The MAX155/MAX156 are high-speed, 8-bit, multichannel analog-to-digital converters (ADCs) with simultaneous track/holds (T/Hs) to eliminate timing differences between input channel samples. The MAX155 has 8 analog input channels and the MAX156 has 4 analog input channels. Each channel has its own T/H, and all T/Hs sample at the same instant. The ADC converts a channel in 3.6µs and stores the result in an internal 8x8 RAM. The MAX155/MAX156 also feature a 2.5V internal reference and power-down capability, providing a complete, sampling data-acquisition system.When operating from a single +5V supply, the MAX155/MAX156 perform either unipolar or bipolar, single-ended or differential conversions. For applications requiring wider dynamic range or bipolar conversions around ground, the VSSsupply pin may be connected to -5V.Conversions are initiated with a pulse to the active-low WR pin, and data is accessed from the ADC’s RAM with a pulse to the active-low RD pin. A bidirectional interface updates the channel configuration and provides output data. The ADC may also be wired for output-only operation.The MAX155 comes in 28-pin PDIP and wide SO packages, and the MAX156 comes in 24-pin narrow PDIP and 28-pin wide SO packages.ApplicationsAC Power MetersDSP Analog InputPhase-Sensitive Data AcquisitionPortable Data LoggersVibration and Waveform Analysis