Texas Instruments TPS3619-33DGKG4

Overview

TPS3619-33DGKG4 from Texas Instruments is a backup-battery supervisor IC for CMOS RAM retention, featuring precision 3.3 V supply monitoring (VIT = 2.93 V typ), 100-ms power-on reset delay, active-low RESET output, and dual-supply switchover between VDD and VBAT. It supports battery-freshness seal activation and provides PFI/PFO for external power-fail detection in portable and industrial systems.

For engineers reviewing the TPS3619-33DGKG4 datasheet, TPS3619-33DGKG4 pinout, TPS3619-33DGKG4 application, or TPS3619-33DGKG4 equivalent, key selection criteria include its 100 nA max battery-supply current, 40 µA max VDD supply current, 8-pin VSSOP (DGK) package, and guaranteed operation from –40°C to +85°C.

Technical Context

The TPS3619-33DGKG4 integrates a precision voltage comparator with 2.93 V threshold (±1.5% over temperature), internal 100-ms reset timer, and dual-path PMOS switchover control that connects VOUT to VDD (rDS(on) ≤ 1 Ω) or VBAT (rDS(on) ≤ 15 Ω) based on real-time VDD/VBAT comparison and reset state logic.

Its power-fail comparator monitors PFI against a 1.15 V reference with 12 mV hysteresis, while the battery freshness seal (exclusive to TPS3619 family) isolates VBAT until first power-up sequence completes - preventing pre-deployment discharge of backup cells.

Key Specifications

Pinout & Package

TPS3619-33DGKG4 uses an 8-pin VSSOP (DGK) package measuring 3.05 mm × 4.98 mm with 0.65 mm lead pitch and 1.1 mm max height. The exposed thermal pad is not electrically connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar backup-battery supervisor applications.

Compared with TPS3619-33DGKG4, TPS3620-33DGKR offers identical supervision accuracy and switchover performance without freshness seal - reducing complexity where shelf-life protection is redundant; MAX819MESA+ provides legacy pin compatibility but omits critical RAM-retention features like dual-supply control and nanoamp battery current.

Availability

TPS3619-33DGKG4 is available at Aetrix Electronics and suitable for fax machines, set-top boxes, portable battery-powered equipment, and automotive systems requiring stable component supply with guaranteed long-term availability.

Supply support for TPS3619-33DGKG4 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 connectivity technologies, with decades of expertise in power management and supervisory ICs.

The TPS3619 family was designed specifically for RAM retention in battery-backed systems - integrating precision voltage monitoring, ultra-low-quiescent switchover, and factory-sealed battery isolation to maximize data integrity and shelf life.

FAQ

What is the reset threshold voltage of the TPS3619-33DGKG4?

The TPS3619-33DGKG4 has a nominal reset threshold voltage (VIT) of 2.93 V, specified from 2.88 V (min) to 3.00 V (max) over the full –40°C to +85°C operating temperature range. This value is factory-trimmed and applies to both power-on assertion and brownout detection on the VDD pin. The TPS3619-33DGKG4 uses this threshold to control the active-low RESET output and initiate VDD-to-VBAT switchover.

Does the TPS3619-33DGKG4 support battery freshness seal functionality?

Yes, the TPS3619-33DGKG4 includes a battery freshness seal feature unique to the TPS3619 family. This function electrically isolates the VBAT pin from internal circuitry until the first valid power-up sequence occurs - preventing pre-deployment discharge of backup lithium cells. Activation requires grounding PFO, connecting PFI to VDD, and applying VDD > VIT for 5–35 ms. The TPS3619-33DGKG4 automatically exits seal mode upon RESET deassertion.

What is the maximum continuous output current capability of the TPS3619-33DGKG4?

The TPS3619-33DGKG4 supports up to 300 mA continuous output current at VOUT, with typical VDD-to-VOUT rDS(on) ≤ 1 Ω and VBAT-to-VOUT rDS(on) ≤ 15 Ω. At 300 mA, the worst-case voltage drop is 300 mV on VDD path and 4.5 V on VBAT path - limiting practical VBAT loads to ≤7.5 mA for <100 mV drop. The TPS3619-33DGKG4 datasheet specifies absolute maximum VOUT current as 400 mA, but sustained operation above 300 mA risks thermal overload in the VSSOP package.

How does the TPS3619-33DGKG4 handle power-fail detection?

The TPS3619-33DGKG4 uses its PFI pin to monitor external voltages against an internal 1.15 V reference, generating an active-low PFO signal when the input falls below VPFI (1.15 V typ). Hysteresis of 12 mV prevents chatter near threshold. For monitoring rails other than VDD, a resistor divider scales the target voltage to match the 1.15 V reference. Unused PFI must be grounded and PFO left floating. The TPS3619-33DGKG4 does not regulate or switch based on PFI - it only provides status signaling.

Is the TPS3619-33DGKG4 pin-compatible with industry-standard supervisors?

Yes, the TPS3619-33DGKG4 is explicitly designed as a pin-for-pin compatible replacement for MAX819, MAX703, and MAX704 in 8-pin SO and MSOP packages. Its DGK (VSSOP) footprint matches the mechanical outline of those devices, and all terminal functions - including VOUT, VDD, GND, PFI, PFO, MR, RESET, and VBAT - align directly. However, the TPS3619-33DGKG4 adds battery freshness seal and lower quiescent current not present in the MAX parts, making it a functional upgrade without PCB changes.