NAU82011WG 2.9 W Mono Filter-Free Class-D Audio Amplifier 1 Description The NAU82011WG is a mono high efficiency filter-free Class-D audio amplifier with variable gain, which is capable of driving a 4 load with up to 2.9W output power. This device provides chip enable pin with extremely low standby current and fast start-up time of 4ms. The NAU82011WG is ideal for the portable applications of battery drive, as it has advanced features like 91% efficiency, low quiescent current (i.e. 1.2mA at 3.6V) and superior EMI performance. It has the ability to configure the inputs in either single-ended or differential mode. NAU82011WG is available in MSOP-8 package. Key Features Low Quiescent Current: * 1.2mA at 3.6V * 1.7mA at 5V Powerful Mono Class-D Amplifier: * 2.9W (4 @ 5V, 10% THD+N) * 2.3W (4 @ 5V, 1% THD+N) * 1.7W (8 @ 5V, 10% THD+N) * 1.38W (8 @ 5V, 1% THD+N) Low Output Noise: 20 VRMS Low Current Shutdown Mode Integrated Image Reject Filter Click-and Pop Suppression Integrated feedback resistor of 300 k VIN * * * * Applications Smartphones Tablet PCs Personal Navigation Devices R1 Class D Modulator VIP 1.48 W (4 @ 3.6V, 10% THD+N) 1.2 W (4 @ 3.6V, 1% THD+N) 0.88 W (8 @ 3.6V, 10% THD+N) 0.71 W (8 @ 3.6V, 1% THD+N) Output Driver R1 NAU82011WG Click / Pop Suppression Current / Thermal Protection VDD VSS EN Figure 1: NAU82011WG Block Diagram NAU82011WG Datasheet Rev1.0 Page 1 of 16 Dec, 2012 2 3 Pin out EN 1 8 VOUTN NC 2 7 GND VIP 3 6 VDD VIN 4 5 VOUTP NAU82011WG Part Number Dimension Package Package Material NAU82011WG 3mm x 3mm MSOP-8 Green Pin Descriptions Pin # Name Type Functionality 1 2 3 4 5 6 7 8 EN NC VIP VIN VOUTP VDD GND VOUTN Digital Input NC Analog Input Analog Input Analog Output Supply Supply Analog Output Chip Enable (High = Power Up; Low = Power Down) No Connection Positive Differential Input Negative Differential Input Positive BTL Output Power Supply High Current Ground Negative BTL Output Table 1: NAU82011WG Pin description NAU82011WG Datasheet Rev1.0 Page 2 of 16 Dec, 2012 Electrical Characteristics Conditions: EN = VDD = 5V, VSS = 0V, Av = 6dB, ZL = , unless otherwise specified, R1 = 150k, Bandwidth = 20Hz to 22 kHz, TA = 25 oC Parameter Symbol Power Delivered Output Power Pout Comments/Conditions ZL = 4 + 33H THD + N = 10% ZL = 4 + 33H THD + N = 1% ZL = 8 + 68H THD + N = 10% ZL = 8 + 68H THD + N = 1% Parameter Chip Enable (EN) Voltage Enable High Voltage Enable Low Input Leakage Current Thermal and Current Protection Thermal Shutdown Temp Thermal Shutdown Hysteresis Over Current Threshold Gain Resistance (EN pin to GND) NAU82011WG Datasheet Rev1.0 Symbol VEN H VEN L Min VDD = 5.0V VDD = 3.6V VDD = 5.0V VDD = 3.6V VDD = 5.0V VDD = 3.6V VDD = 5.0V VDD = 3.6V Comments/Conditions VDD = 2.5V to 5.5V VDD = 2.5V to 5.5V Typ 2.9 1.48 2.3 1.2 1.7 0.88 1.38 0.71 Min Typ VDD = 2.5V to 5.5V, R1 in k REN 255/R1 150 20 2.0 300/R1 Max 0.35 2.0 Units V V A o C C A V/V o 345/R1 k 300 Page 3 of 16 Units W 1.3 0.1 IOC AV Max Dec, 2012 Electrical Characteristics (continued) Conditions: EN = VDD = 5V, VSS = 0V, Av = 6dB, R1 = 150k, ZL = , unless otherwise specified, Bandwidth = 20Hz to 22 kHz, TA = 25 oC Parameter Symbol Comments/Conditions Min Typ Max Units Normal Operation Quiescent Current Consumption IQUI Shut Down Current Oscillator Frequency Efficiency Start Up Time Output Offset Voltage Common Mode Rejection Ratio Click-and-Pop Suppression IOFF fOSC Tstart VOS CMRR Power Supply Rejection Ratio PSRR Noise Performance VDD = 3.6V VDD = 5V EN = 0 RL = 8 fIN = 1kHz 1Hz Shutdown (ZL=8) DC PSRR AC PSRR VRIPPLE = 0.2Vpp@1kHz VDD = 3.6V (A-weighted) 1.2 1.7 0.5 300 91 4 1 63 83 95 60 mA mA A kHz % msec mV dB dBV dB dB 20 VRMS Absolute Maximum Ratings Parameter Min Max Units -0.50 +5.50 V Industrial operating temperature -40 +85 C Storage temperature range -65 +150 C Junction temperature range -40 +150 C Analog supply CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely influence product reliability and result in failures not covered by warranty. NAU82011WG Datasheet Rev1.0 Page 4 of 16 Dec, 2012 Recommended Operating Conditions Parameter Symbol Min Typical Max Units Analog supply range VDD 2.50 5.00 5.50 V Ground VSS 0 Input Resistor (Gain 26dB ) R1 15 Common mode Input voltage range VDD = 2.5V to 5.5V and CMRR 49dB VIC 0 V k VDD - 1.0 V Test Set up VDD 0.1uF + + Audio Precision Output - NAU82011 ZL 30kHz low pass RC filter Audio Precision Input - 0.1uF Note: The 30kHz low pass RC filter is implemented by using R= 1k Ohm and C = 4.7nF NAU82011WG Datasheet Rev1.0 Page 5 of 16 Dec, 2012 5 Typical Operating Characteristics Conditions: EN = VDD = 5V, VSS = 0V, Av = 6dB (R1=150k), ZL = , unless otherwise specified, Bandwidth = 20Hz to 22 kHz, TA = 25 oC, unless otherwise noted THD+N vs Frequency 1 0.01 0.01 0.001 0.001 ZL= 8 + 68H VDD 5V 20 ZL= 8 + 68H VDD 3.6V 0.0001 0.0001 20 200 2000 20000 Frequency (Hz) 0.001 0.0001 ZL= 4 +33H VDD 5V 0.0001 200 2000 20000 Frequency( HZ) NAU82011WG Datasheet Rev1.0 0.01 0.001 ZL= 8 + 68H VDD 2.5V 20 20000 Pout 100mW Pout 500mW Pout 2W 0.1 THD+N (%) 0.01 2000 THD+N vs Frequency 1 Pout 15mW Pout 75mW Pout 200mW 0.1 200 Frequency (Hz) THD+N vs Frequency 1 THD+N(%) Pout 25mW Pout 125mW Pout 500mW 0.1 THD+N (%) THD+N (%) 1 Pout 50mW Pout 250mW Pout 1W 0.1 THD+N vs Frequency 20 Page 6 of 16 200 2000 20000 Frequency (Hz) Dec, 2012 THD+N vs Frequency THD+N vs Frequency 1 1 Pout 50mW Pout 250mW Pout 1W 0.1 Pout 30mW Pout 150mW Pout 400mW THD+N (%) THD+N (%) 0.1 0.01 ZL= 4 + 33H VDD 3.6V 0.001 ZL = 4 +33 H VDD 2.5V 0.0001 20 0.01 0.001 200 2000 20000 Frequency (Hz) 20 THD+N vs Output Power 2000 Frequency (Hz) 20000 THD+N vs Output Power 100 100 VDD 2.5V VDD 3.6V VDD 5V 10 VDD 2.5V VDD 3.6V VDD 5V 10 1 THD+N [%] THD+N [%] 200 0.1 0.01 1 0.1 0.01 ZL= 8 + 68H ZL= 4+ 33H 0.001 0.01 0.1 1 10 Output Power [W] NAU82011WG Datasheet Rev1.0 Page 7 of 16 0.001 0.01 0.1 1 Output Power [W] Dec, 2012 10 Supply Current vs Output Power 0.7 0.4 Vdd 5V Vdd 3.6V Vdd 2.5V 0.3 0.25 0.2 0.15 ZL=8 + 68H 0.1 VDD 5V VDD 3.6V VDD 2.5V 0.6 Supply Current [A] 0.35 Supply Current [A] Supply Current vs Output Power 0.5 0.4 0.3 ZL=4 + 33H 0.2 0.1 0.05 0 0 0.00 0.50 1.00 1.50 Output Power [W] 0 2.00 Efficiency vs Output Power 100 2 3 Output Power [W] 4 Efficiency vs Output Power 100 90 1 90 70 70 Efficiency [%] 80 Efficiency [%] 80 60 50 VDD 5V VDD 3.6V VDD 2.5V 40 30 20 10 1.00 1.50 Output Power [W] NAU82011WG Datasheet Rev1.0 40 VDD 5V VDD 3.6V VDD 2.5V 30 10 ZL=4 + 33H 0 0 0.50 50 20 ZL=8 + 68H 0.00 60 2.00 Page 8 of 16 0 1 2 3 Output Power [W] Dec, 2012 4 PSRR vs Frequency PSRR vs Frequency 0 0 -10 -10 -20 -40 -30 PSRR [dB] PSRR [dB] -30 VDD 5V VDD 3.6V VDD 2.5V -20 VDD 5V VDD 3.6V VDD 2.5V -50 -60 -70 -40 -50 -60 -70 -80 -80 ZL= 8 + 68H -90 ZL = 4 + 33H -90 -100 20 200 2000 Frequency [Hz] -100 20000 20 CMRR vs Frequency -10 VDD 2.5V VDD 3.6V VDD 5V -20 -30 CMRR [dB] CMRR [dB] -30 20000 -10 VDD 2.5V VDD 3.6V VDD 5V -20 2000 Frequency [Hz] CMRR vs Frequency 0 0 200 -40 -40 -50 -50 -60 -60 -70 -70 -80 ZL=8+68H -80 ZL=4+33H -90 -90 20 200 2000 20 20000 200 2000 20000 Frequency [Hz] Frequency [Hz] Note1: All the above plots are captured with 0.1uF input capacitor. It is recommended to use 2.2uF input capacitor to get a flat low frequency response. Note2 : The above PSRR plots are captured with input capacitors 2.2uF NAU82011WG Datasheet Rev1.0 Page 9 of 16 Dec, 2012 6 Special Feature Description The NAU82011WG offers excellent quantity performance as high efficiency, high output power and low quiescent current. It also provides the following special features. 6.1 Device Protection The NAU82011WG includes device protection for three operating scenarios. They are 1. 2. 3. Thermal Overload Short circuit Supply under voltage 6.1.1 Thermal Overload Protection When the device internal junction temperature reaches 150C, the NAU82011WG will disable the output drivers. When the device cools down and a safe operating temperature of 130C has been reached for at least about 100ms, the output drivers will be enabled again. 6.1.2 Short Circuit Protection If a short circuit is detected on any of the pull-up or pull-down devices on the output drivers for at least 16.7s, the output drivers will be disabled for 100ms. The output drivers will then be enabled again and check for the short circuit. If the short circuit is still present, the output drivers are disabled after 16.7s. This cycle will continue until the short circuit is removed. The short circuit threshold is 2.0A at 3.6V. 6.1.3 Supply under Voltage Protection If the supply voltage drops under 2.1V, the output drivers will be disabled while the NAU82011WG control circuitry still operates. This will avoid the battery supply to drag down too low before the host processor can safely shut down the devices on the system. If the supply drops further below 1.6 V the internal power on reset is activated and puts the entire device in power down state. 6.2 Power up and Power down Control When the supply voltage ramps up, the internal power on reset circuit gets triggered. At this time all internal circuits will be set to power down state. The device can be enabled by setting the EN pin high. Upon setting the EN pin high, the device will go through an internal power up sequence in order to minimize `pops' on the speaker output. The complete power up sequence will take about 4ms. The device will power down in about 30s, when the EN pin is set low. It is important to keep the input signal at zero amplitude in order to minimize the `pops' when the EN pin is toggled. NAU82011WG Datasheet Rev1.0 Page 10 of 16 Dec, 2012 7 Application Information 7.1 Application diagram 7.1.1 Single ended input configuration 0.1F 150 k VIN Class D Modulator 0.1F 150 k VIP Click / Pop Suppression NAU82011WG VIN VIP Current / Thermal Protection VSS VDD 0.1F 10F EN VDD 7.1.2 Output Driver Differential input configuration 0.1F 150 k Class D Modulator 0.1F 150 k Click / Pop Suppression NAU82011WG Current / Thermal Protection VSS VDD 0.1F EN VDD NAU82011WG Datasheet Rev1.0 Output Driver Page 11 of 16 Dec, 2012 10F 7.2 Component selection 7.2.1 Input resistors for Gain NAU82011WG has a provision for variable gain setting by using external input resistors. The gain is expressed as the ratio of the internal feedback resistor of 300k and the external input resistor R. The Gain is expressed as = 7.2.2 300 1 () = 20 log 300 1 Coupling Capacitors An ac coupling capacitor (Cin) is used to block the dc content from the input source. The input resistance of the amplifier (R) together with the Cin will act as a high pass filter. So depending on the required cut off frequency the Cin can be calculated by using the following formula = 1/21 Where is the desired cut off frequency of the High pass filter. Input Cin R1 Output Amplifier 7.2.3 Bypass Capacitors Bypass capacitors are required to remove the ac ripple on the VDD pins. The value of these capacitors depends on the length of the VDD trace. In most cases, 10uF and 0.1uF are enough to get the good performance. 7.3 Layout considerations Good PCB layout and grounding techniques are essential to get the good audio performance. It is better to use low resistance traces as these devices are driving low impedance loads. The resistance of the traces has a significant effect on the output power delivered to the load. In order to dissipate more heat, use wide traces for the power and ground lines. NAU82011WG Datasheet Rev1.0 Page 12 of 16 Dec, 2012 7.4 Class D without filter The NAU82011WG is designed for use without any filter on the output line. That means the outputs can be directly connected to the speaker in the simplest configuration. This type of filter less design is suitable for portable applications where the speaker is very close to the amplifier. In other words, this is preferable in applications where the length of the traces between the speaker and amplifier is short. The following diagram shows this simple configuration. VOUTP VOUTN NAU82011WG outputs connected to speaker without filter circuit 7.5 Class D with filter In some applications, the shorter trace lengths are not possible because of speaker size limitations and other layout reasons. In these applications, the long traces will cause EMI issues. There are two types of filter circuits available to reduce the EMI effects. These are ferrite bead and LC filters. 7.5.1 Ferrite Bead filter The ferrite bead filters are used to reduce the high frequency emissions. The typical circuit diagram is shown in the figure. Ferrite Bead VOUTP 1nF Ferrite Bead VOUTN 1 nF NAU82011WG outputs connected to speaker with Ferrite Bead filter The characteristic of ferrite bead is such that it offers higher impedance at high frequencies. For better EMI performance select ferrite bead which offers highest impedance at high frequencies, so that it will attenuate the signals at higher frequencies. Usually the ferrite beads have low impedance in the audio range, so it will act as a pass through filter in the audio frequency range. NAU82011WG Datasheet Rev1.0 Page 13 of 16 Dec, 2012 7.5.2 LC filter The LC filter is used to suppress the low frequency emissions. The following diagram shows the NAU82011WG outputs connected to the speaker with LC filter circuit. RL is the resistance of the speaker coil. VOUTP L RL C L VOUTN C NAU82011WG outputs connected to speaker with LC filter L Input Output R C Standard Low pass LCR filter The following are the equations for the critically damped ( = 0.707) standard low pass LCR filter 2 = 1 () is the cutoff frequency = 0.707 = 1 2 The L and C values for differential configuration can be calculated by duplicating the single ended configuration values and substituting RL = 2R. NAU82011WG Datasheet Rev1.0 Page 14 of 16 Dec, 2012 8 8.1 Package Dimensions 8 pin MSOP package NAU82011WG Datasheet Rev1.0 Page 15 of 16 Dec, 2012 9 Ordering Information Nuvoton Part Number Description NAU82011WG Package Material: G = Green Package Package Type: W = 8-pin MSOP Package Version History VERSION NAU82011WG Datasheet Rev1.0 DATE PAGE DESCRIPTION Dec, 2012 NA Revision1.0 Table 1: Version History Important Notice Nuvoton Products are neither intended nor warranted for usage in systems or equipment, any malfunction or failure of which may cause loss of human life, bodily injury or severe property damage. Such applications are deemed, "Insecure Usage". Insecure usage includes, but is not limited to: equipment for surgical implementation, atomic energy control instruments, airplane or spaceship instruments, the control or operation of dynamic, brake or safety systems designed for vehicular use, traffic signal instruments, all types of safety devices, and other applications intended to support or sustain life. All Insecure Usage shall be made at customer's risk, and in the event that third parties lay claims to Nuvoton as a result of customer's Insecure Usage, customer shall indemnify the damages and liabilities thus incurred by Nuvoton. NAU82011WG Datasheet Rev1.0 Page 16 of 16 Dec, 2012