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  1. Allegro MicroSystems Europe announces its first ever 1MHz bandwidth Hall-effect current sensor IC with a lightning fast 210 ns response time. The ACS730 provides an economical and precise solution for AC or DC current sensing. Allegro’s ACS730 is targeted at industrial, commercial, and communications systems. Typical applications include motor control, load detection and management, switched-mode power supplies, and over-current fault protection. This device consists of a precise, low-offset, linear Hall-sensor circuit with a copper conduction path located near the surface of the die. Applied current flowing through this copper conduction path generates a magnetic field which is sensed by the integrated Hall IC and converted into a proportional voltage. Device accuracy is optimised through the close proximity of the magnetic field to the Hall transducer. A precise, proportional voltage is provided by the Hall IC, which is programmed for accuracy after packaging. The output of the device has a positive slope when an increasing current flows through the primary copper conduction path (from pins 1 and 2, to pins 3 and 4), which is the path used for current sensing. The internal resistance of this conductive path is typically 1.2 mΩ, providing low power loss. The terminals of the conductive path are electrically isolated from the sensor leads (pins 5 through 8). This allows the ACS730 current sensor IC to be used in high-side current sense applications without the use of high-side differential amplifiers or other costly isolation techniques. The ACS730 is provided in a small, low-profile surface-mount SOIC-8 package. The lead frame is plated with 100% matt tin, which is compatible with standard lead (Pb) free printed-circuit-board assembly processes. Internally, the device is Pb-free, except for flip-chip high-temperature Pb-based solder balls, currently exempt from RoHS. The device is fully calibrated prior to shipment from the factory.
  2. Hi everyone I am trying to measure the loop gain of my Boost Converter (Vin = 15V, Vout = 30V, up to 10A load) using the free version of the SIMetrix software, SIMetrix/SIMPLIS Intro 7.00. I am measuring the overall loop gain (outer voltage loop, including the current loop) in order to check the phase and gain plots for stability purposes. The controller used is the UC3843 controller also available in SIMetrix.The problem is I can't believe that I am doing it right since the resulting plots are exactly the same regardless of whether I shut down the IC, change the compensation values drastically. The magnitude gain is very low ~ -50dB below at 1Hz up to 100kHz which is weird. It is weird since the resulting plots of output voltage curves are totally good and ok from no load up to 10A.I used AC analysis. Attached here are images of the schematic, the options I chose in the Simulator->Choose Analysis window, and the plot which remains the same regardless of compensator values. The plots change when I change the load, but the magnitude gain is still very low.Some explanations to the schematic: input voltage is V1 (displayed as 15V in schematic), load is I1 (displayed as 8A in the schematic), C4,R15,C5 are the compensators Type II compensator, Q2 and R10 comprise the slope compensator, I used 3 parallel NMOSFETS IRF32105 each having Rg = 10 ohms and Rgs = 30kohms. V3 is the perturbation, and the probe used is the Bode Plot Probe.