AD7940BRMZ Integrated Circuit Chip 14-Bit Analog to Digital Converter

3 mW, 100 kSPS, 14-Bit ADC in 6-Lead SOT-23 AD7940

FEATURES

• Fast throughput rate: 100 kSPS

• Specified for V_DD of 2.5 V to 5.5 V

• Low power

    4 mW typ at 100 kSPS with 3 V supplies

    17 mW typ at 100 kSPS with 5 V supplies

• Wide input bandwidth: 81 dB SINAD at 10 kHz input frequency

• Flexible power/serial clock speed management

• No pipeline delays

• High speed serial interface

    SPI®/QSPI™/MICROWIRE™/DSP compatible

• Standby mode: 0.5 µA max

• 6-Lead SOT-23 and 8-Lead MSOP packages

APPLICATIONS

• Battery-powered systems

    Personal digital assistants

    Medical instruments

    Mobile communications

• Instrumentation and control systems

• Remote data acquisition systems

GENERAL DESCRIPTION

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

FUNCTIONAL BLOCK DIAGRAM

ABSOLUTE MAXIMUM RATINGS T_A = 25°C, unless otherwise noted

1 Transient currents of up to 100 mA will not cause SCR latch-up.

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

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