SLVAFU9 January   2025 TPS62840 , TPS62843

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Inverting Buck-Boost Topology
    1. 1.1 Concept
    2. 1.2 Output Current Calculations
    3. 1.3 VIN and VOUT Range
  5. 2Design Considerations
    1. 2.1 Additional Input Capacitor
    2. 2.2 Digital Input Pin Configurations
    3. 2.3 Startup Behavior and Switching Node Consideration
  6. 3External Component Selection
    1. 3.1 Inductor Selection
    2. 3.2 Capacitor Selection
  7. 4Typical Performance
  8. 5Summary
  9. 6References

4 Typical Performance

The reference design with VOUT = -1.8V, as shown in Figure 4-1 was used to generate the typical characteristic graphs presented in this section and shown in Figure 4-2 through Figure 4-9.

Schematic of the Tested CircuitFigure 4-1 Schematic of the Tested Circuit
Efficiency vs Load Current with VIN = 3.3V, VOUT = 1.8VFigure 4-2 Efficiency vs Load Current with VIN = 3.3V, VOUT = 1.8V
Load Regulation at VIN = 3.3V, VOUT = -1.8VFigure 4-4 Load Regulation at VIN = 3.3V, VOUT = -1.8V
Line Regulation at 320mA LoadFigure 4-3 Line Regulation at 320mA Load
Startup on VIN at 450mA Load, VIN = 3.3V, VOUT = -1.8VFigure 4-5 Startup on VIN at 450mA Load, VIN = 3.3V, VOUT = -1.8V
Load Transient Response, 0mA to 400mA at 1A/μs With VIN = 3.3V, VOUT = -1.8VFigure 4-7 Load Transient Response, 0mA to 400mA at 1A/μs With VIN = 3.3V, VOUT = -1.8V
Shutdown on VIN at 450mA Load, VIN = 3.3V, VOUT = -1.8VFigure 4-6 Shutdown on VIN at 450mA Load, VIN = 3.3V, VOUT = -1.8V
Output Voltage Ripple, VIN = 3.3V, VOUT = -1.8V and IOUT = 450mAFigure 4-8 Output Voltage Ripple, VIN = 3.3V, VOUT = -1.8V and IOUT = 450mA
Bode Plot at VIN = 3.3V, VOUT = -1.8V and 450mA LoadFigure 4-9 Bode Plot at VIN = 3.3V, VOUT = -1.8V and 450mA Load