1/4 Structure : Silicon Monolithic Integrated Circuit Product : Band-pass filter for spectrum analyzer for car audio systems Type :: BA3835F Function : 1. Built-in band pass filter for spectrum analyzer. BA3835F is for 5 bands. 2. Designed for 5V microcomputer power voltage. Absolute Maximum Ratings (Ta=25℃) Symbol Rating Parameter Power Supply voltage Vcc 7 Power dissipation Pd 450※ Operating temperature Topr -25～+75 Storage temperature Tstg -55～+125 ※This value decreases 4.5 mW/℃ for Ta=25℃ or more. Operating Voltage Range（Ta＝25℃） Parameter Symbol Vcc Power supply voltage Min. 4.5 Typ. 5.0 Unit V mW ℃ ℃ Max. 6.5 Unit V Electrical Characteristics （Unless specified particularly, Ta＝25℃，VCC＝5V，RL＝10MΩ,VAIN＝－30dBV，SEL＝1） Limit Symbol Parameter Unit Conditions Min. Typ. Max. VAIN＝0V，A，B，C，SEL＝0 Circuit current ICC － 8.5 13 mA Maximum output level VOM 4.0 4.8 － V Output offset voltage VOS － 30 150 mV Standard output level 1 VO1 0.65 1.35 1.70 V VAIN＝－14dBV,，Measured at each output VAIN＝0V，SEL＝0/1， Measured at each output （cycle time：Ts＝50ms） fIN＝105Hz，A＝0，B＝0，C＝1 Standard output level 2 VO2 0.65 1.35 1.70 V fIN＝340Hz，A＝0，B＝1，C＝0 Standard output level 3 VO3 0.65 1.35 1.70 V fIN＝1kHz，A＝1，B＝0，C＝0 Standard output level 4 VO4 0.65 1.35 1.70 V fIN＝3.4kHz，A＝1，B＝1，C＝0 Standard output level 5 VO5 0.65 1.35 1.70 V fIN＝10.5kHz，A＝1，B＝1，C＝1 Application example Note that ROHM cannot provide adequate confirmation of patents. The product described in this specification is 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 this product with equipment or devices which require an extremely high level of reliability and the malfunction of which 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. REV. G 2/4 Parameter Symbol Limit Min. Typ. Max. Unit Conditions RIN 80 100 120 kΩ fIN＝1kHz CMRR 25 50 － dB fIN＝1kHz，VAIN＝VCIN Logic input high level VIH 2.5 5.0 － V Logic input low level VIL － 0 0.5 V Output response time*1 TO － 5 10 μsec － Not applicable in the whan item 10 of operation notes applies. － Discharge level DL － 3 － dB Reset pulse width TR＝10μsecTyp.*2 Input impedance Common-mode rejection ratio *1 The time from the rise of A, B, C or SEL until the rise of AOUT (90％ of peak). If the output selection time is less than this, the output voltage is not guaranteed and the reset pulse is not generated. *2 Automatically generated internally based on the output select signal. For the duration that this signal is “H”, a resister is connected to the peak hold capacitor, and the output level drops by –3dB (typ.) for one pulse. *3 The Q of the bandpass filter is 3.5 ◎ Not designed for radiation resistance. Output select logic table SEL 0 1 1 1 1 1 1 1 1 A × 0 0 0 0 1 1 1 1 B × 0 0 1 1 0 0 1 1 C × 0 1 0 1 0 1 0 1 ×: Don't Care. Timing chart REV. G AOUT GND GND 105Hz 340Hz GND 1kHz GND 3.4kHz 10.5kHz 3/4 Block Diagram BIASC GND ＢＩ Ａ Ｓ １ １ ８ AOUT VREFC ２ Ｖ Ｒ Ｅ Ｆ １ ７ TEST RREF RE F F E R E N C E C U R R E N T ３ １ ６ N.C N.C １ ５ ４ 105Hz BPF PEAK HOLD DIFOUT ５ SEL RES A-C 340Hz BPF １ ４ PEAK HOLD RES N.C. 1kH z BPF ６ PEAK HOLD N.C MPX １ ３ ７ C DIF 3.4kH z BPF Terminal Number Terminal Name 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 BIASC VREFC RREF N.C DIFOUT N.C CIN AIN VCC A B C N.C SEL N.C TEST AOUT GND Outline Dimension RES CIN Terminal Number/ Terminal Name C PEAK HOLD １ ２ RES 10.5 k H z BPF AI N ８ A BA3835F PEAK HOLD B １ １ RES LOT No. VCC ９ A １ ０ DEC SOP18 （Unit：mm） Application example (1) Numbers and data in entries are representative design values and are not guaranteed values of the items. (2) Although we are confident in recommending the sample application circuits, carefully check their characteristics further when using them. When modifying externally attached component constants before use, determine them so that they have sufficient margins by taking into account variations in externally attached components and the Rohm LSI, not only for static characteristics but also including transient characteristics. (3) Absolute maximum ratings If applied voltage, operating temperature range, or other absolute maximum ratings are exceeded, the LSI may be damaged. Do not apply voltages or temperatures that exceed the absolute maximum ratings. If you think of a case in which absolute maximum ratings are exceeded, enforce fuses or other physical safety measures and investigate how not to apply the conditions under which absolute maximum ratings are exceeded to the LSI. (4) GND potential Make the GND pin voltage such that it is the lowest voltage even when operating below it. Actually confirm that the voltage of each pin does not become a lower voltage than the GND pin, including transient phenomena. REV. G 4/4 (5) Thermal design Perform thermal design in which there are adequate margins by taking into account the allowable power dissipation in actual states of use. (6) Shorts between pins and misinstallation When mounting the LSI on a board, pay adequate attention to orientation and placement discrepancies of the LSI. If it is misinstalled and the power is turned on, the LSI may be damaged. It also may be damaged if it is shorted by a foreign substance coming between pins of the LSI or between a pin and a power supply or a pin and a GND. (7) Operation in strong magnetic fields Adequately evaluate use in a strong magnetic field, since there is a possibility of malfunction. (8) Frequency characteristics The frequency characteristics of this IC are determined by the resistor connected between the RREF terminal and GND. For the specification conditions, the value of this resistor is 100kΩ. If it is necessary to set the frequency characteristics accurately, use a variable resistor (note: all bands will shift together). (9) Load characteristics To convert the bias sense output signal to the GND sense signal, the IC performs a V / I conversion, and then an I /V conversion using a 10kΩresistor (Typ.) for the output. Therefore, if the load circuit connected to the AOUT pin has a MOS structure there is no problem (eg. Microprocessor input port), but if the connected circuit has a low input impedance, it may cause the output level to drop. (10) External resistor for the control pin When using a common port for the output select control and FL drive, you must add a diode and resistor as shown in the right figure to prevent the FL drive “L” voltage from destroying the IC. BA3835F Provided that the IC is operated within the recommended operating conditions and the recommended temperature range, the basic circuit functions are guaranteed. Within these ranges, ratings for electrical characteristics for conditions other than those stipulated cannot be guaranteed, but the inherent function of the band pass filter will be maintained. (12) Output offset voltage The relationship between the output offset voltage and the output selection cycle (cycle time) for this IC is shown in Fig.5. The maximum output offset voltage of 150mV that is given in the electrical characteristics table is under the condition that Ts = 200ms. When Ts is greater than 50ms, the graph of the output offset voltage is a straight line at 150mV. When Ts is below 50ms, due to transient characteristics of the peak hold circuit, the graph is a line sloping downwards to the right. In other words, the shorter the cycle, the larger the output offset voltage. Furthermore, the output offset voltage may shift due to soldering or other temperature stresses from the surroundings. Therefore, when setting the spectral analyzer light level, take into consideration the points given above and make sure that it does not light by mistake during quiescent periods. Use the chart below as a guide for this, and, if necessary, leave even a larger margin. In this case, the “L” voltage applied to the internal comparator input terminal V1 is given by: R1 +R V1 = × Vref R1+R2+R To maintain a noise margin of at least 2.5V with respect to the comparator threshold level VREF, the representative values for VREF, R1 and R2 are 1.5V, 20kΩ, and 10kΩrespectively. This gives: 20kΩ+R × 1.5V+0.25V ＜ 1.5V 20kΩ+20kΩ+R And from this, the following condition is obtained: R＜30kΩ In this case, the “L” level voltage V2 for the IC will be: V2＜0.75V (11) Recommended operating ranges REV. G Notice Notes No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. The content specified herein is subject to change for improvement without notice. The content specified herein is for the purpose of introducing ROHM's products (hereinafter "Products"). If you wish to use any such Product, please be sure to refer to the specifications, which can be obtained from ROHM upon request. Examples of application circuits, circuit constants and any other information contained herein illustrate the standard usage and operations of the Products. The peripheral conditions must be taken into account when designing circuits for mass production. Great care was taken in ensuring the accuracy of the information specified in this document. However, should you incur any damage arising from any inaccuracy or misprint of such information, ROHM shall bear no responsibility for such damage. The technical information specified herein is intended only to show the typical functions of and examples of application circuits for the Products. ROHM does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by ROHM and other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the use of such technical information. The Products specified in this document are intended to be used with general-use electronic equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices). The Products specified in this document are not designed to be radiation tolerant. While ROHM always makes efforts to enhance the quality and reliability of its Products, a Product may fail or malfunction for a variety of reasons. Please be sure to implement in your equipment using the Products safety measures to guard against the possibility of physical injury, fire or any other damage caused in the event of the failure of any Product, such as derating, redundancy, fire control and fail-safe designs. ROHM shall bear no responsibility whatsoever for your use of any Product outside of the prescribed scope or not in accordance with the instruction manual. The Products are not designed or manufactured to be used with any equipment, device or system which requires an extremely high level of reliability the failure or malfunction of which may result in a direct threat to human life or create a risk of human injury (such as a medical instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuelcontroller or other safety device). ROHM shall bear no responsibility in any way for use of any of the Products for the above special purposes. If a Product is intended to be used for any such special purpose, please contact a ROHM sales representative before purchasing. If you intend to export or ship overseas any Product or technology specified herein that may be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to obtain a license or permit under the Law. Thank you for your accessing to ROHM product informations. More detail product informations and catalogs are available, please contact us. ROHM Customer Support System http://www.rohm.com/contact/ www.rohm.com © 2011 ROHM Co., Ltd. All rights reserved. R1120A