Texas Instruments LM3280TLX-275/NOPB

Overview

LM3280TLX-275/NOPB from Texas Instruments is an integrated RF power management IC combining a synchronous step-down DC-DC converter with three 2.85V LDOs and an internal bypass FET. It delivers adjustable output (0.8–3.6V) via analog VCON control (VOUT = 3 × VCON), supports 300mA PWM / 500mA bypass loads, and operates from a single Li-ion cell (2.7–5.5V). It is engineered for dynamic efficiency optimization of linear RF power amplifiers in cellular handsets.

For engineers reviewing the LM3280TLX-275/NOPB datasheet, LM3280TLX-275/NOPB pinout, LM3280TLX-275/NOPB application, or LM3280TLX-275/NOPB equivalent, key selection criteria include VCON-controlled voltage scaling, forced/automatic bypass mode behavior, per-output enable logic sequencing (ENBUCK dependency), thermal shutdown threshold (150°C), and DSBGA-16 package layout constraints for high-density RF PCBs.

Technical Context

The LM3280TLX-275/NOPB implements a current-mode synchronous buck architecture with 2MHz fixed-frequency PWM, enabling low-noise operation near sensitive IF/data paths. Its VCON analog input directly sets output voltage without external resistors, while auto-bypass detection compares SVIN–VOUT against hysteresis thresholds (VBYPASS− = 160–320mV, VBYPASS+ = 350–540mV) to transition between PWM and low-dropout FET conduction.

All three LDOs share identical 2.85V ±2% output accuracy, 70–115mV dropout at 20mA, and independent digital enables (ENLDO1/2/3) that require ENBUCK to be asserted first. The buck converter integrates PFET/NFET switches (RDSON(P) = 320–450mΩ, RDSON(N) = 310–450mΩ) and a dedicated BYPOUT terminal for direct connection to the output capacitor.

Key Specifications

Pinout & Package

The LM3280TLX-275/NOPB is housed in a 16-pin lead-free DSBGA package (Package Number YZR0016QQA) with 0.5mm bump pitch, optimized for space-constrained mobile RF designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF power management applications.

Compared with TPS62740DRYR and TPS6286518ARQYR, the LM3280TLX-275/NOPB uniquely integrates VCON-based analog voltage scaling, three dedicated LDOs with sequenced enables, and automatic bypass mode-making it the only solution that eliminates external DACs, discrete LDOs, and bypass switch controllers in compact RF handset designs.

Availability

LM3280TLX-275/NOPB is available at Aetrix Electronics and suitable for cellular handset design, multi-band RF front-end development, and battery-efficient transceiver integration requiring stable component supply and long-term lifecycle support.

Supply support for LM3280TLX-275/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 and embedded processing technologies, with decades of expertise in power management ICs for mobile and RF applications.

The LM3280TLX-275/NOPB belongs to TI's RF power management product line, designed specifically to optimize efficiency and board space in space-constrained, battery-powered cellular devices using linear RF power amplifiers.

FAQ

What is the minimum input voltage required to enable the LM3280TLX-275/NOPB buck converter?

The LM3280TLX-275/NOPB requires SVIN and PVIN to exceed 2.7V before ENBUCK can be asserted to initiate operation. The device lacks internal UVLO, so system controller must hold ENBUCK low until input stabilizes above this threshold. Below 2.7V, the buck remains disabled even if ENBUCK is high, preventing unstable regulation.

How does the VCON pin control output voltage in the LM3280TLX-275/NOPB?

The LM3280TLX-275/NOPB uses a fixed 3× gain from VCON to VOUT: VOUT = 3 × VCON. With VCON ranging from 0.267V to 1.200V, this yields 0.801V to 3.600V output. The relationship holds across temperature and load, enabling precise analog programming without external resistive dividers or digital interfaces.

Can the three LDOs in the LM3280TLX-275/NOPB operate independently?

No - the LM3280TLX-275/NOPB LDOs require ENBUCK to be high before any ENLDOx pin can activate its respective output. If ENBUCK goes low, all LDOs disable immediately. However, once ENBUCK is active, ENLDO1, ENLDO2, and ENLDO3 can be toggled individually to power specific RF bands without affecting others.

What triggers automatic bypass mode in the LM3280TLX-275/NOPB?

Automatic bypass mode engages when SVIN – VOUT falls below VBYPASS− (160–320mV) for longer than TBYP (10–20µs). The device exits bypass when SVIN – VOUT exceeds VBYPASS+ (350–540mV) for the same duration. This hysteresis prevents oscillation near the transition point and sustains PA operation during battery sag.

Is the LM3280TLX-275/NOPB compatible with standard DSBGA reflow profiles?

Yes - the LM3280TLX-275/NOPB uses a lead-free DSBGA package qualified for IPC/JEDEC J-STD-020D reflow profiles. Peak temperature must not exceed 260°C for ≤10 seconds. Due to its fine-pitch (0.5mm) bumps, stencil design, solder paste volume, and placement accuracy must meet Class 3 assembly standards to ensure reliable interconnects.