SBASA84A February   2021  – July 2021 AMC3302-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Power Ratings
    6. 6.6  Insulation Specifications
    7. 6.7  Safety-Related Certifications
    8. 6.8  Safety Limiting Values
    9. 6.9  Electrical Characteristics
    10. 6.10 Switching Characteristics
    11. 6.11 Timing Diagram
    12. 6.12 Insulation Characteristics Curves
    13. 6.13 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Input
      2. 7.3.2 Data Isolation Channel Signal Transmission
      3. 7.3.3 Analog Output
      4. 7.3.4 Isolated DC/DC Converter
      5. 7.3.5 Diagnostic Output
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Shunt Resistor Sizing
        2. 8.2.2.2 Input Filter Design
        3. 8.2.2.3 Differential to Single-Ended Output Conversion
      3. 8.2.3 Application Curve
    3. 8.3 What to Do and What Not to Do
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

9 Power Supply Recommendations

The AMC3302-Q1 is powered from the low-side power supply (VDD) with a nominal value of 3.3 V or 5 V. TI recommends a low-ESR decoupling capacitor of 1 nF (C8 in Figure 9-1) placed as close as possible to the VDD pin, followed by a 1-µF capacitor (C9) to filter this power-supply path.

The low-side of the DC/DC converter is decoupled with a low-ESR 100-nF capacitor (C4) positioned close to the device between the DCDC_IN and DCDC_GND pins. Use a 1-µF capacitor (C2) to decouple the high-side in addition to a low-ESR, 1-nF capacitor (C3) placed as close as possible to the device and connected to the DCDC_OUT and DCDC_HGND pins.

For the high-side LDO, use low-ESR capacitors of 1-nF (C6), placed as close as possible to the AMC3302-Q1, followed by a 100-nF decoupling capacitor (C5).

The ground reference for the high-side (HGND) is derived from the terminal of the shunt resistor that is connected to the negative input (INN) of the device. For best DC accuracy, use a separate trace to make this connection instead of shorting HGND to INN directly at the device input. The high-side DC/DC ground terminal (DCDC_HGND) is shorted to HGND directly at the device pins.

As shown in Figure 9-1, TI recommends placing ferrite beads in the INP, INN, and HGND signal lines for best EMI performance. For more information on reducing radiated emissions and guidelines for component selection, see the Best Practices to Attenuate AMC3301 Family Radiated Emissions EMI application note available for download at www.ti.com

Figure 9-1 Decoupling the AMC3302-Q1

Capacitors must provide adequate effective capacitance under the applicable DC bias conditions they experience in the application. Multilayer ceramic capacitors (MLCC) typically exhibit only a fraction of their nominal capacitance under real-world conditions and this factor must be taken into consideration when selecting these capacitors. This problem is especially acute in low-profile capacitors, in which the dielectric field strength is higher than in taller components. Reputable capacitor manufacturers provide capacitance versus DC bias curves that greatly simplify component selection.

Table 9-1 lists components suitable for use with the AMC3302-Q1. This list is not exhaustive. Other components may exist that are equally suitable (or better), however these listed components have been validated during the development of the AMC3302-Q1.

Table 9-1 Recommended External Components
DESCRIPTION PART NUMBER MANUFACTURER SIZE (EIA, L x W)
VDD
C8 1 nF ± 10%, X7R, 50 V 12065C102KAT2A(1) AVX 1206, 3.2 mm x 1.6 mm
C0603C102K5RACTU Kemet 0603, 1.6 mm x 0.8 mm
C9 1 µF ± 10%, X7R, 25 V 12063C105KAT2A(1) AVX 1206, 3.2 mm x 1.6 mm
CGA3E1X7R1E105K080AC TDK 0603, 1.6 mm x 0.8 mm
DC/DC CONVERTER
C4 100 nF ± 10%, X7R, 50 V C0603C104K5RACAUTO Kemet 0603, 1.6 mm x 0.8 mm
C3 1 nF ± 10%, X7R, 50 V C0603C102K5RACTU Kemet 0603, 1.6 mm x 0.8 mm
C2 1 µF ± 10%, X7R, 25 V CGA3E1X7R1E105K080AC TDK 0603, 1.6 mm x 0.8 mm
HLDO
C1 100 nF ± 10%, X7R, 50 V C0603C104K5RACAUTO Kemet 0603, 1.6 mm x 0.8 mm
C5 100 nF ± 5%, NP0, 50 V C3216NP01H104J160AA(1) TDK 1206, 3.2 mm x 1.6 mm
100 nF ± 10%, X7R, 50 V C0603C104K5RACAUTO Kemet 0603, 1.6 mm x 0.8 mm
C6 1 nF ± 10%, X7R, 50 V 12065C102KAT2A(1) AVX 1206, 3.2 mm x 1.6 mm
C0603C102K5RACTU Kemet 0603, 1.6 mm x 0.8 mm
FERRITE BEADS
FB1, FB2, FB3 Ferrite bead(2) 74269244182 Wurth Elektronik 0402, 1.0 mm x 0.5 mm
BLM15HD182SH1 Murata 0402, 1.0 mm x 0.5 mm
BKH1005LM182-T Taiyo Yuden 0402, 1.0 mm x 0.5 mm
(1) Component used for parametric validation.
(2) No ferrite beads used for parametric validation.