Electronic Design

In-Circuit Offset Adjustment Debuts With New Op Amp

A new high-slew-rate dual precision CMOS operational amplifier can change the input offset while in circuit. Developed by Advanced Linear Devices Inc. of Sunnyvale, Calif., the ALD2724E and ALD2724 offer an alternative to junction FET (JFET) input op amps.

The ALD2724E permits optional user-programmable offset voltage trimming using the patented EPAD (Electrically Programmable Analog Device) technology. The ALD2724 is pre-programmed at the factory under standard operating conditions for minimum Vos. This fixed device also is intended for applications where mechanical potentiometer trimming for offset isn't a viable alternative, like portable instruments, sensor pre-amplifiers, transducer biasing, and precision gain circuits.

Both parts start with credible Vos values. Standard offset voltage specifications for the ALD2724E and ALD2724 are typically 25 µV at 0.01-pA input bias current. Each provides rail-to-rail input and output voltage ranges, tolerance to overvoltage input of 300 mV beyond supply rails, ±5-V supply operation, and high capacitive loading up to 4000 pF. Other features include input currents of 0.01 pA typical, high open loop voltage gain, 2.1-MHz bandwidth, 5-V/µs slew rate, and 5.0-mA supply current.

The ALD2724E and ALD2724 cost $1.83 and $1.46, respectively, in 1000-unit quantities. Delivery is available from stock. They come in 14-pin PDIP, SOIC, and ceramic DIP packages. They're also available as standard cells for mixed analog/digital ASIC arrays.

Advanced Linear Devices
(408) 747-1155

See associated figure

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.