ADM13305

Dual Processor Supervisors with Watchdog ADM13305 FEATURES Dual supervisory circuits Supply voltage range of 2.7 V to 5.5 V Pretrimmed threshold options: 1.8 V, 2.5 V, 3.3 V, and 5 V Adjustable 0.6 V voltage reference Maximum supply current of 40 μA 140 ms (minimum) reset timeout Watchdog timer with 1.6 sec (typical) timeout RESET valid from VDD ≥ 1.1 V Push-pull RESET and RESET outputs 8-lead, narrow body SOIC package Temperature range: −40°C to +85°C VDD 14kΩ MR RESET SENSE1 R1 R2 RESET LOGIC + TIMER RESET R3 GND 1.25V R4 FUNCTIONAL BLOCK DIAGRAMS ADM13305-18 ADM13305-25 ADM13305-33 SENSE2 APPLICATIONS Supervising DSPs/microcontrollers Industrial and portable equipment Wireless systems Notebook/desktop computers WDI OSCILLATOR WATCHDOG LOGIC + TIMER Figure 1. GENERAL DESCRIPTION The ADM13305 is a dual voltage supervisor designed to monitor two supplies and provide a reset signal to DSP and microprocessor-based systems. There are five models available, all of which feature a combination of internally pretrimmed undervoltage threshold options for monitoring 1.8 V, 2.5 V, 3.3 V, and 5 V supplies. There is also an adjustable input option with an undervoltage threshold voltage of 0.6 V. The ADM13305-18, ADM13305-25, and ADM13305-33 models have two internally fixed thresholds. The ADM13305-4 and ADM13305-5 offer one internally fixed threshold and one externally programmable threshold via a resistor string. See the Ordering Guide for a list of all available options. During p...