AD7940

The AD79401 is a 14-bit, fast, low power, successive approximation ADC. The part operates from a single 2.50 V to 5.5 V power supply and features throughput rates up to 100 kSPS. The part contains a low noise, wide bandwidth track-and-hold amplifier that can handle input frequencies in excess of 7 MHz.

The conversion process and data acquisition are controlled using CS and the serial clock, allowing the devices to interface with microprocessors or DSPs. The input signal is sampled on the falling edge of CS and the conversion is also initiated at this point. There are no pipelined delays associated with the part.

The AD7940 uses advanced design techniques to achieve very low power dissipation at fast throughput rates. The reference for the part is taken internally from V_DD, which allows the widest dynamic input range to the ADC. Thus, the analog input range for this part is 0 V to V_DD. The conversion rate is determined by the SCLK frequency.

This part features a standard successive approximation ADC with accurate control of the sampling instant via a CS input and once off conversion control.

PRODUCT HIGHLIGHTS

1. First 14-bit ADC in a SOT-23 package.
2. High throughput with low power consumption.
3. Flexible power/serial clock speed management. The conversion rate is determined by the serial clock, allowing the conversion time to be reduced through the serial clock speed increase. This allows the average power consumption to be reduced when a power-down mode is used while not converting. The part also features a shutdown mode to maximize power efficiency at lower throughput rates. Power consumption is 0.5 µA max when in shutdown.
4. Reference derived from the power supply.
5. No pipeline delay.

APPLICATIONS

• Battery-powered systems
  Personal digital assistants
  Medical instruments
  Mobile communications
• Instrumentation and control systems
• Remote data acquisition systems