Analog Devices Inc. LTC2905HTS8#TRMPBF

Overview

LTC2905HTS8#TRMPBF from Analog Devices (formerly Linear Technology) is a precision dual-supply voltage monitor IC with adjustable reset timeout, designed for high-reliability power sequencing and brownout detection in automotive-grade embedded systems. It monitors two independent supply rails (e.g., 5V/3.3V, 3.3V/1.2V), provides ±1.5% threshold accuracy over –40°C to +125°C, supports 5%/7.5%/10% tolerance selection via three-state pins, and guarantees RST output functionality down to V₁ ≥ 1V or V₂ ≥ 1V. It is used in engine control units, ADAS domain controllers, and industrial PLCs requiring AEC-Q100-aligned supervision.

For engineers reviewing the LTC2905HTS8#TRMPBF datasheet, LTC2905HTS8#TRMPBF pinout, LTC2905HTS8#TRMPBF application, or LTC2905HTS8#TRMPBF equivalent, key selection criteria include its –40°C to +125°C operating range, TSOT-23-8 package compatibility, adjustable 200μs–10s reset delay via external capacitor, open-drain RST output with guaranteed low-state operation at 1V supply, and nine programmable voltage threshold combinations without external resistors.

Technical Context

The LTC2905HTS8#TRMPBF implements a dual-input comparator architecture with a bandgap reference and integrated resistor network, enabling precise threshold generation across temperature. Its three-state programming pins (S1, S2, TOL) configure both input voltage pairs and common tolerance without trimming components - eliminating BOM variants during design-in.

Unlike fixed-threshold supervisors, it uses an external capacitor on the TMR pin to set reset timeout (t_RST = 9 ms/nF), supporting system-specific power-up sequencing requirements. The internal V_CC auto-selects as the greater of V₁ or V₂, ensuring functional reset assertion even during asymmetric rail ramp-up, and its glitch-immune design prevents false resets from sub-150μs transients.

Key Specifications

Pinout & Package

Package: 8-lead Plastic TSOT-23, 1.95mm × 2.80mm footprint, 0.65mm pitch, exposed pad not present (unlike DFN variant). Pin 1 marked by beveled corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6816EUT+T and TPS3808G18DBVR, the LTC2905HTS8#TRMPBF delivers superior design flexibility through pin-selectable thresholds, single-device dual-rail supervision, and guaranteed operation across the full automotive temperature range - reducing validation effort and improving system-level robustness.

Availability

LTC2905HTS8#TRMPBF is available at Aetrix Electronics and suitable for automotive ECU development, industrial PLC manufacturing, and medical imaging equipment production requiring stable component supply with extended temperature qualification and traceable sourcing.

Supply support for LTC2905HTS8#TRMPBF 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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving aerospace, automotive, industrial, and healthcare markets.

The LTC2905HTS8#TRMPBF belongs to Linear's precision power supervision product line, engineered specifically for mission-critical systems demanding wide-temperature operation, high threshold accuracy, and minimal external component count.

FAQ

What is the maximum reset timeout period achievable with LTC2905HTS8#TRMPBF?

The LTC2905HTS8#TRMPBF supports reset timeout periods up to 10 seconds using a 1μF capacitor on the TMR pin (t_RST = 9 ms/nF). Larger capacitors are limited by leakage current; the TMR charging current must exceed 2.1μA (typical) to ensure reliable timing. For timeouts beyond 10s, external timing circuitry is recommended. The LTC2905HTS8#TRMPBF datasheet specifies CTMR = t_RST × 110 nF/s for accurate calculation.

Can LTC2905HTS8#TRMPBF monitor asymmetric supply rails like 3.3V and 1.2V simultaneously?

Yes, the LTC2905HTS8#TRMPBF supports nine V1/V2 combinations including 3.3V/1.2V, configured via S1 and S2 pins per Table 1 in the datasheet. When S1 = Open and S2 = Open, V1 = 3.3V and V2 = 1.2V are selected. Thresholds are calculated as ±5%/7.5%/10% of nominal values (e.g., 3.3V × 0.95 = 3.135V), and the LTC2905HTS8#TRMPBF maintains ±1.5% accuracy across –40°C to +125°C.

Does LTC2905HTS8#TRMPBF require external pull-up resistors on the RST pin?

The LTC2905HTS8#TRMPBF features an internal weak pull-up (~6μA) to V_CC on the RST pin, sufficient for non-critical rise-time applications. However, an external pull-up resistor (≤100kΩ) is recommended when RST state integrity is critical at low V_CC (e.g., near 1V), as internal pull-up strength diminishes. For faster rise times (<1μs), a 10kΩ external pull-up reduces t_RISE from ~86μs to ~3.3μs with 150pF load. The LTC2905HTS8#TRMPBF RST pin remains fully compatible with wired-OR configurations.

How does LTC2905HTS8#TRMPBF handle power-up sequencing when V1 and V2 ramp at different rates?

The LTC2905HTS8#TRMPBF uses internal V_CC = max(V1, V2), so it powers up as soon as the higher rail reaches 1V. RST asserts low immediately upon power application and remains low until both V1 and V2 exceed their programmed thresholds for the full t_RST period. This ensures reset is held during asymmetric ramp-up, preventing premature release. The LTC2905HTS8#TRMPBF guarantees correct RST logic state down to V1 ≥ 1V or V2 ≥ 1V, making it robust for staggered supply architectures.

Is LTC2905HTS8#TRMPBF pin-compatible with other members of the LTC2904/LTC2905 family?

The LTC2905HTS8#TRMPBF shares identical pinout and footprint with all TSOT-23 variants in the LTC2904/LTC2905 family (e.g., LTC2905CTS8#TRMPBF, LTC2905ITS8#TRMPBF), differing only in temperature grade (–40°C to +125°C). Electrical characteristics including threshold accuracy, t_RST range, and input current specs are consistent across grades. No PCB redesign is needed when upgrading from commercial or industrial versions to the H-grade LTC2905HTS8#TRMPBF.