LM317

LM317 3-Terminal Adjustable Output Positive Voltage Regulators Features • Output current in excess of 1.5 ampere • Output adjustable between 1.2V and 37V • Internal thermal overload protection • Internal short-circuit current limiting constant with temperature TO-220 • Output transistor safe-area compensation • Floating operation for high voltage applications 1 3 2 1. Adjust 2. Vout 3. Vin • Eliminates stocking many fixed voltages Heatsink is connected to pin 2 Standard Application Vin LM317 Cin 0.1µF Functional Block Diagram Input Vout IADJ R1 Adjust 240Ω 3 Co 1µF + R2 -Notes: Cin is required if regulator is located an appreciable distance from power supply filter. Voltage Reference Protection Circuitry Rlimit Co is not needed for stability, however, it does improve transient response. Vout = 1.25V (1 + R2 / R1) + IAdj R2 1 Since IAdj is controlled to less than 100µA, the error associated with this term is negligible in most applications Maximum Ratings 2 Output Vadj Ratings at 25°C ambient temperature unless otherwise specified. Parameter Symbol Value Unit Vi-Vo 40 Vdc RθJC 3.0 °C Power Dissipation, 25°C Case Temperature PD 15 W Operating Junction Temperature Range TJ 0 to +125 °C Tstg –65 to +150 °C Input-Output Voltage Differential Junction-to-Case Thermal Resistance Storage Junction Temperature Range www.slkormicro.com 1 LM317 Electrical Characteristics Vi -Vo = 5V, Io = 0.5A, TJ = Tlow to Thigh (see Note 1), Imax and Pmax per Note 2, unless otherwise noted. Parameter Symbol Line Regulation (Fig. 1) (3) 3.0V ≤ VI – Vo ≤ 40V REG line Load Regulation (Fig. 2) (3) TJ = 25°C, 10mA ≤ Io ≤ 1.5A REG load Load Regulation (Fig. 2) (3) 10mA ≤ Io ≤ 1.5A REG load Thermal Regulation REG therm Adjustment Pin Current (Fig. 3) Conditions Min. Typ. Max. TA = 25°C – 0.01 0.04 TJ = 0°C thru 125°C – 0.02 0.07 Vo ≤ 5.0 – 5 25 mV Vo ≥ 5.0 – 0.1 0.5 %Vo Vo ≤ 5.0 – 20 70 mV Vo ≥ 5.0 – 0.3 1.5 %Vo TJ = 25°C, 20ms Pulse – 0.03 0.07 %Vo/W – 50 100 µA IAdj Unit %Vo/V Adjustment Pin Current Change ∆IAdj 10mA ≤ IL ≤ 1.5A 2.5V ≤ VI – Vo ≤ 40V – 0.2 5 µA Reference Voltage (Fig. 3) (4) Vref 10mA ≤ Io ≤ 1.5A 3V ≤ VI – Vo ≤ 40V 1.225 1.25 1.275 V Temperature Stability (Fig. 3) TS Tlow ≤ TJ ≤ Thigh – 1 – %Vo Min. Load Current to Maintain Regulation (Fig. 3) ILmin VI – Vo = 40V – 3.5 10 mA Maximum Output Current (Fig. 3) Imax VI – Vo ≤ 15V 1.5 2.2 – VI – Vo = 40V, TJ = 25°C 0.15 0.4 – N TJ = 25°C, 10HZ ≤ f ≤ 10KHZ — 0.003 – %Vo RR Vo = 10V, f = 120HZ(5) CAdj = 10µF — 66 65 80 – – dB S TJ = 125°C(6), TJ = 25°C for Endpoint Measurements – 0.3 1.0 % RθJC Tlow ≤ TJ ≤ Thigh – 5.0 – °C/W RMS Noise, % of Vo Ripple Rejection (Fig. 4) Long-Term Stability (after 1000 hr) Fig. 3 Thermal Resistance Junction to Case Notes: (1) Tlow = 0°C Thigh = 125°C (2) Imax = 1.5A Pmax is internally limited (3) Load and line regulation are specified at constant junction temperature. Changes in Vo due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used. (4) Selected devices with tightened tolerance reference voltage available. www.slkormicro.com 2 A LM317 Fig. 1 – Line Regulation Test Circuit Fig. 2 – Load Regulation and ∆Iadj /Load Test Circuit V V Line Regulation (%/V) = OH -- OL x100 VOL VIH VIL Vin Load Regulator (mV) = Vo(min. Load) -- Vo(max. Load) Vo(min. Load) -- Vo(max. Load) Load Regulator (%Vo) = x100 Vo(min. Load) VOH VOL Vout VI Vin LM317 IADJ IL LM317 240Ω 1% Adjust R1 IADJ Co Adjust R1 240Ω 1% Cin RL Cin 0.1µF VOH (min. Load) VOL (max. Load) Vout 1µF 0.1µF R2 1% Pulse Testing Required: 1% Duty Cycle is Suggested RL (min. Load) Co 1µF R2 1% Pulse Testing Required: 1% Duty Cycle is Suggested Fig. 3 – Standard Test Circuit Fig. 4 – Ripple Rejection Test Circuit 24V 14V f = 120HZ Vin Vin Vout IL LM317 IADJ VI Adjust R1 240 1% R1 Vref Adjust Cin Co 0.1µF 1µF 240 1% *D1 1N4002 Co Vo RL 0.1µF R2 1% www.slkormicro.com Vo = 10V Cin RL ISET Pulse Testing Required: 1% Duty Cycle is Suggested Vout LM317 CAdj R2 1% To Calculate R2: Vo = ISET R2 + 1.250V Assume ISET = 5.25mA *D1 Discharges CADJ if Output is Shorted to Ground 3 10µF 1µF Vo LM317 Ratings and Characteristic Curves (T A = 25°C unless otherwise noted) Fig. 6 – Current Limit Fig. 5 – Load Regulation 4 0.4 0.2 Io -- Output Current (A) ∆Vo -- Output Voltage Change (%) 0.6 IL = 0.5A 0 --0.2 IL = 1.5A --0.4 --0.6 VI = 15V Vo = 10V 3 TJ = 25°C 2 1 --0.8 --1.0 --75 0 --50 --25 0 25 50 75 0 100 125 150 175 10 Fig. 7 – Adjustment Pin Current 30 40 Fig. 8 – Dropout Voltage VI -- Vo -- Input -- Output Voltage Differential (Vdc) 70 65 60 55 50 45 40 35 --75 20 3.0 75 IADJ -- Adjustment Pin Current (µA) TJ = --55°C TJ = 150°C --50 --25 0 25 50 75 ∆Vo = 100mV 2.5 IL = 1.5A IL = 1.0A 2.0 IL = 500mA 1.5 IL = 200mA IL = 20mA 1.0 --75 100 125 150 175 Fig. 9 – Temperature Stability --50 --25 0 25 50 75 100 125 150 175 Fig. 10 – Minimum Operating Current 5.0 1.260 IO -- Quiescent Current (mA) Vref -- Reference Voltage (V) 4.5 1.250 1.240 1.230 4.0 TJ = 25°C 3.5 TJ = --55°C TJ = 150°C 3.0 2.5 2.0 1.5 1.0 0.5 1.220 --75 0 --50 --25 0 www.slkormicro.com 25 50 75 100 125 150 175 0 4 10 20 30 40 50 LM317 Ratings and Characteristic Curves (T A = 25°C unless otherwise noted) Fig. 12 – Ripple Rejection vs. Output Current Fig. 11 – Ripple Rejection vs. Output Voltage 140 100 120 80 RR -- Ripple Rejection (db) RR -- Ripple Rejection (db) CAdj = 10µF Without CAdj 60 40 VI -- Vo = 5V IL = 500mA f = 120HZ TJ = 25°C 20 0 0 5 10 15 20 25 30 35 CAdj = 10µF 100 80 Without CAdj 60 40 VI = 15V Vo = 10V f = 120HZ TJ = 25°C 20 0 0.01 40 0.1 Fig. 13 – Ripple Rejection vs. Frequency Fig. 14 – Output Impedance 100 101 VI = 15V Vo = 10V IL = 500mA TJ = 25°C 80 Output Impedance (Ω) RR -- Ripple Rejection (db) 10 Io -- Output Current (A) Vo -- Output Voltage (V) CAdj = 10µF 60 Without CAdj 40 IL = 500mA VI = 15V Vo = 10V TJ = 25°C 20 0 10 100 100 10--1 Without CAdj 10--2 CAdj = 10µF 1K 10K 100K 10--3 10 1M 100 f -- Frequency (Hz) 1K 10K 100K 1M f -- Frequency (Hz) Fig. 15 – Line Transient Response Fig. 16 – Load Transient Response Vo -- Output Voltage Deviation (V) 3 1.5 1.0 CL = 1µF CAdj = 10µF 0.5 0 --0.5 Vo = 10V IL = 50mA TJ = 25°C --1.0 2 1 CL = 1µF CAdj = 10µF 0 --1 --2 CL = 0 Without CAdj --3 IL -- Load Current (A) ∆VI -- Input Voltage ∆Vo -- Output Voltage Change (V) Deviation (V) 1 CL = 0 Without CAdj --1.5 1.0 VI 0.5 0 VI = 15V Vo = 10V INL = 50mA TJ = 25°C 1.5 1.0 IL 0.5 0 0 10 20 30 40 0 t -- Time (µs) www.slkormicro.com 10 20 t -- Time (µs) 5 30 40 LM317 TO-220 Case Outline 10.25 ± 0.25 4.85 ± 0.375 1.27 ± 0.12 3.84 ± 0.6 Dia. 2.69 ± 0.25 6.26 ± 0.25 14.8 ± 0.51 8.54 ± 0.26 28.7 ± 0.92 3.94 ± 0.375 13.9 ± 0.41 Dimensions in millimeters 2.53 ± 0.185 www.slkormicro.com 1.3 ± 0.185 0.387 ± 0.09 2.55 ± 0.375 0.8 ± 0.12 6