Reading Time: 2 Minutes

The ESP32-CAM uses the fixed, linear voltage regulator AMS1117-3.3 from Advanced Monolithic Systems (AMS) that possesses a built-in protection against short circuit and thermal overloads:

ESP32-CAM w/ ASM1117 highlighted
AMS1117 SOT-223 Top View

For instance, the circuitry-wise thermal protection will shut-down the linear regulator in case the junction temperature is above 165 °C at the sense point. It provides an output voltage of 3.3V by a maximum output current of 1.5A and a maximum input voltage of 15V. The AMS1117-3.3 guarantees a low dropout voltage (input-to-output differential: VDROPOUT = VIN – VOUT) of maximum 1.3V at the maximum output current of 1.5A. The dropout voltage decreases at lower load currents and operates down to 1V dropout voltage. The on-chip trimming develops a reference voltage of 1.25V between the output and the ground with a precise reference tolerance of 1.5%.

Electrical Characteristics

The table below shows the electrical characteristics of the AMS1117-3.3 at IOUT = 0 mA, and TJ = +25°C (unless specified otherwise):

Reference VoltageIOUT = 10 mA
1.5 V ≤ (VIN – VOUT) ≤ 12 V
Output VoltageVIN = 4.8V3.2013.3003.399V
Line Regulation1.5V ≤ (VIN – VOUT) ≤ 12V1.010mV
Load RegulationVIN = 4.75V, 0 ≤ IOUT ≤ 0.8A725mV
Dropout Voltage∆VOUT, ∆VREF = 1%, IOUT = 0.8A1.11.3V
Current Limit(VIN – VOUT) = 1.5V90011001500mA
Minimum Load
(VIN – VOUT) = 1.5V510mA
Quiescent Current(VIN – VOUT) = 1.5V511mA
Cf. data sheet of the AMS1117