The AD9239 is a quad, 12-bit, 250 MSPS analog-to-digital converter (ADC) with an on-chip temperature sensor and a high speed serial interface. It is designed to support digitizing high frequency, wide dynamic range signals with an input bandwidth up to 780 MHz. The output data are serialized and presented in packet format, consisting of channel-specific information, coded samples, and error correction code. The ADC requires a single 1.8 V power supply and the input clock may be driven differentially with a sine wave, LVPECL, TTL, or LVDS. A clock duty cycle stabilizer allows high performance at full speed with a wide range of clock duty cycles. The on-chip reference eliminates the need for external decoupling and can be adjusted by means of SPI control. Various power-down and standby modes are supported. The ADC typically consumes 145 mW per channel with the digital link still in operation when standby operation is enabled.