LDO regulator (TPS7A20)
Low-dropout linear regulator, modelled after the TI TPS7A20: adjustable output voltage, dropout resistance and quiescent current.
Key data
- Category
- ICs
- Simulation model
- Built-in circuit element
- Manufacturer part number
- TPS7A20
- Reference prefix
- U
- Pins
- 4
- Land pattern
- SOT-23-5
Notes
The regulator holds OUT at the set voltage as long as the input is high enough. When the input falls, the output follows it, reduced by the load current times the dropout resistance. The enable input switches the output off below its threshold; the quiescent current loads the input.
- Tie EN to IN when the regulator should always be on; an open EN keeps the output off.
- Place input and output capacitors (about 1 µF each, as in the datasheet) close to the pins.
- The model has no current limit and no thermal shutdown: check the dissipated power (V_IN − V_OUT) · I in the heat view.
Simulation model
Behavioural regulator: regulated output with dropout resistance, enable threshold and quiescent current.
- Primitive
- LDO
Model and limitations
Simplified behavioural regulator
Included effects
- Output regulation with finite resistance, a smooth dropout transition and an enable threshold.
- Input quiescent load represented by a conductance; it varies with input voltage.
Model limitations
- No current limiting, thermal shutdown, noise, PSRR or internal control-loop dynamics.
- Startup timing and stability depend only on the external circuit in this model. Reverse current and output sinking are not qualified.
Offline reference checks
- Analytical DC cases for regulation, dropout, disabled output and quiescent load.
- Finite-difference check of the dropout Jacobian.
DC reference cases cover selected inputs from 2.5 to 4.2 V and loads up to 10 mA. This is not the manufacturer operating range or a calibrated TPS7A20 model.
Documented test coverage, not a live test result or manufacturer approval. Simulation results depend on the selected parameters and circuit.
Pins 4
| Pin | Name | Use |
|---|---|---|
| IN | INSupply pin | Input voltage: 1 µF to GND close to the pin |
| EN | ENInput pin | Enable: tie to IN for always-on, or drive from a GPIO |
| OUT | OUTSupply pin | Regulated output: 1 µF to GND close to the pin |
| GND | GNDGround pin | Ground |
Parameters 3
VOUTRDOIQPCB
SOT-23-5