Texas Instruments LME49724MR

Overview

LME49724MR from Texas Instruments is a fully-differential audio operational amplifier optimized for ultra-high-fidelity signal amplification. It delivers 0.00003% THD+N at 1 kHz, ±18 V/μs slew rate, and 2.1 nV/√Hz input noise density, driving 600 Ω loads to 52 V_P-P on ±15 V supplies in professional audio line drivers and ADC front-ends.

For engineers reviewing the LME49724MR datasheet, LME49724MR pinout, LME49724MR application, or LME49724MR equivalent, key selection considerations include its differential output architecture, VOCM-controlled common-mode voltage setting, ±2.5 V to ±18 V supply flexibility, and 100 pF capacitive load drive capability without external compensation.

Technical Context

The LME49724MR implements a fully-differential topology with integrated VOCM input for precise control of output DC common-mode level, enabling seamless interfacing with differential-input ADCs and balanced transmission lines. Its high open-loop gain (125 dB) and exceptional PSRR (125 dB typ) and CMRR (102 dB typ) ensure robust rejection of supply and common-mode interference across audio bandwidth.

Designed for unity-gain stability, it maintains phase margin when driving complex loads up to 100 pF, supported by internal compensation and low-output-impedance (0.01 Ω closed-loop) performance. The ENABLE pin provides active-low standby control, reducing quiescent current to <0.3 mA while preserving fast wake-up response.

Key Specifications

Pinout & Package

The LME49724MR is housed in an 8-pin SO PowerPad (DDA0008B) package with exposed thermal pad, requiring PCB copper plane connection to VEE for optimal thermal dissipation (θ_JA = 49.6 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA1632 and AD8138, the LME49724MR uniquely balances ultra-low audio distortion, flexible VOCM control, and integrated ENABLE functionality within a thermally enhanced SO PowerPad package-making it the preferred choice for high-end audio line drivers and ADC interface circuits demanding both fidelity and system integration.

Availability

LME49724MR is available at Aetrix Electronics and suitable for professional audio line drivers, high-fidelity ADC front-ends, and ultra-low-distortion preamplifiers requiring stable component supply across production lifecycles.

Supply support for LME49724MR 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 leadership in high-performance audio signal conditioning.

The LME49724MR belongs to TI's LME audio op-amp family, engineered specifically for ultra-low-distortion, high-slew-rate fully-differential amplification in premium consumer, professional, and studio audio equipment.

FAQ

What is the maximum capacitive load the LME49724MR can drive without instability?

The LME49724MR is specified to drive capacitive loads up to 100 pF while maintaining stability and minimal overshoot (<5%). For loads exceeding 100 pF-such as long cables or high-input-capacitance ADCs-a series resistor (typically 10–47 Ω) must be placed between each output and the load to isolate the capacitance and preserve phase margin. This is confirmed in the "DRIVING A CAPACITIVE LOAD" section of the SNAS438A datasheet.

How does the VOCM pin function in the LME49724MR, and what voltage range is acceptable?

The VOCM pin on the LME49724MR sets the DC common-mode voltage of both differential outputs. It accepts an externally applied voltage between VEE + 1.5 V and VCC − 1.5 V, with 50 kΩ input impedance. When left unconnected, an internal resistor divider sets VOCM to the midpoint of VCC and VEE. For optimal PSRR, VOCM should be driven by a low-noise, low-impedance source-such as an ADC reference or buffered DAC-and bypassed with a 0.1–1 μF capacitor to ground.

Can the LME49724MR operate from a single supply, and what are the constraints?

Yes, the LME49724MR supports single-supply operation from 5 V to 36 V total supply (e.g., 0 V to +15 V). In this mode, VEE is connected to ground, VCC to the positive rail, and the VOCM pin must be used to set the output common-mode voltage (typically to VCC/2). The datasheet specifies that the common-mode input voltage range remains functional, and the ENABLE pin logic shifts: tie to ground for standby, to VCC for active operation. Minimum supply is 5 V-not ±2.5 V-as the absolute minimum total voltage.

What is the thermal design requirement for the LME49724MR's exposed PowerPad?

For reliable operation at full output current, the LME49724MR's exposed thermal pad (DDA0008B package) must be soldered to a PCB copper plane connected to VEE. Thermal vias (≥6× 0.3 mm diameter) should connect the pad to inner or bottom-layer ground planes. Solder mask openings are required on the top layer under the pad, but vias on the bottom layer should be covered to prevent solder wicking. This configuration achieves θ_JA = 49.6 °C/W and prevents junction temperatures from exceeding 150 °C under worst-case ±15 V/±80 mA conditions.

How does the ENABLE pin affect quiescent current and wake-up time in the LME49724MR?

When the ENABLE pin is pulled below VEE + 1.75 V (e.g., tied to VEE), the LME49724MR enters standby mode with total quiescent current reduced to <0.3 mA (typ). When raised above VEE + 2.35 V, full operation resumes with typical ICCQ of 10–15 mA. Wake-up time is not explicitly characterized in the datasheet, but measurements show sub-microsecond recovery due to the absence of deep sleep circuitry-the device behaves as a fast analog switch, making it suitable for real-time mute/unmute functions in live audio systems using the LME49724MR.