Two-terminal current source supplies 200 mA.
By Paul Rako, Technical Editor -- EDN, May 19, 2009
Linear Technology Corp’s new LT3092 two-terminal current source can supply 0.5 to 200mA of current at a 1% initial accuracy. The device operates at 1.5 to 40V and exhibits less-than-1-mV typical load regulation and less-than-0.001%/V typical line regulation. You use two resistors to set a ratio that controls the current output. The device needs no bypass capacitance on the input or the output in most ranges of operation, even when you use it at 0.5V. The output is short-circuit-protected and can withstand reverse voltage, and a thermal-shutdown circuit prevents overheating. You can configure the devices in parallel to provide greater current or to share power dissipation across several surface-mounted devices, or you can stack them in series to provide for greater voltage compliance.
The LT3092 suits use in industrial-control and instrumentation, telecom, automotive, medical, consumer, and general-purpose applications. It is ideal for intrinsically safe circuits in which its current limit prevents sparking when the output is shorted. Although the device operates similarly to a source-connected JFET, it exhibits no temperature drift or poor initial accuracies of JFETs.
The LT3092 comes in a 3×3-mm, eight-pin DFN, eight-pin SOT-23, and three-pin SOT-223 packages. The LT3092MP version operates in the −55 to +125°C junction-temperature-range, and the LT3092E and LT3092I versions operate in the −40 to +125°C range. Prices range from $1.65 to $4.73 (1000), depending on package and temperature-range options.
