LT1166CS8#PBF Analog Devices

LT1166 Power Output Stage Automatic Bias System FEATURES DESCRIPTION n Set Class AB Bias Currents The LT 1166 is a bias generating system for controlling n Eliminates Adjustments class AB output current in high powered amplifiers. When n Eliminates Thermal Runaway of I connected with external transistors, the circuit becomes Q n Corrects for Device Mismatch a unity-gain voltage follower. The LT1166 is ideally suited n Simplifies Heat Sinking for driving power MOSFET devices because it eliminates n Programmable Current Limit all quiescent current adjustments and critical transistor n May Be Paralleled for Higher Current matching. Multiple output stages using the LT1166 can n Small SO-8 or PDIP Package be paralleled to obtain higher output current. Thermal runaway of the quiescent point is eliminated APPLICATIONS because the bias system senses the current in each power transistor by using a small external sense resistor. A high n Biasing Power MOSFETs speed regulator loop controls the amount of drive applied n High Voltage Amplifiers to each power device. The LT1166 can be biased from a n Shaker Table Amplifiers pair of resistors or current sources and because it oper- n Audio Power Amplifiers ates on the drive voltage to the output transistors, it oper- ates on any supply voltage. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and C-Load is a trademark of Analog Devices, Inc. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Unity Gain Buffer Amp Driving 1 Load R1 15V MPS2907 100 47 220F R2 2N2907 100 IRF530 1 I = 15mA TOP 300pF INPUT 0V V TOP 5.6k 8 + SENSE 1k 7 + I LIM + R SENSE 1F 0.33 4.3k 3 2 V OUT V V LT1166 V IN IN OUT R 1 1F SENSE 0.33 1k 6 I OUTPUT 0V LIM 5 SENSE V BOTTOM R3 4 I = 15mA 100 BOTTOM IRF9530 1166 TA01 300pF 2N2222 220F R4 100 47 15V 1166 F01 MPS2222 Figure 1. Unity Gain Buffer with Current Limit 1166fa 1 For more information www.linear.com/LT1166 + +LT1166 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Supply Current (Pin 1 or Pin 4) ..............................75mA + V 1 SENSE 8 TOP Differential Voltage (Pin 2 to Pin 3) ...........................6V + V 2 +1 7 I IN LIM Output Short-Circuit Duration (Note 1) .........Continuous V 3 I 6 OUT LIM Specified Temperature Range (Note 2) ........ 0C to 70C V 4 5 SENSE BOTTOM Operating Temperature Range .................40C to 85C Storage Temperature Range .................. 65C to 150C N8 PACKAGE S8 PACKAGE 8-LEAD PDIP 8-LEAD PLASTIC SO Junction Temperature (Note 3) ............................. 150C T = 150C, = 100C/W (N8) JMAX JA T = 150C, = 150C/W (S8) JMAX JA Lead Temperature (Soldering, 10 sec) ...................300C ORDER INFORMATION