SBAT004 June   2022

Integrated instrumentation amplifiers have long been inaccessible for many designers building extremely cost-optimized products due to their price tag. However, not every design needs the precision and accuracy that comes with the vast majority of instrumentation amplifiers. Many designers instead build discrete instrumentation amplifier circuits using three amplifiers of a quad-channel op amp and a network of resistors. This was the only option that fit the budget of these designs until the release of the INA35x family. INA35x re-defines the instrumentation amplifier landscape by offering an integrated solution within the price range of a discrete solution as shown in Table 1-1.

Figure 1-1 Instrumentation Amplifier Landscape
Table 1-1 Instrumentation Amplifier Key Specification Comparison
Key SpecificationsDiscreteINA350Existing INAs

Maximum gain error

Minimum CMRR

About 60 dB85 dB> 100 dB

Maximum offset

About 3 mV1.2 mV< 0.25 mV

Web price(1)

$0.14>$0.50
Web price at time of writing
Approximate price based on online price of general-purpose op amp (LM324LV) + 1% discrete resistors

In addition to the performance benefits, the INA35x also extends TI’s instrumentation amplifier package lineup with new smaller packages that help reduce the amount of printed-circuit-board (PCB) space compared to discrete solutions by up to 70%, as shown in Figure 1-2. This figure compares a typical layout including the resistor network, decoupling capacitors, and a voltage reference buffer. The TLV9041 is used as the reference buffer for INA350, and the fourth channel in a quad-amplifier is used for the discrete solution.

Figure 1-2 PCB Layout Comparison of a Discrete Solution Using TSSOP-14 (Left) vs INA350 in the WSON Package Plus TLV9041 in the X2SON Package (Right)

Learn more about how INA35x can help reduce space and improve performance while simplifying the BOM, and start your evaluation with the following content:

## Evaluate the Design

Generic Part NumberOrderable Part NumberGain OptionsPackageShutdown
INA350INA350ABSIDDFR10 or 202.9 × 2.8 mm (SOT-23-THN)Yes
INA350ABSIDSGR10 or 202 × 2 mm (WSON)
INA350CDSIDDFR30 or 502.9 × 2.8 mm (SOT-23-THN)
INA350CDSIDSGR30 or 502 × 2 mm (WSON)

For additional assistance, ask questions to TI engineers on the TI E2E™ Amplifiers Support Forum.