UC1637

· 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

Supply Voltage (±Vs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±20V
Output Current, Source/Sink (Pins 4, 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500mA
Analog Inputs (Pins 1, 2, 3, 8, 9, 10, 11 12, 13, 14, 15, 16) . . . . . . . . . . . . . . . . . .±Vs
Error Amplifier Output Current (Pin 17) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..±20mA
Oscillator Charging Current (Pin 18). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. -2mA
Power Dissipation at TA = 25°C (Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000mW
Power Dissipation at TC = 25°C (Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000mW
Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Lead Temperature (Soldering, 10 Seconds). . . . . . . . . . . . . . . . . . . . . . . . . . . .+300°C
Note 1: Currents are positive into, negative out of the specified terminal.
Note 2: Consult Packaging Section of Databook for thermal limitations and considerations of package.

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 bidirectional 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.