Texas Instruments TPS3606-33DGSRG4

Overview

TPS3606-33DGSRG4 from Texas Instruments is a precision 3.3-V supply voltage supervisor IC with integrated watchdog timer, battery switchover control, and power-fail monitoring. It delivers 40 µA max supply current, features a fixed 100-ms reset delay, and supports manual reset and battery freshness seal functionality. It is used in portable battery-powered equipment to maintain processor operation during brownout via seamless VBAT-to-VOUT switchover.

For engineers reviewing the TPS3606-33DGSRG4 datasheet, TPS3606-33DGSRG4 pinout, TPS3606-33DGSRG4 application, or TPS3606-33DGSRG4 equivalent, key selection considerations include its 2.93-V reset threshold (±30 mV), 800-ms watchdog timeout, 2-Ω VDD/VBAT switch on-resistance, −40°C to 85°C operating range, and MSOP-10 package compatibility with space-constrained embedded systems.

Technical Context

The TPS3606-33DGSRG4 integrates dual-supply supervision (VDD and VBAT), a precision bandgap-based voltage monitor for VOUT, and an independent power-fail comparator (PFI/PFO) referenced to 1.15 V. Its internal logic enables automatic switchover when VOUT falls below V(SWN) = VIT + 1%–3.2%, with VIT = 2.93 V nominal.

It implements a state-controlled switchover path using internal 2-Ω NMOS switches between VDD/VBAT and VOUT, supports manual override via MSWITCH, and includes a transition-detecting watchdog timer requiring WDI toggling every 0.8 s. RESET is active-low with 100-ms fixed delay after VOUT exceeds VIT.

Key Specifications

Pinout & Package

TPS3606-33DGSRG4 is housed in a 10-pin VSSOP (DGS) package measuring 3.05 mm × 4.98 mm with 0.5-mm lead pitch and maximum height of 1.1 mm - optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervision and battery switchover applications.

Compared with TPS3606-33DGSRG4, TPS3619-33DGSR adds flexibility in reset timing but increases complexity, while MAX6361LUT46+T reduces size and current but sacrifices switchover, watchdog, and auxiliary monitoring - making TPS3606-33DGSRG4 the only option supporting full battery-backed supervision in a single 10-pin MSOP.

Availability

TPS3606-33DGSRG4 is available at Aetrix Electronics and suitable for portable medical monitors, point-of-sale terminals, advanced modems, and fax machines requiring stable component supply across extended production lifecycles.

Supply support for TPS3606-33DGSRG4 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 with emphasis on reliability, precision, and energy efficiency.

The TPS3606 family was designed specifically for battery-backed microprocessor systems requiring robust power supervision, automatic switchover, and fail-safe reset generation - targeting portable, industrial, and telecom infrastructure applications.

FAQ

What is the reset threshold voltage of the TPS3606-33DGSRG4?

The TPS3606-33DGSRG4 has a nominal reset threshold voltage of 2.93 V with a tolerance of ±30 mV (2.87 V to 2.99 V). This value is factory-trimmed and specified over the full −40°C to 85°C temperature range. The threshold is sensed at the VOUT pin, and RESET remains active until VOUT rises above this level and sustains it for the 100-ms delay period. This precise 3.3-V supervision ensures compatibility with standard LDO outputs and avoids premature release during rail settling.

Does the TPS3606-33DGSRG4 support automatic switchover to backup battery?

Yes, the TPS3606-33DGSRG4 supports fully automatic switchover to VBAT when VDD fails. It connects VBAT to VOUT only when VOUT falls below V(SWN) (VIT + 1%–3.2%) and VBAT exceeds VDD - preventing backfeed and enabling use of higher-voltage backup cells (e.g., 3.6-V Li). The internal 2-Ω NMOS switch ensures low-loss conduction, and the battery freshness seal keeps VBAT disconnected until first power-up to preserve shelf life.

How does the watchdog timer function in the TPS3606-33DGSRG4?

The TPS3606-33DGSRG4 watchdog timer has a typical timeout of 800 ms and is triggered by edges on the WDI pin - either low-to-high or high-to-low transitions reset the internal counter. If WDI remains static beyond timeout, RESET is asserted. When unused, WDI can be left floating (internally disabled) or tied to GND. For lowest current, drive WDI low for 7/8 of the timeout and pulse high briefly to reset - avoiding continuous 125-µA leakage that occurs if WDI is held high.

Can the TPS3606-33DGSRG4 monitor voltages other than the main 3.3-V supply?

Yes, the TPS3606-33DGSRG4 includes a dedicated power-fail comparator with PFI and PFO pins. PFI compares an external voltage against a 1.15-V internal reference; when the input falls below this threshold (with 12-mV hysteresis), PFO goes low. By connecting two precision resistors (≈1 MΩ total) between the target rail and GND, any voltage ≥1.15 V can be monitored - enabling supervision of 5-V, 12-V, or custom auxiliary rails without additional ICs.

What package type and dimensions does the TPS3606-33DGSRG4 use?

The TPS3606-33DGSRG4 uses a 10-pin VSSOP (DGS) package with 0.5-mm lead pitch, measuring 3.05 mm × 4.98 mm and 1.1 mm maximum height. It is RoHS-compliant, NIPDAU lead-finished, and rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH). The package marking is "AKE", and it is supplied in tape-and-reel format (2500 units per reel), matching TI's standard DGS footprint for drop-in PCB compatibility.