This document introduces the TL494AN/C/D/E functions and features, including precision current control, ±800mA load current, 1.25V total VSAT at 800mA, controlled velocity head parking, precision dual supply monitor with indicator, limit input to force output extremes, inhibit input and UVLO, 4V to 15V operation.
The Unitrode UC3175B is a full-bridge power amplifier rated for a continuous output current of 0.8 Amperes. It is specifically intended for demanding servo applications, such as head positioning for high-density disk drives. The device features a precision current sense amplifier for accurate load current control using a single series resistor and operates with supply levels as low as 4V.
Key auxiliary functions include a dual-input under-voltage comparator that can force a built-in constant voltage source for head parking when either supply voltage drops below a minimum. Additional features include a POWER OK flag output, a LIMIT input to force maximum drive output, and an INHIBIT input to disable all amplifiers and reduce quiescent supply current. The device is available in PLCC and SOIC surface mount packages.
| Operating Supply Voltage Range | 4V to 15V |
|---|---|
| Output Saturation Voltage (Total, 800mA) | 1.25V |
| Unity Gain Bandwidth (Amplifier A) | 2 MHz |
| Thermal Shutdown Temperature | 165 °C |
It can operate down to 4V supply levels and includes a controlled velocity head parking function that activates when supply voltage falls below 3.0 Volts.
The INHIBIT input overrides the amplifier inputs to convert the power outputs to a programmable constant voltage source and reduces quiescent supply current.