THAT 2150 Series
Blackmer® Voltage-Controlled Amplifier ICs

We have discontinued all 2150-series Blackmer Voltage Controlled Amplifier ICs. This includes the 2151, 2150A and 2155. We offer the pin-compatible 218x series VCAs as a better, more advanced alternative to the 215x series. Our 218x series offers greater performance at a comparable cost.

Substituting THAT 218x series VCAs for 2150 series VCAs in Existing Designs
All 2181Lx VCAs are pin-compatible with all 215x ICs, requiring only that you delete one resistor and change the value of one other. No circuit board (PCB) changes are required to support a 2181Lx VCA in place of a 215x-series part. One minor potential inconvenience is that the 2181Lx package is a little taller than the 215x; however, we do not anticipate a problem in practical application. 

To simplify things, below we have provided a chart of recommended conversions between 215x parts and 2181Lx parts. Of course, you may wish to consider the full range of available 218x ICs at this time, but the chart below shows the default choices.

Additionally, we offer a variation of the 2181 series -- the 2180 Series ICs, which are pre-trimmed for low distortion during wafer processing. In many applications, by switching to one of these ICs you can eliminate a trim pot and two resistors from your current designs, along with the time and labor required to adjust the trim. The 2180Lx ICs are a little more expensive than their 2181Lx counterparts, but the savings in trim components and time more than offsets the additional cost.

For complete specifications on THAT VCAs download the product datasheets:

2181series datasheet            2180 series datasheet           2150 series datasheet 

For some specific advice on converting from the 215x-series to one of the 218x-series VCAs, see our Design Note 137,
"Substituting THAT2180- and 2181-Series VCAs for THAT2150-Series VCAs in Existing Designs"

For detailed specifications and assistance on the entire 2180- and 2181-series, please contact Technical Support.

For sales questions, or for samples of any of our 218x series, please contact Sales Administration via phone at +1.508.634.9922 or via email at