* MAX5025 MACROMODEL * ------------------------------ * Revision 1, 6/2005 * Model platform : PSpice * ------------------------------ *This is a small signal macromodel of the MAX5025, in boost converter configuration *made using an averaged model of the PWM switch. This model can be used for analyzing *stability and system response in time domain and frequency domain except for the *effects of switching frequency. *System efficiency is assumed to be 0.75. *Boost inductor is internal to the model and the inductance value can be entered as a *parameter during simulation. Default inductance value is 40uH. Do not use an external *boost inductor. Connect the output capacitor directly from LX pin to ground. * ********************************************* * PARAMETERS TO BE ENTERED DURING SIMULATION: ********************************************* * L :Inductance of the external inductor connected(Default is 47uH). * * ***************** * Connections * 2 = GND * 3 = FB * 4 = SHDN\ * 5 = VCC * 6 = LX *$ ***************** .SUBCKT MAX5025 2 3 4 5 6 +PARAMS: L = 47u ***************** *UVLO VCC(2.65V and 100mV hyst) VUV 33 2 2.65V GUV 2 34 POLY(2) 5 33 34 2 0 1M 100U DUV2 2 34 DS CUV 34 2 1P DUV1 34 20 DS ************** *SHDN(1.6V AND 100mV hyst) VSH 38 2 1.6V GSH 2 37 POLY(2) 4 38 37 2 0 1M 100U DSH1 2 37 DS CSH 37 2 1P DSH2 37 20 DS ESH 39 2 37 2 1 DSH3 17 39 DS ************** *REFERENCE VREF 15 2 1.25 ***************** GBIAS 5 12 5 2 1.6U IBIAS 5 12 8U QI1 14 15 91 QP QI2 13 16 92 QP RE1 12 91 3K RE2 12 92 3K VS1 16 3 0V RC1 13 2 41.1K RC2 14 2 41.1K ***************** *ILpeak, V(17) G1 2 17 13 14 1.05M R1 17 2 1K D1 2 17 DS D2 17 18 DS ECL1 18 A18 5 2 52M VL1 A18 2 0.0 EUV 35 2 34 2 1 DUV3 17 35 DS ***************** *VO-VIN, V(19) RL1 6 2 1MEG G2 2 19 6 5 1M R2 19 2 1K DL1 20 19 DS VL2 20 2 1V ***************** *PULSE SKIP FCL1 31 20 VL1 10 DCL2 31 20 DS DCL1 20 32 DS VCL1 32 31 0.8V RCL1 31 20 10MEG RCL2 18 2 100K ***************** *OUTPUT GOUT1 5 27 VALUE={(V(17,2)**2*L*0.5*0.75*V(31,2)*500K)/V(19,2)} GIN1 5 2 VALUE={(V(17,2)**2*L*0.5*500K*V(31,2))/V(5,36)} VMIN 2 36 0.1V DOUT 5 27 DS VOUT 27 6 0V ***************** .MODEL QP PNP(IS=16E-15 BF=160) .MODEL DS D(N=1M) ***************** .ENDS ***************** *$