Analog Devices Inc. LTC2905HTS8#TRPBF

Overview

LTC2905HTS8#TRPBF from Analog Devices (formerly Linear Technology) is a precision dual supply monitor IC with adjustable reset timeout, pin-selectable voltage thresholds (5V/3.3V/2.5V/1.8V/1.5V/1.2V/1.0V), ±1.5% threshold accuracy over –40°C to 125°C, open-drain RST output, and TMR pin for external capacitor-based delay programming. It serves as a system-level power-good supervisor in high-reliability industrial and automotive embedded control units.

For engineers reviewing the LTC2905HTS8#TRPBF datasheet, LTC2905HTS8#TRPBF pinout, LTC2905HTS8#TRPBF application, or LTC2905HTS8#TRPBF equivalent, key selection criteria include its –40°C to 125°C operating range, programmable 5%/7.5%/10% tolerance, guaranteed RST operation down to V1 ≥ 1V or V2 ≥ 1V, and TSOT-23-8 package compatibility with space-constrained PCB layouts.

Technical Context

The LTC2905HTS8#TRPBF implements two independent comparators with a shared reset pulse generator and three-state input decoder for threshold/tolerance selection. Its internal bandgap reference and resistor network enable ±1.5% threshold accuracy across temperature without trimming.

Unlike the fixed 200ms delay of LTC2904, the LTC2905HTS8#TRPBF uses the TMR pin to accept an external capacitor (e.g., 22nF for 200ms), providing design flexibility for microprocessor reset timing requirements while maintaining glitch immunity via integrated low-pass filtering and programmable delay.

Key Specifications

Pinout & Package

Package: 8-Lead Plastic TSOT-23 (TS8), 1.95 mm × 2.80 mm × 0.80–0.90 mm height, exposed pad not present (unlike DFN), RoHS-compliant lead-free finish.

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 LTC2905HTS8#TRPBF uniquely combines dual-rail monitoring, field-programmable thresholds/tolerance/delay, and full automotive-grade temperature range in a single TSOT-23-8 package-reducing component count and enabling flexible system-level power management.

Availability

LTC2905HTS8#TRPBF is available at Aetrix Electronics and suitable for industrial automation, automotive ADAS, medical imaging, and telecom infrastructure applications requiring stable component supply, long-term lifecycle support, and guaranteed high-temperature performance.

Supply support for LTC2905HTS8#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 its high-performance analog and mixed-signal product lines, including precision supervisors and power management ICs.

The LTC2905 series belongs to Linear's precision power monitoring product line, designed specifically for systems demanding accurate, glitch-immune dual-rail supervision with minimal board space and zero external components for threshold setting.

FAQ

What is the maximum operating temperature of the LTC2905HTS8#TRPBF?

The LTC2905HTS8#TRPBF is rated for continuous operation from –40°C to +125°C. This H-grade temperature specification is explicitly defined in the manufacturer's ordering information table and validated across electrical parameters including threshold accuracy, reset timeout, and RST output behavior. The device meets automotive under-hood thermal requirements and is commonly deployed in engine control modules and industrial motor drives where ambient temperatures exceed 105°C.

How do I configure the LTC2905HTS8#TRPBF for 5V and 3.3V monitoring with 5% tolerance?

To configure the LTC2905HTS8#TRPBF for 5V/3.3V monitoring with 5% tolerance, connect S1 = V1, S2 = V1, and TOL = V1 per Table 1 and Table 2 in the datasheet. V1 must be supplied at 5V and V2 at 3.3V. The internal resistor network then selects the corresponding threshold pair (VRT50 = 4.675V typ, VRT33 = 3.086V typ) with ±1.5% accuracy. No external resistors or calibration are needed.

Can the LTC2905HTS8#TRPBF operate with only one supply voltage applied?

Yes - the LTC2905HTS8#TRPBF can operate with only V1 or only V2 applied, provided that the active input is ≥1V. The greater of V1 or V2 becomes the internal VCC, powering all circuitry including the RST output driver. If only V1 = 3.3V is present and V2 is unconnected, the device functions as a single-supply monitor for V1, with RST asserting low if V1 drops below its programmed threshold. V2 must be left floating (not tied to GND) to avoid unintended current paths.

What capacitor value gives a 200ms reset timeout on the LTC2905HTS8#TRPBF?

A 22nF capacitor connected between the TMR pin and GND yields a nominal 200ms reset timeout for the LTC2905HTS8#TRPBF. This follows the linear relationship tRST = CTMR × 9 ms/nF specified in the Applications Information section. The 22nF value is a standard EIA-198 E24 capacitor and is used in the typical application diagram (TA04). At 25°C, measured tRST ranges from 140ms to 295ms depending on CTMR tolerance and temperature.

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

The LTC2905HTS8#TRPBF includes a weak internal pull-up to VCC (typically 6μA), so external pull-up resistors are optional. They are recommended only when faster rise time (<10μs) or higher VOH (>VCC) is required, or when RST must remain valid at VCC < 1.5V. For standard microprocessor reset inputs, the internal pull-up suffices; a 10kΩ external resistor reduces rise time from ~86μs to ~3.3μs with 150pF load capacitance.