LM5118-Q1: PSpice simulation fails to converge

Hello,

I'm simulating the buck-boost converter reference design found in TIDA-01179, however the simulation fails with various convergence problems:

WARNING(ORPSIM-16534): Using high values of ITL4 for Speed Level > 0 may increase total simulation job time.
Reducing minimum delta to make the circuit converge.
Reducing minimum delta to make the circuit converge.
Reducing minimum delta to make the circuit converge.
Reducing minimum delta to make the circuit converge.

ERROR(ORPSIM-15138): Convergence problem in Transient Analysis at Time = 124.8E-06.
Time step = 291.0E-21, minimum allowable step size = 1.000E-18

These voltages failed to converge:

V(X_U1.conv3) = 37.65uV \ 4.915uV
V(X_X3.10) = 924.83mV \ 938.30mV
V(X_X3.7) = 924.83mV \ 938.30mV
V(X_X3.4) = 924.83mV \ 938.30mV

These supply currents failed to converge:

I(X_L1.Edc) = 37.75mA \ 37.88mA
I(X_U1.Errout) = 47.20uA \ 47.28uA
I(V_V_Icout1) = -102.05mA \ -101.94mA
I(X_U1.XA_DFF.V2) = -19.09nA \ -1.399nA

These devices failed to converge:
X_D4_1.D4 X_D4.D4 X_D1.D1 X_D1_1.D1 X_X3.M1 X_X3.M2

I am using TI's PSPICE design for the LM5118 startup model as template. If I modify the value for the ramp resistor (R7), the simulation fails. This is also the case if I modify the value for the soft-start capacitor (C16) or the error amplifier compensation circuit (R4, C17 and C18). 

I also tried modifying all values according to the reference design in TIDA-01179, but as expected, the simulation fails as well. 

I found this answer here, suggesting to change the simulation parameters, but this didnt work either. 

See attached PSpice project. 

e2e.ti.com/.../6431.tida_2D00_01179.zip