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// license:BSD-3-Clause
// copyright-holders:Couriersud
/*
* nld_r2r_dac.cpp
*
* DMR2R_DAC: R-2R DAC
*
* Generic R-2R DAC ... This is fast.
* 2R
* Bit n >----RRR----+---------> Vout
* |
* R
* R R
* R
* |
* .
* .
* 2R |
* Bit 2 >----RRR----+
* |
* R
* R R
* R
* |
* 2R |
* Bit 1 >----RRR----+
* |
* R
* R 2R
* R
* |
* V0
*
* Using Thevenin's Theorem, this can be written as
*
* +---RRR-----------> Vout
* |
* V
* V V = VAL / 2^n * Vin
* V
* |
* V0
*
*/
#include "nl_base.h"
#include "nl_factory.h"
#include "analog/nlid_twoterm.h"
namespace netlist::analog
{
class nld_r2r_dac : public nld_two_terminal
{
public:
nld_r2r_dac(constructor_param_t data)
: nld_two_terminal(data)
, m_VIN(*this, "VIN", nlconst::one())
, m_R(*this, "R", nlconst::one())
, m_num(*this, "N", 1)
, m_val(*this, "VAL", 1)
{
register_sub_alias("VOUT", P());
register_sub_alias("VGND", N());
}
NETLIB_UPDATE_PARAMI();
// NETLIB_RESETI();
protected:
param_fp_t m_VIN;
param_fp_t m_R;
param_int_t m_num;
param_int_t m_val;
};
NETLIB_UPDATE_PARAM(r2r_dac)
{
nl_fptype V = m_VIN() / static_cast<nl_fptype>(1 << m_num())
* static_cast<nl_fptype>(m_val());
change_state(
[this, &V]()
{ this->set_G_V_I(plib::reciprocal(m_R()), V, nlconst::zero()); });
}
} // namespace netlist::analog
namespace netlist::devices
{
NETLIB_DEVICE_IMPL_NS(analog, r2r_dac, "R2R_DAC", "VIN,R,N")
} // namespace netlist::devices
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