Overview
The ADM1232ARN-REEL, produced by Analog Devices Inc., is a microprocessor supervisory circuit designed to monitor and protect microprocessor systems. It is pin-compatible with the MAX1232, DS1232LP, and DS1232, making it a versatile option for various applications. This component can monitor the microprocessor supply voltage, detect if the microprocessor has locked up, and handle external interrupts. The ADM1232 is available in several package options, including an 8-lead MSOP (RM-8), 8-lead PDIP (N-8), 16-lead wide SOIC (RW-16), and 8-lead narrow SOIC (R-8).
Key Specifications
| Parameter | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|
| Temperature Range | −40 | +85 | °C | TA = TMIN to TMAX | |
| Power Supply Voltage | 4.5 | 5.0 | 5.5 | V | VCC = full operating range |
| Power Supply Current (CMOS levels) | 20 | 50 | 500 | μA | VIL, VIH = CMOS levels |
| Power Supply Current (TTL levels) | 200 | 500 | μA | VIL, VIH = TTL levels | |
| STROBE and PB RESET Input High Level | 2.0 | VCC + 0.3 | V | ||
| STROBE and PB RESET Input Low Level | −0.3 | +0.8 | V | ||
| Input Leakage Current (STROBE, TOLERANCE) | −1.0 | +1.0 | μA | ||
| PB RESET Time | 20 | ms | PB RESET must be held low for a minimum of 20 ms to guarantee a reset | ||
| RESET Active Time | 250 | 610 | 1000 | ms | |
| STROBE Pulse Width | 20 | ns | |||
| STROBE Timeout Period | 62.5 | 150 | 250 | ms | TD = 0 V |
| VCC Fall Time | 10 | μs | Guaranteed by design | ||
| VCC Rise Time | 0 | μs | Guaranteed by design | ||
| VCC Fail Detect to RESET Output Delay | 50 | μs | After VCC falls below the set tolerance voltage |
Key Features
- Pin-compatible with MAX1232 and Dallas DS1232, DS1232LP
- Adjustable precision voltage monitor with 4.5 V and 4.75 V options
- Adjustable strobe monitor with 150 ms, 600 ms, or 1.2 sec options
- No external components required
- Specified from −40°C to +85°C
- Push-button reset input with debouncing to ignore pulses less than 1 ms
- Time delay set input to select the maximum time for STROBE input inactivity
- Tolerance input to set the supply voltage tolerance (5% or 10%) before a RESET is asserted
- Active high logic output for RESET and open drain, active low logic output for RESET
Applications
- Microprocessor systems
- Portable equipment
- Computers
- Controllers and intelligent instruments
- Automotive systems
Q & A
- What is the ADM1232ARN-REEL used for?
The ADM1232ARN-REEL is used as a microprocessor supervisory circuit to monitor and protect microprocessor systems by checking the supply voltage, detecting microprocessor lock-up, and handling external interrupts.
- What are the package options available for the ADM1232?
The ADM1232 is available in several package options: 8-lead MSOP (RM-8), 8-lead PDIP (N-8), 16-lead wide SOIC (RW-16), and 8-lead narrow SOIC (R-8).
- How does the tolerance input work on the ADM1232?
The tolerance input determines how much the supply voltage can decrease before a RESET is asserted. Connecting this pin to VCC sets a 10% tolerance, while connecting it to GND sets a 5% tolerance.
- What is the purpose of the PB RESET input?
The PB RESET input is a push-button reset input that ignores pulses less than 1 ms and guarantees a reset if held low for more than 20 ms.
- How does the STROBE timeout selection work?
The STROBE timeout period can be selected using the TD input, allowing the user to set the maximum time the STROBE input can remain inactive before a RESET pulse is generated.
- What are the temperature specifications for the ADM1232?
The ADM1232 is specified to operate from −40°C to +85°C.
- Does the ADM1232 require any external components?
No, the ADM1232 does not require any external components.
- What are the typical applications of the ADM1232?
The ADM1232 is typically used in microprocessor systems, portable equipment, computers, controllers, intelligent instruments, and automotive systems.
- How does the RESET output work on the ADM1232?
The RESET output is an active high logic output that is asserted when the supply voltage drops below the set tolerance, when the PB RESET is forced low, or when there are no high-to-low transitions within the set STROBE timeout period.
- Is the ADM1232 pin-compatible with other supervisory circuits?
Yes, the ADM1232 is pin-compatible with the MAX1232 and Dallas DS1232, DS1232LP.
