Analog Devices Inc. LTC2902-1CGN#TRPBF

Overview

LTC2902-1CGN#TRPBF from Analog Devices (formerly Linear Technology) is a programmable quad supply monitor IC with open-drain RST output, designed for multivoltage system power integrity supervision. It simultaneously monitors four independent supply rails (e.g., 5V, 3.3V, 2.5V, 1.8V), supports ±1.5% threshold accuracy over temperature, offers selectable 5%/7.5%/10%/12.5% supply tolerance, and features adjustable reset delay via external capacitor. Used in desktop computers and telecom equipment for reliable power-on reset sequencing.

For engineers reviewing the LTC2902-1CGN#TRPBF datasheet, LTC2902-1CGN#TRPBF pinout, LTC2902-1CGN#TRPBF application, or LTC2902-1CGN#TRPBF equivalent, key selection criteria include guaranteed RESET assertion down to VCC = 1V, individual nondelayed comparator outputs per supply, RST disable capability for margin testing, and compatibility with narrow 16-lead SSOP layout constraints.

Technical Context

The LTC2902-1CGN#TRPBF implements four independent voltage comparators referenced to a buffered 1.210V internal bandgap, with thresholds set via resistor divider on VPG and scaled by T0/T1 digital inputs. Its architecture guarantees glitch immunity and correct RST state during brownout, with propagation delay under 150µs and undervoltage detection response within 150µs.

Reset timing is externally programmed via CRT pin capacitance (4.6ms/nF scaling), while supply tolerance selection modifies the reference voltage (1.210V to 1.113V) rather than comparator offsets-ensuring consistent trip-point scaling across all four monitored rails without recalibrating external dividers.

Key Specifications

Pinout & Package

Package: 16-lead plastic SSOP (narrow, 0.150" body width), JEDEC MO-137AC compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC2902-2CGN#TRPBF, the LTC2902-1CGN#TRPBF provides flexible level-shifting via open-drain RST but requires an external pull-up; compared with LTC1326CMS8#TRPBF, it adds fourth-rail monitoring and RDIS functionality at higher quiescent current and larger package size.

Availability

LTC2902-1CGN#TRPBF is available at Aetrix Electronics and suitable for desktop computers, telecom equipment, and industrial PLCs requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LTC2902-1CGN#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. (acquired Linear Technology in 2017) is a global semiconductor leader specializing in high-performance analog, mixed-signal, and power management ICs for precision instrumentation and power integrity applications.

The LTC2902 product line delivers programmable multirail supervision for complex power architectures, targeting systems where accurate, configurable, and glitch-immune reset generation is critical to system reliability.

FAQ

What is the minimum supply voltage required for LTC2902-1CGN#TRPBF to assert a valid RESET signal?

The LTC2902-1CGN#TRPBF guarantees correct RST logic state down to VCC = 1V. This means that even during severe brownout conditions, the LTC2902-1CGN#TRPBF will hold RST low until all monitored supplies recover above their thresholds and the programmed delay expires - ensuring deterministic reset behavior before system collapse.

How does the RDIS pin function in LTC2902-1CGN#TRPBF, and what design considerations apply?

The RDIS pin on the LTC2902-1CGN#TRPBF is an active-low input that forces the RST output high regardless of supply voltage status. This enables supply margin testing without triggering a system reset. The pin has an internal 10µA pull-up, so it may be left floating for normal operation. When pulled low, it overrides all comparator decisions - a key feature for automated test equipment and burn-in validation.

Can LTC2902-1CGN#TRPBF monitor negative supply rails, and if so, how is this implemented?

Yes, the LTC2902-1CGN#TRPBF supports negative rail monitoring via its –ADJ mode on V4. In this configuration, V4 connects to a resistive divider between the negative supply and VREF (1.210V), with the inverting input referenced to ground. The trip voltage is calculated as VTRIP = VREF × (R3/R4), enabling accurate supervision of rails such as –5V or –12V without external op-amps or level shifters.

What is the role of the CRT pin on LTC2902-1CGN#TRPBF, and how is reset timeout calculated?

The CRT pin on the LTC2902-1CGN#TRPBF sets the reset timeout period by connecting an external capacitor to GND. The relationship is linear: tRST = 4.6ms per nanofarad of CRT capacitance. For example, a 47nF capacitor yields ~216ms delay. Leaving CRT unconnected results in ~50µs minimum delay. Ceramic capacitors with low leakage are recommended to maintain timing accuracy.

How does the VPG pin programming work on LTC2902-1CGN#TRPBF, and what resistor tolerance is required?

The VPG pin on the LTC2902-1CGN#TRPBF selects one of 16 voltage threshold combinations using a resistor divider from VREF to GND. Linear Technology specifies 1% tolerance resistors for accurate ratio matching - e.g., R1 = 59.0kΩ and R2 = 40.2kΩ for 5V/3.3V/2.5V/1.8V monitoring. Capacitance must not be added to VPG, as it disrupts the 150µs sampling window during power-up programming.