Analog Devices Inc. LTC1727IS8-5#TRPBF

Overview

LTC1727IS8-5#TRPBF from Analog Devices is a micropower precision triple supply monitor IC in an 8-lead SO package, designed for systems requiring simultaneous monitoring of 5V, 3.3V, and an adjustable supply. It features ±1.5% threshold accuracy over temperature, 10µA typical supply current, 200ms reset delay, individual open-drain comparator outputs (COMP3, COMP5, COMPA), and a common active-low RST output guaranteed functional down to VCC ≥ 1V. It is used in notebook computers and intelligent instruments for reliable power-up sequencing and brownout detection.

For engineers reviewing the LTC1727IS8-5#TRPBF datasheet, LTC1727IS8-5#TRPBF pinout, LTC1727IS8-5#TRPBF application, or LTC1727IS8-5#TRPBF equivalent, this page delivers verified technical context, exact pin functions, real-world use scenarios, and validated alternative options - all grounded in the official Rev. E datasheet and Analog Devices' product documentation.

Technical Context

The LTC1727IS8-5#TRPBF implements three independent voltage comparators with internal bandgap reference, each monitoring a dedicated input (VCC5, VCC3, VCCA) against precise thresholds: 4.675V (±1.5%), 3.086V (±1.5%), and 1.000V (±1.5%). Its power-detect architecture dynamically selects the highest-voltage supply (VCC5 or VCC3) as the internal power source, enabling guaranteed RST assertion down to 1V on either rail.

Reset assertion requires all three supplies to fall below their respective thresholds; deassertion occurs only after all are valid for 200ms. The device includes glitch immunity via 50µs minimum overdrive requirement and integrates slow-response comparators that inherently filter ripple, reducing false triggering without external hysteresis.

Key Specifications

Pinout & Package

The LTC1727IS8-5#TRPBF is housed in an 8-lead plastic SO (S8) package, 0.150-inch narrow body, with JEDEC MS-012AC compliance and RoHS-compliant lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1326-5 and LTC1726-5, the LTC1727IS8-5#TRPBF offers superior glitch immunity and guaranteed 1V RST operation but trades off adjustable timing and tighter threshold tolerance - making it optimal for cost-sensitive, fixed-timing computing applications where robustness under marginal supply conditions is paramount.

Availability

LTC1727IS8-5#TRPBF is available at Aetrix Electronics and suitable for desktop computers, notebook computers, and intelligent instruments requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for LTC1727IS8-5#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and computing markets.

The LTC1727 product line delivers micropower, high-accuracy supply monitoring ICs optimized for multi-rail computing and instrumentation systems where reliability, low quiescent current, and precise voltage thresholds are critical.

FAQ

What is the operating temperature range for the LTC1727IS8-5#TRPBF?

The LTC1727IS8-5#TRPBF is rated for operation from –40°C to +85°C (Industrial grade). This range is explicitly specified in the "Order Information" table of the Rev. E datasheet and applies to all electrical characteristics unless otherwise noted. The device is characterized and assured across this full range, making it suitable for demanding industrial and commercial computing environments where ambient temperatures fluctuate significantly.

Does the LTC1727IS8-5#TRPBF support monitoring of a single 5V supply without false RST assertion between 3.1V and 4.15V?

Yes, the LTC1727IS8-5#TRPBF supports robust single 5V monitoring using the VCC5 override function. When VCC5 is tied directly to VCC3, the part asserts RST low until VCC5 reaches ~4.675V (VRT5), avoiding the ambiguous 3.1V–4.15V window. Alternatively, adding a series diode (e.g., MMBD914) between VCC5 and VCC3 disables override entirely, guaranteeing RST remains low until VCC5 exceeds VRT5 - a documented solution in Figure 4 of the datasheet.

What are the exact threshold voltages monitored by the LTC1727IS8-5#TRPBF?

The LTC1727IS8-5#TRPBF monitors three precise thresholds: VCC5 at 4.675V (±1.5%), VCC3 at 3.086V (±1.5%), and VCCA at 1.000V (±1.5%). These values are specified in the "ELECTRICAL CHARACTERISTICS" table (page 3) of the Rev. E datasheet under VRT5, VRT3, and VRTA parameters, and are guaranteed over the full –40°C to +85°C temperature range.

Can the LTC1727IS8-5#TRPBF be powered solely from the VCCA pin?

No, the LTC1727IS8-5#TRPBF cannot be powered from VCCA alone. Per the "PIN FUNCTIONS" section (page 7), VCCA is a high-impedance sense input only, with no power delivery capability. Internal circuitry requires either VCC3 or VCC5 to be ≥1V to operate - VCCA serves exclusively as a monitoring node for adjustable supplies and relies on VCC3 or VCC5 for bias.

How does the LTC1727IS8-5#TRPBF handle power-down sequencing?

During power-down, the LTC1727IS8-5#TRPBF holds RST low as soon as any monitored supply (VCC5, VCC3, or VCCA) falls below its threshold. RST remains asserted until all supplies drop below 1V, ensuring the host system completes orderly shutdown. This behavior is guaranteed by the "Power-Down" section (page 10) and confirmed by the absolute maximum ratings specifying VCC operation down to 1V for correct RST state.