Analog Devices Inc. LTC2935IDC-3

Overview

LTC2935IDC-3 from Analog Devices (formerly Linear Technology) is an ultra-low power voltage supervisor IC with pin-selectable reset and power-fail thresholds, open-drain RST/PFO outputs, and –40°C to 85°C industrial temperature rating. It delivers 500nA typical quiescent current, ±1.5% threshold accuracy over temperature, and 200ms reset timeout - enabling reliable system initialization and controlled shutdown in battery-powered portable equipment.

For engineers reviewing the LTC2935IDC-3 datasheet, LTC2935IDC-3 pinout, LTC2935IDC-3 application, or LTC2935IDC-3 equivalent, key selection considerations include its eight binary-configurable reset thresholds (1.60V–2.40V), fixed 120mV power-fail margin above reset, open-drain output compatibility with mixed-voltage logic, and DFN (2mm × 2mm) package for space-constrained designs.

Technical Context

The LTC2935IDC-3 integrates two precision comparators: one for reset generation at a user-selected falling VCC threshold (eight options), and a second for early power-fail warning at a fixed offset (120mV) above that threshold. Its internal 5% hysteresis on reset and 2.5% on PFO prevents chatter during supply transients.

Threshold selection is implemented via three logic-level inputs (S2/S1/S0), each referenced to VCC with 0.3×VCC/0.7×VCC switching points. The manual reset input (MR) features internal 900kΩ pull-up and 20μs minimum pulse width requirement, while both RST and PFO outputs are open-drain with <100mV VOL at 3mA pull-up current.

Key Specifications

Pinout & Package

Package: 8-lead (2mm × 2mm) plastic DFN with exposed pad (pin 9, optional GND connection). Pin-compatible with TSOT-23 variant but distinct footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with LTC2935ITS8-3#TRPBF, the LTC2935IDC-3 saves 35% board area and improves thermal performance (θJA = 102°C/W); compared with LTC2934IDC-3#TRPBF, it eliminates BOM cost and layout complexity of external resistors while delivering tighter threshold accuracy.

Availability

LTC2935IDC-3 is available at Aetrix Electronics and suitable for portable medical sensors, wireless IoT endpoints, point-of-sale terminals, security system peripherals, and battery-backed industrial controllers requiring stable component supply across extended product lifecycles.

Supply support for LTC2935IDC-3 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 precision analog portfolio, including supervisory ICs, with focus on high-reliability, low-power signal conditioning and power management solutions.

The LTC2935 product line was designed specifically for ultra-low-power battery monitoring in space- and energy-constrained portable electronics, emphasizing nanoscale quiescent current and factory-trimmed threshold accuracy without external components.

FAQ

What is the exact reset threshold for LTC2935IDC-3 when S2=S1=S0=GND?

The LTC2935IDC-3 reset threshold is 2.40V (min 2.364V, typ 2.400V, max 2.436V) when all three threshold select inputs are tied low. This value is confirmed in the Electrical Characteristics table for LTC2935-3/LTC2935-4 variants under VRTF8. The power-fail threshold is fixed at +120mV above this, or 2.52V nominal.

Does LTC2935IDC-3 require external pull-up resistors on RST and PFO?

Yes - the LTC2935IDC-3 uses open-drain outputs (RST and PFO), so external pull-up resistors are mandatory for proper logic-level operation. Recommended values range from 10kΩ to 470kΩ depending on speed and power requirements; 100kΩ is typical for low-current battery applications. The LTC2935IDC-3 itself does not provide internal pull-ups on these pins.

Can LTC2935IDC-3 monitor a 1.8V supply rail?

Yes - the LTC2935IDC-3 supports VCC from 1V to 5.5V and offers eight selectable thresholds down to 1.60V. With S2=High, S1=High, S0=High, its reset threshold is 1.60V (typ), making it suitable for monitoring 1.8V rails with 200mV safety margin before assertion. The 5% hysteresis ensures clean release at ~1.68V.

How does the manual reset function work on LTC2935IDC-3?

When MR is pulled low for ≥20μs, the LTC2935IDC-3 forces RST low immediately. After MR returns high, RST remains low for a full 200ms timeout before releasing - identical to the power-on reset timing. This behavior is independent of VCC level as long as VCC ≥1V, and the internal 900kΩ pull-up ensures default high state when unused.

Is the exposed pad on the LTC2935IDC-3 DFN package required to connect to ground?

No - the exposed pad (pin 9) on the LTC2935IDC-3 DFN package is optional per the datasheet. It may be left floating or connected to PCB ground to improve thermal dissipation. When connected, it must be soldered to a thermal pad; no electrical functionality depends on this connection, and grounding it does not affect the LTC2935IDC-3's electrical performance or specifications.