Filterless 2.2W Stereo Class D Audio Subsystem

LM49270 Filterless 2.2W Stereo Class D Audio Subsystem with OCL Headphone Amplifier, 3D Enhancement, and Headphone Sense December 2006 LM49270  Filterless 2.2W Stereo Class D Audio Subsystem with OCL Headphone Amplifier, 3D Enhancement, and Headphone Sense General Description The LM49270 is a fully integrated audio subsystem designed for stereo multimedia applications. The LM49270 combines a 2.2W stereo Class D amplifier with a 155mW stereo headphone amplifier, volume control, headphone sense, and National’s unique 3D sound enhancement into a single device. The LM49270 uses flexible I2C control interface for multiple application requirements. The filterless stereo class D amplifiers delivers 2.2W/channel into a 4Ω load with less than 10% THD+N with a 5V supply. The headphone amplifier features National’s Output Capacitor-less (OCL) architecture that eliminates the output coupling capacitors required by traditional headphone amplifiers. The IC features a headphone sense input (HPS) that automatically detects the presence of a headphone and configures the device accordingly. The LM49270 can automatically switch from OCL headphone output to a line driver output. If the VOC pin is pulled to GND, the VOC amplifier is disabled and the VOC pin is internally set to GND. This feature allows the LM49270 to be used as a line driver in OCL mode without a GND conflict on the headphone jack sleeve. Additionally, the headphone amplifier can be configured as capacitively coupled (CC). The LM49270 features a 32 step volume control for the headphone and stereo outputs. The device mode select and volume are controlled through an I2C compatible interface. Output short circuit and thermal shutdown protection prevent the device from being damaged during fault conditions. Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. The LM49270 is available in a space saving 28-pin, 5x5mm LLP package. Key Specifications ■ Stereo Class D Amplifier Efficiency:  VDD = 3.3V, 450mW/Ch into 8Ω  VDD = 5V, 1W/Ch into 8Ω ■ Quiescent Power Supply Current, VDD = 3.3V  Speaker Mode  Headphone Mode (OCL) ■ Power Output/Channel, VDD = 5V  Class D Speaker amplifier: RL = 4Ω, THD+N = ≤ 10% RL = 8Ω, THD+N = ≤ 1% 2.2W 1.06W 5.5mA 4mA 84% 84%  Headphone amplifier: RL = 16Ω, THD+N = ≤ 1% RL = 32Ω, THD+N = ≤ 1% 155mW 90mW 0.02μA ■ Shutdown current Features ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Stereo filterless Class D amplifier Selectable OCL/CC headphone amplifier Headphone sense ability National’s 3D Enhancement RF suppression I2C control interface 32-step digital volume control 6 Operating Modes Output short circuit protection and thermal shutdown protection Minimum external components Click and Pop suppression Micro-power shutdown Independent speaker and headphone volume controls Available in space-saving 28 pin LLP package Applications ■ ■ ■ ■ Portable DVD players Smart phones PDAs Laptops Boomer® is a registered trademark of National Semiconductor Corporation. © 2007 National Semiconductor Corporation 202129 www.national.com LM49270 Typical Application 20212994 FIGURE 1. Typical Audio Amplifier Application Circuit www.national.com 2 LM49270 Connection Diagrams SQ Package 5mm x 5mm x 0.8mm 20212990 Top View Order Number LM49270SQ See NS Package Number NSQAQ028 SQ Markings 20212901 Top View NS = National Logo U = Fab Code Z = Assembly Plant XY = 2 Digit date code TT = Die Traceability 49270SQ = LM49270SQ 3 www.national.com LM49270 TABLE 1. Pin Descriptions PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 NAME RHP VOC LHP HPVDD R3DIN L3DIN BYPASS LIN RIN GND NC LSVDD RLS+ RLSNC NC I2CVDD LSGND VDD ADR NC LLSLLS+ LSVDD SDA SCL HPS GND Right channel headphone output VDD/2 buffer output Left channel headphone output Headphone supply input Right channel 3D input Left channel 3D input Bias bypass Left channel input Right channel input Analog ground No connect Speaker supply voltage input Right channel non-inverting speaker output Right channel inverting speaker output No connect No connect I2C supply voltage input Speaker ground Power supply Address No connect Left channel inverting speaker output Left channel non-inverting speaker output Speaker supply voltage input Serial data input Serial clock input Headphone sense input Headphone ground DESCRIPTION www.national.com 4 LM49270 Absolute Maximum Ratings (Notes 1, 2) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (Note 1) Storage Temperature Input Voltage Power Dissipation (Note 3) ESD Susceptibility(Note 4) ESD Susceptibility (Note 5) Junction Temperature (TJMAX) 6.0V −65°C to +150°C –0.3V to VDD +0.3V Internally Limited 2000V 200V 150°C Thermal Resistance  θJA 35.1°C/W (Notes 1, 2) −40°C ≤ TA ≤ 85°C 2.4V ≤ VDD ≤ 5.5V 2.4V ≤ I2CVDD ≤ 5.5V Operating Ratings Temperature Range TMIN ≤ TA ≤ TMAX Supply Voltage (VDD, LSVDD, HPVDD) I2C Voltage (I2CVDD) Electrical Characteristics VDD = 3.3V (Notes 1, 2) The following specifications apply for Headphone: AV = 0dB, RL(HP) = 32Ω; for Loudspeakers: AV = 6dB, RL(SP) = 15μH + 8Ω + 15μH , f = 1kHz, unless otherwise specified. Limits apply for TA = 25°C. LM49270 Symbol Parameter Conditions VIN = 0, RL = No Load, Both channels active Speaker ON, HP OFF Speaker OFF, CC HP ON Speaker OFF, OCL HP ON Headphone Speaker Speaker Mode, f = 1kHz THD+N = 1% RL = 4Ω RL = 8Ω THD+N = 10% RL = 4Ω RL = 8Ω CC Headphone Mode, f = 1kHz THD+N = 1% RL = 16Ω POUT Output Power RL = 32Ω THD+N = 10% RL = 16Ω RL = 32Ω OCL Headphone Mode, f = 1kHz THD+N = 1% RL = 16Ω RL = 32Ω THD+N = 10% RL = 16Ω RL = 32Ω 60 36 73 55 mW mW (min) mW mW 60 36 74 55 mW mW (min) mW mW 700 450 870 560 mW mW (min) mW mW Typical (Note 6) Limit (Notes 7, 8) Units (Limits) IDD Supply Current 5.5 3 4 0.02 10 10 7.6 4.7 5.75 2 25 60 mA (max) mA (max) mA (max) μA (max) mV (max) mV (max) ISD VOS Shutdown Supply Current Output Offset Voltage 400 30 30 5 www.national.com LM49270 LM49270 Symbol Parameter Conditions Speaker Mode, f = 1kHz POUT = 100mW, RL = 8Ω CC Headphone Mode, f = 1kHz Total Harmonic Distortion + Noise POUT = 12mW, RL = 32Ω OCL Headphone Mode, f = 1kHz POUT = 12mW, RL = 32Ω Speaker Mode, A-Wtg, Input Referred eN Noise CC Headphone Mode, A-Wtg, Input Referred OCL Headphone Mode, A-Wtg, Input Referred η Efficiency Speaker Mode RL = 8Ω Speaker Mode, f = 1kHz, VIN = 1Vp-p Xtalk Crosstalk CC Headphone Mode, f = 1kHz, VIN = 1Vp-p OCL Headphone Mode, f = 1kHz, VIN = 1Vp-p TON TOFF ZIN Turn-on Time Turn-off Time Input Impedance Maximum Gain Minimum Gain Maximum Gain, Speaker Mode AV Gain Minimum Gain, Speaker Mode Maximum Gain, Headphone Mode Minimum Gain, Headphone Mode Speaker Mode, VRIPPLE = 200mVp-p Sine f = 217Hz f = 1kHz Headphone Mode, VRIPPLE = 200mVp-p Sine, CC Mode f = 217Hz f = 1kHz Headphone Mode, VRIPPLE = 200mVp-p Sine, OCL Mode f = 217Hz f = 1kHz HPS(Th) Headphone Sense Threshold Detect Headphone Detect no Headphone Typical (Note 6) 0.02 Limit (Notes 7, 8) Units (Limits) % THD+N 0.015 % 0.02 47 10 11 84 71 70 55 30 64 23.5 210 30 –47 18 –59 % μV μV μV % dB dB dB ms ms kΩ kΩ dB dB dB dB 68 68 dB dB PSRR Power Supply Rejection Ratio 73 73 dB dB 75 79 2.9 1.8 dB dB V (min) V (max) www.national.com 6 LM49270 Electrical Characteristics VDD = 5.0V (Notes 2, 1) The following specifications apply for Headphone” AV = 0dB, RL(HP) = 32Ω,: for Loudspeakers: AV = 6dB, RL(SP) = 15μH + 8Ω + 15μH, f = 1kHz unless otherwise specified. Limits apply for TA = 25°C. LM49270 Symbol Parameter Conditions VIN = 0, RL = No Load, Both channels active Speaker ON, HP OFF Speaker OFF, CC HP ON Speaker OFF, OCL HP ON Headphone Speaker Speaker Mode, f = 1kHz, THD+N = 1% RL = 4Ω RL = 8Ω THD+N = 10 % RL = 4Ω RL = 8Ω CC Headphone Mode, f = 1kHz, THD+N = 1% RL = 16Ω POUT Output Power RL = 32Ω THD+N = 10% RL = 16Ω RL = 32Ω OCL Headphone Mode, f = 1kHz, THD+N = 1% RL = 16Ω RL = 32Ω THD+N = 10% RL = 16Ω RL = 32Ω Speaker Mode, f = 1kHz POUT = 100mW, RL = 8Ω Total Harmonic Distortion + Noise CC Headphone Mode, f = 1kHz POUT = 12mW, RL = 32Ω OCL Headphone Mode, f = 1kHz POUT = 12mW, RL = 32Ω Speaker Mode, A-Wtg, Input Referred eN Noise CC Headphone Mode, A-Wtg, Input Referred OCL Headphone Mode, A-Wtg, Input Referred η Efficiency Speaker Mode RL = 8Ω 155 90 175 140 0.03 mW mW mW mW % 155 90 177 140 mW mW mW mW 1.75 1.06 2.2 1.35 W W W W Typical (Note 6) Limit (Notes 7, 8) Units (Limits) IDD Supply Current 8.5 3.6 4.7 0.15 10 10 12.4 5.5 6.5 2 25 60 mA (max) mA (max) mA (max) μA (max) mV (max) mV (max) ISD VOS Shutdown Supply Current Output Offset Voltage THD+N 0.02 % 0.03 47 10 11 84 % μV μV μV % 7 www.national.com LM49270 LM49270 Symbol Parameter Conditions Speaker Mode, f = 1kHz, VIN = 1Vp-p Xtalk Crosstalk CC Headphone Mode, f = 1kHz, VIN = 1Vp-p OCL Headphone Mode, f = 1kHz, VIN = 1Vp-p TON TOFF ZIN Turn-on Time Turn-off Time Input Impedance Maximum Gain Minimum Gain Maximum Gain, Speaker Mode AV Gain Minimum Gain, Speaker Mode Maximum Gain, Headphone Mode Minimum Gain, Headphone Mode Speaker Mode, VRIPPLE = 200mVp-p Sine f = 217Hz f = 1kHz Headphone Mode, VRIPPLE = 200mVp-p Sine, CC Mode f = 217Hz f = 1kHz Headphone Mode, VRIPPLE = 200mVp-p Sine, OCL Mode f = 217Hz f = 1kHz HPS(Th) Headphone Sense Threshold Detect Headphone Detect no Headphone Typical (Note 6) –85 –70 –58 43 100 23.5 210 30 –47 18 –59 Limit (Notes 7, 8) Units (Limits) dB dB dB ms ms kΩ kΩ dB dB dB dB 61 61 dB dB PSRR Power Supply Rejection Ratio 75 74 dB min 78 75 4.4 3 dB dB V (min) V (max) Note 1: All voltages are measured with respect to the ground pin, unle