Analog Devices Inc. LTC2900-1IMS#TR

Overview

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

For engineers reviewing the LTC2900-1IMS#TR datasheet, LTC2900-1IMS#TR pinout, LTC2900-1IMS#TR application, or LTC2900-1IMS#TR equivalent, key selection criteria include its 10-lead MSOP package, open-drain RST output with V2-referenced weak pull-up, manual reset input (PBR), guaranteed RST assertion down to VCC = 1V, and support for ±adjustable thresholds on V3/V4 inputs.

Technical Context

The LTC2900-1IMS#TR implements four independent high-accuracy comparators referenced to a buffered 1.210V internal bandgap, with threshold selection via a resistor divider on VPG pin enabling 16 preset combinations. Its architecture guarantees glitch immunity and correct RST state during power-up/down transitions.

Reset timing is controlled by an external capacitor on CRT pin (4.6ms/nF scaling), while the manual reset path (PBR) triggers a full reset pulse with programmed duration. The open-drain RST output is pulled low when any monitored rail falls below its threshold and remains asserted for the programmed delay after all rails recover.

Key Specifications

Pinout & Package

Package: 10-lead MSOP (plastic, 3mm × 3mm body, 0.5mm pitch). Pin 1 marked with dot; exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2901CMS#TR and LTC2902IMS#TR, the LTC2900-1IMS#TR delivers focused quad-supply monitoring in the smallest MSOP footprint without added complexity-ideal for cost-sensitive, space-constrained designs where watchdog or margining are unnecessary.

Availability

LTC2900-1IMS#TR is available at Aetrix Electronics and suitable for desktop computers, telecom equipment, and network servers requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LTC2900-1IMS#TR 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 IC portfolio, emphasizing precision, reliability, and signal integrity for demanding industrial and communications applications.

The LTC2900 family was designed specifically for multivoltage system supervision-delivering accurate, low-power, programmable monitoring of up to four independent rails with flexible reset control and robust noise immunity.

FAQ

What is the function of the CRT pin on the LTC2900-1IMS#TR?

The CRT pin on the LTC2900-1IMS#TR sets the reset timeout period by connecting an external capacitor to ground. With a scaling factor of 4.6ms/nF, a 47nF capacitor yields a 216ms delay. Leaving CRT unconnected results in a minimum ~50µs timeout. This adjustable timing allows precise alignment with microprocessor or FPGA boot requirements in the target system using LTC2900-1IMS#TR.

How does the LTC2900-1IMS#TR handle negative voltage monitoring?

The LTC2900-1IMS#TR supports negative voltage monitoring on V4 via the –ADJ mode, where an external resistor divider connects between the negative rail and VREF (1.210V). The comparator's inverting input references ground, and VREF provides level-shifting. For example, a –5.2V rail uses R3 = 487kΩ and R4 = 121kΩ to achieve –4.87V trip point. This capability is confirmed in the LTC2900-1IMS#TR datasheet Figure 6 and Table 3.

What is the maximum input voltage rating for the V1–V4 pins of the LTC2900-1IMS#TR?

The absolute maximum rating for V1, V2, V3, V4, VPG, and PBR pins of the LTC2900-1IMS#TR is –0.3V to 7V. This allows safe monitoring of standard logic rails (e.g., 5V, 3.3V) and higher intermediate rails (e.g., 12V via ADJ mode with appropriate divider), provided input currents remain within specified limits (e.g., IV1 ≤ 75µA at 5V). Exceeding 7V risks permanent damage to LTC2900-1IMS#TR.

Can the LTC2900-1IMS#TR be used with only two or three supply rails?

Yes, the LTC2900-1IMS#TR can monitor fewer than four rails. Unused inputs (e.g., V3 or V4) should be tied above their respective threshold voltages-such as connecting V3 to V2 or using a resistor divider-to prevent false reset assertion. The device draws only 43µA quiescent current regardless of active inputs, making it efficient for partial-rail supervision in the LTC2900-1IMS#TR application.

What is the difference between LTC2900-1IMS#TR and LTC2900-2IMS#TR?

The LTC2900-1IMS#TR features an open-drain RST output with weak internal pull-up to V2, while the LTC2900-2IMS#TR uses a push-pull (active pull-up) RST output referenced to V2. This makes LTC2900-1IMS#TR suitable for wired-OR reset buses and level-shifting, whereas LTC2900-2IMS#TR provides faster rise times and eliminates need for external pull-ups-confirmed in the LTC2900-1IMS#TR datasheet Features section and Electrical Characteristics table.