NAME_TABLE:

C_Function_Name: cm_limit

Spice_Model_Name: limit

Description: "limit block"

PORT_TABLE:

Port Name: in out

Description: "input" "output"

Direction: in out

Default_Type: v v

Allowed_Types: [v,vd,i,id] [v,vd,i,id]

Vector: no no

Vector_Bounds: - -

Null_Allowed: no no

PARAMETER_TABLE:

Parameter_Name: in_offset gain

Description: "input offset" "gain"

Data_Type: real real

Default_Value: 0.0 1.0

Limits: - -

Vector: no no

Vector_Bounds: - -

Null_Allowed: yes yes

PARAMETER_TABLE:

Parameter_Name: out_lower_limit out_upper_limit

Description: "output lower limit" "output upper limit"

Data_Type: real real

Default_Value: 0.0 1.0

Limits: - -

Vector: no no

Vector_Bounds: - -

Null_Allowed: yes yes

PARAMETER_TABLE:

Parameter_Name: limit_range

Description: "upper & lower smoothing range"

Data_Type: real

Default_Value: 1.0e-6

Limits: -

Vector: no

Vector_Bounds: -

Null_Allowed: yes

PARAMETER_TABLE:

Parameter_Name: fraction

Description: "smoothing fraction/absolute value switch"

Data_Type: boolean

Default_Value: FALSE

Limits: -

Vector: no

Vector_Bounds: -

Null_Allowed: yes

• Description:
  The Limiter is a single input, single output function similar to the Gain Block. However, the output of the Limiter function is restricted to the range specified by the output lower and upper limits. This model will operate in DC, AC and Transient analysis modes. Note that the limit range is the value below the upper limit and above the lower limit at which smoothing of the output begins. For this model, then, the limit range represents the delta with respect to the output level at which smoothing occurs. Thus, for an input gain of 2.0 and output limits of 1.0 and -1.0 volts, the output will begin to smooth out at (\pm)0.9 volts, which occurs when the input value is at (\pm)0.4.

Example SPICE Usage:

a5 1 2 limit5

.model limit5 limit(in_offset=0.1 gain=2.5 out_lower_limit=-5.0

+ out_upper_limit=5.0 limit_range=0.10 fraction=FALSE)