Engee documentation

CMOS AND

CMOS logic circuits.

CMOS AND

cmos and

CMOS BUFFER

cmos buffer

CMOS NAND

cmos nand

CMOS NOR

cmos nor

CMOS NOT

cmos not

CMOS OR

cmos or

CMOS XOR

cmos xor

Description

The CMOS blocks are CMOS logic gates. The truth table shows the dependence of the output logic level of CMOS blocks on their input level.

Block

Input logic level of the block

Output logic level of the block

CMOS AND

(1, 1)

HIGH

all other values

LOW

CMOS BUFFER

1

HIGH

all other values

LOW

CMOS NAND

(0, 0), (1, 0), (0, 1)

HIGH

all other values

LOW

CMOS NOR

(0, 0)

HIGH

all other values

LOW

CMOS NOT

0

HIGH

all other values

LOW

CMOS OR

(1, 0), (0, 1), (1, 1)

HIGH HIGH

all other values

LOW

CMOS XOR

(1, 0), (0, 1)

HIGH

all other values

LOW

The block defines the logic levels of the valve inputs as follows:

  • If the voltage at the valve is greater than the threshold voltage, the block interprets the input as logic 1.

  • Otherwise the block interprets the input as logic 0.

The Threshold Voltage is the voltage value at the midpoint between the value of the High level input voltage parameter and the value of the Low level input voltage parameter.

To increase the speed of the simulation, the block does not model all the internal individual MOSFET devices that make up the valve. Assumptions and limitations.

Unit models the valve as follows:

  • The inputs of the valve have infinite resistance and finite or zero capacitance.

  • The output of the valve offers a choice of two models: Linear and Quadratic. Use the Output current-voltage relationship parameters to specify the output model.

  • You can specify the propagation delay for both valve models. For the Linear output, the block sets the value of the output capacitor of the valve so that the resistor-capacitor time constant is equal to the value of the Propagation delay parameters. For the `Quadratic' output, the input demand of the valve is delayed to approximate the value of the Propagation delay parameters.

The initial block conditions depend on the selected output model:

  • For the Linear model, a high initial condition corresponds to the value of the High level output voltage parameter, V_OH, and a low initial condition corresponds to the value of the Low level output voltage parameter, V_OL.

  • For the `Quadratic' model, the high initial state is the value close to the value of the Supply voltage parameter, `Vcc', and the low initial state is the value of `0'.

The output voltage of the unit depends on the selected output model:

  • For the Linear model, a high output value is the value of the High level output voltage parameter and a low value is the value of the Low level output voltage parameter.

  • For the Quadratic model, the output voltage for the High and Low states is a function of the output current. At zero load current, the high level output voltage is Vcc (the value of the Supply voltage parameters) and the low level output voltage is 0.

Constructing the waveform of the input and output signals

You can plot the input and output waveforms of the CMOS NOT block without building a complete model. Use these graphs to study the effect of your selected parameters on the performance of the unit.

  • If you set the block parameters based on a data table, you can compare your graphs to the data table to make sure you set the block parameters correctly.

  • If you have a complete working model but are unsure which manufactured part to use, you can compare your graphs to the datasheets to help you decide.

Assumptions and limitations

This block does not model the internal individual MOSFET devices that make up the valve (except for the last pair of MOSFETs if you have selected Quadratic for the Output current-voltage relationship parameters). This limitation has the following implications:

  • The block does not accurately model the valve response to input noise and inputs near the logic threshold voltage.

  • The block does not accurately model the dynamic response.

In circuits with feedback around a set of logic gates, it may be necessary to set a non-zero propagation delay on one or more gates.

Ports

Conserving

# J — output J
electricity

Details

Non-directional port associated with the J block output.

Program usage name

output_pin

# A — input A (for AND, NAND, NOR, OR or XOR)
electricity

Details

A non-directional port associated with the A input of the unit.

Dependencies

To use this port, set Type to AND, NAND, NOR, OR or XOR.

Program usage name

input_pin_a

# B — input B
electricity

Details

Non-directional port associated with the B input of the unit.

Dependencies

To use this port, set Type to AND, NAND, NOR, OR or XOR.

Program usage name

input_pin_b

# A — input A (for BUFFER or NOT)
electricity

Details

A non-directional port associated with the A input of the unit.

Dependencies

To use this port, set Type to BUFFER or NOT.

Program usage name

input_pin

Parameters

Main

# Type — CMOS type
AND | BUFFER | NAND | NOR | NOT | OR | XOR

Details

The Type parameter makes it possible to change the CMOS type without recreating a new component. The following values are possible:

  • Components with two input ports:

    • AND

    • NAND

    • NOR

    • OR

    • * XOR

  • Components with one input port:

    • BUFFER

    • NOT

Dependencies

You need to rebuild the circuit when switching a dual-port component to a single-port component or vice versa.

Values

AND | BUFFER | NAND | NOR | NOT | OR | XOR
Default value

—
Program usage name

type
Evaluatable

No

Inputs

# Low level input voltage — lower threshold voltage at the input
V | MV | kV | mV

Details

The voltage value below which the block interprets the input voltage as a logical `LOW'.

Units

V | MV | kV | mV
Default value

2.0 V
Program usage name

V_IL
Evaluatable

Yes

# High level input voltage — upper threshold voltage at the input
V | MV | kV | mV

Details

The voltage value above which the unit interprets the input voltage as logic `HIGH'.

Units

V | MV | kV | mV
Default value

3.0 V
Program usage name

V_IH
Evaluatable

Yes

# Average input capacitance — average input capacitance
F | mF | nF | pF | uF

Details

A fixed capacitance that approximates the input capacitance for the gate of a transistor. The capacitance of a MOSFET depends on the applied voltage.

If you control this block with another valve, the Average input capacitance sets the voltage rise time, similar to the transistor voltage rise time. You can usually find the value of this capacitance in the manufacturer’s data sheet.

Setting this parameter to 0 may result in faster simulation times.
Units

F | mF | nF | pF | uF
Default value

5.0 pF
Program usage name

C_input
Evaluatable

Yes

Outputs

# Output current-voltage relationship — relationship between output current and voltage
Linear | Quadratic

Details

Output signal model. The following values are possible:

  • Linear.

  • Quadratic

Values

Linear | Quadratic
Default value

Linear
Program usage name

output_type
Evaluatable

No

# Low level output voltage — lower output threshold voltage
V | MV | kV | mV

Details

The value of the output voltage below which the unit sets the output voltage as logic `LOW'.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to Linear.

Units

V | MV | kV | mV
Default value

0.0 V
Program usage name

V_OL
Evaluatable

Yes

# High level output voltage — upper threshold output voltage
V | MV | kV | mV

Details

The value of the output voltage above which the unit sets the output voltage as logic `HIGH'.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to Linear.

Units

V | MV | kV | mV
Default value

5.0 V
Program usage name

V_OH
Evaluatable

Yes

# Output resistance — output impedance
Ohm | GOhm | MOhm | kOhm | mOhm

Details

The resistance value of the series output resistor, which is used to simulate the output voltage drop caused by the output current. You can obtain this value from the product data sheet or technical specification catalogue by dividing the high level output voltage by the maximum low level output current.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to Linear.

Units

Ohm | GOhm | MOhm | kOhm | mOhm
Default value

25.0 Ohm
Program usage name

R_output
Evaluatable

Yes

# Supply voltage — power supply voltage
V | MV | kV | mV

Details

The value of the power supply voltage applied to the valve in your circuit.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to `Quadratic'.

Units

V | MV | kV | mV
Default value

5.0 V
Program usage name

V_supply
Evaluatable

Yes

# Measurement voltage — signal voltage
V | MV | kV | mV

Details

Valve supply voltage for which the output resistances and currents of the reference data are determined.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to `Quadratic'.

Units

V | MV | kV | mV
Default value

5.0 V
Program usage name

V_measurement
Evaluatable

Yes

# Logic HIGH output resistance at zero current and at I_OH — output resistance at the HIGH state on the valve at zero current and at current
Ohm | GOhm | MOhm | kOhm | mOhm

Details

Vector [ ] containing two resistance values.

  • - is the gradient of the output voltage/current dependence when the valve is in the logic HIGH state and there is no output current.

  • - is the gradient of the current dependence of the output voltage when the valve is in the logic HIGH state and the output current is .

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to Quadratic.

Units

Ohm | GOhm | MOhm | kOhm | mOhm
Default value

[25.0, 250.0] Ohm
Program usage name

R_OH_vector
Evaluatable

Yes

# Logic HIGH output current I_OH when shorted to ground — output current for earth faults
A | MA | kA | mA | nA | pA | uA

Details

The magnitude of current when the valve is in the logic HIGH state and the load causes the output voltage to tend to zero.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to `Quadratic'.

Units

A | MA | kA | mA | nA | pA | uA
Default value

63.0 mA
Program usage name

I_OH
Evaluatable

Yes

# Logic LOW output resistance at zero current and at I_OL — output resistance at the LOW state on the valve at zero current and at current
Ohm | GOhm | MOhm | kOhm | mOhm

Details

Vector [ ] containing two resistance values.

  • - is the gradient of the output voltage/current dependence when the valve is in the logical LOW state and there is no output current.

  • - is the gradient of the current dependence of the output voltage when the valve is in the logical LOW state and the output current is .

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to Quadratic.

Units

Ohm | GOhm | MOhm | kOhm | mOhm
Default value

[30.0, 800.0] Ohm
Program usage name

R_OL_vector
Evaluatable

Yes

# Logic LOW output current I_OL when shorted to Vcc — output current at LOW state on the valve when is shorted on the valve
A | MA | kA | mA | nA | pA | uA

Details

The magnitude of current when the valve is in the logic LOW state but the load forces the output voltage to reach the supply voltage .

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to Quadratic.

Units

A | MA | kA | mA | nA | pA | uA
Default value

-45.0 mA
Program usage name

I_OL
Evaluatable

Yes

# Propagation delay — signal propagation delay
d | s | hr | ms | ns | us | min

Details

The time for a signal to go from LOW to HIGH or from HIGH to LOW after a change in input logic levels.

Units

d | s | hr | ms | ns | us | min
Default value

25.0 ns
Program usage name

delay
Evaluatable

Yes

# Protection diode on resistance — resistance of the open protective diode
Ohm | GOhm | MOhm | kOhm | mOhm

Details

Voltage-current gradient for protection diodes at direct bias.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to `Quadratic'.

Units

Ohm | GOhm | MOhm | kOhm | mOhm
Default value

5.0 Ohm
Program usage name

R_on_diode
Evaluatable

Yes

# Protection diode forward voltage — protection diode forward voltage
V | MV | kV | mV

Details

Voltage above which the protection diode opens.

Dependencies

To use this parameter, set the Output current-voltage relationship parameter to `Quadratic'.

Units

V | MV | kV | mV
Default value

0.6 V
Program usage name

V_forward_diode
Evaluatable

Yes

Initial Conditions

# Output initial state — initial output state
Low | High

Details

Specify the initial output state of the block as High or Low.

This parameter is used for both linear and quadratic output models, provided that the Propagation delay parameter is greater than zero and the Start simulation from steady state parameter is turned off in the block Solver Configuration.

Values

Low | High
Default value

Low
Program usage name

output_initial_state
Evaluatable

No