Texas Instruments TPS3123G15DBVT

Overview

TPS3123G15DBVT from Texas Instruments is an ultra-low-voltage processor supervisory IC with 1.40 V reset threshold, 180 ms power-on reset delay, manual reset (MR) input, and watchdog timer (WDI) functionality. It operates from 0.75 V to 3.3 V supply, draws 14 µA typical supply current, and delivers open-drain active-low RESET output - used for reliable power sequencing in low-voltage DSPs and microcontrollers.

For engineers reviewing the TPS3123G15DBVT datasheet, TPS3123G15DBVT pinout, TPS3123G15DBVT application, or TPS3123G15DBVT equivalent, key selection criteria include its fixed 1.40 V threshold accuracy (±50 mV), MR-triggered reset assertion, WDI timeout of 0.8–2.1 s, SOT-23-5 package compatibility, and -40°C to 85°C industrial temperature range.

Technical Context

The TPS3123G15DBVT integrates a precision voltage reference, internal timing circuitry for 180 ms reset delay, and a watchdog timer requiring periodic WDI transitions. Its reset assertion occurs when VDD falls below 1.40 V (VIT−) or MR is pulled low, with hysteresis of 15 mV for noise immunity.

It features open-drain RESET output compatible with 0.75–3.3 V logic domains, supports manual reset via internal 27 kΩ pull-up on MR, and requires no external components. The device uses a fixed-sense threshold set by an internal high-precision voltage divider and remains functional down to 0.75 V supply.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.9 mm × 1.6 mm × 1.15 mm body, surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar supervisory circuit applications.

Compared with TPS3123G15DBVT, TPS3123G15DBVR offers identical performance in larger reel format for production efficiency, while TPS3808G15DBVR trades fixed delay and open-drain flexibility for improved accuracy and programmability - making it suitable for next-generation designs demanding tighter margins.

Availability

TPS3123G15DBVT is available at Aetrix Electronics and suitable for low-voltage DSP initialization, portable microcontroller reset management, and wireless transceiver power supervision requiring stable component supply across design, qualification, and production phases.

Supply support for TPS3123G15DBVT 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The TPS312x family was designed specifically for ultralow-voltage processor supervision in DSP- and microcontroller-based systems, emphasizing minimal supply voltage operation, integrated watchdog capability, and compact SOT-23-5 packaging.

FAQ

What is the exact reset threshold voltage of the TPS3123G15DBVT?

The TPS3123G15DBVT has a nominal reset threshold voltage (VIT−) of 1.40 V, with a guaranteed range of 1.35 V to 1.45 V over the full -40°C to +85°C temperature range. This value is factory-trimmed and specified in Table 1 of the SLVS227B datasheet. The "G15" suffix explicitly denotes the 1.40 V threshold variant within the TPS3123 family, and the TPS3123G15DBVT maintains this specification under all recommended operating conditions.

Does the TPS3123G15DBVT require an external pull-up resistor on the RESET pin?

Yes, the TPS3123G15DBVT features an open-drain RESET output, which requires an external pull-up resistor to the appropriate logic rail (e.g., 1.5 V or 1.8 V). The datasheet specifies a maximum sink current of 1.4 mA at VDD = 1.5 V, so a typical 10 kΩ pull-up yields ~14 µA static current. No internal pull-up exists on RESET - unlike the MR pin, which includes a 27 kΩ internal pull-up to VDD.

Can the TPS3123G15DBVT operate with a supply voltage below 1.0 V?

Yes, the TPS3123G15DBVT is fully specified to operate down to 0.75 V supply voltage (VDD), as confirmed in the Recommended Operating Conditions table. It asserts RESET when VDD rises above 0.75 V and continues supervision down to this minimum, enabling use with sub-1 V processor cores and ultra-low-power sleep modes. Operation below 0.75 V is not guaranteed and may result in undefined RESET behavior.

What is the watchdog timeout period for the TPS3123G15DBVT?

The watchdog timeout (ttout) for the TPS3123G15DBVT is 0.8 s (minimum), 1.4 s (typical), and 2.1 s (maximum), measured from the last valid WDI transition. This interval is fixed and not user-adjustable. If the supervising system fails to toggle WDI within this window, RESET is asserted for the full 180 ms delay period, then released - reinitializing the watchdog timer upon release.

Is the TPS3123G15DBVT pin-compatible with other devices in the TPS312x family?

The TPS3123G15DBVT shares the same SOT-23-5 (DBV) pinout with all TPS3123/3124/3125/3126/3128 variants in the family, including identical pin assignments for VDD, WDI, RESET, GND, and MR. However, functional differences exist: TPS3124 lacks MR, TPS3125/3126 lack WDI, and TPS3126/3128 offer push-pull RESET. Thus, while physically pin-compatible, direct substitution requires verification of MR and WDI signal routing and RESET topology requirements.