AD7451:  Pseudo Differential Input, 1 MSPS, 12-Bit ADC in an 8-Lead SOT-23

The AD7441/AD7451 are, respectively, 10-/12-bit high speed, low power, single-supply, successive approximation (SAR), analog-to-digital converters (ADCs) that feature a pseudo differential analog input. These parts operate from a single 2.7 V to 5.25 V power supply and achieve very low power dissipation at high throughput rates of up to 1 MSPS.

The AD7441/AD7451 contain a low noise, wide bandwidth, differential track-and-hold (T/H) amplifier that handles input frequencies up to 3.5 MHz. The reference voltage for these devices is applied externally to the V_REF pin and can range from 100 mV to V_DD, depending on the power supply and what suits the application.

The conversion process and data acquisition are controlled using overbar: CS and the serial clock, allowing the device to interface with microprocessors or DSPs. The input signals are sampled on the falling edge of overbar: CS when the conversion is initiated. The SAR architecture of these parts ensures that there are no pipeline delays.

Product Highlights

1. Operation with 2.7 V to 5.25 V Power Supplies.
2. High Throughput with Low Power Consumption. With a 3 V supply, the AD7441/AD7451 offer 4 mW maxi-mum power consumption for a 1 MSPS throughput rate.
3. Pseudo Differential Analog Input.
4. Flexible Power/Serial Clock Speed Management. The conversion rate is determined by the serial clock, allowing the power to be reduced as the conversion time is reduced through the serial clock speed increase. These parts also feature a shutdown mode to maximize power efficiency at lower throughput rates.
5. Variable Voltage Reference Input.
6. No Pipeline Delays.
7. Accurate Control of Sampling Instant via overbar: CS Input and Once-Off Conversion Control.
8. ENOB > 10 Bits Typically with 500 mV Reference.

Applications

• Transducer interface
• Battery-powered systems
• Data acquisition systems
• Portable instrumentation