Author Archives: sue proud

81dB Sinad isolated ADC

analog devices AD7403_fblAnalog Devices is claiming to have the industry’s highest-accuracy isolated sigma-delta (∑Δ) data converter for DC and AC current and voltage measurement.

The AD7403 achieves 81dBmin signal-to-noise and distortion ratio (Sinad) at 78ksample/s over -40°C to 125°C.

“Higher Sinad enables more accurate current and voltage measurement which improves the performance of motor drives by reducing torque ripple on the motor shaft,” said ADI.

It has a second-order ∑Δ modulator that converts an analogue input signal into a single-bit data stream with on-chip digital isolation (1,250Vpeak) through on-chip transformers.

Power on the output (and control) side is 5V or 3V.

 

Low-cost VNA performs 40GHz s-parameter tests

11jun14anritsuWEBAnritsu has introduced a range of low-cost vector network analysers (VNAs) for s-parameter measurement of passive components, cables, connectors, filters, and antennas.
The VNAs can perform the single-ended and mixed-mode S-parameter measurements typically required for production testing of passive devices, offering frequency coverage up to 40GHz. They can also conduct path loss characterisation of more complex systems.
Prices start at €10,000 (£8,070) for the MS46322A two-port model.
The slimmed down VNAs, branded ShockLine, have no display or keypad, and are controlled remotely by computer via a LAN or other connection.
The MS46522A VNA features a 70µs/point sweep speed, greater than 110dB dynamic range and corrected directivity of greater than 42dB. The MS46524A four-port model is for differential and multi-port device testing up to 7GHz. The two-port MS46522A is priced at €19,700 (£15,830)and the 4-port MS46524A is priced at €25,500 (£20,599).
The VNAs use SCPI command programming and have software driver support, so they can be easily integrated into most programming environments.

Hall switch has regulator

11jun14melexisMelexis Technologies has introduced a Hall-effect switch device with an integrated voltage regulator and on-chip non-volatile memory. On-chip EEPROM is used to enable the various tolerances that need to be defined for a specific application to be set, via the device’s Vdd pin, which can be readjusted before finally being locked.

“The range and resolution of programmable magnetic thresholds and thermal sensitivity coefficients allows the sensor, working in conjunction with a magnet, to easily implement a ferrous metal proximity-sensing system,” says the supplier.

It says the temperature compensation programmability of the MLX92242 means it can be used with all kinds of magnets, including the low-cost ferrite materials. It supports two-wire rather than a three-wire implementation, only using the Vdd and GND pins, but still providing all the necessary diagnostic capacity to respond to malfunctions.

“The advantage of this is that far less wiring/cable harnessing is needed, allowing deployment into confined spaces and reducing the overall weight in applications where this could otherwise be a disadvantage. The voltage range, which covers 2.7V to 24V, enables design flexibility to be maximised,” says the company.

Likely automotive applications include seat-belt latch detectors and seat position sensors. Designed for automotive and industrial environments, the device has a very high resilience to electro-static discharge (ESD) , with 8kV human body mode ESD compliance, and operational temperature range spans from -40°C to 150°C.

Reverse supply voltage and under-voltage lockout protection mechanisms are incorporated.
It is supplied as either a three-pin TO-92-Flat for through-hole mount assembly or in three-pin TSOT for surface mount assembly.