Analog Devices Inc. LTC1232CN8#PBF

Overview

LTC1232CN8#PBF from Analog Devices (formerly Linear Technology) is a precision microprocessor supervisory circuit with integrated voltage monitoring, watchdog timer, and push-button reset control. It features dual VCC trip points (4.62V/4.37V), guaranteed RST assertion down to VCC = 1V, 600ms power-ok delay, 2.0mA max supply current, and 8-pin PDIP package. It is used in embedded controllers requiring reliable power-up sequencing and fault recovery.

For engineers reviewing the LTC1232CN8#PBF datasheet, LTC1232CN8#PBF pinout, LTC1232CN8#PBF application, or LTC1232CN8#PBF equivalent, key selection criteria include VCC trip point tolerance (5% vs 10% via TOL pin), selectable watchdog timeout (150ms/600ms/1.2s via TD pin), open-drain RST output drive capability, and guaranteed reset hold at VCC ≥ 1V.

Technical Context

The LTC1232CN8#PBF integrates a bandgap-based precision voltage comparator with 40mV hysteresis, a programmable watchdog timer with three timeout options (150ms/600ms/1.2s selected by TD pin state), and a debounced push-button input (PB RST) that guarantees ≥250ms active-low reset pulse after release. Its RST output remains valid down to VCC = 1V, enabling robust brownout hold-off.

It supports dual threshold operation: 4.62V typical with TOL = GND (±5% trip), 4.37V typical with TOL = VCC (±10% trip). The ST strobe input resets the watchdog on each high-to-low transition, and the internal oscillator drives timing without external components - fulfilling "minimum external component count" design intent.

Key Specifications

Pinout & Package

Package: 8-lead PDIP (N8), 0.300-inch width, JEDEC MS-001 compliant. RoHS-compliant lead finish (Pb-free with NiPdAu plating).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with LTC699 and LTC1326, the LTC1232CN8#PBF uniquely combines dual-threshold voltage monitoring, user-accessible push-button reset, and programmable watchdog timeout in an 8-pin PDIP - making it optimal for cost-sensitive, single-rail embedded controllers needing full reset autonomy.

Availability

LTC1232CN8#PBF is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical diagnostic instruments, and point-of-sale terminals requiring stable component supply and long-term obsolescence management.

Supply support for LTC1232CN8#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-reliability analog IC portfolio. Linear's legacy products emphasize precision, robustness, and minimal external component count.

The LTC1232CN8#PBF belongs to Linear's µP supervisory product line, designed specifically for deterministic power-up sequencing, brownout protection, and autonomous fault recovery in resource-constrained embedded systems.

FAQ

What is the function of the TOL pin on the LTC1232CN8#PBF?

The TOL pin selects the VCC trip point hysteresis mode: when tied to GND, the LTC1232CN8#PBF triggers reset at 4.62V (±5%); when tied to VCC, it triggers at 4.37V (±10%). This allows adaptation to varying 5V rail tolerances without external components. The LTC1232CN8#PBF uses this pin to provide two distinct fail-safe thresholds within a single device.

Does the LTC1232CN8#PBF require external timing components for its watchdog function?

No. The LTC1232CN8#PBF implements an internal oscillator for watchdog timing, eliminating the need for external capacitors or resistors. The timeout period (150ms/600ms/1.2s) is selected solely by the TD pin state - GND, floating, or VCC - making the LTC1232CN8#PBF a true single-chip supervisory solution.

Can the LTC1232CN8#PBF operate reliably during deep brownout conditions?

Yes. The LTC1232CN8#PBF guarantees RST output remains logic-low down to VCC = 1V, ensuring the microprocessor stays in reset even during severe undervoltage events. This behavior is confirmed in the Absolute Maximum Ratings and DC Electrical Characteristics tables, and is a defining feature of the LTC1232CN8#PBF.

What is the purpose of the dual RST and RST outputs on the LTC1232CN8#PBF?

The LTC1232CN8#PBF provides both active-low open-drain RST and active-high push-pull RST outputs to accommodate diverse µP reset architectures. RST interfaces with processors requiring external pull-up and low-voltage reset assertion, while RST directly drives logic-high reset inputs without additional buffering - increasing design flexibility for the LTC1232CN8#PBF.

How does the PB RST input on the LTC1232CN8#PBF handle mechanical switch bounce?

The LTC1232CN8#PBF includes on-chip hardware debounce for the PB RST pin: it requires a minimum 40ms low pulse to register a valid push-button press and guarantees a minimum 250ms active reset pulse upon release. This eliminates need for external RC filters or firmware debouncing routines, simplifying implementation of user-reset functionality in the LTC1232CN8#PBF.