The AD565A and AD566A are fast 12-bit digital-to-analog converters that incorporate the latest advances in analog circuit design to achieve high speeds at low cost. The AD565A and AD566A use 12 precision， high speed bipolar current-steering switches， a control amplifier， and a laser-trimmed thin-film resistor network to produce a very fast， high accuracy analog output current. The AD565A also includes a buried Zener reference that features low noise， long-term stability， and temperature drift characteristics comparable to the best discrete reference diodes. The combination of performance and flexibility in the AD565A and AD566A has resulted from major innovations in circuit design， an important new high speed bipolar process， and continuing advances in laser-wafer-trimming techniques （LWT）。 The AD565A and AD566A have a 10%–90% full-scale transition time less than 35 ns and settle to within ±1/2 LSB in 250 ns max （350 ns for AD566A）。 Both are laser-trimmed at the wafer level to ±1/8 LSB typical linearity and are specified to ±1/4 LSB max error （K and T grades） at +25°C. High speed and accuracy make the AD565A and AD566A the ideal choice for high speed display drivers as well as for fast analog-to-digital converters. The laser trimming process that provides the excellent linearity is also used to trim both the absolute value and the temperature coefficient of the reference of the AD565A， resulting in a typical full-scale gain TC of 10 ppm/°C. When tighter TC performance is required or when a system reference is available， the AD566A may be used with an external reference.