IS31AP4913 3D AND BASS ENHANCEMENT STEREO HEADPHONE DRIVER December 2013 GENERAL DESCRIPTION FEATURES The IS31AP4913 is a stereo headphone driver designed to allow the removal of the output DC-blocking capacitors for reduced component count and cost. The IS31AP4913 is ideal for small portable electronics where size and cost are in concerns. The IS31AP4913 also features 3D and bass enhancement which can be externally adjusted by a simple RC network. IS31AP4913 is available in QFN-20 (3mm x 3mm) packages. It operates from 2.7V to 5.5V over the temperature range of -40C to +85C. No output DC-blocking capacitors Bass enhancement 3D enhancement Low output noise (8V) High SNR (102dB) -92dB PSRR Pulse Count Control serial interface Thermal protection circuit Integrated click-and-pop suppression circuitry QFN-20 (3mm x 3mm) package APPLICATIONS Cellular handsets and PDAs Notebook PC MP3 Portable gaming TYPICAL APPLICATION CIRCUIT Figure 1 Typical Application Circuit Note: The SGND and PGND pins of the IS31AP4913 must be routed separately back to the decoupling capacitor in order to provide proper device operation. If the SGND and PGND pins are connected directly to each other, the part will function without the risk of failure, but the noise and THD performance do not meet the specifications. Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 1 IS31AP4913 PIN CONFIGURATION Package Pin Configuration (Top View) QFN-20 INFR 1 15 OUTL INR 2 14 OUTR 3DR 3 13 VREF 3DL 4 12 VCC INL 5 11 CTRL PIN DESCRIPTION No. Pin Description 1 INFR Right channel feedback loop in. 2 INR Right channel audio input. 3 3DR 3D control input. 4 3DL 3D control input. 5 INL Left channel audio input. 6 BASSL Left channel bass control out. 7 INFL Left channel feedback loop in. 8, 9 NC No connection. 10 SGND Signal Ground. 11 CTRL Shutdown and 3D/Bass enable control terminal. 12 VCC Supply voltage. 13 VREF Internal produced supply voltage for charge pump and audio power amplifier. 14 OUTR Right channel audio output. 15 OUTL Left channel audio output. 16 CP Charge pump flying capacitor positive terminal. 17 PGND Power ground. 18 VSS Output from charge pump. 19 CN Charge pump flying capacitor negative terminal. 20 BASSR Right channel bass control out. Thermal Pad Connect to GND. Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 2 IS31AP4913 ORDERING INFORMATION Industrial Range: -40C to +85C Order Part No. Package QTY/Reel IS31AP4913-QFLS2-TR QFN-20, Lead-free 2500 Copyright (c) 2013 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that: a.) the risk of injury or damage has been minimized; b.) the user assume all such risks; and c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 3 IS31AP4913 ABSOLUTE MAXIMUM RATINGS Supply voltage, VCC Voltage at any input pin Maximum junction temperature, TJMAX Storage temperature range, TSTG Operating temperature range, TA ESD (HBM) ESD (CDM) -0.3V ~ +6.0V -0.3V ~ VCC+0.3V 150C -65C ~ +150C -40C ~ +85C 5kV 1kV Note: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS VCC = 2.7V ~ 5.5V, TA = 25C, unless otherwise noted. Typical value is TA = 25C, VCC = 3.6V. Symbol Parameter Condition VCC Supply voltage ICC Quiescent current No load ISD Shutdown current VSDB = 0V fOSC Operating frequency |VOS| Output offset voltage Min. Typ. 2.7 VIH High-level input voltage VIL Low-level input voltage 3 VIN = 0V Max. Unit 5.5 V 5.5 mA 1 A 250 kHz 1 mV 1.4 V 0.4 V Max. Unit ELECTRICAL CHARACTERISTICS (Note 1) TA = 25C, VCC = 3.6V, unless otherwise noted. Symbol PO THD+N tWU Parameter Condition Output power THD+N = 1%, RL = 32, f = 1kHz Total harmonic plus noise Wake-up shutdown Min. distortion time VNO Output voltage noise SNR Signal-to-noise ratio 30 mW 0.05 % 39 ms VP-P = 200mV, RL = 32, f = 217Hz -92 dB VP-P = 200mV, RL = 32, f = 1kHz -90 dB 8 V 102 dB PO = 20mW, RL = 32, f = 1kHz from PSRR Power supply rejection ratio Typ. PO = 30mW, THD+N = 1% tLO Mode control low time 1 10 s tHI Mode control high time 1 10 s tOFF CTRL off time for shutdown 200 s Note 1: Guaranteed by design. Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 4 IS31AP4913 TYPICAL PERFORMANCE CHARACTERISTIC 20 10 5 20 VCC = 3.0V RL = 32 10 5 2 THD+N(%) THD+N(%) 2 VCC = 3.6V RL = 32 1 0.5 f = 10kHz 0.2 0.1 1 0.5 f = 10kHz 0.2 0.1 0.05 0.05 f = 1kHz f = 1kHz 0.02 0.01 1m 0.02 f = 20Hz 2m 5m 10m 20m 0.01 1m 100m 50m f = 20Hz 2m 5m Output Power(W) Figure 2 5 THD+N vs. Output Power Figure 3 VCC = 4.2V RL = 32 0.5 THD+N(%) THD+N(%) 1 0.5 f = 10kHz 0.2 100m THD+N vs. Output Power VCC = 3.0V~4.2V RL = 32 PO = 20mW 0.2 0.1 0.05 0.1 0.05 f = 1kHz 0.02 0.02 f = 20Hz 2m 5m 10m 20m 0.01 20 100m 50m 50 100 200 Output Power(W) Figure 4 500 1k 2k 5k 10k 20k 5k 10k 20k Frequency(Hz) THD+N vs. Output Power Figure 5 20u THD+N vs. Frequency +0 VCC = 3.6V, 4.2V RL = 32 -20 10u VCC = 3.6V, 4.2V RL = 32 Input Grounded -40 7u PSRR(dB) Output Voltage(V) 50m 1 2 0.01 1m 20m Output Power(W) 20 10 10m 5u 3u -60 -80 2u -100 1u 20 50 100 200 500 1k 2k 5k 10k 20k -120 20 50 100 Noise Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 500 1k 2k Frequency(H z) Frequency(Hz) Figure 6 200 Figure 7 PSRR vs. Frequency 5 IS31AP4913 +10 +8 Gain(dB) +6 +4 +2 0 -2 -4 20 VCC = 3.6V RL = 32 Bass Enable 50 100 200 500 1k 2k 5k 10k 20k Frequency(Hz) Figure 8 Gain vs. Frequency (Bass Enable Mode) Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 6 IS31AP4913 FUNCTIONAL BLOCK DIAGRAM VCC Bass&3D Control INR INL OUTL POR CTRL OUTR Channel Contrl Sequence Thermal Charge Pump VREF BG&Bias SGND PGND Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 7 IS31AP4913 APPLICATION INFORMATION GENERAL DESCRIPTION GAIN SETTING The IS31AP4913 is a high quality stereo headphone driver with 3D and bass enhancement. The input resistors (RIN) and feedback resistors (RF) set the gain of the amplifier according to Equation (1). OPERATING MODE The operating mode is controlled by Pulse Count Control (PCC wire) serial interface. The interface records rising edges of the CTRL pin and decodes them into 4 operating mode (Figure 9). If the CTRL pin is pulled to high, receiving one rising edge, the IC starts up and operates in Mode 1. If the CTRL pin receives two rising edges, the IC operates in Mode 2. If the CTRL pin receives three rising edges, the IC operates in Mode 3. If the CTRL pin receives four rising edges, the IC operates in Mode 4. Mode 1--IC starts up, basic operating mode. Gain RF RF 1 RF 2 RF 3 (2) RF 1 RF 2 RF 3 For example, in Figure 1: RF1 = 20k, RF2 = 20k, RF3 = 120k, RIN = 30k, therefore, R F Mode 3--IC starts up, enable bass enhance function. If the CTRL pin is pulled to low last at least 200s, the IC will be into shutdown mode. (1) The RF is given by Equation (2) below: Mode 2--IC starts up, enable 3D enhance function. Mode 4--IC starts up, enable 3D and bass enhance function. RF V RIN V 20 20 120 30 k 20 20 120 30 V Gain 1 30 V Resistor matching is very important in fully differential amplifiers. The balance of the output on the reference voltage depends on matched ratios of the resistors. CMRR, PSRR, and cancellation of the second harmonic distortion diminish if resistor mismatch occurs. Therefore, it is recommended to use 1% tolerance resistors or better to keep the performance optimized. Matching is more important than overall tolerance. Resistor arrays with 1% matching can be used with a tolerance greater than 1%. Place the input resistors very close to the IS31AP4913 to limit noise injection on the high-impedance nodes. BASS AUDIO ENHANCEMENT EFFECT When the bass enhancement is enabled, the low frequency input signal will be amplified (Figure 8). The cutoff frequency is fB. The signal below fB will be enhanced. fB is given by Equation (3): Figure 9 fB Operating Mode Selected CHARGE PUMP CONVERTER IS31AP4913 integrates a charge pump converter to change input supply voltage (VCC) into a negative voltage providing a 0V reference for the output. The charge pump converter only needs three external components: supply decoupling capacitor, output bypass capacitor and flying capacitor. 2 R F 1 1 R F 2 C B (3) For example, in Figure 1: RF1 = 20k, RF2 = 20k, CB = 22nF, so, f B 1 181 Hz 2 20 k 20 k 22 nF The capacitors should have a tolerance of 10% or better, because any mismatch in capacitance causes an impedance mismatch at the startup frequency and below. Choose low ESR capacitors to ensure the best operating performance and place the capacitors as close as possible to the IS31AP4913. Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 8 IS31AP4913 3D AUDIO ENHANCEMENT EFFECT DESIGN NOTE The 3D audio enhancement effect can be adjusted by the resistor, R3D. Decreasing the resistor size will make the 3D effect more pronounced and decreasing the capacitor size will raise the cutoff frequency for the effect. COMPONENT SELECTION The cutoff frequency, f3D, is determined by Equation (4): f3D 1 2R3 D C 3 D (4) For example, in Figure 1: R3D = 4.7k, C3D = 47nF, so, f3D 1 721 Hz 2 4.7 k 47 nF Setting f3D below 1kHz is recommended to get better 3D enhancement. INPUT CAPACITOR (CIN) The input capacitors and input resistors form a high pass filter with the corner frequency, fC, determined in Equation (5). 1 f c 2R C IN IN (5) For example, in Figure 1: RIN = 30k, CIN = 0.47F, therefore, 1 f 11 Hz c 2 30 k 0.47 F The value and ESR of the output capacitor for charge pump will affect output ripple and transient performance. A X7R or X5R ceramic capacitor in 2.2F is recommended. The flying capacitor should be a 2.2F X7R or X5R ceramic capacitor. All capacitors should support at least 10V. PCB LAYOUT The decoupling capacitors should be placed close to the VCC pin and the output capacitors should be placed close to the VSS pin. The flying capacitor should be placed close to the CN and CP pins. The input capacitors and input resistors should be placed close to the INR and INL pins and the traces must be parallel to prevent noise. The traces of OUTR and OUTL pins connected to the headphone should be as short and wide as possible. The recommended width is 0.5mm. Trace width should be at least 0.75mm for the power supply and the ground plane. The thermal pad and the PGND pin should connect directly to a strong common ground plane for heat sinking. The SGND and PGND pins of the IS31AP4913 must be routed separately back to the decoupling capacitor in order to provide proper device operation. If the SGND and PGND pins are connected directly to each other, the part functions without risk of failure, but the noise and THD performance will not meet the specifications. The value of the input capacitor is important to consider as it directly affects the bass (low frequency) performance of the circuit. The capacitors should have a tolerance of 10% or better, because any mismatch in capacitance causes an impedance mismatch at the corner frequency and below. Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 9 IS31AP4913 CLASSIFICATION REFLOW PROFILES Profile Feature Pb-Free Assembly Preheat & Soak Temperature min (Tsmin) Temperature max (Tsmax) Time (Tsmin to Tsmax) (ts) 150C 200C 60-120 seconds Average ramp-up rate (Tsmax to Tp) 3C/second max. Liquidous temperature (TL) Time at liquidous (tL) 217C 60-150 seconds Peak package body temperature (Tp)* Max 260C Time (tp)** within 5C of the specified classification temperature (Tc) Max 30 seconds Average ramp-down rate (Tp to Tsmax) 6C/second max. Time 25C to peak temperature 8 minutes max. Figure 10 Classification Profile Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 10 IS31AP4913 PACKAGING INFORMATION QFN-20 Note: All dimensions in millimeters unless otherwise stated. Integrated Silicon Solution, Inc. - www.issi.com Rev. C, 12/25/2013 11