Texas Instruments TPS3851G33EQDRBRQ1

Overview

TPS3851G33EQDRBRQ1 from Texas Instruments is a high-accuracy AEC-Q100 Grade 1 automotive voltage supervisor with integrated programmable watchdog timer, 0.8% undervoltage threshold accuracy (–40°C to +125°C), 200 ms reset timeout (±15%), and open-drain RESET/WDO outputs. It monitors 3.3V rails in ADAS domain controllers and front camera ECUs where tight supply tolerance and fault-detection resolution are critical.

For engineers reviewing the TPS3851G33EQDRBRQ1 datasheet, TPS3851G33EQDRBRQ1 pinout, TPS3851G33EQDRBRQ1 application, or TPS3851G33EQDRBRQ1 equivalent, key selection criteria include factory-programmed 1.6 s watchdog timeout (SET1 = 1, CWD unconnected), 10 µA typical supply current, 0.5% hysteresis, manual reset input (MR), and wettable-flank 3mm × 3mm VSON-8 packaging for automated optical inspection.

Technical Context

The TPS3851G33EQDRBRQ1 implements a precision bandgap-based comparator for undervoltage detection on VDD, with internal 4.5 MΩ resistor divider yielding a nominal 3.3V threshold (VITN = 3.3V). Its state-machine-controlled watchdog uses either factory-set timing (via CWD/SET1 logic) or user-adjustable capacitor timing (CCWD = 0.1–1000 nF), delivering two distinct timeout modes: standard (170–230 ms) and extended (1.36–1.84 s).

RESET assertion occurs when VDD falls below VITN; recovery requires VDD > VITN + VHYST (0.5% of VITN) followed by tRST delay. WDO operates independently-asserting only when watchdog expires and RESET is deasserted-enabling fault isolation without full system reset. The device supports dynamic watchdog enable/disable via SET1, with 150 µs setup time after enabling.

Key Specifications

Pinout & Package

TPS3851G33EQDRBRQ1 is housed in a 3.00 mm × 3.00 mm, 8-pin VSON package with wettable flanks for solder-joint inspection. Thermal pad is internally connected to GND and must be soldered to a large-area ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3851G33QDRBRQ1, the TPS3851G33EQDRBRQ1 provides extended watchdog timing ideal for complex ADAS firmware; versus MAX6373KA33+T, it delivers superior accuracy, dual-output fault signaling, and functional safety support - making it the only option qualified for ASIL-B decomposition.

Availability

TPS3851G33EQDRBRQ1 is available at Aetrix Electronics and suitable for automotive ADAS domain controllers, front camera modules, surround-view ECUs, and vehicle occupant detection sensors requiring stable component supply across extended product lifecycles.

Supply support for TPS3851G33EQDRBRQ1 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, embedded processing, and automotive ICs, with decades of experience in high-reliability power management and supervisory solutions.

The TPS3851-Q1 product line was designed specifically for functional safety-compliant automotive systems, integrating precision voltage monitoring and configurable watchdog functionality into a single AEC-Q100 qualified package.

FAQ

What is the undervoltage threshold voltage of the TPS3851G33EQDRBRQ1?

The TPS3851G33EQDRBRQ1 has a nominal undervoltage threshold (VITN) of 3.3 V, with ±0.8% accuracy over –40°C to +125°C. This value is factory-trimmed and applies specifically to the "G33" variant, which targets 3.3V rail supervision in automotive microcontrollers and SoCs.

How does the watchdog timeout work on the TPS3851G33EQDRBRQ1?

The TPS3851G33EQDRBRQ1 offers two watchdog timeout modes: extended (1.36–1.84 s typical) when CWD is unconnected and SET1 = 1, or standard (170–230 ms) when CWD is pulled up to VDD via 10 kΩ and SET1 = 1. Timeout is disabled when SET1 = 0. The TPS3851G33EQDRBRQ1 does not use external clock sources - timing is derived from an internal constant-current source charging the CWD pin.

Can the TPS3851G33EQDRBRQ1 be used for non-automotive applications?

Yes, the TPS3851G33EQDRBRQ1 functions reliably in industrial and medical applications requiring high-accuracy supervision and watchdog capability. However, its AEC-Q100 qualification, functional safety documentation, and 125°C ambient rating make it especially valuable in automotive contexts. For non-automotive use, ensure compliance with applicable safety standards separately.

What is the purpose of the SET1 pin on the TPS3851G33EQDRBRQ1?

The SET1 pin on the TPS3851G33EQDRBRQ1 controls watchdog enable/disable functionality: grounding SET1 disables the watchdog timer and ignores WDI signals, while pulling SET1 high enables normal watchdog operation. This allows safe development-mode disable and dynamic runtime control - a feature explicitly supported in the TPS3851G33EQDRBRQ1's functional safety architecture.

Does the TPS3851G33EQDRBRQ1 support multiple supply voltage rails?

No, the TPS3851G33EQDRBRQ1 monitors only its own VDD supply pin, which serves as both power source and monitored rail. It is configured for 3.3V supervision (G33 variant) and does not support multi-rail monitoring. Separate TPS3851-Q1 devices (e.g., G18, G25, G50) are required for 1.8V, 2.5V, or 5.0V rails - each with dedicated factory-trimmed thresholds.