LT1794 Dual 500mA, 200MHz xDSL Line Driver Amplifier UFEATURESDESCRIPTIO ■ Exceeds All Requirements For Full Rate, The LT®1794 is a 500mA minimum output current, dual op Downstream ADSL Line Drivers amp with outstanding distortion performance. The ampli- ■ ± 500mA Minimum IOUT fiers are gain-of-ten stable, but can be easily compensated ■ ± 11.1V Output Swing, VS = ± 12V, RL = 100 Ω for lower gains. The extended output swing allows for ■ ± 10.9V Output Swing, VS = ± 12V, IL = 250mA lower supply rails to reduce system power. Supply current ■ Low Distortion: – 82dBc at 1MHz, 2VP-P Into 50 Ω is set with an external resistor to optimize power dissipa- ■ Power Saving Adjustable Supply Current tion. The LT1794 features balanced, high impedance in- ■ Power Enhanced Small Footprint Packages: puts with low input bias current and input offset voltage. 20-Lead TSSOP and 20-Lead SW Active termination is easily implemented for further sys- ■ 200MHz Gain Bandwidth tem power reduction. Short-circuit protection and thermal ■ 500V/µs Slew Rate shutdown insure the device’s ruggedness. ■ Specified at ±15V, ±12V and ±5V The outputs drive a 100Ω load to ±11.1V with ±12V U supplies, and ±10.9V with a 250mA load. The LT1794, APPLICATIO S with its increased swing on lower supplies, can be used to ■ High Density ADSL Central Office Line Drivers upgrade LT1795 line driver applications. ■ High Efficiency ADSL, HDSL2, G.lite, The LT1794 is available in the very small, thermally SHDSL Line Drivers enhanced, 20-lead TSSOP for maximum port density in ■ Buffers line driver applications. The 20-lead SW is also available. ■ Test Equipment Amplifiers , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Cable Drivers UTYPICAL APPLICATIOHigh Efficiency ± 12V Supply ADSL Central Office Line Driver 12V RBIAS 24.9k +IN + SHDN 1/2 12.7Ω LT1794 – 1k 1:2* 110Ω • • 100Ω 1000pF 110Ω 1k – *COILCRAFT X8390-A OR EQUIVALENT ISUPPLY = 10mA PER AMPLIFIER 1/2 12.7Ω WITH RBIAS = 24.9k LT1794 SHDNREF –IN + 1794 TA01 –12V 1