Using Deep N Wells in Analog Design
May 7, 2015 · In summary, the use of deep N well devices can significantly reduce noise coupling between sensitive analog areas and more noisy digital regions in mixed-signal designs. ESSDERC 2012. Analog layout: Why wells, taps, and guard rings are crucial. Automating Analog Layout. Additional structures in analog layout beyond schematic.
Operational Transconductance Amplifier (OTA) - Planet Analog
Aug 17, 2022 · Operational transconductance amplifiers (OTAs) have become essential building blocks of many modern analog and mixed signal circuits. OTAs are used as a key element in a wide variety of circuits that benefit from voltage control. In essence, an OTA is a direct-coupled differential voltage-controlled current source (DVCCS) with high output ...
The Basics of SerDes (Serializers/Deserializers) - Planet Analog
Sep 16, 2010 · In a serial bus, a device called SerDes (Serializer/ Desrializer) is used to transmit and receive data over the serial link. In essence, a SerDes is a serial transceiver which converts parallel data into a serial data stream on the transmitter side and converts the serial data back to parallel on the receiver side.
Layout Dependent & LOD Effects in Analog Design
Oct 9, 2014 · This stress affects carrier mobility in the devices and, hence, current. This is known as “length of diffusion” or LOD effect, where the characteristics of a device vary according to the distance of its gate from the diffusion edge. To design with LDE effects, various layout techniques can be used: Use similar diffusion size, shape ...
Miller Effect and Theorem - Planet Analog
Jul 3, 2017 · Miller’s theorem readily generalizes to amplifiers in which Rf is replaced by a reactance, such as a capacitor. Because of the Miller effect, a common-emitter (CE) transistor stage with base-collector capacitance, Cbc will cause this capacitance to appear as 1 + K greater at the base, where K is the base-to-collector voltage gain of the CE stage.
Matching in Analog Layout
May 20, 2014 · One common matching technique is known as common centroid. In this case, two devices to be matched are split into several fingers and placed in a pattern, as shown in Figure 1. The key points are that the centroids of each device should coincide, the devices should be symmetrical, their orientation should be the same, and the array should be as ...
The basics of 4-20mA current loop transmitters - Planet Analog
May 5, 2016 · The sensor, sensor-conditioning circuitry, and 4-20 mA transmitting circuitry must consume less than 4 mA of operating current, or the transmitter cannot output the 4 mA zero-scale level [3]. Note that the V LOOP GND is not one of two connections provided to the 2-wire sensor transmitter. Therefore, the transmitter must create a local ground ...
Understanding JESD204B Link Parameters - Planet Analog
Sep 10, 2013 · The JESD204B specification allows for this parameter to be greater than one, but it is simpler to set S to one such that the frame clock (FC ) and sample clock of the converter can be equal. For a 500MSPS converter and S = 1, the frame clock rate is 500MHz. The next parameter to set is the number of lanes, L .
An Analog Tutorial: Current sources - Planet Analog
Mar 28, 2019 · James Bryant, retired Analog Devices ‘guru’ says, “…current outputs offer advantages in a number of situations, including analog current-loop signaling (0 mA to 20 mA and 4 mA to 20 mA) in high-noise environments, and level shifting an analog signal across a large potential difference without the use of optical or magnetic isolation techniques.” (See Reference 4)
Analog layout: Why wells, taps, and guard rings are crucial
Aug 23, 2021 · An N-well is constructed around and beneath the device’s P-well. The N-channel device operates in the P-well. Both the P-well and the deep N-well need to be tapped, but in many cases, both wells are protected with guard rings. This means that the device has two rings around it, greatly improving the isolation of the device, but requiring a ...