P A ASP AP8111 PRELIMINARY TruBass Audio Enhancement Processor 1 Overview The AP8111 is a bass enhancement processor based on SRS Labs, Inc.’s patented TruBass technology. TruBass is a revolutionary psychoacoustic bass enhancement technology that provides deep, rich bass to small speakers without the need for a subwoofer or additional extra physical components. Deep bass now becomes possible even through speakers with limitations in driver and cabinet design. TruBass circuitry actively monitors the low-frequency content of an audio signal and optimizes the frequency and amplitude spectrum of the output signal to enhance bass perception. For systems with a subwoofer, TruBass complements and enhances bass performance. TruBass is therefore most suitable for applications that use small size speakers yet need to deliver the best audio quality or home theatre effect: Mini or Micro Stereo Sound Systems, TV, CD, Boombox, Car Audio, DVD Receiver, Set-Top-Box, and other compact hi-fi systems such as Discman, MD, MP3 player, as well as PCs. 2 Features Operating Voltage 4.75V to 5.25V Low Operation Current 10mA typ Power down and Bypass mode selection Analog switch for mode and gain control External adjustment for speaker size setting (small, medium and large) Bipolar Technology Chip Package 28 pins SOP The TruBass technology rights in the AP8111 are owned by SRS Labs, a United States. Corporation and licensed to ASP Microelectronics Ltd. TruBass is protected under US and foreign patents issues and/or pending. TruBass and the symbol are trademarks of SRS Labs, Inc. in the United State and selected foreign countries. Neither the purchase of the AP8111, nor the corresponding sale of audio enhancement equipment conveys the right to sell commercialized recordings made with any SRS technology. SRS Labs requires all set makers to comply with all rules and regulations as outlined in the SRS Trademark Usage Manual separately provided. For further information, please contact: SRS Labs, Inc. 2909 Daimler Street, Santa Ana, CA 92705 USA Tel: 949-442-1070 Fax: 949-852-1099 http://www.srslabs.com [CAUTION] The information in this publication is believed to be accurate in all respects at the time of publication but is subject to change without notice. ASP Microelectronics Ltd. assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from the use of information included herein. Additionally, ASP Microelectronics Ltd. assumes no responsibility for the functioning of undocumented features or parameters. ASP Microelectronics Ltd. Unit 218, 2/F., Tech Centre, 72 Tat Chee Ave., Kowloon Tong, Hong Kong Tel:(852) 2797 3288 Fax: (852) 2797 3112 http://www.asp.com.hk Revision 2.4 1 15 April., 2002 P A ASP AP8111 3 Device Pin Out and 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 AOUT AIN AI/O DIN PWR Pin Name LOUT LIN VREF NC CB1A CB1B CB1 GND TBGAIN CB2B CB2A CB2 BYPASS COMPI CL1 FOUT COMPC2 NC VCC COMPC1 CB3B CB3A CB3 CL2B NC CL2A RIN ROUT Type AOUT AIN AOUT AI/O AI/O AI/O PWR DIN AI/O AI/O AI/O DIN AIN AI/O AOUT AI/O PWR AI/O AI/O AI/O AI/O AI/O AI/O AIN AOUT Descriptions Left channel audio line output Left channel audio line input 2.25V analog reference Not used 100Hz band-pass filter circuit 100Hz band-pass filter circuit 100Hz band-pass filter circuit Analog ground TruBass gain control. +6dB gain when this pin short to ground. 40/150Hz band-pass filter circuit 40/150Hz band-pass filter circuit 40/150Hz band-pass filter circuit Power down/ Bypass / TruBass-enable selection Compressor input Low-pass filter capacitor Filter output Compressor capacitor Not used. 5 volts power supply Compressor output 60/200Hz band-pass filter circuit 60/200Hz band-pass filter circuit 60/200Hz band-pass filter circuit Low-pass filter capacitor Not used Low-pass filter capacitor Right channel audio line input Right channel audio line output - analog output pin - analog input pin - analog bi-directional pin - digital input pin - power pin Revision 2.4 2 15 April., 2002 P A ASP AP8111 4 Pin Configuration 1 LOUT 2 LIN 3 VREF 4 NC 5 CB1A 6 CB1B ROUT 28 RIN 27 CL2A 26 NC 25 CL2B 24 CB3 23 1 7 CB1 CB3A 22 8 GND CB3B 21 9 TBGAIN COM PC1 20 10 CB2B VCC 19 11 CB2A NC 18 12 CB2 COM PC2 17 13 BYPASS FOUT 16 14 COM PI CL1 15 5 Operating Modes The chip can be configured in 3 modes of operations – Power down mode, bypass mode, TruBass mode. In power down mode, the chip is power down and consumed minimal current. In bypass mode, line in audio signal is pass directly to the output. In TruBass mode, line in audio signal is enhanced with the TruBass algorithm. The Bypass pin (pin 11) is used to select the operating mode. When the pin is forced to 0v, the chip is powered down and when the pin is at float (or Vcc/2) and at 5v, the mode is set to Bypass and TruBass Enabled respectively. An additional +6dB gain is enabled by pulling the pin TBGAIN to ground. 6 Speaker Size and Filter Center Frequencies selection The configuration of the TruBass band-pass filters depends on the speaker size for the system. There are three configurations: small, medium and large. Each configuration uses three bandpass filters, but with different center frequencies for the filters as follows: Speaker Size Small Medium Large Filter Center Frequencies 100Hz 60Hz 40Hz The low pass filter cutoff frequency and the band pass filter center frequencies can be adjusted to match the frequency response of the speakers being used. Generally, the speaker size setting should be selected so that the lowest of the band pass center frequencies is just above the low cutoff frequency of the speaker system. All configurations require the 100Hz filter, so its center frequency is fixed. The center frequencies of the other two filters are configured by the external resistors placed on pins CB2, CB2A, CB2B, CB3, CB3A, CB3B. Revision 2.4 3 15 April., 2002 P A ASP AP8111 C2 4.7U 10U C5 2 3 4 AP8111 LOUT ROUT LIN RIN VREF CL2A NC NC CB1A CL2B 28 27 26 25 C7 0.1U R2 5 4.53K 8.87K 0.01U C17 8 CB3A GND CB3B 22 21 45.3K CB1 23 107K 7 CB3 CB1B R17 6 R16 63.4K C6 0.1U 37.4K R21 2.32K 24 R19 R3 31.6K C4 4.7U C18 0.1U 1 R1 RIN C3 4.7U 33K C1 4.7U R15 LIN LOUT ROUT 7 Application circuit R20 8 6 4 2 J4 22.1K R18 7 5 3 1 0.1U C19 JP2 1 2 9 J1 158K 0.1U C9 7 5 3 1 57.6K 12 R6 21K 3.09K 13 COMPC2 CB2 BYPASS 14 FOUT CL1 COMPI Speaker Setting 17 Small 16 10U C15 J2 15 33K 10U C16 R10 U1 1 2 3 JP3 NC CB2A 19 18 R8 13K VCC VCC 20 0.01U C12 J3 CB2B C13 3300P 56.2K R5 8 6 4 2 11 COMPC1 R9 R7 C8 0.1U 1-2 +6dB open 0dB R4 10 jumper set for gain control TBGAIN J3 J4 1-2, 5-6 1-2, 5-6 Medium J3 J4 1-2, 5-6 3-4, 7-8 Large J3 J4 3-4, 7-8 3-4, 7-8 TruBass open Bypass 2-3 Power Down R13 100K 1-2 R11 10K jumper set for operating mode 10K R12 10U C14 300K C10 4.7U 4.7U C11 37.5K R14 R22 PUNCH CONTROL 10K variable resistor Tolerance all resistors are ±1%, capacitors are ±10% Revision 2.4 4 15 April., 2002 P A ASP AP8111 8 Recommended Operating Condition The following is the recommended operating conditions for the TruBass analog processor Symbol VCC Vi Vo Tamb Parameter DC supply voltage DC input voltage range DC output voltage range Operating ambient temperature range Min 4.75 -0.3 0 0 Max 5.25 VCC+0.3 VCC 70 Unit Volts Volts Volts °C 9 DC Electrical Specifications Symbol Vcc Icc Ipd Rin Vref Rload Cload Vil Vmid Vih Ileak Parameter Chip supply voltage Operating current Power down supply current Left/Right input impedance Analog reference voltage Resistance load at Left/Right output Capacitance load at Left/Right output Digital input logic low Mid-level for Tri-level logic Digital input logic high Digital input leakage ( except TBGAIN ) Conditions Min 4.75 Vcc = 5.0 Vcc = 5.0 10 2.02 10 Typ 5 10 25 Max 5.25 2.25 2.48 50 50 If floated, internal reference will ensure Vmid Vcc/2 – 10% Vcc/2 Vcc – 0.3 -10 Vcc = 5.0 0.3 Vcc/2 + 10% Units V mA uA kΩ V kΩ pF V V 10 V uA Max 20000 1 Units Hz Vrms 1 0.5 Vrms dB 10 AC Electrical Specifications Symbol Freq Vrli Vrlo Gerror SNR THD Xtalk Comp Rate Revision 2.4 Parameter Audio signal operating frequency Audio input signal level (0dB level reference) Audio output level Output gain error Conditions Min 20 Typ Inputs AC coupled Rload = 10kΩ Bypass mode, input signal @ 0dB 1kHz Signal to noise ratio Bypass mode /Aweighted, input signal @ -60dB 1kHz Total harmonic distortion Bypass mode Input @ 0dB 1kHz Channel Crosstalk Bypass mode TruBass Compressor Ratio Punch at maximum gain Attack to decay time constant ratio Absolute value set by external capacitor 5 -0.5 80 dB 1 % -70 dB 2:1 10:1 15 April., 2002