Pins & Power

The Pin object represents the pin/leg/lead/ball of a component. When pins carry power information, typeCAD checks voltage levels and current draw for compatibility — that's the power-aware system, and Power is how a source or consumer enters it.

class

import { Component } from '@typecad/pcb'

One pin of a component. Two access styles: numeric for simple parts, named for complex ones. An optional powerInfo object makes the pin power-aware.

Example first

numeric.ts

import { Resistor } from '@typecad/pcb';
let r1 = new Resistor({ value: '1kohm' });

r1.pin(1);      // first pin
r1.pin(2);      // second pin

Numeric access — component.pin(n)

Use for simple components like passives where pin numbers are straightforward.

Named access — component.PINNAME

Use for complex components (ICs, connectors) with a generated .ts file where Pin objects are defined:

named.ts

import { ATtiny85_20S } from './ATtiny85_20S';
let u1 = new ATtiny85_20S();

u1.VCC      // power pin (internally pin 8)
u1.GND      // ground pin (internally pin 4)
u1.PB0      // GPIO pin PB0

pin (config) `this.pin(number, { type, powerInfo }): Pin`

Parameter	Type	Units / values	Description
type	string	KiCAD type	e.g. 'power_in', 'power_out', 'bidirectional' — used by ERC
powerInfo	object	—	Optional — enables voltage and current compatibility checks

The powerInfo properties:

Property	Meaning
minimum_voltage	Volts the pin can tolerate (minimum)
maximum_voltage	Volts the pin can tolerate (maximum)
current	Maximum current the pin can handle (A)

With data present, typeCAD checks that connected pins have compatible voltage levels and current draw — errors or warnings when the voltage is too high or the draw too much:

pin-config.ts

VCC = this.pin(8, { type: 'power_in', powerInfo: {
  minimum_voltage: -0.5,
  maximum_voltage: 6,
  current: 0.2,
}});

class

Power

import { Power } from '@typecad/pcb'

Extra information used for ERC (pin types), voltage compatibility checks, and automatic trace width calculation. A Power object represents a physical set of pins, not an abstract concept of power or ground.

Example first

coin-cell.ts

import { Component, Power } from '@typecad/pcb';

let bt1 = new Component({ footprint: 'Battery:BatteryHolder_Keystone_3008_1x2450' });
let coin_cell = new Power({
    power: bt1.pin(1),  // Pin 1 is the positive terminal → type set to 'power_out'
    gnd: bt1.pin(2),    // Pin 2 is the ground terminal → type set to 'power_in'
    voltage: 3.7,       // Nominal voltage
    current: 0.5,       // Current capacity
    direction: 'output' // This is a power source (default)
});

Options

Option	Type	Description
power	Pin	Pin that supplies power
gnd	Pin	Pin that supplies ground
voltage	number	Volts
current	number	Current capacity
direction	'output' \| 'input'	'output' (default) for power sources, 'input' for power consumers

How pin types are set

When a Power object is created, pin types are set automatically for ERC — the gnd pin is always power_in, regardless of direction:

direction	power pin type	gnd pin type
direction: output	power_out	power_in
direction: input	power_in	power_in

voltage and current propagate to the pins' powerInfo, used by ERC for voltage checks and by the routing system for trace width calculation.

Shared ground pins

Voltage regulators often have power inputs and outputs sharing one ground pin. Since gnd is always power_in, this typically works without conflict; override the pin type manually if ERC needs it:

regulator.ts

// U1 is a voltage regulator, pin 2 is shared ground
let vin = new Power({ power: U1.pin(1), gnd: U1.pin(2), voltage: 5, direction: 'input' });
let vout = new Power({ power: U1.pin(3), gnd: U1.pin(2), voltage: 3.3, direction: 'output' });

Input Power

An input Power specifies the power requirements of a component or sub-circuit — commonly passed into reusable packages so users can connect a suitable source:

package-power.ts

// 'vin' is an input Power object passed as a parameter
typecad.net(vin.power, U1.VCC);
typecad.net(vin.gnd, U1.GND);

A package can check the incoming voltage as well:

voltage-check.ts

if (vin.voltage != 3.3) {
    throw new Error('Voltage must be 3.3v');
}

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