NXP Semiconductors MC34920EI

Overview

MC34920EI from Freescale Semiconductor is a multifunctional analog ASIC integrating two dual-H-bridge motor drivers, two buck regulators (200 kHz switching), and a reset circuit in a single 44-pin PLCC package. It supports configurable operation as two 2.4 A DC motors, two bipolar stepper motors (quarter-step mode), or mixed configurations, with input voltage range 21–42 V DC and Pb-free EI packaging.

For engineers reviewing the MC34920EI datasheet, MC34920EI pinout, MC34920EI application, or MC34920EI equivalent, this page delivers verified specifications including H-bridge on-resistance (0.73 Ω typical in parallel DC mode), V2 regulator programmability (10–15 V), serial 13-bit control interface, thermal shutdown thresholds (155–175 °C), and dual-mode driver configuration logic.

Technical Context

The MC34920EI implements two independent motor driver blocks, each containing two H-bridges with current-mode bipolar step control or PWM-driven parallel DC drive. Each bridge pair shares dedicated sense inputs (DRxSENSE1/2) and mode-select pins (DRx_MODE) to configure per-driver operation without shared timing constraints.

Its dual buck regulators operate at fixed 200 kHz (V1 duty cycle 37.5%, V2 duty cycle 82.5%), with V1 delivering 3.3 V or 5.0 V ±4% and V2 externally programmable via resistor divider on V2_FB. The RESET output is active-low, triggered by VVB+ undervoltage (13.5–16.5 V threshold) or V1_FB deviation (2.05–2.23 V window), with 15–50 ms assertion delay.

Key Specifications

Pinout & Package

MC34920EI uses a 44-pin Plastic Leaded Chip Carrier (PLCC) package with lead-free (Pb-free) EI suffix, designed for surface-mount assembly and thermal dissipation in motor control modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC34920EI, STSPIN840 lacks integrated regulators and serial configuration, increasing BOM count and reducing flexibility, while TB9051FTG adds automotive-grade features unnecessary for printer/scanner applications but removes the self-contained power solution critical for space-constrained designs.

Availability

MC34920EI is available at Aetrix Electronics and suitable for printer paper feed mechanisms, scanner carriage drives, automated document feeders, and industrial label printer heads requiring stable component supply and long-term industrial lifecycle support.

Supply support for MC34920EI 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

Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in analog and mixed-signal ICs for industrial and automotive systems, known for robust motor control and power management solutions.

The MC34920EI belongs to Freescale's legacy analog ASIC portfolio targeting multi-function printer and scanner subsystems, designed to integrate motor drive, power regulation, and system supervision into a single die for cost-sensitive, high-reliability peripheral applications.

FAQ

What motor configurations does the MC34920EI support?

The MC34920EI supports three configurations per driver block: DC motor (2.4 A peak, two H-bridges paralleled), bipolar stepper (0.6 A peak per phase, quarter-step mode), or mixed (one DC + one stepper). Configuration is set via DR1_MODE/DR2_MODE pins and serial register bits, enabling dynamic reconfiguration without hardware changes. Each mode uses dedicated internal paths-current-mode regulation for steppers, PWM-controlled voltage drive for DC motors-and shares the same VB+ supply and thermal protection logic.

How is the V2 regulator output voltage programmed on the MC34920EI?

The V2 regulator output voltage on the MC34920EI is programmed externally using a resistor divider network connected between V2_SWITCH, V2_FB, and GND. The internal reference is 2.50 V ±2%, so selecting R1 and R2 such that V2_FB = 2.50 V sets VV2 = 2.50 V × (1 + R1/R2). This allows precise setting of VV2 within 10–15 V ±2%, as confirmed in the Electrical Characteristics table. The V2_Enable bit in the serial register independently controls activation of both V2 and all motor drivers.

Does the MC34920EI include overcurrent protection for DC motor operation?

Yes, the MC34920EI includes dedicated overcurrent protection for DC motor operation. In DC mode (DRx_MODE = 0), the device monitors top H-bridge transistors and triggers shutdown at 1.6–2.5 A (typical 2.0 A), with a sustaining current limit of 1.6–2.4 A for ≥100 ms. This protection applies only to motor current paths-not shorts to VB+ or GND-as explicitly noted in the datasheet. Thermal shutdown (155–175 °C) provides secondary protection independent of current sensing.

What is the function of the RESET pin on the MC34920EI?

The RESET pin on the MC34920EI is an active-low open-drain output that asserts when either VVB+ drops below 13.5–16.5 V or V1_FB deviates from its 2.05–2.23 V window. It features a 15–50 ms delay after threshold violation and a 10–30 µs persistence time to reject short glitches. When asserted, RESET forces all motor outputs inactive and loads the serial register with default values. The pin requires an external pull-up resistor and interfaces directly with MCU reset inputs in printer/scanner mainboards.

Can the MC34920EI operate with a 3.3 V logic supply?

Yes, the MC34920EI fully supports 3.3 V ±10% logic supply on the VCC pin, as specified in the Static Electrical Characteristics table. All digital inputs-including CS, SCLK, SDI, DRx_MODE, and DRxPWM-are CMOS-compatible and tolerate 5.0 V logic levels. The serial interface operates reliably at 4–12 MHz regardless of VCC voltage, and internal logic thresholds scale accordingly (e.g., VIH = 2.1 V min at 3.3 V VCC). This dual-voltage compatibility simplifies integration with both legacy 5 V and modern 3.3 V microcontrollers.