. Often referred to as the "Swiss Army Knife" of analog design, this dual-operational transconductance amplifier (OTA) IC is a legendary component that brings voltage-controlled versatility to electronics.
Unlike a traditional Operational Amplifier (Op-Amp) that produces an output voltage proportional to the input, an OTA produces an output current proportional to the input voltage difference. The magic lies in the Amplifier Bias Current ( IABCcap I sub cap A cap B cap C end-sub lm13720
These integrated diodes reduce distortion, allowing higher input signal levels—crucial for audio quality. The magic lies in the Amplifier Bias Current
can be used to build resonant low-pass, high-pass, or band-pass filters where the cutoff frequency is swept by a CV. 3. Voltage-Controlled Oscillator (VCO) By controlling the charging current of a capacitor, the the The core of many compressors
The core of many compressors, limiters, and synth modules, a VCA allows you to control the amplitude of a signal with a control voltage (CV). 2. Voltage-Controlled Filter (VCF)
) of the amplifier—in simple terms, you can control the gain of the chip using a voltage. Key Features of the LM13700
But what makes this decades-old chip still relevant in 2026? Let's dive into the world of OTAs and why the remains indispensable. What is an OTA?