Texas Instruments TPS79650DRBT

Overview

TPS79650DRBT from Texas Instruments is a fixed-output 5.0 V, 1 A ultra-low-noise, high-PSRR low-dropout linear regulator in an 8-pin VSON (DRB) package. It delivers 220 mV typical dropout at 1 A, 78 µV_RMS output noise (new chip), and stable operation with only a 1 µF ceramic output capacitor. It serves as the primary power supply for noise-sensitive RF analog circuitry in TV and home entertainment systems.

For engineers reviewing the TPS79650DRBT datasheet, TPS79650DRBT pinout, TPS79650DRBT application, or TPS79650DRBT equivalent, this page provides verified specifications, validated pin functions, confirmed thermal and transient performance data, and real-world implementation guidance for RF-grade LDO selection.

Technical Context

The TPS79650DRBT employs a high-gain, high-bandwidth error amplifier to achieve >74 dB PSRR at 100 Hz and 42 dB at 100 kHz under 1 A load, enabling robust rejection of switching noise from upstream DC/DC converters. Its internal bandgap reference (1.225 V) feeds a precision feedback loop that maintains ±2.0% output accuracy across –40°C to +125°C junction temperature.

It integrates undervoltage lockout (UVLO) with 1.28 V rising threshold and 130 mV hysteresis, active discharge via internal pulldown MOSFET (RPULLDOWN = 100 Ω), and hybrid brick-wall/foldback current limiting (ICL = 1.04–1.65 A, ISC = 550 mA) - all optimized for fast transient response (<100 µs load step recovery) and safe operation in thermally constrained layouts.

Key Specifications

Pinout & Package

TPS79650DRBT is housed in an 8-pin VSON (DRB) package, 3 mm × 3 mm, with exposed thermal pad on bottom for enhanced heat dissipation. Pin 1 is marked by a dot; top view orientation follows Figure 4-5 (new chip).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS79650DRBT, TPS7A4700RGWR offers superior noise performance but demands more PCB area and lacks integrated enable/discharge, while LP5907MFX-5.0/NOPB achieves ultra-low noise at the cost of current capability and control flexibility - making TPS79650DRBT the optimal balance of noise, current, integration, and package size for mainstream RF/analog LDO use cases.

Availability

TPS79650DRBT is available at Aetrix Electronics and suitable for TV applications, home theater and entertainment systems, connected peripherals and printers, and building automation requiring stable component supply and long-term industrial availability.

Supply support for TPS79650DRBT 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 precision power management ICs.

The TPS796 family was designed specifically for RF and high-fidelity analog applications demanding ultra-low noise, high PSRR, and fast transient response - targeting TV, set-top boxes, and professional audio equipment where power integrity directly impacts signal fidelity.

FAQ

What is the maximum input voltage rating for the TPS79650DRBT?

The TPS79650DRBT has an absolute maximum input voltage of 6.5 V for the new chip revision. Operation above 6.0 V violates recommended conditions and risks permanent damage. For reliable 5.0 V output, VIN should be maintained between 2.7 V and 6.0 V per the datasheet's Recommended Operating Conditions table.

Does the TPS79650DRBT require an external noise-reduction capacitor?

The TPS79650DRBT includes an NR (noise-reduction) pin that accepts an external capacitor (0–100 nF) to further reduce output noise and improve PSRR. While not mandatory - the device is fully functional with only C_OUT - adding a 10 nF capacitor to NR lowers RMS noise from 78 µV to ~40 µV and boosts PSRR by up to 10 dB at 10 kHz.

Is the TPS79650DRBT pin-compatible with other TPS796 variants in the DRB package?

Yes - all TPS796 DRB-package variants (e.g., TPS79633DRBT, TPS79628DRBT) share identical pinout, footprint, and thermal pad layout per Figure 4-4 and Figure 4-5. The FB/NR pin configuration differs between legacy and new chips, but TPS79650DRBT uses the new-chip pinout (Figure 4-5), with Pin 5 designated FB/NC and Pin 8 as NR.

What thermal performance can be expected from the TPS79650DRBT in a standard 2-layer PCB layout?

In a standard 2-layer PCB with 1-in² 2-oz copper pour connected to the exposed thermal pad, the TPS79650DRBT achieves R_θJA ≈ 47.8°C/W. At 1 A output with 5.22 V input (220 mV dropout), power dissipation is 220 mW - resulting in ~10.5°C junction-to-ambient rise above ambient, well within the 125°C max operating junction temperature.

How does the active discharge feature of the TPS79650DRBT function during shutdown?

When the EN pin is driven low, the TPS79650DRBT activates an internal 100 Ω pulldown MOSFET between OUT and GND, discharging the output capacitor rapidly. This prevents residual voltage from interfering with downstream logic reset timing. Discharge time depends on C_OUT; for a 10 µF capacitor, V_OUT falls from 5 V to <1 V in ~500 µs.