For further study, download the official Texas Instruments TL494 datasheet (SLVS074G). It contains 20+ reference designs that directly match the circuit diagrams discussed here.
). The frequency of this oscillator determines the switching rate of the power stages.
This is the most common for converting a higher voltage (e.g., 24V battery) to a lower voltage (e.g., 12V at 10A). tl494 circuit diagram
: Connected to pin 4, this comparator provides a fixed or adjustable minimum "off" period. This is critical in push-pull configurations to prevent "shoot-through," where both switching transistors are on at the same time, causing a short circuit. Output Steering Flip-Flop
A basic TL494 circuit diagram is shown below: For further study, download the official Texas Instruments
Controls the maximum duty cycle. Applying a small voltage (0V to 3.3V) limits the "on" time to prevent transformer saturation.
The TL494 is a monolithic pulse-width modulation (PWM) control circuit designed by Texas Instruments. Introduced decades ago, it remains an industry-standard building block for switched-mode power supplies (SMPS), DC-to-DC converters, and inverter circuits. Its architectural flexibility allows designers to configure it for push-pull, half-bridge, or single-ended topologies. The frequency of this oscillator determines the switching
: This determines the operation mode. Grounding this pin sets it to "single-ended" mode (both transistors pulse together), while connecting it to the internal 5V reference (Pin 14) enables "push-pull" mode (alternating pulses). Pin 14 (REF)
High-gain operational amplifiers (Pins 1, 2 and 15, 16) configured to monitor output voltage and current. They operate via an OR-gate configuration, meaning whichever amplifier demands a lower duty cycle takes control.
If you cannot find the exact TL494, similar ICs like the or TL3842 can be considered, although they may have different pinning or specific performance characteristics.
Before diving into circuits, it is crucial to understand the pins. The TL494 is available in DIP-16, SOIC-16, and TSSOP-16 packages.