TPS3808G01DBVR: A Powerful Power Monitoring Reset Chip
29 February 2024
Ⅱ. Functions of the TPS3808G01DBVR
Ⅲ. TPS3808G01DBVR functional block diagram
Ⅳ. Specifications of TPS3808G01DBVR
Ⅴ. TPS3808G01DBVR shift register application in reality
Ⅵ. Application circuit diagram of TPS3808G01DBVR
Ⅶ. How to use TPS3808G01DBVR for system reset?
TPS3808G01DBVR is a low quiescent current programmable delay monitor circuit manufactured by Texas Instruments. In this article, we will discuss some of the key points related to TPS3808G01DBVR including specifications, features and application areas so that you can get an in-depth understanding of the device. So let's get started!
The TPS3808G01DBVR is a monitor and reset chip that monitors system voltages from 0.4V to 5V. The chip sends out an open drain reset signal when the sensed voltage drops below a preset threshold or when the manual reset (MR) pin drops to a logic low. After the sensed voltage and manual reset (MR) recover above their respective thresholds, the reset output remains low for a user-adjustable delay time. The chip utilizes a precision voltage reference that can achieve a threshold accuracy of 0.5 percent when VIT ≤ 3.3V. The reset delay time can be set to 300ms by disconnecting the CT pin. Alternatively, by connecting the CT pin to an external capacitor, the user can adjust the reset delay time in the range of 1.25ms to 10s.
Replacements and equivalents:
The functions of TPS3808G01DBVR shift register mainly include the following aspects:
1. Precise monitoring: The shift register provides precise voltage monitoring function, enabling the system to make timely response when the power supply voltage reaches a predetermined threshold to ensure stable system operation.
2. Power monitoring: TPS3808G01DBVR can monitor the voltage condition of the system power supply to ensure that it is within the safe range. It can monitor the rising and falling process of the power supply and trigger the corresponding operation, such as issuing a warning or reset, when an abnormal situation is detected.
3. Reset: When an abnormal system voltage is detected or the microprocessor is out of control, the TPS3808G01DBVR can issue a reset signal to restore the system to a predetermined safe state. This helps prevent the system from dying or crashing due to power problems or other abnormalities.
• TPS3808G01DBVR is manufactured by Texas Instruments
• Its installation method is SMD or SMT.
• Its threshold voltage is 405mV.
• Its operating supply current is 2.4uA.
• The shift register has a reset delay time of 1.25 ms to 10 s.
• This shift register has 6 pins and is available in SOT-23-6 package and tape & reel (TR) packaging.
• TPS3808G01DBVR has a length of 2.9 mm, a width of 1.6 mm, and a height of 1.15 mm.
• The shift register has a minimum operating temperature of -40°C and a maximum operating temperature of 125°C.
• The minimum operating supply voltage of this shift register is 1.65V and the maximum operating supply voltage is 6.5V.
• TPS3808G01DBVR belongs to the category of supervisory circuits.
Listed below are some common applications of the TPS3808G01DBVR shift register.
1. Analog signal conversion: Shift registers can be used for analog signal conversion. For example, in an analog signal acquisition circuit, a shift register can be used to convert analog signals into digital signals. TPS3808G01DBVR can be used to monitor the power supply voltage and reset the output of the shift register when the power supply voltage is lower than a certain threshold, thereby protecting the analog signal acquisition circuit.
2. Serial communication: When multiple bits of data need to be transmitted simultaneously, they are often organized into parallel data. However, in serial communication, these data bits must be transmitted one by one. At this time, the TPS3808G01DBVR shift register can load parallel data into the register, and then shift the data out serially from the output end of the register by bit-by-bit shifting, thereby generating a data stream that meets the requirements of serial communication.
3. Digital circuit testing: The TPS3808G01DBVR shift register can be used for digital circuit testing, especially during the verification phase of chip design. This shift register not only has the core functions of a traditional shift register, but also provides additional monitoring and reset functions, making it a powerful assistant in digital circuit testing.
4. Timing control: TPS3808G01DBVR can be used to control the reset of the shift register, thereby controlling the start and stop of the entire timing control circuit. It can trigger the reset of the shift register under specific conditions, thereby ensuring the accuracy of data transmission or processing. When the system fails, is abnormal, or needs to be re-initialized, TPS3808G01DBVR can respond quickly and reset the shift register and the timing control circuit connected to it to the initial state through its reset function.
5. Sequence detection: Shift registers can be used for sequence detection. For example, in sequence detection, a shift register can be used to detect whether an input sequence conforms to a certain rule. The TPS3808G01DBVR can be used to monitor the supply voltage and reset the output of the shift register when the supply voltage falls below a certain threshold, thereby protecting the sequence detection circuit.
6. Data collection: The TPS3808G01DBVR shift register has excellent data processing capabilities. It can sample and convert analog signals from sensors bit by bit, convert them into digital signals, and store them in registers. This conversion process not only ensures the accuracy of the data, but also greatly improves the efficiency of data collection.
7. LED light control: LED light control is a common application for shift registers and the TPS3808G01DBVR. By controlling the output of the shift register, we can turn the LED light on and off. At the same time, TPS3808G01DBVR can detect changes in the power supply voltage and reset the output of the shift register to the initial state when the power supply voltage is lower than a certain threshold, thereby achieving effective protection of the LED lamp.
The voltage range of chip pin 6 (VDD) is from 1.7V to 6.5V. Pin 1 (RESETn) is an open-drain output, so a pull-up resistor needs to be connected in the application. Pin 2 (GND) is the ground terminal, and a ceramic filter capacitor is added between it and pin 6. Pin 3 (MRn) is used for mechanical reset. C3 in the picture is used to eliminate mechanical jitter. Pin 4 (CT) is used to set the length of time that pin 1 outputs a low level. When pin 4 is open, the delay is 20μs. If connected to the power supply VDD through a resistor with a value between 40kΩ and 200kΩ, the delay will be extended to 300ms. In addition, a capacitor is connected between it and the ground, and its delay time can be referred to the calculation formula in the figure. Pin 5 (SENSE) is the voltage monitoring pin, and its monitoring voltage range can refer to the formula in the figure. The relationship between pin 1, pin 3, and pin 5 is as follows: as long as either pin 3 or pin 5 is in a low state, pin 1 will output a low level. For example, if pin 5 detects that the D3V3 voltage drops below 2.5V, pin 1 will be pulled low regardless of whether pin 3 is high or low. Likewise, if the voltage at pin 3 is lower than 0.3*D3V3, pin 1 will also be pulled low regardless of whether pin 5 is high or low.
First of all, we need to make sure that the system voltage is within the monitoring range of the TPS3808G01DBVR, i.e. 0.4V to 5V, and only if the system voltage is within this range, the chip can work properly. Next, we connect the TPS3808G01DBVR's reset output pin (usually labeled "RESET") to the system or device that needs to be reset. According to the actual demand, we can adjust the threshold setting of TPS3808G01DBVR to change its reset behavior. For example, we utilize an external resistor or capacitor to adjust the reset threshold. Once the system voltage drops below the preset threshold, or the manual reset (MR) pin drops to a logic low, the TPS3808G01DBVR will emit an open drain reset signal. This signal will trigger a reset operation of the system or device to ensure its stability and reliability.
In addition, the TPS3808G01DBVR has an adjustable reset delay function. As needed, we can adjust the reset delay time by disconnecting the CT pin, using a resistor to connect the CT pin to VDD, or connecting to an external capacitor. In this way, we can set an appropriate delay time after the system voltage or manual reset (MR) returns above their respective thresholds, allowing the system enough time for initialization operations. During the reset delay period, we should closely monitor the status of the system to ensure that the system starts up properly and operates stably. Once the system starts up normally and operates stably, the reset output of the TPS3808G01DBVR will return high, indicating that the system is working normally and no further reset operation is required.
Frequently Asked Questions
1. What is a shift register used for?
Shift registers are commonly used in digital circuits for a variety of applications, including data storage, serial-to-parallel and parallel-to-serial data conversion, shift and rotate operations, and frequency division. They are also used in communications systems, such as in serial data transmission and reception.
2. What is the quiescent current consumption of the TPS3808G01DBVR?
The TPS3808G01DBVR has a low quiescent current consumption of typically 3.5µA, making it suitable for battery-powered applications where power efficiency is essential.
3. What is the typical application of the TPS3808G01DBVR?
The TPS3808G01DBVR is commonly used in electronic systems to ensure proper operation by monitoring voltage levels and initiating a reset if necessary. It finds applications in various devices such as consumer electronics, industrial control systems, automotive electronics, and more.
