SGLS228C December   2003  – September 2015 TPS3805H33-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Dissipation Ratings
    9. 7.9 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 VDD and SENSE Monitoring
      2. 8.3.2 Transient Immunity
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 TPS3803G15-Q1
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 TPS3803-01-Q1
        1. 9.2.2.1 Design Requirements
      3. 9.2.3 TPS3805H33-Q1
        1. 9.2.3.1 Design Requirements
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Examples
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Device Nomenclature
    2. 12.2 Related Links
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DCK|5
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8 Detailed Description

8.1 Overview

The TPS380x-Q1 devices are low-current supervisory circuits used to monitor system voltages above 1.226 V. The devices assert an active low RESET signal when VDD ,SENSE, or both voltages drop below a preset threshold. The RESET output remains low until the VDD, SENSE, or both voltages return above their thresholds. The devices are also designed to be immune to short negative transients on the VDD and SENSE pins.

8.2 Functional Block Diagrams

TPS3803-01-Q1 TPS3803G15-Q1 TPS3805H33-Q1 fdb_gls228.gif

8.3 Feature Description

8.3.1 VDD and SENSE Monitoring

The VDD and SENSE inputs provide a pin at which a system voltage can be monitored. If the voltage on this pin drops below VIT, RESET is asserted low. The comparator has a built-in hysteresis to ensure smooth RESET assertions and de-assertions. Refer to the Device Comparison Table to determine the VDD and SENSE voltage thresholds for each device. The adjustable version TPS3803-01-Q1 can be used to monitor any voltage rail down to 1.226 V using the circuit shown in Figure 13, where VIT' is the Vin threshold voltage.

TPS3803-01-Q1 TPS3803G15-Q1 TPS3805H33-Q1 adj_version_sgls228.gif Figure 13. Using Adjustable Version

8.3.2 Transient Immunity

The TPS380x-Q1 devices are immune to short negative transients on the VDD and SENSE pins. Sensitivity to transients is dependent on threshold overdrive as shown in Figure 15 and Figure 16. These graphs show the duration that the transient is below VIT compared to the magnitude of the voltage drop below VIT, called the threshold overdrive voltage. Any combination of transient duration and overdrive voltage which lies above the curves will result in RESET being asserted low. Any transient which lies below the curves will be ignored by the device.

TPS3803-01-Q1 TPS3803G15-Q1 TPS3805H33-Q1 overdrive_sgls228.gif Figure 14. Overdrive Voltage
TPS3803-01-Q1 TPS3803G15-Q1 TPS3805H33-Q1 g_tw_vdd_gls228.gif
Figure 15. Minimum Pulse Duration at VDD vs VDD Threshold Overdrive Voltage
TPS3803-01-Q1 TPS3803G15-Q1 TPS3805H33-Q1 g_tw_sense_gls228.gif
Figure 16. Minimum Pulse Duration at Sense vs Sense Threshold Overdrive Voltage

8.4 Device Functional Modes

TPS3803-01-Q1 and TPS3803G15-Q1 monitor only one supply, which is SENSE and VDD respectively. When that supply is above the VIT threshold, RESET will be high. Otherwise, RESET will be low. TPS3805H33-Q1 monitors both VDD and SENSE. When both VDD and SENSE are above the VIT threshold, RESET will be high. Otherwise, RESET will be low.

Table 1. Function and Truth Table

TPS3803-01-Q1
SENSE > VIT RESET
0 L
1 H

Table 2. Function and Truth Table

TPS3803G15-Q1
VDD > VIT RESET
0 L
1 H

Table 3. Function and Truth Table

TPS3805H33-Q1
VDD > VIT SENSE > VIT RESET
0 0 L
0 1 L
1 0 L
1 1 H