AD53509G

The AD53509 is a single chip that performs the pin electronics functions of driver, comparator, and active load in ATE VLSI and memory testers. In addition, a Schottky diode bridge for the active load and a VCOM buffer are included internally.

The driver is a proprietary design that features three active states: data high mode, data low mode, and term mode as well as an inhibit state. The output voltage range is −2 V to +7 V to accommodate a wide variety of test devices. The output leakage is typically <250 nA over the signal range.

The dual comparator, with an input range equal to the driver output range, features built-in latches and ECL-compatible outputs. The outputs are capable of driving 50 Ω signal lines terminated to −2 V. Signal tracking capability is >5 V/ns.

The active load can be set up to 40 mA load current with less than a 10 μA linearity error through the set range. I_OH, I_OL, and the buffered VCOM are independently adjustable. On-board Schottky diodes provide high speed switching and low capacitance.

Also included on the chip is an on-board temperature sensor whose purpose is to give an indication of the surface temperature of the DCL. This information can be used to measure θ_JC and θ_JA or flag an alarm if proper cooling is lost. Output from the sensor is a current sink that is proportional to absolute temperature. The gain is trimmed to a nominal value of 1.0 μA/K. For example, the output current can be sensed by using a 10 kΩ resistor connected from 10 V to the THERM pin. A voltage drop across the resistor then develops that equals

10 K × 1 μA/K = 10 mV/K = 2.98 V (at room temperature)

Applications

Data Sheet, Rev. B, 3/08