LMP90100MHE National Semiconductor, LMP90100MHE Datasheet - Page 4

• Manufacturer Part Number: LMP90100MHE
• Description: AFE, SENSOR, 28TSSOP
• Manufacturer: National Semiconductor

Specifications of LMP90100MHE

• Brief Features: 24bit Low Power Sigma Delta ADC, Automatic Channel Sequencer
• Supply Voltage Range: 2.7V To 5.5V
• Operating Temperature Range: -40°C To +105°C
• Digital Ic Case Style: TSSOP
• No. Of Pins: 28
• Base: RoHS Compliant
• Ic Function: Multi-Channel, Low Power 24-bit Sensor AFE
• Rohs Compliant: Yes

www.national.com
19.0 Physical Dimensions .................................................................................................................... 58
FIGURE 1. Block Diagram ......................................................................................................................... 2
FIGURE 2. Timing Diagram ...................................................................................................................... 11
FIGURE 3. Simplified VIN Circuitry .............................................................................................................. 21
FIGURE 4. CLK Register Settings ............................................................................................................... 22
FIGURE 5. Digital Filter Response, 1.6775 SPS and 3.355 SPS .......................................................................... 23
FIGURE 6. Digital Filter Response, 6.71 SPS and 13.42 SPS .............................................................................. 23
FIGURE 7. Digital Filter Response, 26.83125 SPS and 53.6625 SPS .................................................................... 24
FIGURE 8. Digital Filter Response 107.325 SPS and 214.65 SPS ........................................................................ 24
FIGURE 9. Digital Filter Response for a 3.5717MHz versus 3.6864 MHz XTAL ........................................................ 25
FIGURE 10. GPIO Register Settings ............................................................................................................ 25
FIGURE 11. Types of Calibration ................................................................................................................ 26
FIGURE 12. BgcalMode2 Register Settings ................................................................................................... 26
FIGURE 13. System Calibration Data-Flow Diagram ......................................................................................... 27
FIGURE 14. Burnout Currents .................................................................................................................... 29
FIGURE 15. Burnout Currents Injection for ScanMode3 ..................................................................................... 29
FIGURE 16. Sensor Diagnostic Flags Diagram ............................................................................................... 30
FIGURE 17. Register Read/Write Protocol ..................................................................................................... 31
FIGURE 18. DRDYB Behavior for a Complete ADC_DOUT Reading ..................................................................... 32
FIGURE 19. DRDYB Behavior for an Incomplete ADC_DOUT Reading .................................................................. 32
FIGURE 20. DrdybCase1 Connection Diagram ............................................................................................... 33
FIGURE 21. Timing Protocol for DrdybCase1 ................................................................................................. 33
FIGURE 22. DrdybCase2 Connection Diagram ............................................................................................... 34
FIGURE 23. Timing Protocol for DrdybCase2 ................................................................................................. 34
FIGURE 24. Timing Protocol for Reading SPI_CRC_DAT .................................................................................. 35
FIGURE 25. Active, Power-Down, Stand-by State Diagram ................................................................................ 36
FIGURE 26. ADC_DOUT vs. VIN of a 24-Bit Resolution (VREF = 5.5V, Gain = 1). .................................................... 37
FIGURE 27. Register-Write Example 1 ......................................................................................................... 38
FIGURE 28. Register-Write Example 2 ......................................................................................................... 38
FIGURE 29. Register-Read Example ........................................................................................................... 39
FIGURE 30. Normal Streaming Example ....................................................................................................... 40
FIGURE 31. Setting up SPI_STREAMCN ...................................................................................................... 41
FIGURE 32. Controlled Streaming Example ................................................................................................... 42
FIGURE 33. Topology #1: 3-wire RTD Using 2 Current Sources ........................................................................... 43
FIGURE 34. Topology #2: 3-wire RTD Using 1 Current Source ............................................................................ 44
FIGURE 35. Thermocouple with CJC ........................................................................................................... 45
TABLE 1. ENOB (Noise Free Resolution) vs. Sampling Rate and Gain at VA = VIO = VREF = 3V ................................. 10
TABLE 2. RMS Noise (µV) vs. Sampling Rate and Gain at VA = VIO = VREF = 3V .................................................... 10
TABLE 3. ENOB (Noise Free Resolution) vs. Sampling Rate and Gain at VA = VIO = VREF = 5V .................................. 10
TABLE 4. RMS Noise (µV) vs. Sampling Rate and Gain at VA = VIO = VREF = 5V .................................................... 10
TABLE 5. Digital Filter Attenuation ............................................................................................................... 23
TABLE 6. Data First Mode Transactions ........................................................................................................ 35
18.6 Sensor Diagnostic Registers .................................................................................................. 54
18.7 SPI Registers ....................................................................................................................... 55
18.8 GPIO Registers .................................................................................................................... 57
List of Figures
List of Tables
4