onsemi STK682-010-E Hybrid IC Stepper Motor Driver: Datasheet, Pinout, and Application Circuit Guide
The onsemi STK682-010-E is a hybrid IC (HIC) designed as a complete, high-performance driver for 2-phase bipolar stepper motors. It integrates critical control logic and power output stages into a single, compact module, significantly simplifying design and reducing the component count required for motor control applications. This guide provides an overview of its key specifications, pinout configuration, and a typical application circuit.
Datasheet Overview and Key Features
The STK682-010-E is built using thick-film hybrid technology, which allows for the creation of a robust and thermally efficient power circuit. According to its datasheet, it operates within a wide supply voltage range (VCC2) of +10V to +40V, making it suitable for driving a variety of motors at different power levels. The driver can deliver a maximum output current of 1.5A per phase, which is sufficient for many industrial and consumer automation tasks.
A standout feature of this HIC is its built-in dual full-bridge MOSFET output stage. This eliminates the need for external power transistors and their associated drive circuits. Furthermore, it includes internal protection circuits such as thermal shutdown (TSD) and overcurrent protection (ISD), which safeguard the IC from damage due to excessive heat or short-circuit conditions. The logic section operates on a lower voltage (VCC1) of +5V, making it directly compatible with microcontrollers and digital logic circuits without the need for level shifters.
Pinout Configuration
Understanding the pinout is crucial for proper PCB layout and system integration. The STK682-010-E is housed in a 15-pin SIP (Single In-line Package).
Key pins include:
VCC2 (Pins 1, 15): The main power supply input for the motor (VMOT).
GND (Pins 2, 14): Ground terminals for both power and logic.
OUT (Pins 3, 4, 12, 13): Motor phase outputs (OUT A+, OUT A-, OUT B+, OUT B-).
VCC1 (Pin 5): Logic power supply input (+5V).
IN A, IN B (Pins 6, 7): Control input signals for Phase A and Phase B.
/ENABLE A, /ENABLE B (Pins 8, 9): Active-low enable inputs for each phase bridge.
CP (Pin 10): Connection point for a charge pump capacitor.
VREG (Pin 11): Regulator output for internal logic.
Typical Application Circuit Guide
Implementing the STK682-010-E in a design is straightforward. A basic application circuit requires only a handful of external components:
1. Power Supplies: Two decoupled power rails: a stable +5V for VCC1 and a +10V to +40V motor supply for VCC2.
2. Control Inputs: The IN A, IN B, /ENABLE A, and /ENABLE B pins are typically connected directly to a microcontroller's GPIO pins. The input logic controls the motor's direction and step mode (e.g., full-step, wave-drive).
3. Charge Pump Circuit: A capacitor (typically 100pF to 1000pF) must be connected between the CP and VREG pins. This circuit generates a voltage above VCC2 to ensure the high-side N-channel MOSFETs are fully saturated, improving efficiency and reducing heat generation.
4. Decoupling Capacitors: Place a large electrolytic capacitor (e.g., 100µF) near the VCC2 pins to handle high current demands and a smaller ceramic capacitor (e.g., 0.1µF) near the VCC1 pin for high-frequency noise suppression.
5. Protection Diode (Optional): For highly inductive loads, an external flyback diode may be added across the motor supply, although the internal MOSFET body diodes often provide sufficient protection.
ICGOODFIND Summary
The onsemi STK682-010-E is a highly integrated and robust solution for driving bipolar stepper motors. Its combination of a wide operating voltage range, substantial output current, and comprehensive built-in protection makes it an excellent choice for designers seeking to simplify their motor drive architecture while maintaining high performance and reliability in applications like printers, scanners, and automated equipment.
Keywords: Stepper Motor Driver, Hybrid IC, Thick-Film Hybrid, Application Circuit, Thermal Shutdown
