Texas Instruments TPS3828-33DBVT

Overview

TPS3828-33DBVT from Texas Instruments is a 3.3V supply voltage supervisor IC with open-drain active-low reset output, integrated watchdog timer (1.6s timeout), manual reset input, and 200ms reset delay. It monitors VDD in microcontroller-based systems, asserts RESET when VDD drops below 2.93V (typical), and requires no external components. Used in industrial controllers and battery-powered embedded devices for reliable power-on initialization and fault recovery.

For engineers reviewing the TPS3828-33DBVT datasheet, TPS3828-33DBVT pinout, TPS3828-33DBVT application, or TPS3828-33DBVT equivalent, key selection criteria include its open-drain RESET output compatibility with wired-OR logic, fixed 3.3V threshold with ±70mV hysteresis, −40°C to 85°C operating range, 15μA typical supply current, and SOT-23-5 package footprint.

Technical Context

The TPS3828-33DBVT implements a precision bandgap-based voltage reference and comparator to detect VDD excursions below its 2.93V nominal threshold. Its internal watchdog timer triggers reset if WDI receives no falling edge within 1.6s, and its manual reset input (MR) forces immediate reset assertion independent of VDD level.

Unlike push-pull variants (e.g., TPS3823), the open-drain RESET output requires an external pull-up resistor and supports multi-source reset arbitration. The device uses a fixed internal voltage divider for threshold setting and includes built-in hysteresis (50mV) to prevent oscillation during slow-rising or noisy supply transitions.

Key Specifications

Pinout & Package

TPS3828-33DBVT is housed in a 5-pin SOT-23 (DBV) package measuring 2.90mm × 1.60mm, optimized for high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3823-33DBVT, the TPS3828-33DBVT enables shared reset arbitration via open-drain output, while MAX6326–T33 trades watchdog capability for simpler reset-only operation-making TPS3828-33DBVT optimal for systems requiring both robust power monitoring and autonomous fault recovery.

Availability

TPS3828-33DBVT is available at Aetrix Electronics and suitable for industrial programmable controllers, portable medical monitors, wireless sensor gateways, and notebook embedded controller subsystems requiring stable component supply and long-term production continuity.

Supply support for TPS3828-33DBVT 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 specializing in analog and embedded processing technologies, with decades of expertise in power management and system supervision ICs.

The TPS382x product line delivers compact, low-power voltage supervisors for DSP, microcontroller, and microprocessor systems-designed specifically to ensure reliable power-on initialization, brownout protection, and watchdog-based firmware recovery in demanding industrial and portable environments.

FAQ

What is the exact reset threshold voltage for TPS3828-33DBVT?

The TPS3828-33DBVT has a nominal negative-going input threshold voltage (VIT−) of 2.93V, with guaranteed minimum 2.86V and maximum 3.00V across −40°C to 85°C. This fixed threshold is set by an internal voltage divider and requires no external components, making it ideal for precise 3.3V rail supervision in TPS3828-33DBVT-based designs.

Does TPS3828-33DBVT require an external pull-up resistor on the RESET pin?

Yes, TPS3828-33DBVT features an open-drain RESET output and requires an external pull-up resistor to a valid logic voltage (e.g., 3.3V or 5V). The value is typically 10kΩ to balance rise time and power consumption. This design enables wired-OR reset bus configurations not possible with push-pull outputs like those in TPS3828-33DBVT's sibling TPS3823-33DBVT.

How does the watchdog timer in TPS3828-33DBVT operate?

The TPS3828-33DBVT watchdog timer times out after 1.6s (typical) if no falling edge is detected on the WDI pin. A falling edge resets the timer; if WDI floats, the device generates internal pulses to prevent timeout. When timeout occurs, RESET asserts for 200ms. This behavior ensures autonomous recovery from firmware hangs in TPS3828-33DBVT-supervised systems.

Can TPS3828-33DBVT be used with supply voltages below 3.3V?

TPS3828-33DBVT operates from 1.1V to 5.5V supply range but supervises only the 3.3V nominal rail. Its internal threshold is fixed at ~2.93V, so it remains functional down to VDD = 1.1V (enabling basic reset assertion), but accurate 3.3V rail monitoring requires VDD ≥ 3.3V ± tolerance. For lower-voltage rails, select TPS3828-25DBVT or TPS3828-30DBVT instead of TPS3828-33DBVT.

What is the function of the MR pin on TPS3828-33DBVT?

The MR (Manual Reset) pin on TPS3828-33DBVT is an active-low input that forces immediate RESET assertion regardless of VDD level or watchdog state. Internally pulled up to VDD via 90kΩ, it can be driven low by an external switch, FPGA GPIO, or system controller. When unused, MR should be left open or tied to VDD-never left floating-to avoid unintended resets in TPS3828-33DBVT applications.