NXP Semiconductors MC34931EK

Overview

MC34931EK from NXP Semiconductors is a monolithic 5.0 A H-Bridge Power IC in a 32-pin SOICW-EP package, designed for low-voltage DC brushed and servo motor control. It supports external PWM frequencies up to 11 kHz, features integrated current feedback (0.24% proportional output on FB pin), and provides overcurrent, overtemperature, and undervoltage fault reporting via open-drain SF pin. Used in industrial motion control systems requiring precise bidirectional torque regulation.

For engineers reviewing the MC34931EK datasheet, MC34931EK pinout, MC34931EK application, or MC34931EK equivalent, this page delivers verified electrical parameters, thermal behavior under load, real-world timing constraints (e.g., 18 µs ON delay), functional truth table states, and validated alternative options for motor driver selection.

Technical Context

The MC34931EK implements SMARTMOS technology with dual independent half-bridge totem-pole outputs, controlled by TTL/CMOS-compatible IN1/IN2 logic inputs and tri-state disabled via D1 or EN/D2. Its internal constant-OFF-time PWM current regulation activates at 6.5 A ±1.5 A peak, with junction-temperature-dependent foldback reducing ILIM to 4.2 A above 165 °C before thermal shutdown at 175 °C.

It integrates a charge pump (CCP pin, 30–100 nF capacitor required) enabling high-side MOSFET drive at VPWR down to 5.0 V, while delivering 235 mΩ max R_DS(on) per MOSFET at T_J = 150 °C. The FB pin provides ground-referenced analog current sensing (0.24% of high-side load current), compatible with standard MCU ADC inputs using a 270 Ω termination resistor.

Key Specifications

Pinout & Package

MC34931EK is housed in a thermally enhanced 32-pin SOICW-EP (Small Outline Integrated Circuit Wide, Exposed Pad) package. The exposed pad (EP) serves as primary heatsink path and must be soldered to PGND. Pin functions are validated per NXP Rev. 4.0 datasheet (2016), Table 2 and Figure 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar H-Bridge motor driver applications.

Compared with MC33886 and DRV8876N, the MC34931EK uniquely combines 5.0 A capability, 0.24% proportional current feedback, junction-temperature-aware foldback, and SOICW-EP thermal performance in a single 32-pin package-making it optimal for cost-sensitive, thermally constrained industrial motion control.

Availability

MC34931EK is available at Aetrix Electronics and suitable for industrial servo positioning, POS/ATM actuation, and vending machine dispenser applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MC34931EK includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor leader focused on automotive, industrial, and IoT applications, delivering secure, scalable silicon solutions with deep system-level expertise.

The MC34931EK belongs to NXP's SMARTMOS H-Bridge family, engineered specifically for robust, thermally efficient DC motor control in industrial automation, security systems, and commercial equipment where reliability under sustained load is critical.

FAQ

What is the maximum PWM frequency supported by the MC34931EK?

The MC34931EK supports external PWM frequencies up to 11 kHz, as specified in NXP's Rev. 4.0 datasheet. This limit ensures reliable high-side MOSFET enhancement across the full 15–85% duty cycle range. Exceeding 11 kHz may cause incomplete gate drive and increased conduction losses. The MC34931SEK variant supports 20 kHz, but MC34931EK must remain within its rated 11 kHz ceiling for stable operation.

How does the FB pin on the MC34931EK provide current feedback?

The FB pin on the MC34931EK sources a current equal to 0.24% of the high-side output current (e.g., 1.2 mA at 5.0 A load). When terminated with a 270 Ω resistor to AGND, it produces a ground-referenced voltage linearly proportional to load current-enabling direct sampling by an MCU's ADC. Accuracy is ±20% from 0.5 A to 6.0 A, and the pin requires no external amplification or calibration for basic closed-loop torque control.

What happens when the MC34931EK enters overtemperature shutdown?

When the MC34931EK junction temperature reaches 175 °C, it triggers overtemperature shutdown: both OUT1 and OUT2 enter tri-state latch-OFF, and the SF pin pulls low. Recovery requires toggling either D1, EN/D2, or VPWR. Crucially, the device first enters current foldback (ILIM reduced to 4.2 A) above 165 °C-providing graceful degradation before shutdown. This allows brief overload tolerance (<30 s non-repetitive) without immediate fault lockout.

Can the MC34931EK operate from a 5.0 V supply?

Yes, the MC34931EK operates from 5.0 V to 36 V steady-state, with transient tolerance up to 40 V for ≤500 ms. At 5.0 V, the charge pump still functions (V_CP–V_PWR ≥3.5 V), enabling full H-Bridge operation. However, R_DS(on) increases by ~50% below 8.0 V, raising conduction loss. For 5.0 A loads, thermal design must account for higher I²R heating at low VPWR.

What is the purpose of the CCP pin on the MC34931EK?

The CCP pin on the MC34931EK connects to the external charge pump reservoir capacitor (30–100 nF), which is mandatory for proper high-side MOSFET gate drive. Without this capacitor, the internal charge pump cannot generate sufficient gate voltage above VPWR, resulting in incomplete high-side enhancement, excessive R_DS(on), and potential thermal failure. The capacitor must be placed close to CCP and VPWR pins with low-inductance routing.