From Dallas Semiconductor, the DS4303 is a sample-and-infinite-hold voltage reference. The DS4303 replaces a standard voltage reference plus discrete resistor or potentiometer in embedded systems requiring voltage adjustment during factory calibration. Because it is electrically programmable, the DS4303 can be used to automate the calibration process, which contributes to improved quality, increased assembly throughput and lower production costs. Low cost ($0.35 per unit in quantities of /10,000) and small, 5-pin SOT23 packaging makes the DS4303 suitable for a variety of applications.
The DS4303 is intended for use in closed-loop calibration systems. It samples a user-applied input voltage and then "locks in" this voltage at its output, which in turn sets the parameter being calibrated. The system output must then be measured for accuracy and, if necessary, the input voltage can be adjusted and resampled to improve system output accuracy. This procedure can be repeated as many times as necessary.
The DS4303's output can be set to within 300 mV of the supply rails with ±1 mV accuracy when used in a closed-loop calibration system. Once the desired voltage has been locked into the DS4303, the digitized value is permanently stored in on-board nonvolatile memory that will retain the data even when powered down.
The DS4303 has a 2.4-V to 3.6-V supply range and a -40°C to +85°C operating temperature range. A related future product, the DS4305, will provide the same functionality as the new DS4303, but over a 4-V to 5.5-V supply range with ±1.5 mV accuracy.