NXP Semiconductors MCZ34702EWR2

Overview

MCZ34702EWR2 from NXP Semiconductors (formerly Freescale) is a dual-output power management IC integrating a 3.0A synchronous buck switcher and an external-NMOS LDO controller for microprocessor core and I/O supply. It delivers ±1.0% output voltage accuracy (0.800 V reference), supports 2.8–6.0 V input, provides I²C-based voltage margining and programmable power-on reset delay, and targets Power QUICC I/II and MPC8xxx processor power systems.

For engineers reviewing the MCZ34702EWR2 datasheet, MCZ34702EWR2 pinout, MCZ34702EWR2 application, or MCZ34702EWR2 equivalent, key selection criteria include its 300 kHz default switching frequency, integrated boost regulator (7.75 V nominal VBST), precise up/down power sequencing control via EN1/EN2 logic, and dual-regulator supervision with open-drain RST output.

Technical Context

The MCZ34702EWR2 implements a synchronous buck topology with integrated high-side and low-side N-channel MOSFETs (R_DS(ON) = 60 mΩ / 65 mΩ), driven by an internal 300 kHz oscillator adjustable via external resistor on FREQ pin (200–400 kHz range). Its linear regulator section uses external NMOS pass device controlled via LDRV gate drive and current-limited via CS/LDO sensing.

Power sequencing is managed by dedicated logic that interprets EN1/EN2 states to enable standard, inverted, or no-sequencing modes. Supervision includes independent monitoring of VOUT and VLDO feedback paths with 20 µs glitch filtering, programmable reset timeout via RT/CT network, and thermal shutdown at 170 °C (10 °C hysteresis) for both switcher and LDO sections.

Key Specifications

Pinout & Package

MCZ34702EWR2 is housed in a 32-pin SOICW (Small Outline Integrated Circuit, Wide-body) package with exposed thermal pad. Pin pitch is 1.27 mm; body width is 7.5 mm. The package supports Pb-free reflow per JEDEC J-STD-020C and provides thermal resistance of 55 °C/W (junction-to-ambient, 4-layer board).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output PMIC applications.

Compared with MPQ4470AGU-AEC1-P and TPS65023BRSBR, MCZ34702EWR2 uniquely combines external LDO NMOS drive capability, precise EN1/EN2 sequencing logic, and I²C voltage margining-making it irreplaceable for legacy Freescale processor upgrades requiring field-adjustable core voltage and strict sequencing compliance.

Availability

MCZ34702EWR2 is available at Aetrix Electronics and suitable for industrial networking equipment, telecom line cards, and embedded control modules requiring stable component supply, long-term lifecycle support, and compatibility with legacy Freescale Power QUICC designs.

Supply support for MCZ34702EWR2 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 secure connectivity solutions for automotive, industrial, and IoT applications, with deep heritage in Power Architecture and communications processors.

The MCZ34702EWR2 belongs to NXP's legacy Power Management IC portfolio designed specifically for Freescale Power QUICC and MPC8xxx microprocessor families, emphasizing robust power sequencing, thermal resilience, and system-level configurability.

FAQ

What is the default switching frequency of the MCZ34702EWR2 and how is it adjusted?

The MCZ34702EWR2 has a default switching frequency of 300 kHz when the FREQ pin is left open or tied to VDDI. Frequency adjustment is achieved by connecting an external resistor RF between FREQ and GND: values from 7.0 kΩ to 22 kΩ tune the frequency from 400 kHz down to 200 kHz. This resistor-based method allows optimization of efficiency, EMI, and inductor size without requiring external clock sources. The MCZ34702EWR2 datasheet specifies typical oscillator accuracy and temperature drift for design validation.

Does the MCZ34702EWR2 integrate power MOSFETs for both the buck and LDO sections?

The MCZ34702EWR2 integrates high-side and low-side N-channel MOSFETs for the 3.0 A buck regulator (R_DS(ON) = 60 mΩ / 65 mΩ), but does not integrate the pass element for the LDO section. Instead, it provides LDRV gate drive and CS/LDO current-sense inputs to control an external N-channel MOSFET (e.g., IRL2703), enabling scalable I/O rail current handling beyond 1 A. This architecture gives designers flexibility in thermal management and current capability while maintaining integration benefits. The MCZ34702EWR2's LDO control loop remains fully internal and compensated via LCMP.

How does the MCZ34702EWR2 implement power sequencing for Freescale processors?

The MCZ34702EWR2 implements hardware-based power sequencing through dedicated EN1 and EN2 logic inputs. Their binary states select among four modes: regulators disabled (0,0), standard sequencing (0,1), inverted sequencing (1,0), or simultaneous enable (1,1). Sequencing behavior is hardwired-not software-configurable-and ensures VOUT (core) ramps before VLDO (I/O) in standard mode, satisfying Power QUICC I/II boot requirements. The MCZ34702EWR2 also monitors both outputs continuously and asserts RST if either falls outside its tolerance window, providing fail-safe supervision.

What is the function of the VBST pin on the MCZ34702EWR2 and what voltage does it deliver?

The VBST pin on the MCZ34702EWR2 is the output of an internal charge-pump boost regulator, delivering a nominal 7.75 V (range 7.3–8.3 V) at up to 20 mA. This voltage powers the gate drivers for the integrated buck high-side MOSFET and the external LDO NMOS pass transistor driven by LDRV. It eliminates the need for an auxiliary supply and ensures sufficient gate overdrive for low R_DS(ON) operation across input voltage range. The MCZ34702EWR2 includes under-voltage lockout on VBST (5.5–6.5 V) to prevent unreliable gate drive during startup or fault conditions.

Can the MCZ34702EWR2 be used with modern processors beyond Freescale Power QUICC?

Yes-the MCZ34702EWR2's architecture supports any processor requiring tightly regulated dual-rail supplies with programmable sequencing and supervision, including non-Freescale SoCs. Its 0.800 V reference, 3.0 A buck output, external LDO NMOS drive, and I²C interface provide broad applicability. However, its EN1/EN2 sequencing logic and reset timing were optimized for Power QUICC boot sequences, so validation is required for non-legacy use cases. The MCZ34702EWR2 remains viable where proven reliability, long-lifecycle availability, and field-programmable voltage margining outweigh newer feature sets.