Texas Instruments TPS3707-33DR

Overview

TPS3707-33DR from Texas Instruments is a precision 3.3 V supply-voltage supervisor IC with active-low and active-high reset outputs, fixed 200 ms power-on reset delay, power-fail comparator (PFI/PFO), and manual reset input (MR). It operates from 2 V to 6 V, draws ≤50 µA supply current, and is rated for –40°C to 85°C. It is used in microcontroller-based systems requiring reliable power sequencing and brownout detection.

For engineers reviewing the TPS3707-33DR datasheet, TPS3707-33DR pinout, TPS3707-33DR application, or TPS3707-33DR equivalent, key selection criteria include its dual-reset output architecture, 2.93 V threshold accuracy over temperature, absence of watchdog timer (distinguishing it from TPS3705-xx), SOIC-8 package compatibility, and pin-for-pin equivalence with MAX705–MAX708 series for drop-in replacement in legacy designs.

Technical Context

The TPS3707-33DR implements dual-reset supervision: RESET (active-low) and RESET (active-high) outputs are complementary and synchronized to VDD transitions and MR assertion. Its internal voltage reference (1.25 V) and resistor divider set the precise 2.93 V negative-going threshold (VIT–) with 50 mV hysteresis, ensuring stable release during supply recovery.

Unlike the TPS3705-xx family, the TPS3707-xx variant omits the watchdog timer and WDI/WDO pins, instead dedicating pins 7 and 8 in SOIC-8 to complementary RESET outputs. The PFI input accepts external voltage dividers for secondary rail monitoring (e.g., battery or auxiliary supply), with PFO providing an open-drain power-fail warning signal.

Key Specifications

Pinout & Package

TPS3707-33DR is available in 8-pin SOIC (D package), 3.90 mm × 4.90 mm body size, with exposed pad not present. Pin functions are validated per TI SLVS184F Rev F (October 2020).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with TPS3707-33DR, the TPS3707-33DGN offers superior thermal dissipation in compact layouts, while the MAX706RCSA+ provides legacy MAXIM compatibility but sacrifices dual-output flexibility-making TPS3707-33DR optimal for new designs needing polarity versatility and TI supply chain assurance.

Availability

TPS3707-33DR is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and portable medical devices requiring stable component supply, long-term manufacturability, and guaranteed traceability.

Supply support for TPS3707-33DR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The TPS370x-xx product line was designed specifically for robust, low-power microprocessor supervision in harsh environments-emphasizing precision threshold accuracy, integrated power-fail detection, and pin compatibility with industry-standard supervisors.

FAQ

What is the exact supply voltage threshold monitored by the TPS3707-33DR?

TPS3707-33DR monitors the VDD supply at a precise negative-going threshold of 2.93 V (typical), with guaranteed limits of 2.87 V (min) and 3.00 V (max) across –40°C to 85°C. This value is factory-trimmed and does not require external components, making it ideal for 3.3 V systems where ±2.1% tolerance is acceptable.

Does the TPS3707-33DR include a watchdog timer function?

No, the TPS3707-33DR does not include a watchdog timer. Unlike the TPS3705-xx series, the TPS3707-xx family replaces the watchdog input (WDI) and output (WDO) pins with a second RESET output (active-high). This design choice prioritizes dual-polarity reset capability over system-level fault recovery, confirmed in TI's SLVS184F datasheet Section 8.3.3.

Can the TPS3707-33DR be used to monitor a 5 V supply?

No, the TPS3707-33DR is optimized for 3.3 V nominal supply monitoring with a 2.93 V threshold. For 5 V systems, TI specifies the TPS3707-50DR (4.55 V threshold). Using TPS3707-33DR on a 5 V rail would cause immediate, continuous reset assertion since 5 V exceeds its VIT– by >2 V, violating recommended operating conditions.

What is the purpose of the NC pin on the TPS3707-33DR SOIC-8 package?

Pin 6 on the TPS3707-33DR SOIC-8 package is designated NC (No Connection) and is internally unconnected. It must be left floating or tied to GND for mechanical stability-applying voltage or routing signals to this pin has no functional effect and may risk latch-up if misused. This is explicitly defined in TI's Pin Functions table (Section 6.1).

How does the power-fail comparator (PFI/PFO) operate in the TPS3707-33DR?

The PFI input compares an external voltage (e.g., from a resistor divider) against an internal 1.25 V reference. When the PFI voltage drops below 1.25 V (with ±0.05 V hysteresis), the open-drain PFO output pulls low to signal power-fail or low-battery condition. PFO requires an external pull-up resistor and can drive interrupts or status LEDs without additional buffering.