关于运放自激震荡波形幅度问题？大家过来看看~~~~~

只看该作者 · 2020-9-19 10:37

今天用运放搭了一个电压跟随器，电源加正负15V，输入+IN端接地，OUT端接一个104电容，这样运放就自激震荡了，但自激震荡的波形幅度很奇怪用示波器看只有Vpp=1V（F=135K）,理论上不是到运放的正负电源吗？是什么原因只有Vpp=1V？？？

1万 · 2020-9-19 10:44

自激了可就不一定到多少了。。。你得把输入端和输出的电路全部给出来还有你使用的运放

只看该作者 · 2020-9-19 11:04

Siderlee 发表于 2020-9-19 10:44
自激了可就不一定到多少了。。。你得把输入端和输出的电路全部给出来还有你使用的运放 ...

电路图如下，请教一下，自激震荡波形的幅度Vpp值跟什么有关？

1万 · 2020-9-19 11:48

SJKKKKKK123 发表于 2020-9-19 11:04
电路图如下，请教一下，自激震荡波形的幅度Vpp值跟什么有关？

king 已经说出来你的问题了

运放带-----容性负载

1万 · 2020-9-19 11:55

它的输出电流是受限的。
电流驱动力、电容容量、振荡频率决定了振幅能够到多少。

1万 · 2020-9-20 12:25

*$
* OPA277
*****************************************************************************
* (C) Copyright 2019 Texas Instruments Incorporated. All rights reserved.
*****************************************************************************
** This model is designed as an aid for customers of Texas Instruments.
** TI and its licensors and suppliers make no warranties, either expressed
** or implied, with respect to this model, including the warranties of
** merchantability or fitness for a particular purpose.  The model is
** provided solely on an "as is" basis.  The entire risk as to its quality
** and performance is with the customer
*****************************************************************************
*
* This model is subject to change without notice. Texas Instruments
* Incorporated is not responsible for updating this model.
*
*****************************************************************************
*
** Released by: Online Design Tools, Texas Instruments Inc.
* Part: OPA277
* Date: 07FEB2019
* Model Type: Generic (suitable for all analysis types)
* EVM Order Number: N/A
* EVM Users Guide:  N/A
* Datasheet: SBOS079B -MARCH 1999-REVISED JUNE 2015
* Created with Green-Williams-Lis Op Amp Macro-model Architecture
*
* Model Version: Final 1.2
*
*****************************************************************************
*
* Updates:
*
* Final 1.2
* Edits in claw block, vos drift and unique subckt name
*
* Final 1.1
* Release to Web.
*
*****************************************************************************
* Model Usage Notes:
* 1. The following parameters are modeled:
* OPEN-LOOP GAIN AND PHASE VS. FREQUENCY  WITH RL, CL EFFECTS (Aol)
* UNITY GAIN BANDWIDTH (GBW)
* INPUT COMMON-MODE REJECTION RATIO VS. FREQUENCY (CMRR)
* POWER SUPPLY REJECTION RATIO VS. FREQUENCY (PSRR)
* DIFFERENTIAL INPUT IMPEDANCE (Zid)
* COMMON-MODE INPUT IMPEDANCE (Zic)
* OPEN-LOOP OUTPUT IMPEDANCE VS. FREQUENCY (Zo)
* OUTPUT CURRENT THROUGH THE SUPPLY (Iout)
* INPUT VOLTAGE NOISE DENSITY VS. FREQUENCY (en)
* INPUT CURRENT NOISE DENSITY VS. FREQUENCY (in)
* OUTPUT VOLTAGE SWING vs. OUTPUT CURRENT (Vo)
* SHORT-CIRCUIT OUTPUT CURRENT (Isc)
* QUIESCENT CURRENT (Iq)
* SETTLING TIME VS. CAPACITIVE LOAD (ts)
* SLEW RATE (SR)
* SMALL SIGNAL OVERSHOOT VS. CAPACITIVE LOAD
* LARGE SIGNAL RESPONSE
* OVERLOAD RECOVERY TIME (tor)
* INPUT BIAS CURRENT (Ib)
* INPUT OFFSET CURRENT (Ios)
* INPUT OFFSET VOLTAGE (Vos)
* INPUT COMMON-MODE VOLTAGE RANGE (Vcm)
* INPUT OFFSET VOLTAGE VS. TEMPERATURE (Vos Drift)
* INPUT OFFSET VOLTAGE VS. INPUT COMMON-MODE VOLTAGE (Vos vs. Vcm)
* INPUT/OUTPUT ESD CELLS (ESDin, ESDout)
*****************************************************************************
.subckt OPA277 IN+ IN- VCC VEE OUT
******************************************************
* MODEL DEFINITIONS:
.model R_NOISELESS RES(T_ABS=-273.15)
******************************************************
V_ORn    32 VCLP -1.6
V_ORp    33 VCLP 1.6
XV_OS       36 37 VOS_DRIFT_OPA277
V4       ZO_OUT_J1 OUT 0
V_GRp    53 MID 74
V_GRn    54 MID -74
V_ISCp    49 MID 27
V_ISCn    50 MID -27
V11       44 48 0
V12       43 47 0
VCM_MIN    67 VEE_B 2
VCM_MAX    68 VCC_B -2
I_Q       VCC VEE 790U
I_OS       ESDn MID 1F
I_B       37 MID 500P
XU1 Zo_Cleft CL_CLAMP Zo_Cright MID ZO_OUT_J1 AOL_INN_J1 AOL_INP_J1 CLAMP
+ CLAW_CLAMP VSENSE AOL_ZO_0_OPA277
XGR_SRC    26 27 CLAMP MID VCCS_LIM_GR_0_OPA277
XCL_SRC    28 29 CL_CLAMP MID VCCS_LIM_4_0_OPA277
XCLAW_SRC 30 31 CLAW_CLAMP MID VCCS_LIM_3_0_OPA277
XCLAWp    VIMON MID 34 VCC_B VCCS_LIM_CLAW+_0_OPA277
XCLAWn    MID VIMON VEE_B 35 VCCS_LIM_CLAW-_0_OPA277
XU5       VEE VCC ESDn ESDp ESD_0_OPA277
Xi_nn    ESDn MID FEMT_0_OPA277
Xe_n       37 ESDp VNSE_0_OPA277
Xi_np    MID 37 FEMT_0_OPA277
XU4       OUT_J1_38 ESDp MID PSRR_CMRR_0_OPA277
XU2       OUT_J1_39 VCC_B MID PSRR_CMRR_1_OPA277
XU3       OUT_J1 VEE_B MID PSRR_CMRR_2_OPA277
H2       41 MID V11 -1
H3       42 MID V12 1
S1       Zo_Cleft Zo_Cright SW_OL MID  S_VSWITCH_1
S7       VEE OUT VEE OUT  S_VSWITCH_2
S6       OUT VCC OUT VCC  S_VSWITCH_3
SOR_SWp    CLAMP 43 CLAMP 43  S_VSWITCH_4
SOR_SWn    44 CLAMP 44 CLAMP  S_VSWITCH_5
C_CMn    ESDn MID 3P
C_CMp    MID ESDp 3P
C28       45 MID 1P
R77       42 45 R_NOISELESS 100
C27       46 MID 1P
R76       41 46 R_NOISELESS 100
R75       MID 47 R_NOISELESS 1
GVCCS8    47 MID 33 MID  -1
R74       48 MID R_NOISELESS 1
GVCCS7    48 MID 32 MID  -1
XIQPos    VIMON MID MID VCC VCCS_LIMIT_IQ_0_OPA277
XIQNeg    MID VIMON VEE MID VCCS_LIMIT_IQ_0_OPA277
C_DIFF    ESDp ESDn 3P
XCL_AMP    49 50 VIMON MID 51 52 CLAMP_AMP_LO_0_OPA277_0_OPA277
XGR_AMP    53 54 55 MID 56 57 CLAMP_AMP_HI_0_OPA277
R39       53 MID R_NOISELESS 1T
R37       54 MID R_NOISELESS 1T
R42       VSENSE 55 R_NOISELESS 1M
C19       55 MID 1F
R38       56 MID R_NOISELESS 1
R36       MID 57 R_NOISELESS 1
R40       56 26 R_NOISELESS 1M
R41       57 27 R_NOISELESS 1M
C17       26 MID 1F
C18       MID 27 1F
R21       51 MID R_NOISELESS 1
R20       MID 52 R_NOISELESS 1
R29       51 28 R_NOISELESS 1M
R30       52 29 R_NOISELESS 1M
C9       28 MID 1F
C8       MID 29 1F
R22       49 MID R_NOISELESS 1T
R19       MID 50 R_NOISELESS 1T
R12       34 VCC_B R_NOISELESS 1K
R16       34 58 R_NOISELESS 1M
R13       VEE_B 35 R_NOISELESS 1K
R17       59 35 R_NOISELESS 1M
C6       59 MID 1F
C5       MID 58 1F
G2       VCC_CLP MID 58 MID  -1M
R15       VCC_CLP MID R_NOISELESS 1K
G3       VEE_CLP MID 59 MID  -1M
R14       MID VEE_CLP R_NOISELESS 1K
XCLAW_AMP VCC_CLP VEE_CLP VOUT_S MID 60 61 CLAMP_AMP_LO_0_OPA277
R26       VCC_CLP MID R_NOISELESS 1T
R23       VEE_CLP MID R_NOISELESS 1T
R25       60 MID R_NOISELESS 1
R24       MID 61 R_NOISELESS 1
R27       60 30 R_NOISELESS 1M
R28       61 31 R_NOISELESS 1M
C11       30 MID 1F
C10       MID 31 1F
C12       SW_OL MID 100P
R32       62 SW_OL R_NOISELESS 100
R31       62 MID R_NOISELESS 1
XOL_SENSE MID 62 46 45 OL_SENSE_0_OPA277
H1       63 MID V4 1K
R11       MID 64 R_NOISELESS 1T
R18       64 VOUT_S R_NOISELESS 100
C7       VOUT_S MID 1N
E2       64 MID OUT MID  1
C13       VIMON MID 1N
R33       63 VIMON R_NOISELESS 100
R10       MID 63 R_NOISELESS 1T
R47       65 VCLP R_NOISELESS 100
C24       VCLP MID 100P
E4       65 MID CL_CLAMP MID  1
C4       AOL_INP_J1 MID 1F
R9       AOL_INP_J1 66 R_NOISELESS 1M
R7       MID 67 R_NOISELESS 1T
R6       68 MID R_NOISELESS 1T
R8       MID 66 R_NOISELESS 1
XVCM_CLAMP  69 MID 66 MID 68 67 VCCS_EXT_LIM_0_OPA277
E1       MID 0 70 0  1
R89       VEE_B 0 R_NOISELESS 1
R5       71 VEE_B R_NOISELESS 1M
C3       71 0 1F
R60       70 71 R_NOISELESS 1MEG
C1       70 0 1
R3       70 0 R_NOISELESS 1T
R59       72 70 R_NOISELESS 1MEG
C2       72 0 1F
R4       VCC_B 72 R_NOISELESS 1M
R88       VCC_B 0 R_NOISELESS 1
G17       VEE_B 0 VEE 0  -1
G16       VCC_B 0 VCC 0  -1
R_PSR    73 69 R_NOISELESS 1K
G1       69 73 OUT_J1_39 OUT_J1  -1M
R2       AOL_INN_J1 ESDn R_NOISELESS 1M
R1       73 74 R_NOISELESS 1M
R_CMR    36 74 R_NOISELESS 1K
G5       74 36 OUT_J1_38 MID  -1M
R53       ESDn MID R_NOISELESS 1T
R52       MID ESDp R_NOISELESS 1T
R35       IN- ESDn R_NOISELESS 1K
R34       IN+ ESDp R_NOISELESS 1K
.MODEL S_VSWITCH_1 VSWITCH (RON=1M ROFF=1G VON=900M VOFF=800M)
.MODEL S_VSWITCH_2 VSWITCH (RON=50 ROFF=1T VON=500M VOFF=450M)
.MODEL S_VSWITCH_3 VSWITCH (RON=50 ROFF=1T VON=500M VOFF=450M)
.MODEL S_VSWITCH_4 VSWITCH (RON=10M ROFF=1G VON=10M VOFF=0)
.MODEL S_VSWITCH_5 VSWITCH (RON=10M ROFF=1G VON=10M VOFF=0)
.ENDS OPA277
*
.subckt VOS_DRIFT_OPA277 VOS+ VOS-
.param DC = 1U
.param POL = 1
.param DRIFT = 0.1e-6
E1 VOS+ VOS- VALUE={DC+POL*DRIFT*(TEMP-27)}
.ends
*
.SUBCKT AOL_ZO_0_OPA277 ZO_CLEFT CL_CLAMP ZO_CRIGHT MID ZO_OUT AOL_INN AOL_INP CLAMP
+ CLAW_CLAMP VSENSE
C13       77 MID 1.7827P
R35       78 77 R_RES_1 10K
R34       78 79 R_RES_2 3.086167K
R33       79 MID R_RES_3 1
GVCCS10    79 MID 80 MID  -1
C12       81 MID 692.45F
R32       80 81 R_RES_4 10K
R31       80 82 R_RES_5 5.8749621K
R30       82 MID R_RES_6 1
GVCCS9    82 MID 83 MID  -1
C11       84 MID 471.57F
R29       83 84 R_RES_7 10K
R28       83 85 R_RES_8 9.5K
R27       85 MID R_RES_9 1
GVCCS8    85 MID 86 MID  -1
C10       87 MID 648.78F
R26       86 87 R_RES_10 10K
R25       86 88 R_RES_11 9.4838706K
R24       88 MID R_RES_12 1
GVCCS7    88 MID 89 MID  -1
C9       90 MID 489.71F
R23       89 90 R_RES_13 10K
R22       89 91 R_RES_14 51.5714286K
R21       91 MID R_RES_15 1
GVCCS6    91 MID 92 MID  -1
C8       93 MID 73.935P
R20       92 93 R_RES_16 10K
R19       92 94 R_RES_17 98.6850107K
R18       94 MID R_RES_18 1
GVCCS5    94 MID 95 MID  -1
R17       96 MID R_RES_18 1
XVCCS_LIM_ZO 97 MID MID 96 VCCS_LIM_ZO_0_OPA277
R14       97 MID R_RES_19 7.603
C6       97 98 159.15F
R13       97 98 R_RES_20 10K
R12       98 MID R_RES_21 1
GVCCS4    98 MID 78 MID  -1
C5       99 MID 740.57P
R11       95 99 R_RES_22 10K
R10       95 100 R_RES_23 10.5710608K
R9       100 MID R_RES_24 1
GVCCS3    100 MID 101 MID  -2.6852
C4       102 101 8.6431U
R8       101 MID R_RES_25 5.9340176K
R7       101 102 R_RES_26 10K
R6       102 MID R_RES_27 1
GVCCS2    102 MID ZO_CRIGHT MID  -1.9129
C3       ZO_CLEFT ZO_CRIGHT 51.364U
R5       ZO_CRIGHT MID R_RES_28 10.9545455K
R4       ZO_CRIGHT ZO_CLEFT R_RES_29 10K
Rdummy    MID ZO_OUT R_RES_30 6.8582K
Rx       ZO_OUT 96 R_RES_31 68.582K
Rdc       ZO_CLEFT MID R_RES_32 1
G_Aol_Zo ZO_CLEFT MID CL_CLAMP ZO_OUT  -6.8394325K
GVCCS13    104 MID 103 MID  -1U
R38       MID 104 R_RES_33 1MEG
C15       104 MID 2F
C14       103 MID 15F
R37       MID 103 R_RES_34 1MEG
GVCCS12    103 MID 105 MID  -1U
R4_CL    MID CL_CLAMP R_RES_35 1K
GVCCS4_CL CL_CLAMP MID CLAW_CLAMP MID  -1M
R4_CC    MID CLAW_CLAMP R_RES_36 1K
GVCCS4_CC CLAW_CLAMP MID 104 MID  -1M
C3_A3    106 107 3.2P
R6_A3    107 MID R_RES_37 6.67K
R5_A3    107 106 R_RES_38 10K
R4_A3    106 MID R_RES_39 1
GVCCS4_A3 106 MID 108 MID  -2.5
C2       105 MID 15F
R36       MID 105 R_RES_40 1MEG
GVCCS11    105 MID 107 MID  -1U
GVCCS1    109 MID out2 MID  -1
C1       110 MID 28.9P
R3       108 110 R_RES_41 10K
R2       108 109 R_RES_42 17K
R1       109 MID R_RES_43 1
XVCCS_LIM_2 4_A0 MID MID CLAMP VCCS_LIM_2_0_OPA277
C2_A2    out2 MID 2F
R3_A2    MID out2 R_RES_44 1MEG
GVCCS3_A2 out2 MID VSENSE MID  -1U
C1_A0    CLAMP MID 550.27N
R4_A0    MID CLAMP R_RES_45 1MEG
R3_A0    MID 4_A0 R_RES_46 1MEG
XVCCS_LIM_1 AOL_INP AOL_INN MID 4_A0 VCCS_LIM_1_0_OPA277
R4_VS    MID VSENSE R_RES_47 1K
GVCCS4_VS VSENSE MID CLAMP MID  -1M
.MODEL R_RES_1 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_2 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_3 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_4 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_5 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_6 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_7 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_8 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_9 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_10 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_11 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_12 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_13 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_14 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_15 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_16 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_17 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_18 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_19 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_20 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_21 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_22 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_23 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_24 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_25 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_26 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_27 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_28 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_29 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_30 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_31 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_32 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_33 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_34 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_35 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_36 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_37 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_38 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_39 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_40 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_41 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_42 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_43 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_44 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_45 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_46 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_47 RES ( TCE=0 T_ABS=-273.15)
.ENDS
*
.SUBCKT ESD_0_OPA277 VEE VCC ESDn ESDp
SW5       ESDp ESDn ESDp ESDn  S_VSWITCH_1
SW6       ESDn ESDp ESDn ESDp  S_VSWITCH_2
SW1       VEE ESDp VEE ESDp  S_VSWITCH_3
SW3       VEE ESDn VEE ESDn  S_VSWITCH_4
SW4       ESDn VCC ESDn VCC  S_VSWITCH_5
SW2       ESDp VCC ESDp VCC  S_VSWITCH_6
.MODEL S_VSWITCH_1 VSWITCH (RON=50 ROFF=1T VON=700M VOFF=650M)
.MODEL S_VSWITCH_2 VSWITCH (RON=50 ROFF=1T VON=700M VOFF=650M)
.MODEL S_VSWITCH_3 VSWITCH (RON=50 ROFF=1T VON=500M VOFF=450M)
.MODEL S_VSWITCH_4 VSWITCH (RON=50 ROFF=1T VON=500M VOFF=450M)
.MODEL S_VSWITCH_5 VSWITCH (RON=50 ROFF=1T VON=500M VOFF=450M)
.MODEL S_VSWITCH_6 VSWITCH (RON=50 ROFF=1T VON=500M VOFF=450M)
.ENDS
*
.SUBCKT PSRR_CMRR_0_OPA277 OUT IN MID
R80       MID OUT R_RES_1 8.3315
C27       OUT 129 201.08P
R79       129 OUT R_RES_2 100MEG
GVCCS8    129 MID IN MID  -1.2003
R78       MID 129 R_RES_3 1
.MODEL R_RES_1 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_2 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_3 RES ( TCE=0 T_ABS=-273.15)
.ENDS
*
.SUBCKT PSRR_CMRR_1_OPA277 OUT IN MID
G_2       OUT MID 130 MID  -1K
R74       MID OUT R_RES_1 1
R2a       MID 131 R_RES_2 32.8679423K
C1a       131 132 6.9198P
R48       132 131 R_RES_3 100MEG
G_1       132 MID IN MID  -962.43U
Rsrc       MID 132 R_RES_4 1
R2b       MID 130 R_RES_5 100.1001001K
C2a       130 133 2.2736P
R73       133 130 R_RES_6 100MEG
GVCCS1    133 MID 131 MID  -1
R49       MID 133 R_RES_7 1
.MODEL R_RES_1 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_2 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_3 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_4 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_5 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_6 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_7 RES ( TCE=0 T_ABS=-273.15)
.ENDS
*
.SUBCKT PSRR_CMRR_2_OPA277 OUT IN MID
R80       MID OUT R_RES_1 33.3333
C27       OUT 134 1.5915N
R79       134 OUT R_RES_2 100MEG
GVCCS8    134 MID IN MID  -948.68M
R78       MID 134 R_RES_3 1
.MODEL R_RES_1 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_2 RES ( TCE=0 T_ABS=-273.15)
.MODEL R_RES_3 RES ( TCE=0 T_ABS=-273.15)
.ENDS
*
.SUBCKT VCCS_LIM_GR_0_OPA277  VC+ VC- IOUT+ IOUT-
.PARAM GAIN = 1
.PARAM IPOS = 1.2
.PARAM INEG = -1.2
G1 IOUT+ IOUT- VALUE={LIMIT(GAIN*V(VC+,VC-),INEG,IPOS)}
.ENDS
*
.SUBCKT VCCS_LIM_4_0_OPA277  VC+ VC- IOUT+ IOUT-
.PARAM GAIN = 1
.PARAM IPOS = 3.108
.PARAM INEG = -3.108
G1 IOUT+ IOUT- VALUE={LIMIT(GAIN*V(VC+,VC-),INEG,IPOS)}
.ENDS
*
.SUBCKT VCCS_LIM_3_0_OPA277  VC+ VC- IOUT+ IOUT-
.PARAM GAIN = 1
.PARAM IPOS = 1.554
.PARAM INEG = -1.554
G1 IOUT+ IOUT- VALUE={LIMIT(GAIN*V(VC+,VC-),INEG,IPOS)}
.ENDS
*
.SUBCKT VCCS_LIM_CLAW+_0_OPA277  VC+ VC- IOUT+ IOUT-
G1 IOUT+ IOUT- TABLE {(V(VC+,VC-))} =
+(0, 0.0009996)
+(8.9748, 0.0011176)
+(17.9497, 0.0017784)
+(23.9329, 0.0032952)
+(24.232, 0.0033932)
+(24.8304, 0.0035938)
+(25.4287, 0.0038094)
+(26.027, 0.004017)
+(26.6253, 0.0042781)
+(26.9245, 0.0044118)
.ENDS
*
.SUBCKT VCCS_LIM_CLAW-_0_OPA277  VC+ VC- IOUT+ IOUT-
G1 IOUT+ IOUT- TABLE {(V(VC+,VC-))} =
+(0, 0.0001445)
+(8.8288, 0.00062385)
+(17.6577, 0.0015617)
+(23.5436, 0.0028197)
+(23.8379, 0.0029131)
+(24.4264, 0.0031417)
+(25.015, 0.0034281)
+(25.6036, 0.0037723)
+(26.1922, 0.004171)
+(26.4865, 0.0043897)
.ENDS
*
.SUBCKT FEMT_0_OPA277  1 2
.PARAM FLWF=0.1
.PARAM NLFF=1000
.PARAM NVRF=200
.PARAM GLFF={PWR(FLWF,0.25)*NLFF/1164}
.PARAM RNVF={1.184*PWR(NVRF,2)}
.MODEL DVNF D KF={PWR(FLWF,0.5)/1E11} IS=1.0E-16
I1 0 7 10E-3
I2 0 8 10E-3
D1 7 0 DVNF
D2 8 0 DVNF
E1 3 6 7 8 {GLFF}
R1 3 0 1E9
R2 3 0 1E9
R3 3 6 1E9
E2 6 4 5 0 10
R4 5 0 {RNVF}
R5 5 0 {RNVF}
R6 3 4 1E9
R7 4 0 1E9
G1 1 2 3 4 1E-6
.ENDS
*
.SUBCKT VNSE_0_OPA277  1 2
.PARAM FLW=0.1
.PARAM NLF=50
.PARAM NVR=8
.PARAM GLF={PWR(FLW,0.25)*NLF/1164}
.PARAM RNV={1.184*PWR(NVR,2)}
.MODEL DVN D KF={PWR(FLW,0.5)/1E11} IS=1.0E-16
I1 0 7 10E-3
I2 0 8 10E-3
D1 7 0 DVN
D2 8 0 DVN
E1 3 6 7 8 {GLF}
R1 3 0 1E9
R2 3 0 1E9
R3 3 6 1E9
E2 6 4 5 0 10
R4 5 0 {RNV}
R5 5 0 {RNV}
R6 3 4 1E9
R7 4 0 1E9
E3 1 2 3 4 1
.ENDS
*
.SUBCKT VCCS_LIMIT_IQ_0_OPA277  VC+ VC- IOUT+ IOUT-
.PARAM GAIN = 1E-3
G1 IOUT- IOUT+ VALUE={IF( (V(VC+,VC-)<=0),0,GAIN*V(VC+,VC-) )}
.ENDS
*
.SUBCKT CLAMP_AMP_LO_0_OPA277_0_OPA277 VC+ VC- VIN COM VO+ VO-
.PARAM G=1
GVO+ COM VO+ VALUE = {IF(V(VIN,COM)>V(VC+,COM),((V(VIN,COM)-V(VC+,COM))*G),0)}
GVO- COM VO- VALUE = {IF(V(VIN,COM)<V(VC-,COM),((V(VC-,COM)-V(VIN,COM))*G),0)}
.ENDS
*
.SUBCKT CLAMP_AMP_HI_0_OPA277  VC+ VC- VIN COM VO+ VO-
.PARAM G=10
GVO+ COM VO+ VALUE = {IF(V(VIN,COM)>V(VC+,COM),((V(VIN,COM)-V(VC+,COM))*G),0)}
GVO- COM VO- VALUE = {IF(V(VIN,COM)<V(VC-,COM),((V(VC-,COM)-V(VIN,COM))*G),0)}
.ENDS
*
.SUBCKT CLAMP_AMP_LO_0_OPA277  VC+ VC- VIN COM VO+ VO-
.PARAM G=1
GVO+ COM VO+ VALUE = {IF(V(VIN,COM)>V(VC+,COM),((V(VIN,COM)-V(VC+,COM))*G),0)}
GVO- COM VO- VALUE = {IF(V(VIN,COM)<V(VC-,COM),((V(VC-,COM)-V(VIN,COM))*G),0)}
.ENDS
*
.SUBCKT OL_SENSE_0_OPA277  COM SW+ OLN  OLP
GSW+ COM SW+ VALUE = {IF((V(OLN,COM)>10E-3 | V(OLP,COM)>10E-3),1,0)}
.ENDS
*
.SUBCKT VCCS_EXT_LIM_0_OPA277  VIN+ VIN- IOUT- IOUT+ VP+ VP-
.PARAM GAIN = 1
G1 IOUT+ IOUT- VALUE={LIMIT(GAIN*V(VIN+,VIN-),V(VP-,VIN-), V(VP+,VIN-))}
.ENDS
*
.SUBCKT VCCS_LIM_ZO_0_OPA277  VC+ VC- IOUT+ IOUT-
.PARAM GAIN = 1316.2632
.PARAM IPOS = 4800.74
.PARAM INEG = -4800.74
G1 IOUT+ IOUT- VALUE={LIMIT(GAIN*V(VC+,VC-),INEG,IPOS)}
.ENDS
*
.SUBCKT VCCS_LIM_2_0_OPA277  VC+ VC- IOUT+ IOUT-
.PARAM GAIN = 0.0565
.PARAM IPOS = 0.44
.PARAM INEG = -0.44
G1 IOUT+ IOUT- VALUE={LIMIT(GAIN*V(VC+,VC-),INEG,IPOS)}
.ENDS
*
.SUBCKT VCCS_LIM_1_0_OPA277  VC+ VC- IOUT+ IOUT-
.PARAM GAIN = 1E-4
.PARAM IPOS = .5
.PARAM INEG = -.5
G1 IOUT+ IOUT- VALUE={LIMIT(GAIN*V(VC+,VC-),INEG,IPOS)}
.ENDS
*

1万 · 2020-9-20 12:31

上面是运放的模型，可以用的

只看该作者 · 2020-9-21 21:11

和电脑卡死前的鼠标一样.
你向右移动鼠标,眼睛看到鼠标移得不够,于是又向右移.等你眼睛看到光标到达了指定的位置了,就停止移动鼠标,结果你眼睁睁的看着光标跑过了,你这时只能左移鼠标,结果同样又移过了,这就是振荡了.
你给它加了一个大电容,运放一看输出电压没有达到我预定的,就继续增加输出,结果充多了,又减少,结果又减过了.就成振荡了

1万 · 2020-9-21 21:49

本帖最后由 manbo789 于 2020-9-22 10:39 编辑

“理论上不是到运放的正负电源吗？”

你这理论是谁告诉你的？书上有写吗？

只看该作者 · 2020-9-24 09:53

manbo789 发表于 2020-9-21 21:49
“理论上不是到运放的正负电源吗？”

你这理论是谁告诉你的？书上有写吗？ ...

仔细查看了资料，资料上说的“到运放的正负电源”是“各种理想条件下理论上的最大值”，大侠说的对，书上确实没说实际是多少；

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关于运放自激震荡波形幅度问题？大家过来看看~~~~~

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