TE Connectivity 5525DSO-SB005GS

The MS5525DSO is a new generation digital small outline pressure sensor from MEAS, featuring SPI and I²C bus interfaces, designed specifically for high-volume OEM users. The sensor module integrates a pressure sensor and an ultra-low-power 24-bit ΔΣ ADC with internal factory-calibrated coefficients. It provides 24-bit digital pressure and temperature values along with multiple operating modes, enabling users to optimize for conversion speed and current consumption. The MS5525DSO is compatible with virtually any microcontroller. The communication protocol is straightforward, requiring no programming of internal device registers.

This new generation sensor module is based on leading MEMS technology and benefits from TE's proven experience and expertise in high-volume manufacturing of pressure modules that have been widely deployed for over a decade.

The rugged engineering thermoplastic transducer is available in single-port and dual-port configurations, capable of measuring absolute, gauge, compound, and differential pressures from 1 to 30 psi.

The MS5525DSO consists of a piezoresistive sensor and a sensor interface IC. Its primary function is to convert the uncompensated analog output voltage of the piezoresistive pressure sensor into a 24-bit digital value, while also providing a 24-bit digital value for the sensor temperature.

Each module undergoes individual factory calibration at two temperatures and three pressures. Six coefficients are calculated to compensate for process variations and temperature changes, and stored in the 128-bit PROM of each module. These bits are divided into six coefficients C1 through C6, which must be read by the microcontroller software and used to convert D1 and D2 into compensated pressure and temperature values.

Coefficients C0 and C7 are used for factory calibration and CRC.

The MS5525DSO incorporates two serial interfaces: SPI and I²C. Pulling the protocol selection pin PS low selects SPI protocol; pulling PS high activates the I²C bus protocol.

In SPI mode, the external microcontroller inputs data via SCLK (serial clock) and SDI (serial data input). The module supports clock polarity and phase modes 0 and 3 in SPI mode. The sensor responds on the SDO (serial data output) pin. The CSB (chip select) pin enables/disables the interface, allowing other devices to communicate on the same SPI bus. The CSB pin may be pulled high after a command is sent or after command execution completes (e.g., end of conversion). The module achieves optimal noise performance when the SPI bus is idle and not communicating with other devices during ADC conversion.

In I²C mode, the external microcontroller inputs data via SCL (serial clock) and SDA (serial data). The sensor responds on the same SDA pin, which is bidirectional for the I²C bus interface. Consequently, this interface type requires only 2 signal lines with no chip select needed, helping to reduce board space. In I²C mode, the complement of the CSB (chip select) pin represents the LSB of the I²C address. Two sensors with different addresses can be used on the I²C bus. The CSB pin must be connected to VDD or GND — do not leave these pins floating.

The MS5525DSO has only five basic commands:

1. Reset
2. Read PROM (128-bit calibration word)
3. D1 conversion
4. D2 conversion
5. Read ADC result (24-bit pressure/temperature)

Each command is 1 byte (8 bits) in size.

• Small outline IC package
• Barbed pressure port
• Low power, high resolution ADC
• Digital pressure and temperature output

• Factory automation
• Altitude and airspeed measurement
• Medical instrumentation
• Leak detection