December 04, 2019 by Sam Holland
The TPS3870-Q1 overvoltage reset integrated circuit (IC from Texas Instruments is an overvoltage monitor or reset IC also known as a voltage supervisor. The device uses a voltage comparator for overvoltage detection and is suitable for systems that operate on low voltage supply.
TPS3870-Q1 is packaged in the industry's smallest 6-pin DSE package and its body size is 1.50 mm × 1.50 mm. It is powered from an input voltage range of 1.7V to 5.5V.
The device supports open-drain active-low overvoltage monitor and has a low quiescent current ranging from 4.5µA to 7µA.
The pin configuration of the device is as follows:
Sense—input for the monitored supply voltage rail
VDD—supply voltage input pin
CT—capacitor time delay pin
Reset—active-low open-drain output pin
GND—ground
MR—memory reset pin
The TPS3870-Q1 has internal glitch immunity and uses noise filters to eliminate false resets from unwanted signals. This is made possible owing to its built-in hysteresis. It does not require an external resistor for configuring overvoltage reset thresholds. The device has a programmable time delay option with a single external capacitor. Its fixed time delay options range from 50 µs to 200 ms.
The device can be utilised in harsh temperature conditions and it is AEC-Q100-qualified, meeting the recommended operating temperature range of −40 to 125°C with a high threshold accuracy of ±0.7%.
As per the datasheet, the device has three functional modes: the normal operation mode, the under-voltage lockout mode, and the power-on-reset mode. The reset pin of the device enables interfacing with external components such as voltage regulators and digital signal processors. The TPS3870J4080DSERQ1 and TPS3870J4330DSERQ1 are two versions of the reset IC.
A functional block diagram of the TPS3870-Q1 reset integrated circuit. Image Credit: Texas Instruments.
Unlike the TPS3870-Q1 which operates from an input supply voltage ranging from 1.7V to 5.5V, TPS3702—also manufactured by Texas Instruments—operates from an input supply voltage between 2V and 18V. Similarly, TPS3700 has a wide input supply voltage range of 1.8V to 18V. TPS3702 has a high threshold accuracy of 0.9% but fails to meet AEC’s recommended temperature range of −40 to 125°C (like that of the TPS3870-Q1).
The TPS386000 is a comparable voltage supervisor useful for applications where TPS3870-Q1 isn't applicable, such as analogue sequencing, industrial equipment, and telecoms and wireless applications.
The TPS3870-Q1 is an AEC-Q100 qualified device suitable for harsh automotive environments. It finds applications in advanced driver assistance systems (or ADAS) and hybrid electric vehicles (aka HEVs). It is also used in field-programmable gate arrays, application-specific integrated circuit, and digital signal processing systems.
All in all, TPS3870-Q1 has robust features for performing different functions in overvoltage monitoring. It is a low-power device used in systems that operate on low voltage supply. Its reset pin allows interfacing with processors such as digital signal processors.
