Audio ICs Low-current audio headphone driver BA3575FS The BA3575FS is a headphone driver with an AVC circuit that keeps the output below a fixed level. It features low current consumption, and low output noise, and is ideal for use in portable digital audio equipment. Applications Portable CD players Features 1) Low current consumption (when VCC = 2.4 V, the quiescent current is 4.9mA). 2) Suitable for use in digital audio equipment (voltage gain: GV = 11.8dB, output noise voltage: VNO = -102dBm typ.). 3) ATT circuit (gain switch). 4) AVC (Auto Volume Control) circuit, for output limiting. 5) Internal standby switch. 6) Internal mute switch. 7) Internal ripple filter. 8) No output coupling capacitor required. 9) Internal beep circuit. 10) SSOP-A20 package. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 871 Audio ICs Block diagram 872 BA3575FS Audio ICs BA3575FS Pin descriptions 873 Audio ICs 874 BA3575FS Audio ICs BA3575FS 875 Audio ICs 876 BA3575FS Audio ICs BA3575FS Electrical characteristics(unless otherwis noted, Ta = 25C, VCC = 2.4V, RL = 16, f = 1kHz, DIN AUDIO, PWSW = ON, MUTE = OFF, ATT = OFF, and AVC = OFF) 877 Audio ICs Measurement circuit 878 BA3575FS Audio ICs BA3575FS Measurement circuit switch table (Fig.1) 879 Audio ICs Application example 880 BA3575FS Audio ICs BA3575FS Application notes (1) "Pop" sound By operating the BA3575FS according to the timing chart shown in Fig.3, it is possible to suppress generation of "pop" noise in the headphone output. (2) Application circuits Provided the recommended circuit constants are used, the application circuits should function correctly. However, we recommend that you confirm the characteristics of the circuits in actual use. If you change the circuit constants, check both the static and transient characteristics of the circuit, and allow sufficient margin to accommodate variations between both ICs and external components. In particular, the capacitors connected to the OUT 1, OUT 2, and VREF pins must have low impedance at high frequency, and have sufficient margin in their temperature characteristics. Also, use an electrolytic or tantalum capacitor for the capacitor connected to the BIASOUT terminal. (3) The PCB pattern for the external components should be designed carefully to prevent oscillation and degradation of the circuit characteristics. Keep the wiring tracks as short as possible, and ensure that there is no impedance between the common connections. The ripple filter pins (1 and 2) and the bias amplifier pins (3 and 4) cannot be used for external power supplies or reference voltages. 881 Audio ICs (4) Recommended operating conditions The curves in Fig.4 below show the maximum allowable power output (PO (Max.) / ch) plotted against the supply voltage (VCC) for different values of ambient temperature (Ta). When VCC 3.6 V, operate the IC in the region below the dotted line, and do not exceed it. If the maximum allowable power output for each channel (PO (Max.) / ch) is exceeded, the internal power consumption will exceed the power dissipation capacity of the package, and destroy the IC. Electrical characteristics curves 882 BA3575FS Audio ICs BA3575FS External dimensions (Units: mm) 883 Appendix Notes No technical content pages of this document may be reproduced in any form or transmitted by any means without prior permission of ROHM CO.,LTD. The contents described herein are subject to change without notice. The specifications for the product described in this document are for reference only. Upon actual use, therefore, please request that specifications to be separately delivered. Application circuit diagrams and circuit constants contained herein are shown as examples of standard use and operation. Please pay careful attention to the peripheral conditions when designing circuits and deciding upon circuit constants in the set. Any data, including, but not limited to application circuit diagrams information, described herein are intended only as illustrations of such devices and not as the specifications for such devices. ROHM CO.,LTD. disclaims any warranty that any use of such devices shall be free from infringement of any third party's intellectual property rights or other proprietary rights, and further, assumes no liability of whatsoever nature in the event of any such infringement, or arising from or connected with or related to the use of such devices. Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or otherwise dispose of the same, no express or implied right or license to practice or commercially exploit any intellectual property rights or other proprietary rights owned or controlled by ROHM CO., LTD. is granted to any such buyer. Products listed in this document use silicon as a basic material. Products listed in this document are no antiradiation design. The products listed in this document are designed to be used with ordinary electronic equipment or devices (such as audio visual equipment, office-automation equipment, communications devices, electrical appliances and electronic toys). Should you intend to use these products with equipment or devices which require an extremely high level of reliability and the malfunction of with would directly endanger human life (such as medical instruments, transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel controllers and other safety devices), please be sure to consult with our sales representative in advance. About Export Control Order in Japan Products described herein are the objects of controlled goods in Annex 1 (Item 16) of Export Trade Control Order in Japan. In case of export from Japan, please confirm if it applies to "objective" criteria or an "informed" (by MITI clause) on the basis of "catch all controls for Non-Proliferation of Weapons of Mass Destruction. Appendix1-Rev1.0