Voltage Regulator
The one that keeps your circuits singing!
Last updated
The one that keeps your circuits singing!
Last updated
A voltage regulator is always essential in electronic projects. It provides a constant, low-noise supply voltage. A regulator can only provide one supply voltage. On this board, all components require a supply voltage of 3.3V. Therefore, a single voltage regulator is implemented.
The TPS7A02 is an ultra-small, ultra-low quiescent current, low dropout linear regulator (LDO) widely used in electronic applications.
The device has very low power consumption (around 25nA), making it ideal for power management applications. In addition, this LDO can deliver up to 200mA, which is sufficient for the tracker's power requirements.
Input Voltage Range
From 1.5V to 5V
Output Voltage Range
From 0.8V to 5V (fixed)
Output Accuracy
1.5% over temperature
Current consumption
~25nA
Voltage Dropout
250mV at 200mA
The TPS7A02 IC is available in two packages: 4-pin X2SON (1x1mm) or 5-pin SOT-23 (2.9x2.8mm). I chose the SOT-23 package because it's easier to debug if necessary. The voltage regulator is a critical component on a board. It's important to be able to replace it if necessary.
The available pins are listed in the table below:
1
IN
Input Voltage Pin.
Voltage to regulate.
2
GND
GND
3
EN
Driving this pin to high enables the regulation voltage. Driving to a low logic state disables the device.
4
NC
No connect pin. This pin is not internally connected. Connect to ground or leave floating.
5
OUT
Regulated output pin. Voltage regulated
The voltage regulator chip is wired according to the data sheet (see page 26). A 1µF input and output is used for load transient response. Pin 4 is left floating and pin 3 is wired to the input voltage (voltage coming from the battery).
