NAME_TABLE:

C_Function_Name: cm_triangle

Spice_Model_Name: triangle

Description: "controlled triangle wave oscillator"

PORT_TABLE:

Port Name: cntl_in out

Description: "control 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: cntl_array freq_array

Description: "control array" "frequency array"

Data_Type: real real

Default_Value: 0.0 1.0e3

Limits: - [0 -]

Vector: yes yes

Vector_Bounds: [2 -] cntl_array

Null_Allowed: no no

PARAMETER_TABLE:

Parameter_Name: out_low out_high

Description: "output peak low value" "output peak high value"

Data_Type: real real

Default_Value: -1.0 1.0

Limits: - -

Vector: no no

Vector_Bounds: - -

Null_Allowed: yes yes

PARAMETER_TABLE:

Parameter_Name: duty_cycle

Description: "rise time duty cycle"

Data_Type: real

Default_Value: 0.5

Limits: [1e-10 0.999999999]

Vector: no

Vector_Bounds: -

Null_Allowed: yes

• Description:
  This function is a controlled triangle/ramp wave oscillator with parametrizable values of low and high peak output and rise time duty cycle. It takes an input voltage or current value. This value is used as the independent variable in the piecewise linear curve described by the coordinate points of the cntl_array and freq_array pairs.
  From the curve, a frequency value is determined, and the oscillator will output a triangle wave at that frequency. From the above, it is easy to see that array sizes of 2 for both the cntl_array and the freq_array will yield a linear variation of the frequency with respect to the control input. Any sizes greater than 2 will yield a piecewise linear transfer characteristic. For more detail, refer to the description of the piecewise linear controlled source, which uses a similar method to derive an output value given a control input.

Example SPICE Usage:

ain 1 2 ramp1

.model ramp1 triangle(cntl_array = [-1 0 5 6]

+ freq_array=[10 10 1000 1000] out_low = -5.0

+ out_high = 5.0 duty_cycle = 0.9)