+2.7V, Low-Power, 8-Channel, Serial 12-Bit ADCs
DescriptionThe MAX146/MAX147 12-bit data-acquisition systems combine an 8-channel multiplexer, high-bandwidth track/hold, and serial interface with high conversion speed and low power consumption. The MAX146 operates from a single +2.7V to +3.6V supply; the MAX147 operates from a single +2.7V to +5.25V supply. 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 MAX146/MAX147 use either the internal clock or an external serial-interface clock to perform successive-approximation analog-to-digital conversions.
The MAX146 has an internal 2.5V reference, while the MAX147 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-bar pin and a software-selectable power-down, and can be programmed to automatically shut down at the end of a conversion. Accessing the serial interface automatically powers up the MAX146/MAX147, and the quick turn-on time allows them to be shut down between all conversions. This technique can cut supply current to under 60µA at reduced sampling rates.
The MAX146/MAX147 are available in 20-pin DIP and SSOP packages.
For 4-channel versions of these devices, see the MAX1246/MAX1247 data sheet.
- 8-Channel Single-Ended or 4-Channel Differential Inputs
- Single-Supply Operation
- +2.7V to +3.6V (MAX146)
- +2.7V to +5.25V (MAX147)
- Internal 2.5V Reference (MAX146)
- Low Power
- 1.2mA (133ksps, 3V supply)
- 54µA (1ksps, 3V supply)
- 1µA (power-down mode)
- SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire Serial Interface
- Software-Configurable Unipolar or Bipolar Inputs
- 20-Pin DIP/SSOP Packages
- Battery-Powered Applications
- Data Acquisition
- Medical Instruments
- Pen Digitizers
- Portable Data Logging
- Process Control
|Input Channels||Conv. Rate|
|ADC Architecture||Data Bus||Diff/S.E. Input||Internal VREF|
Technical DocumentsApp Note 1108 Understanding Single-Ended, Pseudo-Differential and Fully-Differential ADC Inputs
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|