AS1910 - AS1915

Dual-Voltage Microprocessor Supervisory Circuits

with Reset and Watchdog

Product Brief

© 1997-2005, austriamicrosystems AG, 8141 Unterpremstaetten, Austria-Europe. All Rights Reserved.

www.austriamicrosystems.com

Revision 0.3

1 - 2

1 General Description

The AS1910 - AS1915 microprocessor supervisory cir-

cuits were designed to generate a reset when one of the

two monitored supply voltages falls below a factory-

trimmed threshold, and to maintain the reset for a mini-

mum timeout period when both supplies are above their

reset thresholds. Guaranteed to be in the correct state

multiple-voltage systems with strict monitoring require-

ments.

The AS1913/AS1914/AS1915 feature factory-trimmed

thresholds to monitor a primary voltage between 1.8 and

3.6V, and a secondary voltage between 0.9 and 2.5V.

For the AS1910/AS1911/AS1912, a secondary monitor-

ing voltage can be user-adjusted via an external resistor

divider down to 0.6V.

The devices are available with the reset output types

listed in Table 1.

The AS1910 - AS1915 include a manual-reset input for

systems that never fully power down the microproces-

sor. Additionally, these devices feature a watchdog timer

to help ensure that the processor is operating within

proper code boundaries.

The AS1910 - AS1915 are available in a 6-pin SOT23

package.

Figure 1. Typical Application Diagram

2 Key Features

!

!

(AS1913/AS1914/AS1915)

!

User-Adjustable Threshold Down to +0.63V

(AS1910/AS1911/AS1912)

!

!

Reset Timeout Delay: 215ms

!

Manual Reset Input

!

Three Reset Output Types

- Active-High Push/Pull

- Active-Low Push/Pull

- Active-Low Open-Drain

!

Watchdog Timeout Period: 1.5s

!

!

External Components Not Required

!

6-pin SOT23 Package

3 Applications

The devices are ideal for portable and battery-powered

systems, embedded controllers, intelligent instruments,

automotive systems, critical CPU monitoring, and any

multi-supply application.

Table 1. Standard Products

Model

Reset Output Type

AS1910/AS1913

Active-Low Push/Pull

AS1911/AS1914

Active-High Push/Pull

AS1912/AS1915

Active-Low Open-Drain

External

Reset

CPU

Core

Supply

I/O Supply

GND

RESETN

I/O

4

WDI

6

3

MRN

GND 2

1

RESETN

5

AS1913/

AS1915