Specifying a Solenoid Driver's Hold-Current Control

1. Distinguish activation from sustained hold

A solenoid application can have different current requirements during activation and sustained hold. TI's DRV110 description begins with a rapid current rise, retains a peak for an interval and then reduces the current to a lower hold level. Treat those as different roles in the requested waveform rather than combining them into a single general current rating.

The distinction concerns what the current control is meant to accomplish over time. The activation stage and the later hold stage are not interchangeable operating labels. A sourcing requirement that records only one current level leaves it unclear which stage that level describes and whether the application needs a separate peak interval before entering the sustained state.

Use the actual actuator requirement to identify the needed stages, while retaining TI's description as a named controller example. The example explains the purpose of a controlled waveform but does not establish that an unknown actuator opens, remains held or releases correctly. The current-stage requirement is the starting technical input; mechanical behaviour is a separate application outcome.

2. Read the controller and external power-stage boundary

DRV110 is described as a PWM current controller that drives an external MOSFET. That wording identifies a boundary between the control device and the power-switching element. A request for a controller should not silently become a claim that the supplied IC includes every part of the power stage. The exact candidate's integration description needs to remain visible.

TI also identifies an external sense resistor for current regulation. This gives the current-feedback function a place in the architecture without defining a particular component value or physical connection here. Keep the controller, external switching element and current-sensing role distinguishable when considering what the sourcing request actually covers. A generic solenoid driver label can conceal those differences in scope.

A component comparison should therefore check more than whether both products mention solenoids. Ask whether the proposed device provides the required control function with the expected integration boundary. A controller requiring an external power switch and a differently integrated proposal are not described completely by the same category word. Identifying that distinction does not approve a circuit conversion or external-part selection.

3. Keep peak duration and current levels separate

The peak level, peak duration and hold level are separate controls in TI's description. Current amplitude and time answer different questions: how much current is requested during a stage and how long that stage is retained. Keeping them separate prevents one accepted hold requirement from being mistaken for the complete activation waveform the application needs.

The product introduction describes the peak duration and current levels as independently settable, with PWM frequency also separately described. The existence of independent settings matters because a single adjustable-current feature does not explain the whole waveform. A candidate should be assessed against the actual combination of control requirements, without deriving settings from an abbreviated feature name.

TI notes that defaults may be usable when appropriate to the application. A default is therefore another candidate condition to assess, not evidence that the controller arrives configured for an unidentified solenoid. This guide supplies no resistor, capacitor, frequency or current-ratio values. It preserves the distinction between available control parameters and values accepted for the actual actuator.

4. Preserve application evaluation independently

Lower hold current has a stated purpose in TI's explanation: reducing dissipation after the activation and peak stages. That purpose does not establish the temperature of a particular coil, enclosure or assembled system. The controller feature and an actual thermal result are different forms of evidence. Keep the intended benefit identifiable without reporting that the application's thermal requirement has already been met.

The motor-driver decay guide addresses a different current-control question within a stepper-driver application. Likewise, a stepper-versus-brushed-driver classification identifies another product role. Neither provides the solenoid's required activation interval or sustained hold condition. Sharing current-control terminology is not enough to transfer a motor setting or architecture decision into this actuator requirement.

A focused sourcing description can finish with the required stages, their independently established conditions and the expected controller/power-stage boundary. The application assessment then has a specific waveform question to address. This makes the proposed component understandable without inventing a universal peak-to-hold ratio, a mains connection, a completed thermal evaluation or a mechanical operating result for the customer's equipment.

Sources and further reading

• Texas Instruments — DRV110 Product Description

TI's DRV110 product-description core was reread on 15 October 2026 for the staged waveform, external MOSFET/current-sensing boundary and separate settings. No component values, current ratio, mains circuit or thermal/mechanical result is supplied.