MAX9720 19-2859 Rev 0 4/03 50mW, DirectDrive, Stereo Headphone Amplifier with SmartSense and Shutdown General Description Features The MAX9720 stereo headphone amplifier combines DirectDrive Eliminates Bulky DC-Blocking Maxims DirectDrive architecture and SmartSense, an Capacitors automatic mono/stereo detection feature. Conventional SmartSense Automatic Short Detection headphone amplifiers require a bulky DC-blocking Low 5mA Quiescent Current capacitor between the headphone and the amplifier. Fixed Gain Eliminates External Feedback Network DirectDrive produces a ground-referenced output from MAX9720A: -1V/V a single supply, eliminating the need for large DC- MAX9720B: -1.41V/V blocking capacitors, saving cost, board space, and component height. 50mW per Channel Output Power SmartSense automatically detects the presence of a Ultra-Low 0.003% THD+N short at either the left or right amplifier output. Under a High PSRR (92dB at 217Hz) fault condition, the shorted output is automatically dis- Integrated Click-and-Pop Suppression abled and the stereo input signal is automatically mixed 1.8V to 3.6V Single-Supply Operation and routed to the remaining active channel. This feature is useful in cell phone and PDA applications where a Thermal Overload Protection variety of headphone jacks with unknown loads can be Available in Space-Saving Packages inserted into the headphone jack socket. SmartSense 16-Bump UCSP (2mm x 2mm x 0.6mm) prevents both damage to the amplifier and eliminates 16-Pin TSSOP battery drain into a shorted load. The MAX9720 delivers up to 50mW per channel into a 16 load and has an ultra-low 0.003% THD+N. A high Ordering Information (92dB at 217kHz) power-supply rejection ratio (PSRR) PIN/BUMP- GAIN allows the device to operate from noisy digital supplies PART TEMP RANGE PACKAGE (V/V) without additional power conditioning. The gain of the o o MAX9720 is set internally, further reducing component MAX9720AEBE-T -40 C to +85 C 16 UCSP-16 -1 count. Two gain options are available (-1V/V, MAX9720A o o MAX9720BEBE-T -40 C to +85 C 16 UCSP-16 -1.41 and -1.41V/V, MAX9720B). The headphone outputs o o MAX9720AEUE -40 C to +85 C 16 TSSOP -1 include a comprehensive click-and-pop circuitry that o o eliminates audible glitches on startup and shutdown. A MAX9720BEUE -40 C to +85 C 16 TSSOP -1.41 shutdown mode provides a fast 250s turn-on time. The MAX9720 operates from a single 1.8V to 3.6V supply and consumes only 5mA of supply current. The Simplified Block Diagram MAX9720 also features thermal overload protection, and is specified over the extended -40C to +85C tem- perature range. The MAX9720 is available in a tiny 3.6V TO 1.8V (2mm x 2mm x 0.6mm) 16-bump chip-scale package SUPPLY (UCSP) and a 16-pin TSSOP package. Applications MAX9720 R IN PDAs Smart Phones R OUT Cellular Phones Tablet PCs HPS MP3 Players Portable Audio Equipment MODE1 + SmartSense MODE2 Notebook PCs ALERT L SmartSense and UCSP are trademarks of Maxim Integrated OUT L IN Products, Inc. Pin Configuration and Typical Application Circuit appear at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.50mW, DirectDrive, Stereo Headphone Amplifier with SmartSense and Shutdown ABSOLUTE MAXIMUM RATINGS PGND to SGND .....................................................-0.3V to +0.3V Output Short Circuit to GND or V Continuous DD ............................... PV to SV .........................................................-0.3V to +0.3V Continuous Power Dissipation (T = +70C) SS SS A V to PGND or SGND ............................................-0.3V to +4V 16-Bump UCSP (derate 8.2mW/C above +70C) .......659mW DD PV and SV to PGND or SGND ..........................-4V to +0.3V 16-Pin TSSOP (derate 9.4mW/C above +70C) .......754.7mW SS SS IN , OUT , and HPS to SGND.......(SV - 0.3V) to (V + 0.3V) Junction Temperature......................................................+150C SS DD C1P to PGND...............................(PGND - 0.3V) to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C DD C1N to PGND .............................(PV - 0.3V) to (PGND + 0.3V) Storage Temperature Range .............................-65C to +150C SS ALERT to PGND .......................................................-0.3V to +4V Bump Temperature (soldering) MODE to PGND........................................-0.3V to (V + 0.3V) Reflow ...........................................................................+235C DD TIME to SGND ............................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C DD 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 conditions 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 (V = V = V = 3.0V, PGND = SGND = 0V, R = , C1 = C2 = 2.2F. T = T to T unless otherwise noted. DD MODE1 MODE2 L A MIN MAX, Typical values are at T = +25C.) (Note 1) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS GENERAL Supply Voltage Range V Inferred from PSRR test 1.8 3.6 V DD Stereo mode 5 8.4 Supply Current I mA DD M ono mod e ( M ODE 1 = V , MOD E 2 = GN D ) 3 D D Shutdown Supply Current I MODE1 = MODE2 = GND 6 10 A SHDN Turn-On/Turn-Off Time t 250 s S CHARGE PUMP Oscillator Frequency f 272 320 368 kHz OSC HEADPHONE AMPLIFIERS MAX9720A -1.02 -1 -0.98 Voltage Gain A V/V V MAX9720B -1.443 -1.415 -1.386 Gain Match A Between OUTL and OUTR 1% V MAX9720A -5 -0.8 +3.6 Total Output Offset Voltage V mV OS (Note 3) MAX9720B -6.5 -1 +4.5 Input Resistance R 10 15 20 k IN 1.8V V 3.6V DD DC 76 92 (Note 3) Power-Supply Rejection Ratio PSRR f = 217Hz 92 dB RIPPLE V = 3.0V, DD 200mV ripple f = 1kHz 86 P-P RIPPLE (Note 3) f = 20kHz 61 RIPPLE R = 32 50 THD+N = 1%, f = L IN Output Power P mW OUT 1kHz, T = +25C A R = 16 32 50 L 2 MAX9720