Advantages of LinCMOS Operational Amplifiers

The TLC25 I and TLC27 I series operational amplifiers provide a low input offset voltage (10 mV maximum) that remains highly stable over time and temperature and is not sensitive to input-overdrive voltages. They are also available with tightened, guaranteed input offset voltages.

The TLC251 and TLC271 series operational amplifiers can be adjusted for low-, medium- or high-bias operation. This is accomplished by connecting the bias-select pin to VDD for low bias, to ground for high bias, or to 1/2 VDD for medium bias. By providing a choice of bias conditions, the TLC251 and TLC271 allow users to select between ac performance and power consumption to meet a wide range of circuit requirements. When operated in high-bias with VDD equal to 10V, these devices draw 100 uA of IDD for 10-mW power dissipation and feature 4.5-VIuA slew rate and 2.3-MHz bandwidth. In the low bias mode with VDD equal to 10 V and 100 equal to 100 uA (100 uW power dissipation), the devices have a slew rate of 0.04 VIus a bandwidth of 100 kHz. In low-bias, and at 1 V, the TLC251 consumes just 10 uW making it the ideal choice for battery-operated applications. The bias-select pin can be driven with a logic signal from a microprocessor, allowing the operational amplifier performance to be software-controlled.

Additional features of the TLC251 and TLC271 include a common-mode rejection ratio of 88 dB and a low input noise voltage of 30 to 70 nV/√Hz (depending upon whether the device is operating in high, medium, or low bias).

These capabilities make the TLC251 and TLC271 suited for a wide range of applications. These applications include active filters, transducer interfacing, current drivers, voltage-to-current converters, long-interval timers, and many types of amplifiers. The TLC251 and TLC271 series are particularly suited for low-power designs and instrumentation amplifiers that require stable offsets.

When using the TLC251 or TLC271 LinCMOS devices for design, the following characteristics must be considered:

  • Supply Voltage, VDD
    • TLC251 . . . . . . . . . . . . . . . . . . 1 V to 16 V
    • TLC271 . . . . . . . . . . . . . . . . . . 4 V to 16 V
  • True Single Supply or a Maximum of ± 8 V
  • Adjustable Supply Current, IDD
    • Low Bias = 10 uA typical
    • Medium Bias = 150 uA typical
    • High Bias = 1000 uA typical
  • Extremely Low Input Bias and Offset
    • Currents: 1 pA Typical
  • Low Input Offset Voltage: 3 mV typical
  • Ultra Stable Input-Offset Voltage:
    • 1 uV/Month Typical
  • Noise: 30 nV/Hz Typical
  • Slew Rate. SR
    • High Bias . . . . . . . . . . . . . . . . . . 4.5 V/us typical
    • Medium Bias . . . . . . . . . . . . . . . . . . 0.6 V/us typical
    • Low Bias . . . . . . . . . . . . . . . . . . 0.04 V/us typical
  • BW
    • High Bias . . . . . . . . . . . . . . . . . . 3 MHz
    • Medium Bias . . . . . . . . . . . . . . . . . . 0.7 MHz
    • Low Bias . . . . . . . . . . . . . . . . . . 0.1 MHz