feature

Pin compatible with MAX1232 and Dallas DS1232; 4.5V adjustable precision voltage monitor; 4.75 V option; 150 ms, 600 ms or; 1.2 second option; no external components; specified from -40°C to +85°C.

application

Microprocessor systems; portable devices; computers; controllers; intelligent instrumentation automotive systems.

General Instructions

The ADM1232 is pin compatible with the MAX1232, DS1232LP, and DS1232. The Analog Devices ADM1232 is a microprocessor supervisory circuit that monitors the following:

(1), microprocessor power supply voltage

(2) Whether the microprocessor is locked

(3), external interrupt

The ADM1232 is available in four packages: 8-lead MSOP (RM-8), 8-lead PDIP (N-8), 16-lead wide SOIC (RW-16), and 8-lead narrow SOIC (R-8).

Circuit T information

PB reset

The PB reset input enables manual reset using standard pushbutton switches or a logic low input of the system. The internal demagnetization circuit produces fault immunity when used with the switch, reducing line faults. Disconnecting the circuit will definitely cause the ADM1232 to assert reset for greater than 20 ms if pb reset goes low, guaranteeing to ignore inputs that are low for less than 20 ms for greater than 1 ms.

Gating Timeout Selection

td (time delay) set is used to set the strobe timeout time. This strobe timeout period is the maximum time between high TROW transitions accepted by the gate before being reset. (See Figure 8). The strobe timeout settings are shown in Table 5.

tolerance

The tolerance input is used to determine that VCC can vary below 5 V without requiring the ADM1232 to reset. Connect the tolerance to GND to select a -5% tolerance rating if VCC is below 4.75 V. If the tolerance is tied to VCC, the tolerance is -10% of the level selected, which will cause the ADM1232 to generate a reset. If VCC is below 4.5 V, see the parameters for the VCC trigger point. See the Specifications section for details.

reset and reset output

Reset can source and sink current, whereas reset is an open-drain mosfet that only sinks current. Therefore, it is necessary to pull this output high.

Dimensions