MAX7401/MAX7405 19-4788 Rev 1 6/99 8th-Order, Lowpass, Bessel, Switched-Capacitor Filters General Description Features The MAX7401/MAX7405 8th-order, lowpass, Bessel, 8th-Order, Lowpass Bessel Filters switched-capacitor filters (SCFs) operate from a single Low Noise and Distortion: -82dB THD + Noise +5V (MAX7401) or +3V (MAX7405) supply. These devices draw only 2mA of supply current and allow cor- Clock-Tunable Corner Frequency (1Hz to 5kHz) ner frequencies from 1Hz to 5kHz, making them ideal 100:1 Clock-to-Corner Ratio for low-power post-DAC filtering and anti-aliasing appli- cations. They feature a shutdown mode that reduces Single-Supply Operation supply current to 0.2A. +5V (MAX7401) Two clocking options are available on these devices: +3V (MAX7405) self-clocking (through the use of an external capacitor) Low Power or external clocking for tighter corner-frequency control. 2mA (Operating Mode) An offset adjust pin allows for adjustment of the DC out- 0.2A (Shutdown Mode) put level. The MAX7401/MAX7405 Bessel filters provide low over- Available in 8-Pin SO/DIP Packages shoot and fast settling. Their fixed response simplifies Low Output Offset: 5mV the design task to selecting a clock frequency. Ordering Information Applications PART TEMP. RANGE PIN-PACKAGE ADC Anti-Aliasing CT2 Base Stations MAX7401CSA 0C to +70C 8 SO Post-DAC Filtering Speech Processing MAX7401CPA 0C to +70C 8 Plastic DIP Air-Bag Electronics MAX7401ESA -40C to +85C 8 SO MAX7401EPA -40C to +85C 8 Plastic DIP MAX7405CSA 0C to +70C 8 SO Pin Configuration MAX7405CPA 0C to +70C 8 Plastic DIP MAX7405ESA -40C to +85C 8 SO TOP VIEW MAX7405EPA -40C to +85C 8 Plastic DIP COM 1 8 CLK Typical Operating Circuit IN 2 7 SHDN MAX7401 MAX7405 GND 3 6 OS V 4 5 OUT DD V SUPPLY 0.1F SO/DIP V DD SHDN INPUT IN OUT OUTPUT MAX7401 MAX7405 CLOCK CLK COM OS 0.1F GND Maxim Integrated Products 1 For free samples & the latest literature: 8th-Order, Lowpass, Bessel, Switched-Capacitor Filters ABSOLUTE MAXIMUM RATINGS V to GND Continuous Power Dissipation (T = +70C) DD A MAX7401..............................................................-0.3V to +6V 8-Pin SO (derate 5.88mW/C above +70C)................471mW MAX7405..............................................................-0.3V to +4V 8-Pin DIP (derate 9.09mW/C above +70C)...............727mW IN, OUT, COM, OS, CLK ...........................-0.3V to (V + 0.3V) Operating Temperature Ranges DD SHDN........................................................................-0.3V to +6V MAX740 C A ....................................................0C to +70C OUT Short-Circuit Duration...................................................1sec MAX740 E A .................................................-40C to +85C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10sec) .............................+300C 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 CHARACTERISTICSMAX7401 (V = +5V, filter output measured at OUT, 10k 50pF load to GND at OUT, OS = COM, 0.1F from COM to GND, DD SHDN = V , f = 100kHz, T = T to T , unless otherwise noted. Typical values are at T = +25C.) DD CLK A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS FILTER CHARACTERISTICS Corner Frequency f (Note 1) 0.001 to 5 kHz C Clock-to-Corner Ratio f /f 100:1 CLK C Clock-to-Corner Tempco 10 ppm/C Output Voltage Range 0.25 V - 0.25 V DD Output Offset Voltage V V = V = V / 2 5 25 mV OFFSET IN COM DD DC Insertion Gain with V = V / 2 (Note 2) -0.1 0.15 0.3 dB COM DD Output Offset Removed Total Harmonic Distortion f = 200Hz, V = 4Vp-p, IN IN THD+N -82 dB plus Noise measurement bandwidth = 22kHz OS Voltage Gain to OUT A 1 V/V OS Input Voltage Range at OS V V 0.1 V OS COM V / 2 V / 2 DD DD Input, COM externally driven V / 2 DD - 0.5 + 0.5 COM Voltage Range V V COM V / 2 V / 2 DD DD Output, COM internally biased V / 2 DD - 0.2 + 0.2 Input Resistance at COM R 75 125 k COM Clock Feedthrough 10 mVp-p Resistive Output Load Drive R 10 1 k L Maximum Capacitive Load at C 50 500 pF L OUT Input Leakage Current at COM SHDN = GND, V = 0 to V 0.1 10 A COM DD Input Leakage Current at OS V = 0 to (V - 1V) (Note 3) 0.1 10 A OS DD CLOCK Internal Oscillator Frequency f C = 1000pF (Note 4) 29 38 48 kHz OSC OSC Clock Input Current I V = 0 or 5V 15 30 A CLK CLK Clock Input High V V - 0.5 V IH DD Clock Input Low V 0.5 V IL 2 MAX7401/MAX7405