Analog Devices Inc. LTC2900-2IDD#PBF

Overview

LTC2900-2IDD#PBF from Analog Devices (formerly Linear Technology) is a programmable quad supply monitor IC with push-pull RST output, simultaneously supervising four independent 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 embedded systems requiring reliable power-on reset and brownout detection.

For engineers reviewing the LTC2900-2IDD#PBF datasheet, LTC2900-2IDD#PBF pinout, LTC2900-2IDD#PBF application, or LTC2900-2IDD#PBF equivalent, key selection criteria include its push-pull RST output (vs open-drain), guaranteed RST validity down to VCC = 1V, 10-lead 3mm × 3mm DFN package, and support for ±adjustable thresholds on V3/V4 inputs.

Technical Context

The LTC2900-2IDD#PBF implements four independent high-accuracy comparators with user-programmable thresholds selected via a resistor divider on VPG, enabling 16 preset combinations of 5V/3.3V/3V/2.5V/1.8V/1.5V/±ADJ. Its internal bandgap reference (1.210V) drives both programming and comparator offset circuits.

Reset assertion is synchronized across all monitored supplies; RST remains low until all four VX inputs exceed their thresholds, then holds low for a capacitor-programmed delay (e.g., 216ms with 47nF). The push-pull RST output actively drives high to V2 (not open-drain), ensuring fast rise time (~206ns) and eliminating need for external pull-up resistors.

Key Specifications

Pinout & Package

Package: 10-lead 3mm × 3mm plastic DFN (exposed pad), RoHS-compliant, thermal resistance θJA = 43°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2901CMS#PBF, LTC2900-2IDD#PBF omits watchdog functionality but delivers identical quad monitoring in a smaller, thermally superior DFN package; versus LTC1326IMS8#PBF, it adds a fourth rail, programmable timeout, and bipolar rail support at the cost of slightly relaxed accuracy (±1.5% vs ±0.75%).

Availability

LTC2900-2IDD#PBF is available at Aetrix Electronics and suitable for desktop computers, telecom equipment, and network servers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LTC2900-2IDD#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 high-performance analog and power management portfolio, emphasizing precision, reliability, and signal integrity for demanding industrial and communications applications.

The LTC2900 family was designed specifically for multivoltage digital systems needing accurate, flexible, low-power supply supervision - targeting applications where discrete solutions or less-accurate supervisors risk system instability during power transients.

FAQ

What is the key functional difference between LTC2900-2IDD#PBF and LTC2900-1IDD#PBF?

The LTC2900-2IDD#PBF features a push-pull RST output that actively drives high to V2, while the LTC2900-1IDD#PBF uses an open-drain RST with weak internal pull-up. This means LTC2900-2IDD#PBF eliminates the need for an external pull-up resistor, delivers faster rise times (~206ns), and ensures stronger high-level drive - critical for driving heavy capacitive loads or noisy environments. Both share identical monitoring, programming, and timing capabilities.

Can LTC2900-2IDD#PBF monitor negative supply voltages like –5V?

Yes, LTC2900-2IDD#PBF supports negative rail monitoring via its –ADJ mode on V4 input. By connecting a resistive divider between the negative supply and VREF (pin 8), the device uses VREF's 1.210V reference to level-shift and sense voltages such as –4.64V or –5.2V. The trip point is calculated as VTRIP = –(VREF × R3/R4), and the datasheet provides validated resistor values (e.g., R3 = 464kΩ, R4 = 121kΩ for –4.64V).

What is the minimum VCC required for LTC2900-2IDD#PBF to guarantee correct RST logic state?

LTC2900-2IDD#PBF guarantees correct RST logic state (active-low assertion and release) for VCC ≥ 1V. This specification applies during both power-up and power-down sequences, ensuring reliable reset behavior even under deep brownout conditions where main supplies dip below typical regulator dropout voltages. VCC is defined as the greater of V1 or V2.

How is the reset timeout period set on LTC2900-2IDD#PBF, and what capacitor value yields 200ms delay?

The reset timeout on LTC2900-2IDD#PBF is set by connecting a capacitor (CRT) between pin 3 (CRT) and GND. The relationship is linear: CRT (pF) = tRST (ms) × 217. For a 200ms delay, CRT = 200 × 217 = 43,400pF (43.4nF). A standard 47nF ceramic capacitor yields ~216ms, as confirmed in the datasheet's typical application circuit (TA01). Low-leakage X7R or C0G dielectrics are recommended.

Does LTC2900-2IDD#PBF require external components for basic operation, and which pins need bypassing?

Yes, LTC2900-2IDD#PBF requires external components for full functionality: a CRT capacitor for reset timing, a VPG resistor divider for threshold selection, and 0.1µF bypass capacitors on V1 and V2 (since the greater defines VCC). VREF can drive up to 1000pF, but a 100nF ceramic cap is recommended for stability. No bypass is required on V3/V4 unless filtering transients; PBR may use a simple push-button switch to GND.