Precision op amps operate on 140V supply

August 05, 2014 // By Graham Prophet
LTC6091 and LTC6090-5 are additions to the LTC6090 family of precision operational amplifiers which operate on a supply voltage up to 140V (±70V).

The dual LTC6091 features separate output disable pins, making it useful in high voltage multiplexed applications. The decompensated single LTC6090-5 amplifier offers higher speed and is stable at a gain of 5 or above.

The LTC6090, LTC6090-5, and LTC6091 combine wide supply range, high precision, and low noise. Input offset voltage is 1.25 mV max over temperature, and low frequency (1/f) noise is 3.5 µVP-P from 0.1 Hz to 10 Hz. The CMOS input structure keeps the input bias current to 50 pA maximum at 85°C, making the LTC6090 family suitable for sensor circuits and other applications requiring high input impedance.

The decompensated LTC6090-5 offers 24 MHz gain-bandwidth product and 37 V/µsec slew rate, compared with 12 MHz and 21 V/µsec for the gain-of-1 stable LTC6090 and LTC6091.

Supply current is 3.9 mA per amplifier max. Output short-circuit current is typically ±90 mA. A thermal flag pin (TFLAG) signals when the device junction temperature exceeds 145°C. This pin can be connected to the Output Disable pin for active thermal management.

The LTC6090 and LTC6090-1 come in 8-pin SOIC and 16-pin TSSOP packages. The LTC6091 is in a 16-pin 4 x 6 mm QFN package. Each of these packages includes an exposed pad to minimise thermal resistance. Prices start at $3.45 for the LTC6090 and LTC6090-5, and $6.61 for the LTC6091 (all 1000). LTC6090 is available in three temperature range grades: 0°C to 70°C, -40°C to 85°C and -40°C to 125°C junction temperature. The LTC6091 is available in -40°C to 85°C and -40°C to 125°C junction temperature grades.

Linear Technology; /