The MAX1447/MAX1496/MAX1498 low-power, 3.5- and
4.5-digit, analog-to-digital converters (ADCs) with integrated
light-emitting diode (LED) drivers operate from a
single 2.7V to 5.25V power supply. They include an
internal reference, a high-accuracy on-chip oscillator,
and a multiplexed LED display driver. An internal charge
pump generates the negative supply needed to power
the integrated input buffers for single-supply operation.
The ADC is configurable for either a ±2V or ±200mV
input range and it outputs its conversion results to an
LED. The MAX1496 is a 3.5-digit (±1999 count) device
and the MAX1447/MAX1498 are 4.5-digit (±19,999
count) devices.
The MAX1447/MAX1496/MAX1498 do not require external
precision integrating capacitors, autozero capacitors,
crystal oscillators, charge pumps, or other circuitry
required with dual-slope ADCs (commonly used in
panel meter circuits).
These devices also feature on-chip buffers for the differential
signal and reference input, allowing direct
interface with high-impedance signal sources. In addition,
they use continuous internal offset-calibration and
offer >100dB rejection of 50Hz and 60Hz line noise.
Other features include data hold and peak detection
and overrange/underrange detection. The MAX1447
features on-demand enhanced offset calibration for
improved offset performance.
The MAX1447/MAX1498 are available in a 32-pin, 7mm
? 7mm TQFP package and the MAX1496 is available in
28-pin SSOP and 28-pin PDIP packages. All devices in
this family operate over the -40°C to +85°C extended
temperature range.