Pwm Motor
application INFO available
UC1638 UC2638 UC3638
Advanced PWM Motor Controller
FEATURES
• • • • • • • • Single or Dual Supply Operation Accurate High Speed Oscillator Differential X5 Current Sense Amplifier Bidirectional Pulse-by-Pulse Current Limiting Programmable Oscillator Amplitude and PWM Deadband Dual 500mA Totem Pole Output Drivers Dual 60V, 50mA Open Collector Drivers Undervoltage Lockout
DESCRIPTION
The UC1638 family of integrated circuits are advanced pulse width modulators intended for a variety of PWM motor drive and amplifier applications requiring either uni-directional or bi-directional drive circuits. Similar in architecture to the UC1637, 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. Key features of the UC1638 include a programmable high speed triangle oscillator, a 5X differential current sensing amplifier, a high slew rate error amplifier, high speed PWM comparators, and two 50mA open collector as well as two ±500mA totem pole output stages. The individual circuit blocks are designed to provide practical operation to switching frequencies of 500kHz. Significant improvements in circuit speed, elimination of many external programming components, and the inclusion of a differential current sense amplifier, allow this controller to be specified for higher performance applications, yet maintain the flexibility of the UC1637. The current sense amplifier in conjunction with the error amplifier can be configured for average current feedback. The additional open collector outputs provide a drive signal continued
BLOCK DIAGRAM
UDG-95048-4
SLUS290 - JANUARY 1998
UC1638 UC2638 UC3638 DESCRIPTION (cont.) for the highside switches in a full bridge configuration. The programmable AREFIN pin allows for single or dual supply operation. Oscillator ramp amplitude and PWM deadband are programmable by tapping
UC1638 UC2638 UC3638
Advanced PWM Motor Controller
FEATURES
• • • • • • • • Single or Dual Supply Operation Accurate High Speed Oscillator Differential X5 Current Sense Amplifier Bidirectional Pulse-by-Pulse Current Limiting Programmable Oscillator Amplitude and PWM Deadband Dual 500mA Totem Pole Output Drivers Dual 60V, 50mA Open Collector Drivers Undervoltage Lockout
DESCRIPTION
The UC1638 family of integrated circuits are advanced pulse width modulators intended for a variety of PWM motor drive and amplifier applications requiring either uni-directional or bi-directional drive circuits. Similar in architecture to the UC1637, 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. Key features of the UC1638 include a programmable high speed triangle oscillator, a 5X differential current sensing amplifier, a high slew rate error amplifier, high speed PWM comparators, and two 50mA open collector as well as two ±500mA totem pole output stages. The individual circuit blocks are designed to provide practical operation to switching frequencies of 500kHz. Significant improvements in circuit speed, elimination of many external programming components, and the inclusion of a differential current sense amplifier, allow this controller to be specified for higher performance applications, yet maintain the flexibility of the UC1637. The current sense amplifier in conjunction with the error amplifier can be configured for average current feedback. The additional open collector outputs provide a drive signal continued
BLOCK DIAGRAM
UDG-95048-4
SLUS290 - JANUARY 1998
UC1638 UC2638 UC3638 DESCRIPTION (cont.) for the highside switches in a full bridge configuration. The programmable AREFIN pin allows for single or dual supply operation. Oscillator ramp amplitude and PWM deadband are programmable by tapping