Document
LM4910
www.ti.com
SNAS151G – MAY 2004 – REVISED MARCH 2007
LM4910
Output Capacitor-less Stereo 35mW Headphone Amplifier
Check for Samples: LM4910
FEATURES
1
•2 Eliminates headphone amplifier output coupling capacitors
• Eliminates half-supply bypass capacitor • Advanced pop & click circuitry eliminates
noises during turn-on and turn-off • Ultra-low current shutdown mode • Unity-gain stable • 2.2V - 5.5V operation
• Available in space-saving MSOP, LLP, and SOIC packages
APPLICATIONS
• Mobile Phones • PDAs • Portable electronics devices • Portable MP3 players
DESCRIPTION
The LM4910 is an audio power amplifier primarily designed for headphone applications in portable device applications. It is capable of delivering 35mW of continuous average power to a 32Ω load with less than 1% distortion (THD+N) from a 3.3VDC power supply.
The LM4910 utilizes a new circuit topology that eliminates output coupling capacitors and half-supply bypass capacitors. The LM4910 contains advanced pop & click circuitry which eliminates noises caused by transients that would otherwise occur during turn-on and turn-off.
Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. Since the LM4910 does not require any output coupling capacitors, half-supply bypass capacitors, or bootstrap capacitors, it is ideally suited for low-power portable applications where minimal space and power consumption are primary requirements.
The LM4910 features a low-power consumption shutdown mode, activated by driving the shutdown pin with logic low. Additionally, the LM4910 features an internal thermal shutdown protection mechanism. The LM4910 is also unity-gain stable and can be configured by external gain-setting resistors.
Table 1. Key Specifications
PSRR at f = 217Hz Power Output at VDD = 3.3V, RL = 32Ω, and THD ≤ 1% Shutdown Current
VALUE 65 35 0.1
UNIT dB (typ) mW (typ) µA (typ)
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.
Copyright © 2004–2007, Texas Instruments Incorporated
LM4910
SNAS151G – MAY 2004 – REVISED MARCH 2007
Typical Application
www.ti.com
Figure 1. Typical Audio Amplifier Application Circuit Connection Diagram
Figure 2. MSOP/SO Package Top View
Figure 3. MSOP Marking Top View G - Boomer Family C2 - LM4910MM
Figure 4. SO Marking Top View TT - Die Traceability
Bottom 2 lines - Part Number
2
Submit Documentation Feedback
Product Folder Links: LM4910
Copyright © 2004–2007, Texas Instruments Incorporated
www.ti.com
LM4910
SNAS151G – MAY 2004 – REVISED MARCH 2007
Figure 5. LLP Package Top View
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings (1)
Supply Voltage (2)
6.0V
Storage Temperature
−65°C to +150°C
Input Voltage Power Dissipation (3) ESD Susceptibility Pin 6 (4) ESD Susceptibility (5) ESD Susceptibility (6)
-0.3V to VDD + 0.3V Internally Limited 10kV 2000V 200V
Junction Temperature
150°C
Thermal Resistance
θJC (MSOP) θJA (MSOP) θJC (SOP) θJA (SOP) θJC (LQ) θJA (LQ)
56°C/W 190°C/W
35°C/W 150°C/W
57°C/W 140°C/W
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for
which the device is functional but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which guarantee specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good
indication of device performance.
(2) If the product is in shutdown mode and VDD exceeds 6V (to a max of 8V VDD) then most of the excess current will flow through the ESD protection circuits. If the source impedance limits the current to a max of 10ma then the part will be protected. If the part is enabled
when VDD is above 6V circuit performance will be curtailed or the part may be permanently damaged. (3) The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature,
TA. The maximum allowable power dissipation is PDMAX = (TJMAX - TA)/ θJA or the number given in Absolute Maximum Ratings, whichever is lower. Fo.