A3966 Frequently Asked Questions

No. However, you can run in full, half, and modified half-step modes. 
No, it is not a drop-in replacement, although the A3966 is an excellent functional replacement. 
Package options include a 16-lead batwing SOIC. The 16-pin DIP is no longer available. 
Yes, see technical paper STP98-9, "Low-Cost-Dual-H-Bridge-Motor-Driver-IC".
Yes. We now have two different applications boards that will help simplify a new design using the A3966. Contact the Applications Group in Worcester for more information. 
It is possible. However, there are several considerations, such as optimization of circuit board layout, use of external Schottky diodes in parallel with the internal diodes, use of heat sinks, etc. Please refer to application note numbers 29501.4, "Improving Batwing Power Dissipation", and AN29501.5, "Computing IC Temperature Rise". 
30V. This must not be exceeded. 
Yes. The following components are required: 
  • RS - the external sense resistor. This should be non-inductive. 
  • RT - the external resistive component needed to set the internal oscillator's frequency. 
  • CT - the external capacitive component needed to set the internal oscillator's frequency. 
  • Decoupling capacitor - logic supply. A 0.01 µF ceramic capacitor is recommended. 
  • Decoupling capacitor - load supply. A 47 µF electrolytic capacitor is recommended. 
  • Thermal shutdown (TSD) 
  • Crossover current protection 
  • Under-voltage lockout (UVLO) 
  • Ground-clamp diodes 
  • Flyback diodes 
Yes. Power ground for the sense resistor, Rs, should be connected as close to the device as possible. Also, Rs should be non-inductive, and the circuit board ground run should be as large as physically possible. For further layout consideration, please refer to application note 29501.5A, "Improving Batwing Power Dissipation."
Constant-current. Motor winding current is controlled by internal fixed-frequency, PWM current-control circuitry. This device can also be run in "voltage mode" for DC motor applications. 
Use external Schottky diodes in parallel with the internal diodes. Heat sinks are also a possibility. However, Schottky diodes are typically the preferred solution.