TPS79101DBVR

PMIC - Voltage Regulators - Linear

TPS79101DBVR is a general-purpose linear voltage regulator provided by Texas Instruments (TI). It is an adjustable low drop-out (LDO) voltage regulator with a low quiescent current of 1μA, designed for the most demanding power management applications in the industrial and automotive markets. It is an ideal choice for applications where the input voltage is slightly higher than the regulated output voltage.

Features and Benefits

• High output voltage accuracy - +/- 0.8% over a temperature range of -40°C to +125°C
• Output current capability up to 1.5A
• High input voltage range of 2.8V to 24V
• Very low quiescent current of 1µA in bypass mode
• Output voltage adjustable from 0.8V to 24V via external resistors
• Thermal shutdown and current-limit protection
• Reverse-battery protection
• Floating current sensing

Typical Application Circuit

The following diagram illustrates a typical application circuit for the TPS79101DBVR voltage regulator. It is a simple two-resistor voltage divider circuit and it can be used for output voltages from 0.8V to 24V.

Working Principle

The TPS79101DBVR is a low-dropout voltage regulator with a maximum dropout voltage of 160mV at 1.5A output current. It is designed to regulate an input voltage with a low quiescent current and requires only two external components: an adjustable resistor to set the output voltage and a bypass capacitor to reduce the output voltage ripple. The regulator operates in a three-terminal configuration, with an input, an output and a ground (Bypass) connection.

The device uses an internally generated reference voltage to regulate the output voltage. The output voltage is set by two external resistors, R1 and R2, that form a voltage divider circuit. The output voltage is given by the following equation:

Vo = Vref x (1 + (R2/R1))

where Vref is the reference voltage, typically 1.187V. The output voltage can be adjusted from a minimum of 0.8V to a maximum of 24V by varying the resistance ratios of R1 and R2. The output voltage must remain within the range specified in the device data sheet.

The device is designed to maintain a constant output voltage, regardless of the input voltage variations, by passing current through an internally controlled pass transistor. The current passing through the pass transistor is monitored by the internal current-sense amplifier which senses the floating current in the resistor and continuously adjusts the voltage at the pass-transistor gate to maintain the regulated output voltage.

The device is also designed to protect against excessive current and temperature. The thermal-shutdown feature limits the device maximum junction temperature to protect it from short-circuit or output overcurrent conditions. The current-limit feature will automatically shut down the output current when it exceeds the maximum safe operating limit. In addition, the device features reverse-battery protection, ensuring it is protected against reverse input voltage conditions.

Conclusion

In conclusion, the TPS79101DBVR is a general-purpose low drop-out voltage regulator offering high output voltage accuracy and wide input voltage range for industrial and automotive applications. The device features low quiescent current, reverse-battery protection, thermal protection and current-limit protection, making it an ideal solution for demanding power applications.