ADVANCE INFORMATION First Page of Data Sheet in Preparation __ General Description The MAX291-MAX297 are a family of 8th-order lowpass filters. The filter responses are fixed Butterworth, Bessel, or elliptic, with corner frequencies that are set over a 0.1Hz to 50kHz range by adjusting the clock rate. The Bessel filter is suited for low overshoot applications, while the Butterworth offers minimum passband ampli- tude ripple. Elliptic filters provide the steepest gain rolloff of the three types at the expense of passband ripple. The MAX292 features a typical spurious-free dynamic range of 72dB at 1kHz, making it ideal for dynamic applications such as analog-to-digital converter anti-aliasing and dig- ital-to-analog converter output filtering. MMALAA 8th-Order, Clock-Tunable Lowpass Filters Features @ Clock-Tunable Corner Frequency 0.1Hz to 50kHz Corner-Frequency Range @ Cascadable for Higher-Order Rolloff @ Low Distortion - SFDR 72dB at 1kHz Typ @ Internal or External Clock @ Operate from Single +5V Supply or +5V Supplies 8&-Pin DIP/16-Pin SO Packages Selection Tabie Filters with either 100:1 or 50:1 clock-to-corner frequency PART RESPONSE SHAPE prOCIG CORN roi ratios are available. 100:1 is recommended for corner MAK291 Butterwoth ~ frequencies up to 25kHz. Between 25kHz and SOkHz, utterwo 10:1 the 50:1 ratio filters are recommended. MAX292 Bessel 100:1 , | . . . Elliptic . The MAX291 MAX297 operate with either an internal or MAX293 (15 transition ratio) 100:1 external clock. The internal clock frequency is set by a single external capacitor. An uncommitted op amp (non- MAX294 Fe tansition ratio) 100:1 inverting input grounded) is supplied to build a contin- - ous-time lowpass filter for post-filtering or anti-aliasing. MAX295 Butterworth 50:1 = * MAX296 Bessel 50:1 Applications Enipti Ipuc . Anti-Aliasing Filters MAX297 (15 transition ratio) 50:1 DAC Post-Filtering 50H2/60Hz Line-Noise Filtering Pin Configurations Noise Analysis TOP VIEW 4 cuK IN [4 | ra | IN F ti 1 Di V MAAXLAA __. Functional Diagram [2] ~ maxzor-7 [7] op out [3] 6 | GND op- [4] [| out DIP 8TH ORDER IN af Tf). our WW , ne. fr] he] NC. feuk 700 Nc. [2] AAAXLAA fis) wc MAX291-7 1 CLK CLKIN [3] v4] IN AAAXLM CMOS LEVEL CLOCK v- [4] ha] v MAX292 10Hz 2 5MHz o out FB] 3} oN op- [6] 11] OUT v GND V+ ne. [7 fg] Nc | L | Nc. [3] fa] NC. -5V +5V so MAXI svi Maxim Integrated Products 6-99 MAXIM iS afegistered trademark of Maxim Integrated Products. ZL6CXVWN-L6ECXVUIN