Software Power Switch using Dirctional Switch

[Suke0811]

Current implementation

FetPowerGateNoBtn

PolymorphicBlocks/examples/test_multimeter.py

Lines 156 to 217 in 969ee73

	class FetPowerGateNoBtn(PowerSwitch, KiCadSchematicBlock, Block):
	"""A high-side PFET power gate that has a button to power on, can be latched
	on by an external signal, and provides the button output as a signal.
	"""
	def __init__(self):
	super().__init__()
	self.pwr_in = self.Port(VoltageSink.empty(), [Input])
	self.pwr_out = self.Port(VoltageSource.empty(), [Output])
	self.gnd = self.Port(Ground.empty(), [Common])
	self.btn_out = self.Port(DigitalSingleSource.empty())
	self.control = self.Port(DigitalSink.empty()) # digital level control - gnd-referenced NFET gate
	def contents(self):
	super().contents()
	max_voltage = self.control.link().voltage.upper()
	max_current = self.pwr_out.link().current_drawn.upper()
	self.pull_res = self.Block(Resistor(
	resistance=10*kOhm(tol=0.05) # TODO kind of arbitrary
	))
	self.pwr_fet = self.Block(Fet.PFet(
	drain_voltage=(0, max_voltage),
	drain_current=(0, max_current),
	gate_voltage=(max_voltage, max_voltage), # TODO this ignores the diode drop
	))
	self.amp_res = self.Block(Resistor(
	resistance=10*kOhm(tol=0.05) # TODO kind of arbitrary
	))
	self.amp_fet = self.Block(Fet.NFet(
	drain_voltage=(0, max_voltage),
	drain_current=(0, 0), # effectively no current
	gate_voltage=(self.control.link().output_thresholds.upper(), self.control.link().voltage.upper())
	))
	self.ctl_diode = self.Block(Diode(
	reverse_voltage=(0, max_voltage),
	current=RangeExpr.ZERO, # effectively no current
	voltage_drop=(0, 0.4)*Volt, # TODO kind of arbitrary - should be parameterized
	reverse_recovery_time=RangeExpr.ALL
	))
	self.import_kicad(self.file_path("resources", f"{self.__class__.__name__}.kicad_sch"),
	conversions={
	'pwr_in': VoltageSink(
	current_draw=self.pwr_out.link().current_drawn,
	voltage_limits=RangeExpr.ALL,
	),
	'pwr_out': VoltageSource(
	voltage_out=self.pwr_in.link().voltage,
	current_limits=RangeExpr.ALL,
	),
	'control': DigitalSink(), # TODO more modeling here?
	'gnd': Ground(),
	'btn_out': DigitalSingleSource(
	voltage_out=self.gnd.link().voltage, # TODO model diode drop,
	output_thresholds=(self.gnd.link().voltage.upper(), float('inf')),
	low_signal_driver=True
	)
	})

Original FetPowerGate

• With added switch
  

  PolymorphicBlocks/examples/test_multimeter.py

  Lines 219 to 229 in 969ee73

  	class FetPowerGate(FetPowerGateNoBtn):
  	def contents(self):
  	max_voltage = self.control.link().voltage.upper()
  	self.btn_diode = self.Block(Diode(
  	reverse_voltage=(0, max_voltage),
  	current=RangeExpr.ZERO, # effectively no current
  	voltage_drop=(0, 0.4)*Volt, # TODO kind of arbitrary - should be parameterized
  	reverse_recovery_time=RangeExpr.ALL
  	))
  	self.btn = self.Block(Switch(voltage=0*Volt(tol=0))) # TODO - actually model switch voltage
  	super().contents()

With DirSwitch

• Using FetPowerGateNoBtn, adding directional switch to be used as the power button
  

  PolymorphicBlocks/examples/components_lib.py

  Lines 61 to 107 in 969ee73

  	class OrPowerGateDirSw(OrPowerGate):
  	@init_in_parent
  	def __init__(self, diode_voltage_drop: RangeLike, fet_rds_on: RangeLike) -> None:
  	super().__init__(diode_voltage_drop, fet_rds_on)
  	self.dir = self.Block(DigitalDirectionSwitch())
  	self.dir_a = self.Export(self.dir.a)
  	self.dir_b = self.Export(self.dir.b)
  	self.dir_c = self.Export(self.dir.c)
  	self.dir_d = self.Export(self.dir.d)
  	def contents(self):
  	Block.contents(self) # TODO: generalize the base class, currently completely overwriting it
  	# POWER
  	with self.implicit_connect(
  	ImplicitConnect(self.gnd, [Common]),
  	) as imp:
  	(self.fuse, self.gate, self.prot, self.tp), _ = self.chain(
  	self.pwr_lo,
  	imp.Block(SeriesPowerPptcFuse((2, 4)*Amp)),
  	imp.Block(FetPowerGateNoBtn()),
  	imp.Block(ProtectionZenerDiode(voltage=(4.5, 6.0)*Volt)),
  	self.Block(VoltageTestPoint()))
  	self.vbatt = self.connect(self.gate.pwr_out) # downstream of fuse
  	self.connect(self.dir.gnd, self.gnd)
  	max_voltage = self.gate.btn_out.link().voltage.upper()
  	self.btn_diode = imp.Block(Diode(
  	reverse_voltage=(0, max_voltage),
  	current=RangeExpr.ZERO, # effectively no current
  	voltage_drop=(0, 0.4)*Volt, # TODO kind of arbitrary - should be parameterized
  	reverse_recovery_time=RangeExpr.ALL
  	))
  	self.gate_btn_out = self.connect(self.gate.btn_out, self.btn_diode.cathode.adapt_to(DigitalSink()))
  	self.connect(self.dir.with_mixin(DigitalDirectionSwitchCenter()).center, self.gate.btn_out)
  	self.connect(self.btn_diode.anode.adapt_to(DigitalSink()), self.btn_out)
  	self.pwr_or = self.Block(PriorityPowerOr( # also does reverse protection
  	self.diode_voltage_drop, self.fet_rds_on
  	)).connected_from(self.gnd, self.pwr_hi, self.gate.pwr_out)
  	self.connect(self.pwr_or.pwr_out, self.pwr_out)
  	# Power gait
  	self.connect(self.gate.control, self.control)

Usage

PolymorphicBlocks/examples/test_ballu.py

Lines 41 to 42 in 969ee73

	self.gate = self.Block(OrPowerGateDirSw((0, 1)*Volt, (0, 0.1)*Ohm)).connected_from(self.gnd, self.vusb, self.batt.pwr)
	self.pwr = self.connect(self.gate.pwr_out)

[Suke0811]

#334 merged