Texas Instruments SM72442/NOPB

Overview

SM72442/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 PWM gate drive outputs (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 and delivers MPPT convergence in ≤10 ms under dynamic irradiance. Designed for solar power optimizers and DC-DC converters up to 99.5% efficiency.

For engineers reviewing the SM72442/NOPB datasheet, SM72442/NOPB pinout, SM72442/NOPB application, or SM72442/NOPB equivalent, this page provides verified technical context on its MPPT algorithm behavior, analog input configuration via A0/A2/A4/A6, I²C register mapping (reg0–reg5), 220 kHz PWM switching frequency, and TSSOP-28 package layout - all critical for photovoltaic system integration and firmware co-design.

Technical Context

The SM72442/NOPB implements a digital MPPT controller with proprietary Panel Mode logic that enables direct connection of PV panels to power optimizer outputs. Its 8-channel 12-bit ADC monitors AVIN, AIIN, AVOUT, AIOUT, and four configurable analog inputs (A0, A2, A4, A6) for voltage/current sensing and system parameter setting.

It generates four independent PWM signals (LIA/HIA/LIB/HIB) with 220 kHz switching frequency, dead-time control (tdon/tdoff registers), and soft-start ramp (250 ms). I²C communication (100 kHz only) supports full register read/write access-including reg0 (ADC-configurable thresholds), reg1 (real-time V/I measurements), and reg3 (override modes, open-loop duty control).

Key Specifications

Pinout & Package

TSSOP-28 package (Package Code: PW0028A), thermally enhanced, RoHS-compliant, MSL Level-3 (260°C peak reflow, 168-hour floor life).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT8490IMSE#PBF and MAX17690ATJ+T, the SM72442/NOPB uniquely combines embedded MPPT logic, Panel Mode for direct PV interface, and I²C-configurable thresholds - eliminating need for external MCU coordination in solar optimizer designs.

Availability

SM72442/NOPB is available at Aetrix Electronics and suitable for photovoltaic power optimizers, solar microinverters, utility-scale tracker interfaces, and off-grid charge controllers requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for SM72442/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 experience in renewable energy IC design.

The SM72442/NOPB belongs to TI's photovoltaic controller product line, engineered specifically for high-efficiency, digitally configurable MPPT in module-level power electronics - targeting solar optimizer, microinverter, and smart PV junction box applications.

FAQ

What is the primary function of the SM72442/NOPB in a solar power system?

The SM72442/NOPB serves as a programmable maximum power point tracking (MPPT) controller for photovoltaic solar panels. It generates four PWM signals for a single-inductor four-switch buck-boost converter, integrates an 8-channel 12-bit ADC for real-time voltage/current sensing, and implements proprietary Panel Mode logic to enable direct PV panel connection. The SM72442/NOPB delivers MPPT convergence in ≤10 ms and supports I²C-based configuration of thresholds and operating modes - making it ideal for solar power optimizers and microinverters.

How does the Panel Mode feature work on the SM72442/NOPB?

Panel Mode on the SM72442/NOPB is activated either by pulling the PM pin low or by meeting configured conditions (e.g., time in buck-boost mode or power variation threshold set via ADC channel A2). When active, the SM72442/NOPB outputs a 400 kHz square wave on PM_OUT to drive external FETs for panel-level diagnostics or bypass. This allows direct PV panel interfacing without intermediate conversion stages. The SM72442/NOPB remains in Panel Mode for a user-defined duration (configurable via A6), after which it resumes MPPT operation unless retriggered.

Can the SM72442/NOPB be configured without external resistors?

Yes - the SM72442/NOPB supports dual configuration methods. Analog configuration uses resistor dividers on A0, A2, A4, and A6 to set output voltage, current, Panel Mode timing, and slew rate. Alternatively, the I²C interface allows full register-level control: reg3[46] enables software override of vout_max and iout_max thresholds, while reg0 stores ADC-derived values and reg3 provides direct duty-cycle and dead-time programming. This makes the SM72442/NOPB adaptable to both hardware-defined and firmware-updatable designs.

What are the absolute maximum ratings for the SM72442/NOPB analog and digital supplies?

The SM72442/NOPB has separate analog (VDDA/VSSA) and digital (VDDD/VSSD) supply domains. Absolute maximum analog supply voltage is −0.3 V to +6.0 V; digital supply must remain within −0.3 V to VDDA + 0.3 V (max 6.0 V). Recommended operating range for both is +4.75 V to +5.25 V. Exceeding these limits risks permanent damage. Each supply requires dedicated bypassing: VDDA needs 1 µF + 0.1 µF ceramic capacitors to VSSA, while VDDD requires 0.1 µF to VSSD. These constraints are critical for reliable SM72442/NOPB operation in solar applications with noisy DC bus environments.

Does the SM72442/NOPB support standard I²C speeds like 400 kHz?

No - the SM72442/NOPB only supports I²C communication at 100 kHz (standard mode), as explicitly stated in the datasheet. It does not operate at 400 kHz (fast mode) or higher speeds. The SCL and SDA pins are open-drain and require external pull-up resistors (2–10 kΩ typical). Noise immunity is limited: digital noise >400 mV_p-p or undershoot <500 mV below GND may cause I²C NACK errors. Therefore, robust PCB layout - including short traces, right-angle crossings with noisy lines, and optional series termination - is essential for reliable SM72442/NOPB I²C communication.