Analog Devices Inc. LTC2902-2CGN#PBF

Overview

LTC2902-2CGN#PBF from Analog Devices (formerly Linear Technology) is a programmable quad supply monitor IC with push-pull RST output, simultaneously monitoring up to four voltage rails (5V/3.3V/2.5V/1.8V/1.5V/±adjustable), ±1.5% threshold accuracy over temperature, 43µA typical supply current, and adjustable reset timeout via external capacitor. It serves as a system-level power integrity supervisor in multivoltage embedded controllers.

For engineers reviewing the LTC2902-2CGN#PBF datasheet, LTC2902-2CGN#PBF pinout, LTC2902-2CGN#PBF application, or LTC2902-2CGN#PBF equivalent, key selection criteria include guaranteed RST assertion down to VCC = 1V, selectable 5%/7.5%/10%/12.5% supply tolerance, individual nondelayed comparator outputs per rail, and compatibility with margining via RDIS pin.

Technical Context

The LTC2902-2CGN#PBF implements four independent high-accuracy voltage comparators referenced to a buffered 1.210V bandgap, with thresholds digitally programmed via VPG pin using a 1% resistor divider. Tolerance selection (5–12.5%) is controlled by dual digital inputs T0/T1, scaling the internal reference voltage across four discrete levels.

Its push-pull RST output actively drives high to V2 (not open-drain), enabling faster rise times without external pull-up; reset delay is set by CRT pin capacitance (4.6ms/nF), and RDIS provides hardware-level reset disable for supply margin testing without processor intervention.

Key Specifications

Pinout & Package

Package: 16-lead narrow SSOP (GN), 0.150-inch body width, RoHS-compliant lead-free finish (PBF).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2902-1CGN#PBF, the LTC2902-2CGN#PBF eliminates external pull-up components and improves RST rise time; versus LTC1326-2.5, it adds a fourth rail, tolerance flexibility, and programmable reset timing-critical for modern multirail server and telecom platforms.

Availability

LTC2902-2CGN#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 RoHS-compliant sourcing.

Supply support for LTC2902-2CGN#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/mixed-signal product lines, including precision power supervision ICs.

The LTC2902 family was designed for multivoltage system supervision in computing, communications, and industrial equipment-emphasizing accuracy, configurability, and robustness under brownout and noise.

FAQ

What is the function of the CRT pin on the LTC2902-2CGN#PBF?

The CRT pin on the LTC2902-2CGN#PBF sets the reset timeout period by connecting an external capacitor to GND. The nominal timing coefficient is 4.6ms/nF; a 47nF capacitor yields ~216ms delay. Leaving CRT open results in ~50µs minimum delay. Capacitor leakage directly impacts timing accuracy, so low-leakage ceramic types are recommended.

How does the RDIS pin affect reset behavior in the LTC2902-2CGN#PBF?

The RDIS pin on the LTC2902-2CGN#PBF is a low-active input that forces the RST output high regardless of rail status-enabling supply margin testing without issuing a system reset. When RDIS is pulled low, the processor remains operational while voltages are swept. An internal 10µA pull-up allows floating RDIS for normal operation.

What are the key differences between LTC2902-2CGN#PBF and LTC2902-1CGN#PBF?

The LTC2902-2CGN#PBF features a push-pull RST output actively driven high to V2, while the LTC2902-1CGN#PBF uses an open-drain RST requiring external pull-up. Both share identical pinout, monitoring capability, programming interface, and tolerance selection. Push-pull reduces component count and improves RST rise time.

Can the LTC2902-2CGN#PBF monitor negative supply voltages?

Yes-the LTC2902-2CGN#PBF supports negative voltage monitoring via its –ADJ mode on V4. In this configuration, V4 connects to a resistive divider between the negative rail and VREF (1.21V), enabling accurate trip-point setting (e.g., –4.64V). VREF supplies the level shift, and minimum R4 is constrained by VREF's ±1mA drive capability.

What is the minimum VCC required for valid RST assertion in the LTC2902-2CGN#PBF?

The LTC2902-2CGN#PBF guarantees correct RST logic state for VCC ≥ 1V. Below 1V, pull-down strength degrades significantly; the RST pin may float. For operation near 0V, a 100kΩ pull-down resistor from RST to GND is recommended to ensure deterministic low state during deep brownout.