The MAX7426/MAX7427 are 5th-order lowpass filters that operate from a single supply voltage of +5V (MAX7426) or +3V (MAX7427). The devices draw only 0.8mA of supply current and allow corner frequencies from 1Hz to 12kHz, making them ideal for low-power post-DAC filtering and anti-aliasing applications. They can be put into a low-power mode, reducing supply current to 0.2µA. Two clocking options are available: self-clocking (through the use of an external capacitor) or external clocking for tighter cutoff-frequency control. An offset-adjust pin allows for adjustment of the DC output level. The MAX7426/MAX7427 deliver 37dB of stopband rejection and a sharp rolloff with a transition ratio of 1.25. Their fixed response limits the design task to selecting a clock frequency. Applications include ADC Anti-Aliasing, CT2 Base Stations, Post-DAC Filtering, and Speech Processing.
The MAX7426/MAX7427 family provides 5th‑order elliptic low‑pass filtering for applications such as anti‑aliasing and post‑DAC filtering. They operate from a single +5 V (MAX7426) or +3 V (MAX7427) supply and draw only 0.8 mA in normal mode, dropping to 0.2 µA in shutdown.
Key features include a corner‑frequency range of 1 Hz to 12 kHz, a 100:1 clock‑to‑corner ratio, low output offset of +4 mV, 37 dB stopband rejection, and a transition ratio of 1.25. The devices are offered in 8‑pin UMAX/PDIP packages and support both self‑clocking and external clocking for precise frequency control.
| Supply Voltage | +5 V (MAX7426) / +3 V (MAX7427) |
|---|---|
| Operating Mode Supply Current | 0.8 mA |
| Shutdown Current | 0.2 µA |
| Stopband Rejection | 37 dB |
| Transition Ratio | 1.25 |
| Corner‑Frequency Range | 1 Hz to 12 kHz |
| Clock‑to‑Corner Ratio | 100:1 |
| Power‑Supply Rejection Ratio (PSRR) | 70 dB |
The MAX7426 operates from a single +5 V supply.
The MAX7427 draws 0.2 µA in shutdown mode.
The filters can be tuned from 1 Hz up to 12 kHz.
They provide about 37 dB of stopband rejection.