Analog Devices Inc. LTC2904IDDB#TRPBF

Overview

LTC2904IDDB#TRPBF from Analog Devices (formerly Linear Technology) is a precision dual-supply voltage monitor IC with pin-selectable thresholds and fixed 200ms reset timeout, designed for reliable power-on reset and brownout detection in space-constrained systems. It monitors two independent supply rails (e.g., 5V/3.3V, 3.3V/1.2V), delivers ±1.5% threshold accuracy over –40°C to +85°C, guarantees RST operation down to V1 ≥ 1V or V2 ≥ 1V, and features open-drain RST output with strong pull-down and weak internal pull-up to VCC = max(V1,V2). It is used in industrial embedded controllers requiring deterministic reset behavior under noisy supply conditions.

For engineers reviewing the LTC2904IDDB#TRPBF datasheet, LTC2904IDDB#TRPBF pinout, LTC2904IDDB#TRPBF application, or LTC2904IDDB#TRPBF equivalent, this page provides verified functional specifications, validated DFN-8 pin mapping, confirmed threshold programming logic (S1/S2/TOL), real-world timing behavior (tRST = 140–260ms), and direct alternative part comparisons - all extracted from the official Linear Technology/LTC2904 datasheet (29045fd) and Analog Devices product documentation.

Technical Context

The LTC2904IDDB#TRPBF implements a dual-comparator architecture with a shared reset pulse generator and precision bandgap reference, enabling simultaneous monitoring of V1 and V2 against independently programmed thresholds. Its three-state programming inputs (S1, S2, TOL) configure nine voltage combinations and three tolerance levels (5%/7.5%/10%) without external resistors, while internal VCC auto-selection (VCC = max(V1,V2)) ensures operation during asymmetric power-up sequences.

Glitch immunity is achieved via integrated first-order low-pass filtering at each comparator output plus a 200ms monolithic delay timer, preventing false resets from transient supply noise. The open-drain RST output supports wired-OR configurations and operates correctly even when VCC drops to 1V, with VOL ≤ 0.4V at I_RST = 2.5mA and VOH ≥ VCC–1V at I_RST = –1μA.

Key Specifications

Pinout & Package

Package: 8-lead plastic DFN (3mm × 2mm), exposed pad soldered to PCB ground for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply monitoring applications.

Compared with MAX6816EUT+T and TPS3808G33DBVR, the LTC2904IDDB#TRPBF uniquely integrates dual-rail monitoring, 27-programmable threshold/tolerance combinations, and guaranteed 1V operation in a single DFN-8 package - eliminating external logic, resistors, and layout complexity required by alternatives.

Availability

LTC2904IDDB#TRPBF is available at Aetrix Electronics and suitable for industrial embedded controllers, network servers, and handheld devices requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LTC2904IDDB#TRPBF 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

Analog Devices acquired Linear Technology in 2017 and maintains full technical and manufacturing continuity for the LTC portfolio, including precision analog, power management, and supervisory ICs.

The LTC2904IDDB#TRPBF belongs to Linear Technology's legacy supervisor IC family, engineered specifically for high-accuracy, low-power dual-supply monitoring in space-constrained and thermally demanding environments.

FAQ

What is the operating temperature range of the LTC2904IDDB#TRPBF?

The LTC2904IDDB#TRPBF is rated for –40°C to +85°C (Industrial grade), as confirmed in the "ORDER INFORMATION" table of the official datasheet (29045fd, page 2). This range applies to all electrical characteristics including ±1.5% threshold accuracy, 140–260ms reset timeout, and guaranteed RST operation down to 1V. The DDB package supports this range via its thermal design and exposed GND pad.

How does the LTC2904IDDB#TRPBF determine its internal supply voltage (VCC)?

The LTC2904IDDB#TRPBF automatically selects VCC as the greater of V1 and V2 (per datasheet Note 2 and PIN FUNCTIONS section). This internal VCC powers both RST outputs and internal circuitry, enabling the LTC2904IDDB#TRPBF to assert valid reset states even when only one supply rail is present above 1V - a key feature for asymmetric power-up sequences in complex systems.

Can the LTC2904IDDB#TRPBF monitor a 5V and a 1.2V supply simultaneously?

Yes - the LTC2904IDDB#TRPBF supports V1 = 5V and V2 = 1.2V simultaneously. Per Table 1 (page 10), this combination is configured with S1 = V1, S2 = Open, and TOL set to V1/GND/Open for 5%/10%/7.5% tolerance. The device then monitors both rails against their respective thresholds (e.g., 4.75V ±1.5% for 5V, 1.14V ±1.5% for 1.2V) with independent accuracy.

What is the maximum load capacitance the RST output can drive while maintaining specified rise/fall times?

The RST output of the LTC2904IDDB#TRPBF has a strong internal pull-down (~40Ω typical) and weak pull-up (~260kΩ at VCC = 3.3V). For a 150pF load, fall time is ~13ns and rise time is ~86μs (per Applications Information, page 12). To maintain rise time <1μs, an external 10kΩ pull-up resistor is recommended - confirmed by the datasheet's rise time estimation formula and TA04 schematic.

Is the LTC2904IDDB#TRPBF pin-compatible with the LTC2905 series?

No - the LTC2904IDDB#TRPBF and LTC2905 share identical pinout and package (DDB8), but Pin 2 is RST (output) on the LTC2904IDDB#TRPBF and TMR (capacitor input) on the LTC2905. Swapping them without circuit modification will disable reset functionality. The datasheet explicitly labels Pin 2 as "RST FOR LTC2904" and "TMR FOR LTC2905" (page 2), confirming functional incompatibility despite mechanical similarity.