Texas Instruments SM72442E/NOPB

Overview

SM72442E/NOPB from Texas Instruments is a programmable maximum power point tracking (MPPT) controller for photovoltaic solar panels, integrating an 8-channel 12-bit ADC, I²C interface, and four independent PWM gate drivers (LIA, HIA, LIB, HIB) for single-inductor four-switch buck-boost converter control. It supports Panel Mode operation with 400 kHz square-wave PM_OUT output, VOUT overvoltage protection, and over-current protection. Designed for solar power optimizers and DC-DC converters in renewable energy systems.

For engineers reviewing the SM72442E/NOPB datasheet, SM72442E/NOPB pinout, SM72442E/NOPB application, or SM72442E/NOPB equivalent, key selection considerations include its 220 kHz PWM switching frequency, 4.75–5.25 V dual supply range (VDDA/VDDD), -40°C to +105°C operating temperature, TSSOP-28 package, and configurable analog input thresholds via A0/A2/A4/A6 pins for VOUT_MAX, Panel Mode entry, IOUT_MAX, and slew rate.

Technical Context

The SM72442E/NOPB implements a digital MPPT algorithm that converges to the photovoltaic panel's maximum power point within 0.01 s, enabling rapid response to irradiance changes. Its architecture integrates ADC-based real-time sensing of AVIN, AIIN, AVOUT, and AIOUT with closed-loop duty-cycle control across four PWM outputs.

Panel Mode is triggered either by pulling the PM pin low or via time- and power-variation thresholds set on ADC Channel 2 (A2), while output voltage slew rate, soft-start behavior, and boost ratio are configured via ADC Channel 6 (A6). All operational parameters-including VOUT_MAX (A0) and IOUT_MAX (A4)-are resistor-divider programmable without firmware.

Key Specifications

Pinout & Package

TSSOP-28 package (Package Number PW0028A), 4.4 mm × 9.7 mm body, 0.65 mm pitch, exposed thermal pad optional per TI design guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar MPPT controller applications.

Compared with LT8710 and UCC28950, the SM72442E/NOPB uniquely combines on-chip MPPT computation, 12-bit ADC sensing, Panel Mode hardware bypass, and resistor-programmable limits - reducing BOM, layout complexity, and firmware dependency in module-integrated PV applications.

Availability

SM72442E/NOPB is available at Aetrix Electronics and suitable for photovoltaic power optimizers, solar microinverter DC-DC stages, and renewable energy test equipment requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for SM72442E/NOPB 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in precision analog ICs and energy-efficient power solutions.

The SM72442E/NOPB belongs to TI's renewable-energy-grade MPPT controller product line, designed specifically for high-reliability, module-level solar power conditioning with minimal external components and field-programmable operation.

FAQ

What is the primary function of the SM72442E/NOPB in a solar power system?

The SM72442E/NOPB serves as a fully integrated maximum power point tracking (MPPT) controller for photovoltaic solar panels. It directly manages a four-switch buck-boost converter using internal PWM generation, real-time ADC-based voltage/current sensing, and hardware-accelerated MPPT computation. The SM72442E/NOPB enables per-module optimization, supports Panel Mode for thermal or safety bypass, and operates without external microcontroller intervention - making it ideal for power optimizers and microinverter front-end stages.

How does the SM72442E/NOPB implement Panel Mode, and what triggers it?

Panel Mode in the SM72442E/NOPB is activated either by pulling the PM pin low or automatically based on conditions programmed via ADC Channel 2 (A2), such as time spent in 1:1 buck-boost mode or output power variation thresholds. When active, the SM72442E/NOPB disables normal PWM outputs and drives PM_OUT with a 400 kHz, 5 V square wave - intended to drive an external transformer-coupled FET for direct panel bypass. This feature supports rapid shutdown compliance and thermal derating without software overhead.

Can the SM72442E/NOPB operate without I²C communication, and what functionality remains available?

Yes, the SM72442E/NOPB operates fully autonomously without I²C. All core functions - MPPT, PWM generation, overvoltage/overcurrent protection, Panel Mode, soft-start, and slew rate control - are configured via external resistor dividers on A0, A2, A4, and A6. I²C is optional and provides supplemental capabilities: real-time register reads (Vin, Vout, Iin, Iout), offset calibration (Reg4), and override of analog-configured limits (Reg3). The SM72442E/NOPB retains full solar controller functionality even with I²C unconnected.

What are the supply voltage requirements and decoupling recommendations for the SM72442E/NOPB?

The SM72442E/NOPB requires two separate 4.75–5.25 V supplies: VDDA (analog) and VDDD (digital). VDDA must be bypassed to VSSA with both a 1 µF and 0.1 µF monolithic ceramic capacitor; VDDD requires a 0.1 µF capacitor to VSSD. These decoupling networks suppress noise coupling between analog sensing and digital logic domains - critical for 12-bit ADC accuracy and stable PWM timing. Shared 5 V rails are permitted only if adequately isolated with ferrite beads and local capacitance.

How does the SM72442E/NOPB handle overvoltage and overcurrent protection events?

The SM72442E/NOPB implements hardware-based overvoltage protection (OVP) on AVOUT and overcurrent protection (OCP) via comparison of AIOUT against the threshold set on A4. Upon violation, the device immediately disables all four PWM outputs (LIA/HIA/LIB/HIB) and enters a latched fault state until reset via the RST pin or power cycle. No software or I²C command is needed - protection responds within microseconds, safeguarding external MOSFETs and load circuits without delay or dependency on host processor latency. The SM72442E/NOPB maintains this behavior across its full -40°C to +105°C operating range.