IS31AP4991 1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW STANDBY MODE October 2012 GENERAL DESCRIPTION FEATURES The IS31AP4991 has been designed for demanding audio applications such as mobile phones and permits the reduction of the number of external components. It is capable of delivering 1.2W of continuous RMS output power into an 8 load @ 5V. An externally-controlled standby mode reduces the supply current to much less than 1A. It also includes internal thermal shutdown protection. The unity-gain stable amplifier can be configured by external gain setting resistors. Operating from VCC = 2.7V ~ 5.5V 1.2W output power @ VCC = 5V, THD+N= 1%, f = 1kHz, with 8 load Ultra-low consumption in standby mode (much less than 1A) 65dB PSRR @217Hz in grounded mode Near-zero click-and-pop Ultra-low distortion (0.025%@0.5W, 1kHz) SOP-8 and MSOP-8 package APPLICATIONS Mobile phones PDAs Portable electronic devices Notebook computer TYPICAL APPLICATION CIRCUIT Figure 1 Typical Application Circuit (Single-ended input) Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 1 IS31AP4991 Figure 2 Typical Application Circuit (Differential input) Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 2 IS31AP4991 PIN CONFIGURATION Package Pin Configuration (Top View) SOP-8 MSOP-8 PIN DESCRIPTION No. Pin SOP MSOP IN+ 1 3 Positive input of the first amplifier. OUT- 2 5 Negative output of the IS31AP4991. Connected to the load and to the feedback resistor RF. IN- 3 4 Negative input of the first amplifier, receives the audio input signal. Connected to the feedback resistor RF and to the input resistor RIN. GND 4 7 Ground. BYPASS 5 2 Bypass capacitor pin which provides the common mode voltage (VCC/2). OUT+ 6 8 Positive output of the IS31AP4991. Connected to the load. SDB 7 1 The device enters shutdown mode when a low level is applied on this pin. VCC 8 6 Positive analog supply of the chip. Description Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 3 IS31AP4991 ORDERING INFORMATION Industrial Range: -40C to +85C Order Part No. Package QTY/Reel IS31AP4991-GRLS2-TR SOP-8, Lead-free 2500 IS31AP4991-SLS2-TR MSOP-8, Lead-free 2500 Copyright (c) 2012 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. B, 10/18/2012 4 IS31AP4991 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply voltage, VCC Voltage at any input pin Maximum junction temperature, TJMAX Storage temperature range, TSTG Operating temperature range, TA -0.3V ~ +6.0V -0.3V ~ VCC+0.3V 150C -65C ~ +150C -40C ~ +85C Note 1: 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 The following specifications apply for CIN = 0.22F, RIN = RF = 20k, CBYPASS = 1F, unless otherwise specified. Limits apply for TA = 25C. VCC=5V (Note 2 or specified) Symbol Parameter ICC Quiescent power supply current VCC = 0V, Io = 0A, no Load Standby current VSTBY = GND, RL = VSTBYH Shutdown voltage input high VSTBYL Shutdown voltage input low ISTBY VOS Output offset voltage Po Output power (8) tWU Condition Typ. Limit 4.8 Unit mA (max) 1 A(max) VCC = 5.5V 1.4 V(min) VCC = 2.7V 0.4 V(max) 15 mV (max) THD+N = 1%; f = 1kHz 1.18 THD+N = 10%; f = 1kHz 1.46 Wake-up time (Note 3) CBYPASS = 1F 115 ms THD+N Total harmonic distortion+noise (Note 3) Po = 0.5Wrms; f = 1kHz 0.025 % PSRR Power supply rejection ratio (Note 3) Vripple p-p = 200mV Input Grounded f = 217Hz 65 f = 1kHz 77 W dB The following specifications apply for CIN = 0.22F, RIN = RF = 20k, CBYPASS = 1F, unless otherwise specified. Limits apply for TA= 25C. VCC=3V (Note 2 or specified) Symbol Parameter ICC Quiescent power supply current VCC = 0V, Io = 0A, no Load Standby current VSTBY = GND, RL = ISTBY Typ. Limit 3.8 Unit mA(max) 1 A(max) THD+N = 1%; f = 1kHz 405 THD+N = 10%; f = 1kHz 502 Wake-up time (Note 3) CBYPASS = 1F 102 ms Total harmonic distortion+noise (Note 3) Po = 0.3Wrms; f = 1kHz 0.027 % Po Output power (8) tWU THD+N Condition mW Note 2: Production testing of the device is performed at 25C. Functional operation of the device and parameters specified over other temperature range, are guaranteed by design, characterization and process control. Note 3: Guaranteed by design. Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 5 IS31AP4991 TYPICAL PERFORMANCE CHARACTERISTIC 10 5 2 10 Vcc = 3V RL = 8 f = 1kHz 5 2 1 THD+N (%) THD+N (%) 1 0.5 0.2 0.1 0.5 0.2 0.1 0.05 0.05 0.02 0.02 0.01 10m Vcc = 5V RL = 8 f = 1kHz 20m 50m 100m 200m 500m 1 0.01 10m 2 20m 50m Output Power (W) Figure 3 THD+N vs. Output Power Figure 4 10 5 5 2 1 0.5 0.2 1 2 THD+N vs. Output Power 0.5 0.2 0.1 0.05 0 .05 0.02 0 .02 50 100 200 500 1k 2k 5k 20k Vcc = 5V RL = 8 Power=800mW 1 0.1 0.01 20 500m 10 Vcc = 3V RL = 8 Power=250mW THD+N (%) THD+N (%) 2 100m 200m Output Power (W) 0 .01 20 50 100 200 Frequency (Hz) 500 1k 2k Figure 5 THD+N vs. Frequency Figure 6 THD+N vs. Frequency Figure 7 PSRR vs. Frequency Figure 8 PSRR vs. Frequency Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 20k 5k Frequency (H z) 6 IS31AP4991 100 u Output Noise Voltage (V) 70 u Vcc = 5V RL = 8 PoWeighted A = 800mWFilter 50 u 40 u 30 u 20 u 10 u 20 50 100 200 500 1k 2k 5k 20k Frequency (Hz) Figure 9 Noise Floor Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 Figure 10 Output Power vs. Power Supply 7 IS31AP4991 APPLICATION INFORMATION fCH is in Hz. BTL CONFIGURATION PRINCIPLE The IS31AP4991 is a monolithic power amplifier with a BTL output type. BTL (bridge tied load) means that each end of the load is connected to two single-ended output amplifiers. Thus, we have: Single-ended output 1 = VOUT+ = VOUT (V) Single ended output 2 = VOUT- = -VOUT (V) and VOUT+ - VOUT- = 2VOUT (V) The output power is: POUT (2VOUT RMS ) 2 RL For the same power supply voltage, the output power in BTL configuration is four times higher than the output power in single ended configuration. GAIN IN A TYPICAL APPLICATION SCHEMATIC The typical application schematic is shown in Figure 1 on page 1. In the flat region (no CIN effect), the output voltage of the first stage is (in Volts): VOUT (VIN ) RF RIN For the second stage: VOUT+ = -VOUT- (V) The differential output voltage is (in Volts): VOUT VOUT 2VIN RF RIN The differential gain, GV, is given by: V VOUT R Gv OUT 2 F VIN RIN VOUT- is in phase with VIN and VOUT+ is phased 180 with VIN. This means that the positive terminal of the loudspeaker should be connected to VOUT+ and the negative to VOUT-. LOW AND HIGH FREQUENCY RESPONSE In the low frequency region, CIN starts to have an effect. CIN forms with RIN a high-pass filter with a -3dB cut-off frequency. fCL is in Hz. f CL 1 2RIN C IN In the high frequency region, you can limit the bandwidth by adding a capacitor (CF) in parallel with RF. It forms a low-pass filter with a -3dB cut-off frequency. Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 f CH 1 2RF C F DECOUPLING OF THE CIRCUIT Two capacitors are needed to correctly bypass the IS31AP4991: a power supply bypass capacitor CS and a bias voltage bypass capacitor CBYPASS. CS has particular influence on the THD+N in the high frequency region (above 7kHz) and an indirect influence on power supply disturbances. With a value for CS of 1F, you can expect THD+N levels similar to those shown in the datasheet. In the high frequency region, if CS is lower than 1F, it increases THD+N and disturbances on the power supply rail are less filtered. On the other hand, if CS is higher than 1F, those disturbances on the power supply rail are more filtered. CBYPASS has an influence on THD+N at lower frequencies, but its function is critical to the final result of PSRR (with input grounded and in the lower frequency region). If CBYPASS is lower than 1F, THD+N increases at lower frequencies and PSRR worsens. If CBYPASS is higher than 1F, the benefit on THD+N at lower frequencies is small, but the benefit to PSRR is substantial. Note that CIN has a non-negligible effect on PSRR at lower frequencies. The lower the value of CIN, the higher the PSRR is. WAKE-UP TIME (tWU) When the standby is released to put the device on, the bypass capacitor CBYPASS will not be charged immediately. As CBYPASS is directly linked to the bias of the amplifier, the bias will not work properly until the CBYPASS voltage is correct. The time to reach this voltage is called wake-up time or tWU and specified in the electrical characteristics table with CBYPASS = 1F. POP PERFORMANCE Pop performance is intimately linked with the size of the input capacitor CIN and the bias voltage bypass capacitor CBYPASS. The size of CIN is dependent on the lower cut-off frequency and PSRR values requested. The size of CBYPASS is dependent on THD+N and PSRR values requested at lower frequencies. Moreover, CBYPASS determines the speed with which the amplifier turns on. 8 IS31AP4991 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 11 Classification Profile Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 9 IS31AP4991 PACKAGE INFORMATION SOP-8 Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 10 IS31AP4991 MSOP-8 Integrated Silicon Solution, Inc. - www.issi.com Rev. B, 10/18/2012 11 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: ISSI: IS31AP4991-GRLS2-TR IS31AP4991-SLS2-TR IS31AP4991-SLS2-EB