Texas Instruments LM4995TMBD

Overview

LM4995TMBD from Texas Instruments is a 1.3 W Class AB audio power amplifier in a 9-pin DSBGA package, delivering 1.3 W (typ) into 8Ω at 5V with <1% THD+N, featuring BTL output architecture, shutdown control, and no output coupling capacitors - designed for mobile phone loudspeaker drive.

For engineers reviewing the LM4995TMBD datasheet, LM4995TMBD pinout, LM4995TMBD application, or LM4995TMBD equivalent, this page provides verified electrical specs, thermal performance data, gain configuration guidance, click-and-pop suppression behavior, and real-world supply voltage vs. output power trade-offs across 2.4–5.5 V operation.

Technical Context

The LM4995TMBD implements a two-stage bridged-tied-load (BTL) architecture: the first stage offers externally configurable closed-loop gain via Ri/Rf resistors, while the second stage is fixed unity-gain inverting, yielding differential gain AVD = 2×(Rf/Ri). It operates without output coupling capacitors because both VO1 and VO2 are biased at VDD/2.

It integrates low-threshold logic-controlled shutdown (VSDIL ≤1.2 V, VSDIH ≥1.3 V at 3.6 V), ultra-low shutdown current (0.01 µA typ), and internal thermal shutdown protection. PSRR reaches 75 dB at 217 Hz and 73–76 dB at 1 kHz across 3.0–5.0 V supplies.

Key Specifications

Pinout & Package

LM4995TMBD is packaged in a 9-ball, 0.4 mm pitch DSBGA (YFQ0009) with bottom-side thermal pad. Ball layout matches TI's standard DSBGA footprint for automated assembly and thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar audio amplifier applications.

Compared with TPA2012D2RTJR and MAX9718ETA+, the LM4995TMBD offers minimal external component count, lowest shutdown current, and smallest DSBGA footprint - making it optimal for cost-sensitive, space-constrained, single-channel mobile audio where analog gain control suffices.

Availability

LM4995TMBD is available at Aetrix Electronics and suitable for mobile handset loudspeaker drive, PDA audio playback, portable Bluetooth speaker amplification, smart wearable audio output, and industrial HMI audio prompting requiring stable component supply and long-lifecycle support.

Supply support for LM4995TMBD 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM4995TMBD belongs to TI's Boomer® audio amplifier family, engineered specifically for low-voltage, low-component-count, high-fidelity audio output in battery-powered portable communication devices - emphasizing minimal quiescent current, robust click-and-pop suppression, and BTL efficiency.

FAQ

What is the maximum safe supply voltage for LM4995TMBD?

The absolute maximum supply voltage for LM4995TMBD is 6.0 V. Operation above 5.5 V is not recommended unless current-limited to ≤10 mA, as exceeding this may reduce device lifetime. At 5.5–6.0 V, the ESD protection circuits conduct excess current; sustained operation above 6.5 V without current limiting causes permanent damage. The LM4995TMBD is specified for reliable operation from 2.4 V to 5.5 V.

Does LM4995TMBD require an output coupling capacitor?

No, LM4995TMBD does not require an output coupling capacitor. Its BTL architecture biases both VO1 and VO2 outputs at VDD/2, resulting in zero net DC voltage across the speaker load. This eliminates the need for large electrolytic coupling capacitors, reducing BOM cost and PCB area - a key advantage confirmed in the datasheet's "No Output Coupling Capacitors" feature and Figure 1 application circuit.

How is gain configured on LM4995TMBD?

Gain on LM4995TMBD is configured externally using resistor pairs Ri (to GND) and Rf (feedback from VO1 to –IN). The differential closed-loop gain is AVD = 2 × (Rf/Ri). For example, Ri = 20 kΩ and Rf = 30 kΩ yields AVD = 3. The device is unity-gain stable and supports gains ≥1 without compensation. Gain selection directly impacts THD+N and required input signal level, as detailed in the AUDIO POWER AMPLIFIER DESIGN section of the LM4995TMBD datasheet.

What is the thermal resistance (θJA) of LM4995TMBD in its DSBGA package?

The thermal resistance θJA of LM4995TMBD in the 9-ball DSBGA (YFQ0009) package is 96.5°C/W, measured in free-air conditions. This value assumes minimal PCB copper; adding thermal vias and copper pour under the package reduces effective θJA. The datasheet specifies that junction temperature must remain ≤150°C, so at 1.3 W output power and 25°C ambient, minimum required PCB thermal relief is ~1.3 W × 96.5°C/W = 125.5°C rise - confirming necessity of thermal design per Figure 26 layout guidelines.

Can LM4995TMBD drive capacitive loads like piezo speakers?

Yes, LM4995TMBD is explicitly rated to drive capacitive loads, as stated in its "BTL Output Can Drive Capacitive Loads" feature. It remains stable with loads up to 100 nF in parallel with 8Ω, supporting ceramic piezo transducers and MEMS-based audio actuators. Stability is maintained without snubber networks or external compensation, unlike many Class AB amplifiers - a capability validated in TI's application testing and reflected in the "No Snubber Networks Required" specification.