Analog Devices Inc. LTC2901-3CGN#TRPBF

Overview

LTC2901-3CGN#TRPBF from Analog Devices (acquired Linear Technology) is a programmable quad supply monitor IC with open-drain RST output, adjustable reset and watchdog timers, and 16 selectable voltage threshold combinations for 5V/3.3V/3V/2.5V/1.8V/1.5V/±Adj inputs. It guarantees ±1.5% threshold accuracy over temperature, 43μA typical supply current, and reliable reset assertion down to VCC = 1V. It is used in multivoltage telecom equipment and network servers requiring precise power sequencing and fault detection.

For engineers reviewing the LTC2901-3CGN#TRPBF datasheet, LTC2901-3CGN#TRPBF pinout, LTC2901-3CGN#TRPBF application, or LTC2901-3CGN#TRPBF equivalent, key selection criteria include its 5% or 10% undervoltage tolerance selectability via TOL pin, guaranteed RST behavior at low VCC, open-drain RST output compatibility with external pull-ups, and SSOP-16 package footprint for space-constrained PCBs.

Technical Context

The LTC2901-3CGN#TRPBF implements four independent high-accuracy comparators with glitch immunity, each monitoring one of four user-programmed supply rails. Its internal bandgap reference (1.210V ±1.5%) feeds a resistive divider matrix on VPG to configure thresholds, while CRT and CWT pins set reset and watchdog timeouts via external capacitors (e.g., 47nF → 216ms tRST, 940ms tWD).

It features a logic-controlled TOL pin (Pin 7) that selects between 5% and 10% undervoltage tolerance - active only on LTC2901-3/LTC2901-4 variants - and an open-drain RST output (Pin 6) pulled weakly to V2, enabling flexible level-shifting and wired-OR configurations. All COMPX outputs are nondelayed, active-high, and internally pulled up to V2.

Key Specifications

Pinout & Package

Package: 16-lead narrow plastic SSOP (GN16), 5.0mm × 6.2mm, 0.635mm pitch, RoHS-compliant and lead-free (#TRPBF).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2901-4CGN#TRPBF and TPS3307-33DGNR, the LTC2901-3CGN#TRPBF uniquely combines open-drain RST for bus sharing, TOL-selectable tolerance for test-mode flexibility, and ±adjustable inputs for mixed-signal systems - making it optimal for complex, field-upgradeable power architectures.

Availability

LTC2901-3CGN#TRPBF is available at Aetrix Electronics and suitable for telecom equipment, network servers, and industrial PLCs requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for LTC2901-3CGN#TRPBF 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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC2901 product line delivers precision, low-power, programmable power supply supervision for multirail systems - designed specifically for applications demanding configurable thresholds, robust brownout immunity, and hardware-based reliability without firmware dependency.

FAQ

What is the function of the TOL pin on the LTC2901-3CGN#TRPBF?

The TOL pin (Pin 7) on the LTC2901-3CGN#TRPBF selects undervoltage tolerance: logic low configures 5% tolerance, logic high configures 10%. This feature is exclusive to LTC2901-3 and LTC2901-4 variants and enables field-adjustable margin testing without modifying external components. The LTC2901-3CGN#TRPBF uses this pin to dynamically scale internal threshold references while maintaining ±1.5% accuracy across temperature.

How does the LTC2901-3CGN#TRPBF generate a reset pulse after a watchdog timeout?

Unlike LTC2901-1/LTC2901-2 which assert WDO, the LTC2901-3CGN#TRPBF merges watchdog failure into the RST output: a missed WDI edge triggers a full reset pulse on the open-drain RST pin for the duration set by CRT. This eliminates the need for external OR-ing logic and ensures system-wide restart. The LTC2901-3CGN#TRPBF achieves this using internal state machine integration between watchdog timer and reset generator blocks.

Can the LTC2901-3CGN#TRPBF monitor negative supply voltages?

Yes - the LTC2901-3CGN#TRPBF supports negative rail monitoring in –ADJ mode on V4 (Pin 13). An external resistor divider connects between the negative supply and VREF (1.210V), leveraging VREF as a level-shift reference. The trip point is calculated as VTRIP = VREF × R3/R4, enabling accurate detection of –1.8V, –5V, or other negative rails. This capability is confirmed in the LTC2901-3CGN#TRPBF datasheet Figure 6 and Table 3.

What is the minimum VCC required for the LTC2901-3CGN#TRPBF to guarantee correct RST and COMPX logic states?

The LTC2901-3CGN#TRPBF guarantees correct RST and COMPX logic states for VCC ≥ 1V, as specified in the Absolute Maximum Ratings table. This ensures deterministic reset assertion during deep brownout conditions - critical for safe shutdown in battery-powered or unregulated systems. Below 1V, behavior is undefined; the LTC2901-3CGN#TRPBF will reprogram once VCC rises above 2.4V.

How do I calculate the resistor values for an adjustable threshold on V3 or V4 using the LTC2901-3CGN#TRPBF?

For positive adjustable mode (ADJ), use VTRIP = 0.5V × (1 + R3/R4) with R3 connected to supply and R4 to GND (Figure 5). For negative adjustable mode (–ADJ), use VTRIP = VREF × R3/R4 with R3 connected to negative supply and R4 to VREF (Figure 6). Table 2 and Table 3 in the LTC2901-3CGN#TRPBF datasheet provide verified 1% resistor pairs for common trip points - e.g., 12V → 11.25V uses R3 = 2150kΩ, R4 = 100Ω.