The TS925 is an input/output rail to rail quad BiCMOS operational amplifier. It is able to operate with low supply voltages (2.7V) and to drive low output loads such as 32Ω. This technical note highlights many of the advantages of the device in a global audio application.
This document details an audio application circuit using the TS925, an input/output rail-to-rail quad BiCMOS operational amplifier capable of operating with low supply voltages (2.7V) and driving low output loads such as 32Ω. The circuit utilizes two operators in a preamplifier configuration and two others in a push-pull configuration to drive a headset.
The preamplifier section achieves a gain of 58dB using specific resistor values (R4=22kΩ, R3=500Ω, R17=1.2kΩ, R6=47kΩ, R5=1.2kΩ) or can be adjusted using a JFET transistor for automatic level control (ALC). The headphone amplifier drives a 32Ω load directly from stereo inputs, demonstrating the device's ability to provide high fidelity and maximum output swing.
| Supply Voltage | 2.7V |
|---|---|
| Output Load | 32Ω |
| Preamplifier Gain | 58dB |
The TS925 is an input/output rail to rail quad BiCMOS operational amplifier.
The power supply is delivered from two LR6 batteries (2x1.5V nominal).
Yes, the gain can be adjusted by choosing a JFET transistor instead of a resistor to form an automatic level control (ALC) circuit.