Features: ` Edge triggered manual reset input
` single pulse output
` 49S minimum MR disable period after reset
` CMOS/TTL logic or switch interface
` Debounced input
` Low supply current extends battery life
`4.5A / 10A typ/max at 3.6V
` Long reset period
` 0.8 sec minimum, 2 sec maximum
` Two reset polarity options
` ASM161: Active LOW, open-drain
` ASM162: Active HIGH
` Pinout matches the AS811/812
` Small 4-Pin SOT-143 package
` Two temperature ranges: 0 °to 70 and -40 to +85Application· PDAs
· Appliances
· Computers and embedded controllers
· Wireless communication systems
· Battery operated and intelligent instruments
· Automotive systems
· Safety systems
Specifications
| Parameter |
Min |
Max |
Unit |
| Pin Terminal Voltage with respect to Ground |
|
|
|
| VCC |
-0.3 |
6.0 |
V |
| RESET, RESET and MR |
-0.5 |
VCC + 0.3 |
V |
| Input Current at VCC and MR |
|
20 |
mA |
| Rate of Rise at VCC |
|
100 |
V/s |
| Power Dissipation (TA = 70°C) |
|
320 |
mW |
| Operating Temperature Range |
-40 |
85 |
°C |
| Storage Temperature Range |
-65 |
160 |
°C |
| Lead Temperature (soldering, 10 sec) |
|
300 |
°C |
DescriptionThe ASM161 and ASM162 are cost effective, low power supervisory circuits that monitor power supplies in microprocessor, microcontroller and digital systems. If the power supply drops of ASM161 below the reset threshold level, a reset is asserted and remains asserted for atleast 800ms after VCChas risen above the reset threshold. An improved manual reset architecture gives the system designer additional flexibility.
The debounced manual reset input is negative edge triggered.The reset pulse period generated by a MR transition is a minimum of 800 ms and a maximum of 2 sec duration. In addition, The MR input signal is blocked for an additional 49S minimum after the reset pulse ends. During the MR disable period, the microcontroller is guaranteed a time period free of additional manual reset signals. During this period DRAM contents can be refreshed or other critical system tasks undertaken. Low power consumption makes the ASM161/162 ideal for use in portable and battery operated equipments. With 3V supplies power consumption is 8W typically and 30W maximum. The ASM161 has an open-drain, active-LOW RESET output and requires an external pull-up resistor. The ASM162 has an active HIGH RESET output.
The ASM161/162 are offered in compact 4-pin SOT-143 packages. No external components are required to trim threshold voltage for monitoring different supply voltages. With six different factory set, reset, threshold ranges from 2.63V to 4.63V, the ASM161/162 are suitable for monitoring 5V, 3.6V and 3.0V supplies. The ASM161/162 are available in temperature ranges 0 °to 70 and -40 to +85.
ASM161 Data Sheet
