LT1969 Dual 700MHz, 200mA, Adjustable Current Operational Amplifier UFEATURESDESCRIPTIO ■ 700MHz Gain Bandwidth The LT®1969 is an adjustable current version of the ■ ± 200mA Minimum IOUT popular LT1886, a 200mA minimum output current, dual ■ Adjustable Quiescent Current op amp with outstanding distortion performance. The ■ Low Distortion: –72dBc at 1MHz, 4VP-P, 25 Ω , AV = 2 adjustable current feature is highly desirable in applica- ■ Stable in AV ≥ 10, Simple Compensation for AV < 10 tions where minimum power dissipation is required while ■ ±4.3V Minimum Output Swing, VS = ±6V, RL = 25Ω still being able to provide adequate line termination. ■ Stable with 1000pF Load At nominal supply current, the amplifiers are gain of 10 ■ 6nV/√Hz Input Noise Voltage stable and can easily be compensated for lower gains. The ■ 2pA/√Hz Input Noise Current LT1969 features balanced high impedance inputs with ■ 4mV Maximum Input Offset Voltage 4µA input bias current and 4mV maximum input offset ■ 4µA Maximum Input Bias Current voltage. Single supply applications are easy to implement ■ 400nA Maximum Input Offset Current and have lower total noise than current feedback amplifier ■ ±4.5V Minimum Input CMR, VS = ±6V implementations. ■ Specified at ±6V, ±2.5V The output drives a 25Ω load to ±4.3V with ±6V supplies. U On ±2.5V supplies, the output swings ±1.5V with a 100Ω APPLICATIO S load. The amplifier is stable with a 1000pF capacitive load ■ making it useful in buffer and cable driver applications. DSL Modems ■ xDSL PCI Cards The LT1969 is manufactured on Linear Technology’s ■ USB Modems advanced low voltage complementary bipolar process and ■ Line Drivers is available in a thermally enhanced MS10 package , LTC and LT are registered trademarks of Linear Technology Corporation. UTYPICAL APPLICATIOSingle 12V Supply ADSL Modem Line Driver 12V ADSL Modem Line Driver Distortion 0.1µF –60 IN + + V 12.4Ω S = 12V 1/2 LT1969 AV = 10 f = 200kHz – –70 100Ω LINE 1:2 TRANSFORMER 909Ω *COILCRAFT X8390-A 10k 20k 1:2* OR EQUIVALENT HD2 100Ω –80 100Ω 1µF 10k 20k 1µF 100Ω –90 909Ω HARMONIC DISTORTION (dBc) HD3 I CTRL1 CTRL2 Q ON = 14mA – IQ LOW POWER = 2mA 6 7 I 12.4Ω Q STANDBY = 600µA –100 0 2 4 6 8 10 12 14 16 0.1µF 1/2 LT1969 13k 49.9k STANDBY ON + LINE VOLTAGE (VP-P) IN – LOGIC 1969 TA01b OUTPUT STANDBY 1969 TA01a LOW POWER ON 1