Analog Devices Inc. LTC2900-1CMS#PBF

Overview

LTC2900-1CMS#PBF from Analog Devices (formerly Linear Technology) is a programmable quad supply monitor IC with open-drain RST output, simultaneously supervising up to four independent voltage rails (e.g., 5V, 3.3V, 2.5V, 1.8V), ±1.5% threshold accuracy over temperature, 43µA typical supply current, and adjustable reset timeout via external capacitor. It is used in multivoltage computing systems to ensure reliable power-on reset sequencing and brownout protection.

For engineers reviewing the LTC2900-1CMS#PBF datasheet, LTC2900-1CMS#PBF pinout, LTC2900-1CMS#PBF application, or LTC2900-1CMS#PBF equivalent, key selection factors include its 10-pin MSOP package, open-drain RST output with V2-referenced weak pull-up, guaranteed RST assertion down to VCC = 1V, 16 programmable voltage threshold combinations, and manual reset input with debounced timing.

Technical Context

The LTC2900-1CMS#PBF implements four independent high-accuracy comparators with user-programmable thresholds selected via a resistor divider on the VPG pin, enabling 16 preset or adjustable combinations across 5V/3.3V/3V/2.5V/1.8V/1.5V/±ADJ rails. Its internal bandgap reference (1.210V ±0.7%) feeds both threshold generation and programming circuitry.

Reset assertion is synchronized to power-up, brownout, or manual trigger events; the RST output remains low until all monitored supplies exceed their thresholds and the externally programmed delay (via CRT capacitor) expires. Glitch immunity and guaranteed operation at VCC ≥ 1V ensure robustness in noisy or marginal supply conditions.

Key Specifications

Pinout & Package

Package: 10-lead MSOP (3mm × 3mm), RoHS-compliant, surface-mount. Pin pitch: 0.5mm. Exposed pad not present in MSOP variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2900-2CMS#PBF and LTC2901CMS#PBF, the LTC2900-1CMS#PBF delivers minimal-footprint, low-power quad supervision with open-drain flexibility-ideal for space-constrained designs where external pull-up control or reset bus sharing is required, without paying for unused watchdog features.

Availability

LTC2900-1CMS#PBF is available at Aetrix Electronics and suitable for desktop computers, telecom line cards, and network servers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LTC2900-1CMS#PBF 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 precision analog portfolio, focusing on high-performance signal conditioning, power management, and reliability-critical ICs for industrial, automotive, and communications markets.

The LTC2900 family was designed specifically for multivoltage system supervision-delivering programmable, high-accuracy, low-power monitoring in compact packages for computing, networking, and infrastructure equipment.

FAQ

What is the function of the VPG pin on the LTC2900-1CMS#PBF?

The VPG pin on the LTC2900-1CMS#PBF selects one of 16 voltage threshold combinations by accepting a resistor divider tap between VREF and GND. During a ~150µs programming window after VCC reaches 2.4V, the part samples VPG voltage and configures comparators accordingly. No capacitance may be added to VPG, as it would disrupt sampling accuracy. This enables flexible rail assignment (e.g., 5V/3.3V/2.5V/1.8V) without changing the LTC2900-1CMS#PBF hardware.

Does the LTC2900-1CMS#PBF support monitoring of negative supply voltages?

Yes, the LTC2900-1CMS#PBF supports negative rail monitoring via its –ADJ mode on V4. In this configuration, an external resistor divider connects between the negative supply and VREF (1.210V), with the tap fed to V4. The internal comparator references ground, and VREF provides level shifting. For example, a –5V rail can be monitored at –4.64V trip point using R3 = 464kΩ and R4 = 121kΩ. The LTC2900-1CMS#PBF datasheet specifies V4 input range as –0.3V to 7V, validating this use case.

How is the reset timeout period set on the LTC2900-1CMS#PBF?

The reset timeout period on the LTC2900-1CMS#PBF is set by connecting a capacitor (CRT) between the CRT pin and GND. The relationship is linear: tRST ≈ 4.6ms per nanofarad (or CRT = tRST × 217 pF/ms). A 47nF capacitor yields ~216ms delay, as shown in the典型 application diagram. Leaving CRT unconnected gives a minimum ~50µs timeout. Ceramic capacitors are recommended due to low leakage; electrolytic or high-leakage types degrade timing accuracy. The LTC2900-1CMS#PBF does not require additional timing resistors or external logic.

What is the maximum input voltage allowed on V1–V4 pins of the LTC2900-1CMS#PBF?

The absolute maximum rating for V1, V2, V3, V4, VPG, and PBR pins on the LTC2900-1CMS#PBF is –0.3V to 7V. This allows safe monitoring of common rails such as 5V, 3.3V, and 12V (in ADJ mode with appropriate resistor dividers), as well as negative supplies like –5V or –12V in –ADJ mode. Exceeding 7V risks permanent damage. Note that V1 and V2 also serve as the internal VCC source-the greater of the two defines the device's operating voltage and RST pull-up reference.

Can the LTC2900-1CMS#PBF be used in industrial temperature range applications?

The LTC2900-1CMS#PBF is specified for 0°C to 70°C operation (C-grade). For industrial applications requiring –40°C to 85°C, the pin-compatible LTC2900-1IMS#PBF (MSOP) or LTC2900-1IDD#PBF (DFN) should be used instead. These variants share identical electrical specifications-including ±1.5% threshold accuracy, 43µA supply current, and open-drain RST-but are tested and guaranteed across the extended temperature range. Always verify the suffix: "C" = commercial, "I" = industrial.