The MAX148/MAX149 10-bit data-acquisition systems combine an 8-channel multiplexer, high-bandwidth track/hold, and serial interface with high conversion speed and low power consumption. They operate from a single +2.7V to +5.25V supply, and sample to 133ksps. Both devices’ analog inputs are software configurable for unipolar/bipolar and single-ended/differential operation. The 4-wire serial interface connects directly to SPI™/ QSPI™ and MICROWIRE™ devices without external logic. A serial-strobe output allows direct connection to TMS320-family digital signal processors. The MAX148/ MAX149 use either the internal clock or an external serial- interface clock to perform successive-approximation analog-to-digital conversions. The MAX149 has an internal 2.5V reference, while the MAX148 requires an external reference. Both parts have a reference-buffer amplifier with a ±1.5% voltage- adjustment range. These devices provide a hard-wired SHDN pin and a software-selectable power-down, and can be pro- grammed to automatically shut down at the end of a con- version. Accessing the serial interface automatically powers up the MAX148/MAX149, and the quick turn-on time allows them to be shut down between all conver- sions. This technique can cut supply current to under 60µA at reduced sampling rates. The MAX148/MAX149 are available in a 20-pin DIP and a 20-pin SSOP. For 4-channel versions of these devices, see the MAX1248/MAX1249 data sheet.
The MAX148 and MAX149 are 10‑bit, 8‑channel analog‑to‑digital converters that operate from a single supply of +2.7 V to +5.25 V. They feature a low‑power consumption of about 1.2 mA at 133 ksps (3 V supply) and provide both unipolar/bipolar and single‑ended/differential input configurations. The devices include an internal 2.5 V reference (MAX149) or an external reference option (MAX148) and support a 4‑wire serial interface compatible with many microprocessors.
The datasheet includes absolute maximum ratings, electrical characteristics, timing specifications, pin descriptions, and package dimensions for the 20‑pin DIP and SSOP versions. Detailed sections cover digital input/output voltage levels, shutdown behavior, conversion rate, and typical operating characteristics such as SINAD, THD, and SFDR.
| Supply Voltage Range | +2.7 V to +5.25 V |
|---|---|
| Resolution | 10 bits |
| Maximum Sample Rate | 133 ksps |
| Low‑Power Consumption | 1.2 mA (133 ksps, 3 V supply) |
| Internal Reference Voltage (MAX149) | 2.5 V |
| Shutdown Current (Full Power‑Down) | 12 µA |
The devices operate from a single supply of +2.7 V to +5.25 V.
Both ADCs provide a 10‑bit resolution.
They draw about 1.2 mA when operating at 133 ksps with a 3 V supply.
Yes, the MAX149 includes an internal 2.5 V reference.