SLAA126B April   2001  – September 2018 MSP430F149 , MSP430F149 , TLC3544 , TLC3544 , TLC3548 , TLC3548

 

  1.   Interfacing the TLC3544 or TLC3548 ADC to the MSP430F149 MCU
    1.     Trademarks
    2. 1 Introduction
    3. 2 TLC3544/48 Evaluation Module
    4. 3 Serial Interface
      1. 3.1 Chip Select (CS)
      2. 3.2 Serial Data Input (SDI)
      3. 3.3 Serial Data Output Pin (SDO)
      4. 3.4 Serial Clock Pin (SCLK)
    5. 4 Control and I/O Pins
      1. 4.1 Conversion Start (CSTART)
      2. 4.2 Frame Sync (FS)
      3. 4.3 End of Conversion/Interrupt (EOC/INT)
      4. 4.4 Device Pinout
    6. 5 ADC Initialization and Operation
      1. 5.1 Initializing the ADC
      2. 5.2 Operating the ADC
      3. 5.3 EOC or INT
    7. 6 MSPF149 Code Example
    8. 7 References

2 TLC3544/48 Evaluation Module

The data converter EVM used for this application report can have either the TLC3544 or the TLC3548 installed at location U9. These are 14-bit, 200-ksps serial analog-to-digital converters with four (TLC3544) or eight (TLC3548) analog input channels.

The TLC3544 and TLC3548 devices operate from a single 5-V analog supply and a 3.3-V or 5.0-V digital supply. The EVM contains regulators that provide all the necessary voltages from a standard 12-V laboratory power supply.

The EVM features a convenient onboard signal generator as well as all the necessary hardware to provide accurate reference voltages to the data converters. Connectors J12, J13, and J14 are

10-pin dual-row headers. These headers simplify interfacing a microcontroller-based system. The shorting bars can be removed from headers J13 and J14, allowing the user to define a custom signal-interface to the EVM.

System I/O voltages, as well as the voltage on the digital portion of the ADC, can be set to either 3.3 V or 5.0 V by changing the position of W17. When W17 is in position 2-3, the I/O voltage is set to 5.0 V. Position 1-2 on W17 lowers the I/O voltage to 3.3 V, which is necessary when running the low-power MSP430™ family of microcontrollers.

Although the onboard signal generator was used as the analog source in this application report, the TLC3544/48 EVM contains a variety of input and output connectors, signal conditioning circuits, and reference voltage options, so that users can define custom analog input conditions. It is even possible to tie the EVM directly into an existing control system – see the TLC3578 Family Evaluation Module User's Guide for complete details.

Table 1. EVM to Micro Cable Definition

Pin No. MSP430F149 Port J12 Pin Name Signal Description
1 P3.5 - SS CS HOST_CNTLa Low = ADC CS; High = DAC CS
3 P3.3 - CLKS HOST_CLKXa Serial clock to EVM
5 Not used HOST_CLKRa Serial clock return to HOST
7 P3.1 - MOSI HOST_DXa Serial data to EVM
9 P3.2 - MISO HOST_DRa Serial data to host
11 P3.6 - GPIO HOST_FSXa Frame sync to EVM
13 Not used HOST_FSRa Frame sync return to host
15 P1.1 - EINT HOST_INT* ADC configured as INT
ADC configured as EOC
17 Not used HOST_CLKSa Clock source for host – from EVM
19 P3.7 - GPIO HOST_CNTLb CSTART to ADC
2 to 20 (even) GND DGND Ground connections