DVK90129 Melexis Inc, DVK90129 Datasheet - Page 9

• Manufacturer Part Number: DVK90129
• Description: DEVELOPMENT KIT MLX90129
• Manufacturer: Melexis Inc
• Series: -r
• Type: Development kitr

Specifications of DVK90129

• Contents: Board, Proxima RF™ Desktop Reader
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: MLX90129

7 General Description
3901090129
Rev 007
7.1 Block diagram
The sensor signal conditioner is used to amplify, filter and convert the output voltage of resistive
sensors. There may be an external single-ended or differential resistive sensor, or the internal
temperature sensor. The two external sensors are supplied by a stable reference voltage, provided by an
integrated voltage regulator. The sensor output voltage is amplified thanks to a programmable-gain
amplifier, and has its offset voltage compensated. Then, the conditioned sensor signal fits the input range
of the A/D converter. The ADC converts the signal in a 16-bits code that can be stored or transmitted.
The power management unit deals with the different power modes of the chip: it monitors the battery
level, scavenges the energy coming from a RFID 13,56MHz field and makes the power-on reset signal. A
regulator is used to supply the digital parts, but can also be used to supply some other external devices.
The Oscillators’ block contains different kinds of oscillators: a very low power, low frequency 1kHz RC
oscillator used as a wake-up timer, a low-power 32.768kHz quartz oscillator that can be used for an
accurate time basis, and a high frequency 5MHz RC oscillator used for the digital controller.
The Register File contains all the configuration parameters of the chip. It may be loaded from the
EEPROM after power-on, or as the result of a specific request from RFID or SPI.
The EE-Latches are used when device configuration parameters have to be immediately available.
The RFID front-end receives an external 13,56-MHz magnetic field, sensed on an external antenna coil.
The antenna design is made easy thanks to an internal programmable high-Q capacitance (tuned during
the test phase). From the antenna output voltage, it makes a stable clamped DC supply voltage, recovers
the clock, and controls the modulation of the carrier and the demodulation of the incoming signal.
The EEPROM is a 4-kbits non-volatile memory, organized as 256 words of 16 bits divided in 39 reserved
for configuration, 2 for default trimming value (EE-Latches #03,#04 and #09) backup and 215 available
for the application (around 3.4 kbits user memory). Its access is protected by several security levels.
The Digital Controller manages the accesses of the different interfaces (SPI, RFID) with the different
memories (EEPROM, register file) and the sensor. It comprises the RFID ISO-15693 and SPI protocols,
controls the sensor signal conditioner and stores or sends the ADC output code. It can also run some
standalone applications, thanks to its unit called Direct Memory Access (DMA).
13.56MHZ SENSOR TAG / DATALOGGER IC
Page 9 of 56
MLX90129
Data Sheet
March 2011