Datasheet AD7124-4-EP (Analog Devices) - 3

Enhanced Product AD7124-4-EP GENERAL DESCRIPTION
The AD7124-4-EP is a low power, low noise, completely converts on each enabled channel, simplifying communication integrated analog front end for high precision measurement with the device. As many as 16 channels can be enabled at any applications. The device contains a low noise, 24-bit Σ-Δ analog- time; a channel being defined as an analog input or a diagnostic to-digital converter (ADC), and can be configured to have four such as a power supply check or a reference check. This unique differential inputs or seven single-ended or pseudo differential feature allows diagnostics to be interleaved with conversions. inputs. The on-chip low gain stage ensures that signals of small The AD7124-4-EP also supports per channel configuration. amplitude can be interfaced directly to the ADC. The device allows eight configurations or setups. Each One of the major advantages of the AD7124-4-EP is that it gives configuration consists of gain, filter type, output data rate, the user the flexibility to employ one of three integrated power buffering, and reference source. The user can assign any of modes. The current consumption, range of output data rates, these setups on a channel by channel basis. and rms noise can be tailored with the power mode selected. The AD7124-4-EP also has extensive diagnostic functionality The device also offers a multitude of filter options, ensuring that integrated as part of its comprehensive feature set. These the user has the highest degree of flexibility. diagnostics include a cyclic redundancy check (CRC), signal The AD7124-4-EP can achieve simultaneous 50 Hz and 60 Hz chain checks, and serial interface checks, which lead to a more rejection when operating at an output data rate of 25 SPS (single robust solution. These diagnostics reduce the need for external cycle settling), with rejection in excess of 80 dB achieved at lower components to implement diagnostics, resulting in reduced output data rates. board space needs, reduced design cycle times, and cost savings. The failure modes effects and diagnostic analysis (FMEDA) of a The AD7124-4-EP establishes the highest degree of signal chain typical application has shown a safe failure fraction (SFF) greater integration. The device contains a precision, low noise, low than 90% according to IEC 61508. drift internal band gap reference, and also accepts an external differential reference, which can be internally buffered. Other The device operates with a single analog power supply from 2.7 V key integrated features include programmable low drift excitation to 3.6 V or a dual 1.8 V power supply. The digital supply has a current sources, burnout currents, and a bias voltage generator, range of 1.65 V to 3.6 V. It is specified for the full military which sets the common-mode voltage of a channel to AV temperature range of −55°C to +125°C. The AD7124-4-EP is DD/2. The low-side power switch enables the user to power down housed in a 24-lead TSSOP package. bridge sensors between conversions, ensuring the absolute Note that, throughout this data sheet, multifunction pins, such minimal power consumption of the system. The device also as DOUT/RDY, are referred to either by the entire pin name or allows the user the option of operating with either an internal by a single function of the pin, for example, RDY, when only clock or an external clock. that function is relevant. The integrated channel sequencer allows several channels to be Additional application and technical information can be found enabled simultaneously, and the AD7124-4-EP sequentially in the AD7124-4 data sheet. Rev. 0 | Page 3 of 17 Document Outline FEATURES ENHANCED PRODUCT FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY GENERAL DESCRIPTION SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS OUTLINE DIMENSIONS ORDERING GUIDE