continued) • AN7820, 7820F (20V type) Parameter Symbol Conditions Output voltage VO Output voltage tolerance VO Tj = 25°C VI = 24 to 35V, IO = 5mA to 1A, Tj = 0 to 125°C, PD ≤ * Line regulation Load regulation Bias current REGIN REGL IBias 20.8 V 21 V 400 mV 5 200 mV 12 400 mV 4 200 mV 4.1 8 mA 1 mA 0.5 mA IO = 5mA to 1.5A, Tj = 25°C IO = 250 to 750mA, Tj = 25°C Tj = 25°C Bias current fluctuation to load ∆IBias(L) IO = 5mA to 1A, Tj = 25°C Output noise voltage Vno f = 10Hz to 100kHz Ripple rejection ratio RR VI = 24 to 34V, IO = 100mA, f = 120Hz ZO 19 Unit 15 VI = 23 to 35V, Tj = 25°C Output impedance 20 Max VI = 23 to 35V, Tj = 25°C ∆IBias(IN) VDIF(min) 19.2 Typ VI = 26 to 32V, Tj = 25°C Bias current fluctuation to input Minimum input/output voltage difference Min IO = 1A, Tj = 25°C f = 1kHz Output short-circuit current IO(Short) VI = 35V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C µV 110 53 dB 2 V 22 mΩ 700 mA 2 A −1.2 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 29V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W • AN7824, 7824F (24V type) Symbol Conditions Output voltage Parameter VO Output voltage tolerance VO Tj = 25°C VI = 28 to 38V, IO = 5mA to 1A, Tj = 0 to 125°C, PD≤ * Line regulation Load regulation Bias current REGIN REGL IBias Max Unit 25 V 25.2 V 18 480 mV 6 240 mV 12 480 mV IO = 250 to 750mA, Tj = 25°C 4 240 mV 4.1 8 mA 1 mA 0.5 mA Tj = 25°C VI = 27 to 38V, Tj = 25°C ∆IBias(L) IO = 5mA to 1A, Tj = 25°C Output noise voltage Vno f = 10Hz to 100kHz Ripple rejection ratio RR VI = 28 to 38V, IO = 100mA, f = 120Hz ZO 24 IO = 5mA to 1.5A, Tj = 25°C ∆IBias(IN) VDIF(min) Typ 22.8 VI = 30 to 36V, Tj = 25°C Bias current fluctuation to load Output impedance 23 VI = 27 to 38V, Tj = 25°C Bias current fluctuation to input Minimum input/output voltage difference Min IO = 1A, Tj = 25°C f = 1kHz Output short-circuit current IO(Short) VI = 38V, Tj = 25°C Peak output current IO(Peak) Tj = 25°C Output voltage temperature coefficient ∆VO/Ta IO = 5mA, Tj = 0 to 125°C 170 50 µV dB 2 V 28 mΩ 700 mA 2 A −1.4 mV/°C Note 1) The specified condition Tj = 25°C means that the test should be carried out within so short a test time (within 10ms) that the characteristic value drift due to the chip junction temperature rise can be ignored. Note 2) Unless otherwise specified, VI = 33V, IO = 500mA, CI = 0.33µF and CO = 0.1µF. * AN78xx series: 15W, AN78xxF series: 10.25W 7 AN78xx/AN78xxF Series Voltage Regulators ■ Main Characteristic Curve PD Ta (AN78xxF series) 16 (1) 14 (2) Power dissipation PD (W) 12 10 8 (3) 6 4 (1) 10 8 (2) 6 (3) 4 2 (4) 0 40 80 120 0 160 (4) 0 Ambient temperature Ta (°C) 160 Thermal resistance value: Rth(j-c) = 12.2°C/W (max.) Rth(j-a) = 65°C/W (max.) Installation condition to heat sink Tightening torque 6kg·cm Heat radiation compound used Installation condition to heat sink Tightening torque 6kg·cm Heat radiation compound used (1) Infinite heat sink: 10.25W (2) 5°C/W heat sink: 7.3W (3) 15°C/W heat sink: 4.5W (4) Without heat sink: 1.923W Infinite heat sink: 15.0W 5°C/W heat sink: 12.5W 15°C/W heat sink: 6.3W Without heat sink: 1.923W AN7805 15 10 5 10 0 −10 0 2 4 6 Time t (µs) 8 10 Input voltage VI (V) Output voltage fluctuation (V) Load transient response 20 Output voltage fluctuation (mV) 120 Ambient temperature Ta (°C) Input transient response 8 80 Thermal resistance value: Rth(j-c) = 5°C/W (max.) Rth(j-a) = 65°C/W (max.) (1) (2) (3) (4) −20 40 AN7805 2 1 0 1 0 −1 −2 VDIF(min.) Tj 2.4 2.0 IO = 1A 500mA 1.6 200mA 20mA 1.2 0.8 0mA 0.4 0 −40 0 40 80 120 160 Junction temperature Tj (°C) Current limiting characteristic Load current IO (A) 2 12 7 VI = 10V Tj = 25°C AN7805 6 Output voltage VO (V) Power dissipation PD (W) 14 0 Minimum input/output voltage difference VDIF(min.) (V) PD Ta (AN78xx series) 16 5 4 3 2 1 0 0 10 20 30 Time t (µs) 40 50 0 0.6 1.2 1.8 Output current IO (A) 2.4 Voltage Regulators AN78xx/AN78xxF Series ■ Basic Regulator Circuit Input Output 1 3 AN78xx AN78xxF CI CO 2 CI : CI is necessary when the input line is long. CO: CO improves the transient response. Common ■ Usage Notes 1. Cautions for a basic circuit CI: When a wiring from a smoothing circuit to a three-pin regulator is long, it is likely to oscillate in output. A capacitor of 0.1µF to 0.47µF should be connected near an input pin. CO: When any sudden change of load current is likely to occur, connect an electrolytic capacitor of 10µF to 100µF to improve a transitional response of output voltage. Di: Normally unnecessary. But add it in the case that there is a residual voltage at the output capacitor Co even after switching off the supply power because a current is likely to flow into an output pin of the IC and damage the IC. Di VI VO 3 1 CO 2 CI Figure 1 2. Other caution items 1) Short-circuit between the input pin and GND pin If the input pin is short-circuitted to GND or is cut off when a large capacitance capacitor has been connected to the IC's load, a voltage of a capacitor connected to an output pin is applied between input/output of the IC and this likely results in damage of the IC. It is necessary, therefore, to connect a diode, as shown in figure 2, to counter the reverse bias between input/output pins. In 3 1 Output Out 2 GND + − CO Figure 2 2) Floating of GND pin If a GND pin is made floating in an operating mode, an unstabilized input voltage is outputted. In this case, a thermal protection circuit inside the IC does not normally operate. In this state, if the load is short-circuited or overloaded, it is likely to damage the IC. ■ Application Circuit Examples 1. Current bootstrap circuit VI 2. Adjustable output regulator Q1 VI 3Ω 1 IO 2 1 0.33µF 3 AN78xx AN78xxF 2 VO 3 AN78xx AN78xxF VO' R2 VO 0.1µF V ' VO = VO' + IBias + RO R1 2 IBias R1 Note) VO varies due to sample to sample variation of IBias. Never fail to adjust individually with R1. 9