SLDS204B October 2014 – June 2020 PGA300
PRODUCTION DATA.
The PGA300 can be used in a variety of applications. The most common ones are for pressure and temperature measurement. Depending on the application, the device itself can be configured in different modes. The following sections provide details regarding these configurations.
The PGA300 is a high-accuracy, low-drift, low-noise, low-power, and easily programmable signal-conditioner device for resistive bridge pressure and temperature sensing applications. The PGA300 implements a third-order temperature coefficient (TC) and nonlinearity (NL) compensation algorithm to linearize the analog output. The PGA300 accommodates various sensing element types, such as piezoresistive, ceramic film, and steel membrane. The device supports sensor element sensitivities ranging from 1 mV/V to 135 mV/V. The typical applications supported are pressure sensor transmitters, transducers, liquid-level meters, flow meters, strain gauges, weight scales, thermocouples, thermistors, 2-wire resistance thermometers (RTDs), and resistive field transmitters. The device can also be used in accelerometer and humidity sensor signal-conditioning applications.
The PGA300 provides bridge excitation voltages of 2.5 V, 2 V, and 1.25 V, all ratiometric to the ADC reference level. The PGA300 has a unique one-wire interface (OWI) that supports communication and configuration through the power-supply line during the calibration process. This feature minimizes the number of wires needed for an application.
The PGA300 contains two separated analog front-end (AFE) signal chains; one for resistive-bridge inputs and one for temperature-sensing inputs. Each AFE has its own gain amplifier and a 16-bit ADC operating at a 7.8-kHz output rate. The resistive-bridge input AFE consists of a programmable gain with 32 steps ranging from 5 V/V to 400 V/V. For the temperature-sensing AFE, the PGA300 provides a current source that can supply up to 500 µA for optional external temperature sensing. This current source can also be used as a constant-current bridge excitation. The programmable gain in the temperature sensing AFE has four steps ranging from 1.33 V/V to 20 V/V. In addition, the PGA300 integrates an internal temperature sensor which can be configured as the input of the temperature-sensing AFE.
A 128-byte EEPROM is integrated in the PGA300 to store the calibration coefficients and the PGA300 configuration settings as needed. The PGA300 has a 14-bit DAC followed by a buffer gain stage of 2 V/V to 10 V/V. The device supports three industrial-standard outputs: ratiometric voltage, absolute voltage, and 4-mA to 20-mA current loop.
The diagnostic functions monitor the operating condition of the PGA300. The device can operate with a 3.3-V to 30-V power supply directly, without using an external LDO. The PGA300 has a wide ambient-temperature operating range from –40°C to 150°C. The package form is 6-mm × 6-mm 36-pin VQFN. Within this small package size, the PGA300 integrates all the functions needed for resistive-bridge sensing applications to minimize PCB area and simplify the overall application design.