TPS3700 High Voltage (18V) Window Voltage Detector, Internal Reference for Overvoltage and Undervoltage Monitoring1

1 Features 1? Wide supply voltage range: 1.8 V to 18 V? Adjustable threshold: 400 mV? High threshold accuracy: - 1.0% over temperature - 0.25% (typ.)? Open Channel Output Over and Under Voltage Detection? Internal Hysteresis: 5.5 mV (Typ)? Temperature Range: -40°C to 125°C? Package:- SOT-6 1.5mm x 1.5mm WSON-6

2Applications? Industrial Control Systems? Automotive Systems? Embedded Computing Modules? DSP, Microcontroller or Microprocessor Applications?

The TPS3700 wide supply window voltage detector operates in the 1.8-V to 18-V range. The device has two high precision comparators with an internal 400mV reference and two open drain outputs rated at 18v for over and under voltage detection. The TPS3700 can be used as a window voltage detector or as two independent voltage monitors; the monitored voltage can be set using external resistors.

OUTA is driven low when the voltage at INA+ is below (VITP - VHYS) and high when the voltage returns above their respective thresholds (VITP). When the INB - voltage is above VITP, OUTB is driven low, and when the voltage is below the respective threshold (VITP - VHYS), OUTB is driven high. Both comparators in the TPS3700 include built-in hysteresis for filtering to exclude transient glitches, ensuring stable output operation without false triggering.

Available in SOT-6 and 1.5 mm × 1.5 mm WSON-6 packages, the TPS3700 is specified for a junction temperature range of -40°C to 125°C.

In a typical TPS3700 application, the output is connected to a reset or enable input of a processor (such as a digital signal processor (DSP), central processing unit (CPU), field programmable gate array (FPGA), or application-specific integrated circuit) (ASIC)) or the output is connected to a voltage regulator (such as a DC-DC or low dropout regulator (LDO)) that allows the input.

The TPS3700 device provides two open-drain outputs (OUTA and OUTB). When the output reaches high impedance, pull-up resistors must be used to keep these lines high impedance. By connecting pull-up resistors to the appropriate voltage rails, the output can be connected to other devices with the correct interface voltage levels. The TPS3700 output can be pulled to 18 volts, independent of the device supply voltage. By using wired-OR logic, OUTA and OUTB can be combined into a single logic signal that goes low if one of the outputs is asserted due to a fault condition.

Table 1 and the input (INA+, INB -) sections describe how to assert or de-assert the output. See Figure 1 for a timing diagram depicting the relationship between the threshold voltage and the corresponding output.

7.3.3 Window Voltage Detector

The inverting and non-inverting configurations of the comparators use a resistor divider network to form a window voltage detection circuit, as shown in Figure 14 and Figure 15. The input terminals can monitor any system voltage greater than 400mv using a resistive divider network. INA+ and INB - terminals monitor undervoltage and overvoltage conditions, respectively