www.fairchildsemi.com LM79XX 3-Terminal 1A Negative Voltage Regulator Features Description Output Current in Excess of 1A The LM79XX series of three terminal negative regulators Output Voltages of -5, -6, -8 , -9, -10, -12, -15, -18 and - are available in TO-220 package and with several fixed 24V output voltages, making them useful in a wide range Internal Thermal Overload Protection of applications. Each type employs internal current limiting, Short Circuit Protection thermal shut down and safe operating area protection, Output Transistor Safe Operating Area Compensation making it essentially indestructible. TO-220 (Single Gauge) Vin 1 1. GND 2. Input 3. Output Internal Block Digram GND R1 VOLTAGE R2 REFERENCE OuOutput t + Q1 - Q2 PROTECTION CIRCUITRY I1 I2 Rsc In Input Rev. 1.0.3 2011 Fairchild Semiconductor CorporationLM79XX Absolute Maximum Ratings Parameter Symbol Value Unit Input Voltage V -35 V I Thermal Resistance Junction-Case (Note1) R 5 JC C/W Thermal Resistance Junction-Air (Note1, 2) R 65 JA Operating Temperature Range T 0 ~ +125 C OPR Storage Temperature Range T -65 ~ +150 C STG Note: 1. Thermal resistance test board Size: 76.2mm * 114.3mm * 1.6mm(1S0P) JEDEC standard: JESD51-3, JESD51-7 2. Assume no ambient airflow Electrical Characteristics (LM7905) (V = -10V, I = 500mA, 0C T +125C, C =2.2F, C =1F, unless otherwise specified.) I O J I O Parameter Symbol Conditions Min. Typ. Max. Unit T = +25C -4.8 -5.0 -5.2 J Output Voltage V V O I = 5mA to 1A, P 15W O O -4.75 -5.0 -5.25 V = -7V to -20V I V = -7V to -25V - 35 100 I Line Regulation (Note3) V T = +25C mV O J V = -8V to -12V - 8 50 I T = +25C J -10 100 I = 5mA to 1.5A O Load Regulation (Note3) V mV O T =+25C J -3 50 I = 250mA to 750mA O Quiescent Current I T =+25C-36mA Q J I = 5mA to 1A - 0.05 0.5 O Quiescent Current Change I mA Q V = -8V to -25V - 0.1 0.8 I Temperature Coefficient of V Vo/TI = 5mA - - 0.4 - mV/C D O f = 10Hz to 100kHz Output Noise Voltage V -40 - V N T =+25C A f = 120Hz Ripple Rejection RR 54 60 - dB V = 10V I T = +25C J Dropout Voltage V -2 - V D I = 1A O Short Circuit Current I T =+25C, V = -35V - 300 - mA SC J I Peak Current I T =+25C-2.2-A PK J Note 3. Load and line regulation are specified at constant junction temperature. Changes in V due to heating effects must be taken O into account separately. Pulse testing with low duty is used. 2