TIDUEP0 May   2020

 

  1.    Description
  2.    Resources
  3.    Features
  4.    Applications
  5. 1Design Images
  6. 2System Description
    1. 2.1 Key System Specifications
  7. 3System Overview
    1. 3.1 Block Diagram
    2. 3.2 Design Considerations
      1. 3.2.1 Small Compact Size
      2. 3.2.2 Transformer less Solution
    3. 3.3 Highlighted Products
      1. 3.3.1  TPD4E05U06 4-Channel Ultra-Low-Capacitance IEC ESD Protection Diode
      2. 3.3.2  TPD2EUSB30 2-Channel ESD Solution for SuperSpeed USB 3.0 Interface
      3. 3.3.3  2.3.3 HD3SS3220 10Gbps USB 3.1 USB Type-C 2:1 MUX With DRP Controller
      4. 3.3.4  TPS54218 2.95V to 6V Input, 2A Synchronous Step-Down SWIFT™ Converter
      5. 3.3.5  TPS54318 2.95V to 6V Input, 3A Synchronous Step-Down SWIFT™ Converter
      6. 3.3.6  CSD19538Q3A 100V, N ch NexFET MOSFET™, single SON3x3, 49mOhm
      7. 3.3.7  LM3488 2.97V to 40V Wide Vin Low-Side N-Channel Controller for Switching Regulators
      8. 3.3.8  TPS61178 20-V Fully Integrated Sync Boost with Load Disconnect
      9. 3.3.9  LMZM23601 36-V, 1-A Step-Down DC-DC Power Module in 3.8-mm × 3-mm Package
      10. 3.3.10 TPS7A39 Dual, 150mA, Wide-Vin, Positive and Negative Low-Dropout (LDO) Voltage Regulator
      11. 3.3.11 TPS74201 Single-output 1.5-A LDO regulator, adjustable (0.8V to 3.3V), any or no cap, programmable soft start
      12. 3.3.12 LP5910 300-mA low-noise low-IQ low-dropout (LDO) linear regulator
      13. 3.3.13 LP5907 250-mA ultra-low-noise low-IQ low-dropout (LDO) linear
      14. 3.3.14 INA231 28V, 16-bit, i2c output current/voltage/power monitor w/alert in wcsp
    4. 3.4 System Design Theory
      1. 3.4.1 Input Section
      2. 3.4.2 Designing of SEPIC based High Voltage Supply
        1. 3.4.2.1  Basic Operation Principle of SEPIC Converter
        2. 3.4.2.2  Design of Dual SEPIC Supply using uncoupled inductors
        3. 3.4.2.3  Duty Cycle
        4. 3.4.2.4  Inductor Selection
        5. 3.4.2.5  Power MOSFET Selection
        6. 3.4.2.6  Output Diode Selection
        7. 3.4.2.7  Coupling Capacitor Selection
        8. 3.4.2.8  Output Capacitor Selection
        9. 3.4.2.9  Input Capacitor Selection
        10. 3.4.2.10 Programming the Output Voltage
      3. 3.4.3 Designing the Low Voltage Power Supply
      4. 3.4.4 Designing the TPS54218 through Webench Power Designer
      5. 3.4.5 ± 5V Transmit Supply Generation
      6. 3.4.6 System Clock Synchronization
      7. 3.4.7 Power and data output connector
      8. 3.4.8 System Current and Power Monitoring
  8. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Testing and Results
      1. 4.1.1 Test Setup
      2. 4.1.2 Test Results
        1. 4.1.2.1 High Voltage Power Supply
        2. 4.1.2.2 Output Ripple Measurement
        3. 4.1.2.3 Load Transient Test
        4. 4.1.2.4 Noise Measurement
        5. 4.1.2.5 Thermal Performance
        6. 4.1.2.6 Low Voltage Power Supply
          1. 4.1.2.6.1 Thermal Performance
          2. 4.1.2.6.2 FX3 Supply
  9. 5Layout Guidelines
    1. 5.1 High-Voltage Supply Layout
    2. 5.2 USB Section Layout Guidelines
  10. 6Design Files
    1. 6.1 Schematics
    2. 6.2 Bill of Materials
    3. 6.3 PCB Layout Recommendations
      1. 6.3.1 Layout Prints
    4. 6.4 Altium Project
    5. 6.5 Gerber Files
    6. 6.6 Assembly Drawings
  11. 7Software Files
  12. 8Related Documentation
    1. 8.1 Trademarks
    2. 8.2 Third-Party Products Disclaimer
  13. 9About the Author

2.1 Key System Specifications

The Table 1 shows the complete system specifications of the power design of Smart Probe. The table is divided into two sections describing specifications of HV Circuit and LV Circuit.

Table 1. Key System Specifications

Parameter Specifications Details
System Input Voltage (VIN) 4.25V - 5.5V (USB Type-C) Design supports 1S Battery input (3.3V-4.2V)
External Clock Synchronization 1MHz, 500 kHz & 250 kHz Onboard buffer/divider is used to provide the sync clock from 1MHz source
High Voltage Circuit Specifications Architecture: Single Ended Primary Inductance Converter (SEPIC)
Positive Output Voltage (VOUT+) Up to 80V Symmetric positive and negative output. Can be set by external feedback resistors
Negative Output Voltage (VOUT-) Up to -80V
Output Current (IOUT) up to 30mA per rail
Total High Voltage Power (PHV) 2.4W + 2.4W
Load Regulation <2% Load applied symmetrically on positive and negative rail
Voltage Accuracy <1% Voltage Accuracy: voltage difference between positive and negative rail across the load
Output Voltage Ripple 0.1% of the output voltage
Switching frequency 250 kHz
Transmit Low Voltage Supply (±5V) Specifications
Switcher Output Voltage (positive) 5.7V This Boost output can be fed as input to HV Supply or -5V supply to enable 1S operation.
LDO Output Voltage 5V
Output Current 150 mA Maximum LDO output current
Output Voltage Ripple 10 mV (VOUT : 5.7V IOUT : 1A)
Switcher Output Voltage (negative) -5.3V Inverting Buck Topology
LDO Output Voltage -5V
Output Current 150 mA
Output Voltage Ripple 10 mV (VOUT : -5.3V IOUT : 1A)
Receive Low Voltage Supply Specifications
AFE5832 Supply Rails with Low Noise LDOs 1.2V (300 mA maximum), 1.8V (1.5A maximum), 3.3V (250 mA maximum) LP5910, TPS74201, LP5907 LDOs are used for respective rails followed after TPS54218 DC-DC Buck
Switcher Output Voltage 1.4 V, 2.0 V, 3.5 V Low Dropout to maximize system efficiency
DC-DC Output Voltage Ripple (1.4 V) 8 mV
LP5910 (1.2 V) PSRR (Output Ripple) at 500 kHz -40 dB (80 µV)
DC-DC Output Voltage Ripple (2.0 V) 8 mV
TPS74201 (1.8 V) PSRR (Output Ripple) at 500 kHz -50 dB (25.2 µV)
DC-DC Output Voltage Ripple (3.5 V) 13 mV
LP5910 (3.3 V) PSRR (Output Ripple) at 500 kHz -40 dB (130 µV)
FPGA & FX3 Supply Specifications
Switcher Output Voltage 1 V (2 A maximum), 1.2 V (2 A maximum), 1.8 V(2 A maximum), 2.5 V (2 A maximum) The inductance values are optimized for higher efficiency and load currents of 1A, 400 mA, 1A and 500 mA respectively
Maximum Output Voltage Ripple 15 mV
System Power Measurement Total Power; FPGA Power and TX Power System current, voltage and power measurement of various subsystems using INA231