The UC1637 is a pulse width modulator circuit intended to be used for a variety of PWM motor drive and amplifier applications requiring either uni-directional or bi-directional drive circuits. When used to replace conventional drivers, this circuit can increase efficiency and reduce component costs for many applications. All necessary circuitry is included to generate an analog error signal and modulate two bi-directional pulse train outputs in proportion to the error signal magnitude and polarity.

This monolithic device contains a sawtooth oscillator, error amplifier, and two PWM comparators with ±100mA output stages as standard features. Protection circuitry includes under-voltage lockout, pulse-by-pulse current limiting, and a shutdown port with a 2.5V temperature compensated threshold.

The UC1637 is characterized for operation over the full military temperature range of -55°C to +125°C, while the UC2637 and UC3637 are characterized for -25°C to +85°C and 0°C to +70°C, respectively.

• Single or Dual Supply Operation
• ±2.5V to ±20V Input Supply Range
• ±5% Initial Oscillator Accuracy; ±10% Over Temperature
• Pulse-by-Pulse Current Limiting
• Under-Voltage Lockout
• Shutdown Input with Temperature Compensated 2.5V Threshold
• Uncommitted PWM Comparators for Design Flexibility
• Dual 100mA, Source/Sink Output Drivers