Analog Devices Inc. LTC2902-2IGN#PBF

Overview

LTC2902-2IGN#PBF from Analog Devices (formerly Linear Technology) is a programmable quad supply monitor IC with push-pull RST output, designed for multivoltage system power sequencing and fault detection. It simultaneously monitors four supplies (e.g., 5V, 3.3V, 2.5V, 1.8V), offers ±1.5% threshold accuracy over temperature, selectable 5–12.5% supply tolerance, and adjustable reset delay via external capacitor - used in telecom equipment and network servers for reliable power-up validation.

For engineers reviewing the LTC2902-2IGN#PBF datasheet, LTC2902-2IGN#PBF pinout, LTC2902-2IGN#PBF application, or LTC2902-2IGN#PBF equivalent, key selection criteria include its push-pull RST output (vs open-drain LTC2902-1), guaranteed RESET assertion down to VCC = 1V, 43µA quiescent current, and 16-lead narrow SSOP package compatibility with multivoltage embedded power rails.

Technical Context

The LTC2902-2IGN#PBF implements four independent voltage comparators with nondelayed active-high COMP outputs and a shared active-low RST output with programmable delay. Its internal reference (1.210V nominal) scales with T0/T1 digital inputs to set 5%, 7.5%, 10%, or 12.5% supply tolerance without changing external resistor dividers.

Voltage thresholds are selected via a 1% resistive divider on VPG, enabling 16 preset combinations including ADJ/–ADJ modes for positive/negative rail monitoring. The push-pull RST output actively drives high to V2 (not just weak pull-up), ensuring fast, deterministic release timing and eliminating need for external pull-up resistors in most applications.

Key Specifications

Pinout & Package

Package: 16-lead narrow plastic SSOP (GN16), 0.150" body width, JEDEC MS-013AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2902-1IGN#PBF, the LTC2902-2IGN#PBF eliminates external pull-up needs and improves RST timing determinism; versus LTC1326-2.5, it adds a fourth monitored rail, programmable tolerance, and negative rail support - making it suitable for higher-complexity power architectures requiring configurability and extended rail coverage.

Availability

LTC2902-2IGN#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 guaranteed performance across industrial temperature ranges (–40°C to 85°C).

Supply support for LTC2902-2IGN#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.

The LTC2902 product line delivers precision, low-power, programmable power supply supervisors for multivoltage systems - designed to simplify power sequencing, improve system reliability, and reduce design cycle time in computing, communications, and industrial applications.

FAQ

What is the key functional difference between LTC2902-2IGN#PBF and LTC2902-1IGN#PBF?

The LTC2902-2IGN#PBF features a push-pull RST output that actively drives high to V2, eliminating the need for an external pull-up resistor. In contrast, the LTC2902-1IGN#PBF uses an open-drain RST output requiring external pull-up. This makes the LTC2902-2IGN#PBF preferable for designs prioritizing reduced component count, faster RST rise time (~206ns), and deterministic high-level output without layout dependencies.

How does the LTC2902-2IGN#PBF support negative voltage monitoring?

The LTC2902-2IGN#PBF supports negative rail monitoring via its –ADJ mode on V4 input. In this mode, VREF (1.210V) provides level shifting: the inverting input of the V4 comparator connects to ground, and the external resistor divider links the negative supply to VREF. The trip voltage is calculated as VTRIP = VREF × (R3/R4), enabling accurate monitoring of rails like –5V or –12V without additional op-amps or level-shifters.

What is the minimum VCC required for guaranteed RST operation in LTC2902-2IGN#PBF?

The LTC2902-2IGN#PBF guarantees correct RST logic state for VCC ≥ 1V during rising and falling conditions. Below 1V, RST pull-down capability degrades significantly. For robust operation near 0V, a 100kΩ pull-down resistor from RST to GND is recommended to prevent floating states - especially when interfacing with high-impedance CMOS inputs.

Can the LTC2902-2IGN#PBF monitor fewer than four supplies?

Yes, the LTC2902-2IGN#PBF can be configured to monitor fewer than four supplies. Unused inputs (e.g., V3 or V4) should be tied above their respective reset thresholds - for example, connecting V3 to V2 or using a resistor divider to set a valid ADJ threshold. This preserves comparator functionality while reducing active monitoring channels, optimizing power use in simpler systems.

How is reset delay time programmed on the LTC2902-2IGN#PBF?

Reset delay time on the LTC2902-2IGN#PBF is set by connecting an external capacitor (CRT) between Pin 5 (CRT) and GND. The relationship is linear: tRST ≈ 4.6ms per nanofarad (e.g., 47nF yields ~216ms). Leaving CRT unconnected defaults to ~50µs minimum delay. Low-leakage ceramic capacitors are recommended to maintain timing accuracy, as leakage current affects the 2µA nominal charging current.