Circuit Simulation of LTC3105+Solar Cell(SPICE Model) Using LTspice

1. All Rights Reserved
Circuit Simulation of LTC3105+Solar Cell(SPICE Model)
Using LTspice
400mA Step-Up DC/DC
Converter with Maximum Power
Point Control and 250mV Start-Up
Bee Technologies provide Spice Model of Solar Cell
19JAN2012
Bee Technologies Inc.

2. Content
• Case1: Voltage Source(v1) with LTC3105
• Solar Cell Specification (Ref.1)
• Case2: MPPC Response to Input Source (SOL=100%)
• Case3: MPPC Response to Input Source (SOL=50%)
• Case4: Maximum power point tracking (SOL=30%)
• Output Characteristics vs. Incident Solar Radiation (Ref.2)
• Simulation Folder Index
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3. Case1: Voltage Source(v1) with LTC3105
− Simulation Circuit and Setting
Output Voltage≈ 4.1V
RLOAD= 500Ω
*Analysis directives:
• .tran 0 5m 0 startup
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Input Voltage= 0.5V
Vmppc= 0.4V

4. – Total elapsed time: 410.938sec. ≈ 7min.
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Case1: Voltage Source(v1) with LTC3105
− Simulation Result
Input Voltage
Output Voltage
VMPPC=0.4V
Input Current

5. Solar Cell Specification (Ref.1)
• The information refer to a part number 19_12_93 of CONRAD ELECTRONIC.
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PARAMETER VALUE
Pmax (W) 0.400
Vmp (V) 0.500
Imp (A) 0.800
Isc (A) 0.872
Voc (V) 0.580
66mm
96mm

6. Output Voltage≈ 4.1V
IOUT≈ 8.2mA
*Analysis directives:
• .tran 0 5m 0 startup
• .lib 19_12_93.lib
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Pmax= 400mW
Voc= 0.58V
Isc= 0.872A
Case2: MPPC Response to Input Source (SOL=100%)
− Simulation Circuit and Setting
Vmppc= Vmp= 0.5V
[SOL=100%]

7. – Total elapsed time: 786.766sec. ≈ 13min.
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Case2: MPPC Response to Input Source (SOL=100%)
− Simulation Result
Input Voltage
Output Voltage
VMPPC=0.5V
Input Current

8. Output Voltage≈ 4.1V
IOUT≈ 8.2mA
*Analysis directives:
• .tran 0 5m 0 startup
• .lib 19_12_93.lib
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Pmax= 400mW
Voc= 0.58V
Isc= 0.872A
Case3: MPPC Response to Input Source (SOL=50%)
− Simulation Circuit and Setting
Vmppc= Vmp= 0.5V
[SOL=50%]

9. – Total elapsed time: 387.219sec. ≈ 7min.
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Case3: MPPC Response to Input Source (SOL=50%)
− Simulation Result
Input Voltage
Output Voltage
VMPPC=0.5V
Input Current

10. Output Voltage≈ 4.1V
IOUT≈ 8.2mA
*Analysis directives:
• .tran 0 10m 0 startup
• .lib 19_12_93.lib
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Pmax= 400mW
Voc= 0.58V
Isc= 0.872A
Case4: Maximum power point tracking (SOL=30%)
− Simulation Circuit and Setting
Vmppc= 0.5V, 0.475V
(Ref.2)
[SOL=30%]
●
Parametric Sweep Rmppc: 50kΩ(0.5V), 47.5kΩ(0.475V)
●
Rmppc= Vm/10uA

11. – Total elapsed time: 2082.5sec. ≈ 35min.
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Case4: Maximum power point tracking (SOL=30%)
− Simulation Result
Input Voltage
VMPPC =0.500V ---
VMPPC =0.475V ---
Output Voltage
Input Current

12. Output Characteristics vs. Incident Solar Radiation (Ref.2)
19_12_93 Output Characteristics vs. Incident Solar Radiation
Parameter, SOL is added as
normalized incident radiation, SOL=1
for 100% conditions
Voltage (V)
Current(A)Power(W)
499.876mV,397.284mW
485.393mV,182.125mW
SOL=0.5
SOL=1
SOL=0.3
475.064mV,98.197mW

13. Simulation Index
Simulations Folder name
Case1: Voltage Source(v1) with LTC3105.………………..............
Case2: Case2: MPPC Response to Input Source (SOL=100%)…
Case3: MPPC Response to Input Source (SOL=50%)……………
Case4: Maximum power point tracking (SOL=30%).....................
Output Characteristics vs. Incident Solar Radiation (Ref.2)………
v1_src
sg_cell_pv_src_100%
sg_cell_pv_src_50%
sg_cell_pv_src_vmpp
SOL
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