SLAS605C June   2008  – July 2018 ADS7950 , ADS7951 , ADS7952 , ADS7953 , ADS7954 , ADS7955 , ADS7956 , ADS7957 , ADS7958 , ADS7959 , ADS7960 , ADS7961


  1. Features
  2. Applications
    1.     Detailed Block Diagram
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     Pin Functions: TSSOP Packages
    2.     Pin Functions: VQFN Packages
  7. Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information: TSSOP
    5. 7.5  Thermal Information: VQFN
    6. 7.6  Electrical Characteristics: ADS7950, ADS7951, ADS7952, ADS7953
    7. 7.7  Electrical Characteristics, ADS7954, ADS7955, ADS7956, ADS7957
    8. 7.8  Electrical Characteristics, ADS7958, ADS7959, ADS7960, ADS7961
    9. 7.9  Timing Requirements
    10. 7.10 Typical Characteristics (All ADS79xx Family Devices)
    11. 7.11 Typical Characteristics (12-Bit Devices Only)
    12. 7.12 Typical Characteristics (12-Bit Devices Only)
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Reference
      2. 8.3.2 Power Saving
    4. 8.4 Device Functional Modes
      1. 8.4.1 Channel Sequencing Modes
      2. 8.4.2 Device Programming and Mode Control
        1. Mode Control Register
        2. Program Registers
      3. 8.4.3 Device Power-Up Sequence
      4. 8.4.4 Operating in Manual Mode
      5. 8.4.5 Operating in Auto-1 Mode
      6. 8.4.6 Operating in Auto-2 Mode
      7. 8.4.7 Continued Operation in a Selected Mode
    5. 8.5 Programming
      1. 8.5.1 Digital Output
      2. 8.5.2 GPIO Registers
      3. 8.5.3 Alarm Thresholds for GPIO Pins
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Analog Input
    2. 9.2 Typical Applications
      1. 9.2.1 Unbuffered Multiplexer Output (MXO)
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curves
      2. 9.2.2 OPA192 Buffered Multiplexer Output (MXO)
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Examples
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RGE|24
  • DBT|30
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Alarm Thresholds for GPIO Pins

Each channel has two alarm program registers, one for setting the high alarm threshold and the other for setting the low alarm threshold. For ease of programming, two alarm programming registers per channel, corresponding to four consecutive channels, are assembled into one group (a total eight registers). There are four such groups for 16 channel devices and 3/2/1 such groups for 12/8/4 channel devices respectively. The grouping of the various channels for each device in the ADS79xx family is listed in Table 12. The details regarding programming the alarm thresholds are illustrated in the flowchart in Figure 59. Table 13 lists the details regarding the Alarm Program Register settings.

Table 12. Grouping of Alarm Program Registers

0 High and low alarm for channel 0, 1, 2, and 3 ADS7953..50, ADS7957..54, ADS7961..58
1 High and low alarm for channel 4, 5, 6, and 7 ADS7953..51, ADS7957..55, ADS7961..59
2 High and low alarm for channel 8, 9, 10, and 11 ADS7953 and 52, ADS7957 and 56, ADS7961 and 60
3 High and low alarm for channel 12, 13, 14, and 15 ADS7953, ADS7957, ADS7961

Each alarm group requires 9 CS frames for programming their respective alarm thresholds. In the first frame the device enters the programming sequence and in each subsequent frame it programs one of the registers from the group. The device offers a feature to program less than eight registers in one programming sequence. The device exits the alarm threshold programming sequence in the next frame after it encounters the first ‘Exit Alarm Program’ bit high.

ADS7950 ADS7951 ADS7952 ADS7953 ADS7954 ADS7955 ADS7956 ADS7957 ADS7958 ADS7959 ADS7960 ADS7961 gpio_data_las605.gif


The device continues its operation in selected mode during programming. SDO is valid, however it is not possible to change the range or write GPIO data into the device during programming.
Figure 59. Alarm Program Register Programming Flowchart

Table 13. Alarm Program Register Settings

DI15-12 NA 1100 Device enters ‘alarm programming sequence’ for group 0
1101 Device enters ‘alarm programming sequence’ for group 1
1110 Device enters ‘alarm programming sequence’ for group 2
1111 Device enters ‘alarm programming sequence’ for group 3
Note: DI15-12 = 11bb is the alarm programming request for group bb. Here ‘bb’ represents the alarm programming group number in binary format.
DI11-14 NA Do not care
DI15-14 NA cc Where “cc” represents the lower two bits of the channel number in binary format. The device programs the alarm for the channel represented by the binary number “bbcc”. “bb” is programmed in the first frame.
DI13 NA 1 High alarm register selection
0 Low alarm register selection
DI12 NA 0 Continue alarm programming sequence in next frame
1 Exit Alarm Programming in the next frame. Note: If the alarm programming sequence is not terminated using this feature then the device will remain in the alarm programming sequence state and all SDI data will be treated as alarm thresholds.
DI11-10 NA xx Do not care
DI09-00 All ones for high alarm register and all zeros for low alarm register This 10-bit data represents the alarm threshold. The 10-bit alarm threshold is compared with the upper 10-bit word of the 12-bit conversion result. The device sets off an alarm when the conversion result is higher (High Alarm) or lower (Low Alarm) than this number. For 10-bit devices, all 10 bits of the conversion result are compared with the set threshold. For 8-bit devices, all 8 bits of the conversion result are compared with DI09 to DI02 and DI00, 01 are 'do not care'.