AiSIC circuits for people and AI.
IHP SG13G2 130 nm

Designs

Every design, one page each.

81 designs, each with its purpose, how it works, its testbenches and limits, and a link into the workbench where it runs in your browser.

Analog · Amplifier stages

  • Common-source amplifierA transistor and resistor amplify small voltage changes and invert them. The transistor turns voltage into current; the resistor turns…
  • Differential pairTwo transistors share a current and respond to the difference between their input voltages. Resistors turn the current imbalance into…
  • Source followerA voltage buffer whose output follows the input at a lower voltage. The bias current sets its operating point, while the body connection…
  • Super source followerA source follower with local feedback that lowers its output resistance. A second transistor adjusts the current available to the load,…
  • Differential pair with source degenerationA differential amplifier with a resistor between its input transistors' sources. The resistor opposes current changes, reducing gain but…
  • Cascode common-source stageA voltage amplifier with stacked transistors that hold internal voltages steadier. This raises output resistance and gain, but reduces the…

Analog · Op amps and OTAs

Mixed-signal · Data converters

  • SAR ADCThis ADC converts a sampled voltage into a binary number. A capacitor DAC tries one bit at a time, and a comparator keeps or clears each…
  • Flash ADC (3 bit)This ADC compares an input with seven reference levels at once. A resistor ladder sets the levels, and logic turns the comparator decisions…
  • Sigma-delta modulator (first order)This modulator represents a slowly changing voltage as a stream of ones and zeros. Feedback makes the fraction of ones follow the input…
  • SAR ADC, monotonic switchingThis ADC converts the difference between two sampled voltages into a binary number. It decides the first bit directly, then lowers one…
  • Charge-redistribution DACThis DAC converts a binary number into a voltage by sharing charge between capacitors. Each bit controls a different capacitor weight.…

Analog · Passives and trimming

  • RC low-passA resistor and capacitor pass slow changes and reduce fast ones. Their product sets the ideal cutoff frequency. The physical models show…
  • MOS-triode trim attenuatorThis divider uses a gate voltage to adjust how much of a small reference voltage reaches its output. At enough gate overdrive, the…

Analog · Mirrors, bias and references

  • NMOS current mirrorCopies a reference current into an output branch. Two transistors share a gate voltage; repeated unit devices set the current ratio. The…
  • Cascode current mirrorsCopies a current more accurately as the output voltage changes. A transistor stacked above the output device keeps its drain voltage nearly…
  • Beta-multiplier referenceGenerates a bias current from a resistor and a transistor ratio. A feedback loop settles where two gate-source voltages differ by the…
  • Fractional bandgap reference, 0.76 V outputProduces about 0.76 V from a 1.2 V supply. It combines a bipolar-derived current that falls with temperature with one that rises, then…
  • Two-transistor PTAT sensor with a drain shieldProduces a small voltage that rises almost linearly with temperature. One NMOS supplies leakage current to a second; a third transistor…
  • Self-biased PTAT generatorGenerates a voltage that rises almost linearly with temperature. A current mirror forces two differently sized NMOS branches to carry the…
  • Resistorless four-transistor PTAT cellProduces a temperature-dependent voltage without a resistor. Two mirrors force differently sized NMOS branches to carry the same current,…
  • Threshold-difference voltage referenceGenerates about 0.35 V using a tiny leakage current. Two NMOS types with different thresholds balance opposing temperature effects; a third…

Analog · Comparators

  • StrongARM latch comparatorThis clocked comparator decides which input voltage is higher. A small current difference starts the decision, then positive feedback…
  • Inverter quantizerA CMOS inverter can make a simple voltage decision: low input gives high output, and high input gives low output. Transistor sizing sets…
  • Comparator with hysteresisThis comparator uses different thresholds for rising and falling inputs. Feedback reinforces the current output state, so small input…
  • StrongARM latch comparator, PMOS inputThis clocked comparator uses PMOS input transistors to compare voltages near ground. It resets while the clock is high and makes its…

Analog · Switches and sampling

  • Sample and holdThis circuit captures a voltage on a capacitor. While the switch is on, the capacitor follows the input; when the switch opens, it holds…
  • NMOS track-and-hold, dummy switchThis sampling circuit uses a half-size dummy transistor to reduce the voltage error left when the main switch opens. The dummy absorbs some…
  • Differential chopper, transmission gatesThis switch network repeatedly swaps two signal wires. Straight connections preserve the input difference; crossed connections reverse it,…

Analog · Fully differential

  • Chopper OTA core, common mode set from outsideThis is the amplifier core used inside a chopper amplifier. Two gain stages are separated by switches that can reverse the signal polarity.…
  • Chopper OTA, one CM loop around both stagesThis is a chopper-amplifier core with one common-mode feedback loop around both gain stages. The loop adjusts the first-stage load currents…
  • Chopper OTA, a CM loop for each stageThis chopper-amplifier core uses a separate common-mode feedback loop for each gain stage. One sets the internal average voltage from a…
  • Capacitively coupled chopper IAThis amplifier measures small, slowly changing voltage differences. Clocked switches move the signal away from low-frequency offset and…
  • Capacitively coupled chopper IA, impedance boostThis sensor amplifier uses chopping to reduce low-frequency offset and noise. An extra feedback path supplies most of the charge drawn by…
  • Folded-cascode two-stage op ampThis amplifier produces two outputs whose difference carries the signal. A folded first stage provides gain, and a second stage provides…
  • Two-stage OTA, class-AB outputThis differential amplifier uses an output stage that draws little current at rest but can deliver more during a large signal change.…
  • Telescopic-cascode OTAThis differential amplifier obtains gain from stacked transistors in one stage per side. Most of the signal current is reused through the…
  • Two-stage amplifier, two common-mode loopsThis differential amplifier combines NMOS and PMOS input devices so both contribute to amplification. A second stage provides additional…
  • Five-transistor CMFB, PMOS inputThis block helps a differential amplifier keep its two outputs centred on a reference voltage. Two resistors sense their average, and a…
  • Switched-capacitor CMFBThis block controls the average output voltage of a differential amplifier using stored charge. Sensing capacitors pass changes…
  • Resistive common-mode detectorThis block measures the average of two voltages without amplifying it. Equal resistors provide the average at low frequency, and parallel…

Analog · Voltage regulators

  • Capless LDO, folded cascode and followerRegulates 1.2 V down to about 0.8 V without a large output capacitor. A folded-cascode amplifier senses the output and a follower drives…
  • Folded-cascode LDO, 2.8 V from 3.3 VRegulates a 3.3 V input down to about 2.8 V. A folded-cascode amplifier compares the output directly with a reference and drives a PMOS…
  • Core-supply LDO from 3.3 VRegulates a 3.3 V input down to the 1.2 V core supply. A five-transistor amplifier compares the output with a reference and drives a PMOS…
  • Basic PMOS LDORegulates 1.2 V down to about 0.9 V. An amplifier compares a divided output with a reference and adjusts a PMOS pass transistor. A large…
  • Buffered-reference LDO, 2.5 V from 3.3 VRegulates 3.3 V down to about 2.5 V. A buffer doubles and filters the reference before a two-stage error amplifier drives the PMOS pass…
  • PMOS LDO, Miller and feed-forward compensatedRegulates 1.2 V down to about 0.9 V with a small output capacitor. A capacitor across the PMOS pass device separates the loop's poles;…
  • PMOS LDO, Miller-compensated with a zero resistorRegulates 1.2 V down to about 0.9 V with a small output capacitor. A capacitor and series resistor compensate the PMOS pass stage, adding…
  • Unity-feedback PMOS LDORegulates 1.2 V down to about 0.6 V without a feedback divider. A five-transistor amplifier directly compares output and reference, then…

Digital · Digital logic

  • InverterOne input, the opposite output: the simplest standard-cell example.
  • NAND gateA two-input universal gate, checked against all four input combinations.
  • 2:1 multiplexerSelect one of two inputs; a basic element of datapaths and control logic.
  • D flip-flop with resetCapture one bit on a rising clock edge, with an active-low asynchronous reset.
  • 4-bit synchronous counterFour flip-flops and next-state logic count modulo 16, with enable and reset.

Digital · Processor and IP

  • Ibex RISC-VRun the pinned Ibex small RTL in your browser: inspect instruction retirement, memory waits and program checks.
  • CORE-V CV32E40PAn OpenHW 32-bit RISC-V processor with a four-stage pipeline and configurable floating-point and DSP extensions.
  • Ascon · SP 800-232The standardized Ascon family: authenticated encryption, hashing and extendable output, using the reference author's SystemVerilog…