250 kSPS, 12- Bit ADC in 6 Lead SC70

The AD7910 / AD7920 are 10-bit and 12-bit, high speed, low power, successive-approximation ADCs respectively. The parts operate from a single 2.35 V to 5.25 V power supply and feature throughput rates up to 250 kSPS. The parts contain a low-noise, wide bandwidth track/hold amplifier, which can handle input frequencies in excess of 6 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 AD7910 / AD7920 use advanced design techniques to achieve very low power dissipation at high throughput rates.

The reference for the part is taken internally from VDD. This allows the widest dynamic input range to the ADC. Thus the analog input range for the part is 0 to VDD. The conversion rate is determined by the SCLK.

PRODUCT HIGHLIGHTS

* 10-/12-bit ADCs in SC70 and MSOP packages.

* Low power consumption.

* 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 power-down mode is used while not

converting. The part also features a power-down mode to

maximize power efficiency at lower throughput rates.

Current consumption is 1 μA maximum and 50 nA typically

when in power-down mode.

* Reference derived from the power supply.

* No pipeline delay. The parts feature a standard successive

approximation ADC with accurate control of the sampling

instant via a CS input and once-off conversion control.

APPLICATIONS

* Battery-powered systems

Personal digital assistants

Medical instruments

Mobile communications

* Instrumentation and control systems

* Data acquisition systems

* High speed modems

* Optical sensors

* Throughput Rate: 250 kSPS

* Specified for VDD of 2.35 V to 5.25 V

* Low Power:

3 mW typ at 250 KSPS with 3 V Supplies

12.5 mW typ at 250 KSPS with 5 V Supplies

* Wide Input Bandwidth:

70 dB SNR at 100 kHz Input Frequency