IN Brief:
- STSPIN9P covers half-bridge and full-bridge motor drivers operating from 7V to 75V.
- Integrated MOSFET options provide typical on-resistance down to 16mΩ and support motors rated up to 500W.
- The family integrates current sensing, adjustable slew rate, protection functions, and open-load detection in compact QFN packages.
STMicroelectronics has introduced the STSPIN9P family of integrated motor drivers, combining 75V power stages with current sensing, protection and configurable control in packages measuring as little as 7mm by 7mm.
The range covers half-bridge and full-bridge devices for brushed DC, brushless DC and stepper motors, with operating voltage from 7V to 75V. ST is targeting industrial automation, building systems and other equipment using motors rated up to approximately 500W.
Half-bridge STSPIN9P1 devices are available with integrated MOSFET on-resistance down to 16mΩ typical and current ratings reaching 10A RMS. Other variants use 27mΩ MOSFETs rated at 6A RMS, giving designers a choice between lower conduction loss and device requirements across different motor loads.
The STSPIN9P2 full-bridge devices use a 7mm by 9mm QFN package and integrate the switching arrangement required for brushed DC motors and stepper phases. Using a full bridge in one package reduces the external power-stage component count compared with constructing the same function from discrete MOSFETs and separate gate drivers.
Every device includes an analogue front end containing a differential amplifier for shunt-based current sensing. Selected variants use an integrated comparator to implement current limiting through PWM trimming or fixed off-time control, while others make the comparator available to the application for a different control function.
The integrated current path can reduce the value of the external shunt resistor required for measurement, cutting dissipation in the sensing element. Current information remains important even in relatively simple motor systems because it can be used for torque regulation, stall detection, protection and closed-loop control.
ST has also included adjustable slew-rate control across the family. Changing the switching transition rate allows designers to trade switching loss against electromagnetic interference rather than accepting one fixed edge speed determined entirely by the internal power stage.
Fast voltage transitions can reduce switching loss but increase ringing and radiated or conducted noise through parasitic capacitance and inductance. Slowing the edge can simplify EMC behaviour at the cost of additional switching energy, making adjustable slew rate useful when the same electronics platform has to pass different cable, motor or enclosure configurations.
The protection set includes undervoltage lockout, overcurrent protection and thermal shutdown. Open-load detection can check whether the motor connection is present while the output stage is disabled, providing a diagnostic function without requiring the motor to be energised.
An internal charge pump supports extended high-side operation, while integrated regulators allow the devices to operate without separate gate-drive supply rails. Bringing those support functions into the driver reduces the surrounding bill of materials and can make the motor stage easier to reuse across related products.
Pin-compatible variants are another part of the family structure. ST has developed several devices around common package and interface arrangements while changing MOSFET resistance, topology and control features. An equipment manufacturer can therefore create one board platform and select a different STSPIN9P part where the motor current or control requirements change.
That approach suits industrial equipment families in which the mechanical platform remains similar but motor ratings vary between models. Maintaining common PCB layouts can reduce qualification and inventory work, although thermal design and current handling still have to be checked for each fitted device.
The series sits between low-voltage monolithic motor drivers and power stages built from separate gate drivers and external MOSFETs. Integration offers a smaller footprint and a more defined switching environment, while discrete stages can remain preferable where current, thermal requirements or semiconductor selection exceed the limits of the integrated package.
The 75V ceiling gives the new devices headroom above common 24V and 48V industrial supply systems, allowing margin for switching transients and back electromotive force from the motor. The usable margin in a finished design still depends on supply tolerance, clamp strategy, wiring inductance and the transient conditions generated by the mechanical load.
ST lists members of the STSPIN9P family as active and in volume production. The range therefore enters the market as an immediately selectable motor-control platform rather than an advance announcement, with device choice determined by bridge topology, motor current and the level of integrated current-control functionality required.
