LM49151TL/NOPB

TI Confidential - NDA Restrictions LM49151 www.ti.com SNAS482F – MARCH 2009 – REVISED MARCH 2013 LM49151 Boomer™ Audio Power Amplifier Series Mono Class D Audio Subsystem with Earpiece Driver, Ground Referenced Headphone Amplifiers, Speaker Protection and No Clip with Clip Control Check for Samples: LM49151 FEATURES 1 • • 23 • • • • • • • • 2 E S Class D Amplifier Ground Referenced Outputs — Eliminates Output Coupling Capacitors I2C Programmable No Clip Function with Clip Control Voltage Limiter Speaker Protection I2C Volume and Mode Control Ear Piece Amplifier Advanced Click-and-Pop Suppression Low Supply Current Micro-Power Shutdown 20-bump DSBGA Package APPLICATIONS • • • • • Mobile Phones PDAs Notebook PCs Portable Electronics Devices MP3 Players KEY SPECIFICATIONS • • • Output Power at VDD = 3.3V THD+N ≤ 1% – LS Mode, RL = 8Ω 520mW (Typ) – HP Mode, RL = 32Ω 40mW (Typ) Output Power at VDD = 5V THD+N ≤ 1% – LS Mode, RL = 8Ω 1.25W (Typ) – HP Mode, RL = 32Ω 42mW (Typ) Output Offset – LS Mode 15 6mV (Typ) – HP Mode 15 2mV (Typ) DESCRIPTION The LM49151 is a fully integrated audio subsystem designed for portable handheld applications such as cellular phones. The LM49151 combines a 1.25W mono E2S class D amplifier, 125mW Class AB earpiece driver, 42mW/channel stereo ground referenced headphone drivers, volume control, input mixer/multiplexer, and speaker protection into a single device. The LM49151 class D speaker amplifier features Texas Instruments' unique Automatic Level Control (ALC) that provides both a I2C programmable no-clip feature with Clip Controls and speaker protection. The E2S (Enhanced Emission Suppression) class D amplifier features a patented, ultra low EMI PWM architecture that significantly reduces RF emissions while preserving audio quality and efficiency while delivering 1.25W into an 8Ω load with VDD 5.6VPP 0.6 4.8VPP 4VPP 0.4 0.2 ALC max attenuation 0 0 1 2 3 4 5 7 6 INPUT VOLTAGE (VPP) Figure 57. Voltage Limiter Function VDD = 3.3V, RL = 8Ω+30µH fIN = 1kHz, LS_GAIN = 0 1 10 1.0 100m THD+N (%) OUTPUT POWER (W) No Clip Disabled No Clip Enabled 10m 1m 0.1 0.01 1 2 4 6 8 INPUT VOLTAGE (VPP) Figure 58. No Clip Function VDD = 3.3V, RL = 8Ω+30µH fIN = 1kHz, LS_GAIN = 0 Blue, Green = Output Power vs Input Voltage Gray, Yellow = THD+N vs Input Voltage When No Clip is enabled, class D speaker output reduces when it’s about to enter clipping region and power stay constant as long as VIN is less than VDD for 0 dB volume gain (see Figure 58). For example, in the case of VDD = 3.3V, there is a 6 dB of headroom for the change in input. Please see the ALC typical performance curves for additional plots relating to different supply voltages and LS_GAIN settings for specific application parameters. ATTACK TIME Attack time (tATK) is the time it takes for the gain to be reduced by 6dB (LS_GAIN=0) once the audio signal exceeds the ALC threshold. Fast attack times allow the ALC to react quickly and prevent transients such as symbol crashes from being distorted. However, fast attack times can lead to volume pumping, where the gain reduction and release becomes noticeable, as the ALC cycles quickly. Slower attack times cause the ALC to ignore the fast transients, and instead act upon longer, louder passages. Selecting an attack time that is too slow can lead to increased distortion in the case of the No Clip function, and possible output overload conditions in the case of the Voltage limiter. The attack time is set by a combination of the value of CSET and the attack time coefficient as given by Equation 2: tATK = 20kΩCSET / αATK (s) (2) Where αATK is the attack time coefficient (Table 10) set by bits B4:B3 in the Voltage Limit Control Register (see Table 7). The attack time coefficient allows the user to set a nominal attack time. The internal 20kΩ resistor is subject to temperature change, and it has tolerance between -11% to +20%. 28 Submit Documentation Feedback Copyright © 2009–2013, Texas Instruments Incorporated Product Folder Links: LM49151 TI Confidential - NDA Restrictions LM49151 www.ti.com SNAS482F – MARCH 2009 – REVISED MARCH 2013 Table 10. Attack Time Coefficient B5 B4 αATK 0 0 2.667 0 1 2 1 0 1.333 1 1 1 RELEASE TIME Release time (tRL) is the time it takes for the gain to return from 6dB (LS_GAIN=0) to its normal level once the audio signal returns below the ALC threshold. A fast release time allows the ALC to react quickly to transients, preserving the original dynamics of the audio source. However, similar to a fast attack time, a fast release time contributes to volume pumping. A slow release time reduces the effect of volume pumping. The release time is set by a combination of the value of CSET and release time coefficient as given by Equation 3: tRL = 20MΩCSET / αRL (s) (3) where αRL is the release time coefficient (Table 11) set by bits B4:B3 in the No Clip Control Register. The release time coefficient allows the user to set a nominal release time. The internal 20MΩ is subject to temperature change, and it has tolerance between -11% to +20%. Table 11. Release Time Coefficient αRL B5 B4 0 0 2 0 1 2.5 1 0 3 1 1 5 PROPER SELECTION OF EXTERNAL COMPONENTS ALC Timing (CSET) Capacitor Selection The recommended range value of CSET is between .01μF to 1μF. Lowering the value below .01μF can increase the attack time but LM49151 ALC ability to regulate its output can be disrupted and approaches the hard limiter circuit. This in turn increases the THD+N and audio quality will be severely affected. Charge Pump Capacitor Selection Use low ESR ceramic capacitors (less than 100mΩ) for optimum performance. Charge Pump Flying Capacitor (C1) The flying capacitor (C1), see Figure 1, affects the load regulation and output impedance of the charge pump. A C1 value that is too low results in a loss of current drive, leading to a loss of amplifier headroom. A higher valued C1 improves load regulation and lowers charge pump output impedance to an extent. Above 2.2µF, the RDS(ON) of the charge pump switches and the ESR of C1 and CPVSS dominate the output impedance. A lower value capacitor can be used in systems with low maximum output power requirements. Charge Pump Hold Capacitor (CPVSS) The value and ESR of the hold capacitor (CPVSS) directly affects the ripple on CPVSS. (see Figure 1) Increasing the value of CPVSS reduces output ripple. Decreasing the ESR of CPVSS reduces both output ripple and charge pump output impedance. A lower value capacitor can be used in systems with low maximum output power requirements. Submit Documentation Feedback Copyright © 2009–2013, Texas Instruments Incorporated Product Folder Links: LM49151 29 TI Confidential - NDA Restrictions LM49151 SNAS482F – MARCH 2009 – REVISED MARCH 2013 www.ti.com Input Capacitor Selection Input capacitors may be required for some applications, or when the audio source is single-ended. Input capacitors block the DC component of the audio signal, eliminating any conflict between the DC component of the audio source and the bias voltage of the LM49151. The input capacitors create a high-pass filter with the input resistors RIN. The -3dB point of the high-pass filter is found using Equation 4 below. f = 1/ 2πRINCIN (Hz) (4) Where the value of RIN is given in the Electrical Characteristics Table. High-pass filtering the audio signal helps protect the speakers. When the LM49151 is using a single-ended source, power supply noise on the ground is seen as an input signal. Setting the high-pass filter point above the power supply noise frequencies, 217Hz in a GSM phone, for example, filters out the noise such that it is not amplified and heard on the output. Capacitors with a tolerance of 10% or better are recommended for impedance matching and improved CMRR and PSRR. Revision History 30 Rev Date Description 0.01 02/12/09 Initial PDF. 0.02 02/23/09 Text edits. 0.03 03/05/09 Text edits. 0.04 03/24/09 Text edits and added more graphs. 0.05 03/25/09 Cosmetic fixes. 0.06 03/26/09 Released 1–4 pages. 0.07 04/01/09 Text edits. 0.08 04/09/09 Text edits and edited the Ordering Information table. 0.09 04/15/09 Text edits. 0.10 05/19/09 Text edits. 0.11 09/04/09 Text edits. 0.12 09/18/09 Text edits. 0.13 10/29/09 Fixed typos on Table 4. 0.14 08/20/12 Full D/S to be released. F 03/21/2013 Changed layout of National Data Sheet to TI format Submit Documentation Feedback Copyright © 2009–2013, Texas Instruments Incorporated Product Folder Links: LM49151 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LM49151TL/NOPB ACTIVE DSBGA YZR 20 250 RoHS & Green SNAGCU Level-1-260C-UNLIM -40 to 85 GL7 LM49151TLX/NOPB ACTIVE DSBGA YZR 20 3000 RoHS & Green SNAGCU Level-1-260C-UNLIM -40 to 85 GL7 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of