MAX9725 19-3465 Rev 4 3/09 1V, Low-Power, DirectDrive, Stereo Headphone Amplifier with Shutdown General Description Features Low Quiescent Current The MAX9725AMAX9725D fixed-gain, stereo head- 2.1mA (MAX9725AMAX9725D) phone amplifiers are ideal for portable equipment where 2.3mA (MAX9725E) board space is at a premium. The MAX9725E offers the Single-Cell, 0.9V to 1.8V Single-Supply Operation flexibility to adjust the gain with external input and feed- Fixed Gain Eliminates External Feedback Network back resistors. The MAX9725AMAX9725E use a unique MAX9725A: -2V/V DirectDrive architecture to produce a ground-referenced MAX9725B: -1.5V/V output from a single supply, eliminating the need for large MAX9725C: -1V/V DC-blocking capacitors, saving cost, board space, and MAX9725D: -4V/V component height. Fixed gains of -2V/V (MAX9725A), Adjustable Gain with External Input and Feedback -1.5V/V (MAX9725B), -1V/V (MAX9725C), and -4V/V Resistors (MAX9725D) further reduce external component count. MAX9725E: Minimum Stable Gain of -1V/V The adjustable gain of the MAX9725E DirectDrive head- Ground-Referenced Outputs Eliminate DC Bias phone amplifier allows for any gain down to -1V/V using No Degradation of Low-Frequency Response Due external resistors. to Output Capacitors The MAX9725 delivers up to 20mW per channel into a 20mW per Channel into 32 32 load and achieves 0.006% THD+N. An 80dB at 1kHz Low 0.006% THD+N power-supply rejection ratio (PSRR) allows the MAX9725 High PSRR (80dB at 1kHz) to operate from noisy digital supplies without an additional Integrated Click-and-Pop Suppression linear regulator. The MAX9725 includes 8kV ESD protec- Low-Power Shutdown Control tion on the headphone output. Comprehensive click-and- Short-Circuit Protection pop circuitry suppresses audible clicks and pops at startup and shutdown. A low-power shutdown mode 8kV ESD-Protected Amplifier Outputs reduces supply current to 0.6A (typ). Available in Space-Saving Packages 12-Bump UCSP (1.54mm x 2.02mm x 0.6mm) The MAX9725 operates from a single 0.9V to 1.8V supply, 12-Pin Thin QFN (4mm x 4mm x 0.8mm) allowing the device to be powered directly from a single AA or AAA battery. The MAX9725 consumes only Block Diagrams 2.1mA of supply current, provides short-circuit protection, and is specified over the extended -40C to +85C tem- perature range. The MAX9725 is available in a tiny C3 SINGLE (1.54mm x 2.02mm x 0.6mm) 12-bump chip-scale V DD 1.5V CELL package (UCSP) and a 12-pin thin QFN package AA OR AAA BATTERY (4mm x 4mm x 0.8mm). MAX9725AMAX9725D Applications DirectDrive OUTPUTS MP3 Players Smart Phones INL ELIMINATE DC-BLOCKING Cellular Phones Portable Audio Equipment CAPACITORS. OUTL PDAs Ordering Information C1P PV SS INVERTING T O P G A IN PART PIN-PA CK A G E CHARGE PUMP M A RK ( V/V) C2 C1N V SS MAX9725AEBC+TG 45 12 UC S P+AC K -2 M AX9725AET C+ 12 TQFN-EP* + AAEW - 2 OUTR INR MAX9725BEBC+TG 45 12 UC S P+AC L -1. 5 Ordering Information continued at end of data sheet. Note: All devices are specified over the -40C to +85C operating temperature range. SGND PGND +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. Block Diagrams continued at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. Pin Configurations appear at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE1V, Low-Power, DirectDrive, Stereo Headphone Amplifier with Shutdown ABSOLUTE MAXIMUM RATINGS SGND to PGND .....................................................-0.3V to +0.3V SHDN to SGND or PGND.........................................-0.3V to +4V V to SGND or PGND ............................................-0.3V to +2V Output Short-Circuit Current ......................................Continuous DD V to PV ...........................................................-0.3V to +0.3V SS SS Continuous Power Dissipation (T = +70C) A C1P to PGND..............................................-0.3V to (V + 0.3V) 12-Bump UCSP (derate 6.5mW/C above +70C)....518.8mW DD C1N to PGND............................................(PV - 0.3V) to +0.3V SS 12-Pin Thin QFN (derate 16.9mW/C above +70C) ..1349.1mW V , PV to GND ....................................................+0.3V to -2V Junction Temperature......................................................+150C SS SS OUTR, OUTL, INR, INL to SGND Operating Temperature Range ...........................-40C to +85C (MAX9725AMAX9725D)..............(V - 0.3V) to (V + 0.3V) SS DD Storage Temperature Range .............................-65C to +150C OUTR, OUTL to SGND Bump Temperature (soldering) Reflow............................+230C (MAX9725E)..................................(V - 0.3V) to (V + 0.3V) SS DD Lead Temperature (soldering, 10s) .................................+300C INR, INL to SGND (MAX9725E)...................................-4V to +4V 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 (MAX9725AMAX9725D) (V = 1.5V, V = V = 0V, V = 1.5V, V = V , C1 = C2 = 1F, C = 1F, R = , T = T to T unless other- DD PGND SGND SHDN SS PVSS IN L A MIN MAX, wise noted. Typical values are at T = +25C.) (See the Functional Diagrams.) (Note 1) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage Range V Guaranteed by PSRR test 0.9 1.8 V DD Quiescent Supply Current I Both channels active 2.1 3.3 mA DD T = +25C 0.6 10 A Shutdown Current I V = 0V A SHDN SHDN T = -40C to +85C30 A Shutdown to Full Operation t 180 s ON V V = 0.9V to 1.8V 0.7 x V IH DD DD SHDN Thresholds V V V = 0.9V to 1.8V 0.3 x V IL DD DD SHDN Input Leakage Current I V = 0.9V to 1.8V (Note 2) 1A LEAK DD CHARGE PUMP Oscillator Frequency f 493 580 667 kHz OSC AMPLIFIERS MAX9725A -2.04 -2.00 -1.96 MAX9725B -1.53 -1.5 -1.47 Voltage Gain A V/V V MAX9725C -1.02 -1.00 -0.98 MAX9725D -4.08 -4.00 -3.92 Gain Match A 0.5 % V MAX9725A/MAX9725D 0.3 1.05 Input AC-coupled, Total Output Offset Voltage V R = 32 to GND, MAX9725B 0.45 1.58 mV OS L T = +25C A MAX9725C 0.6 2.1 Input Resistance R 15 25 35 k IN V = 0.9V to 1.8V, T = +25C6080 DD A Power-Supply Rejection Ratio PSRR f = 1kHz 70 dB IN 100mV ripple P-P f = 20kHz 62 IN R = 32 10 20 L V = 1.5V DD R = 16 25 L Output Power (Note 3) P mW OUT V = 1.0V, R = 32 7 DD L V = 0.9V, R = 32 6 DD L 2 MAX9725