ANALOG DEVICES ADM13305 Service Manual

Dual Processor

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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 V
Push-pull RESET and
8-lead, narrow body SOIC package
Temperature range: −40°C to +85°C

APPLICATIONS

Supervising DSPs/microcontrollers
Industrial and portable equipment
Wireless systems
Notebook/desktop computers

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 power-up,
exceeds 1.1 V. The device then monitors the SENSEv input pins
and holds the
inputs remains below the rising threshold voltage, V

Once the supplies monitored at the SENSEv inputs rise above
their associated thresholds, the reset signal remains low for
the reset timeout period before deasserting. Subsequently, if a
voltage monitored by the SENSEv pins falls below its associ­ated falling threshold, V
ADM13305 features both an active high RESET and an active

RESET

low

output.

≥ 1.1 V

DD

RESET

outputs

RESET

is asserted when the supply voltage

RESET

output low as long as either of the SENSEv

RESET

IT−

, the

output asserts. The

IT+

.

Supervisors with Watchdog

ADM13305

FUNCTIONAL BLOCK DIAGRAMS

ADM13305-18

V

DD

14kΩ

MR

SENSE1

SENSE2

GND

SENSE1

GND

SENSE2

WDI

V

MR

WDI

R1

R2

R3

DD

R1

TRANSITIO N

DETECTIO N

14kΩ

R2

TRANSITIO N

DETECTIO N

R4

1.25V

0.6V

WATCHDOG

LOGIC + TIMER

Figure 1.

WATCHDOG

LOGIC + TIMER

Figure 2. .

As well as providing power-on reset signals, an on-chip watchdog
timer can reset the microprocessor if it fails to strobe within the
preset timeout period. A reset signal can also be asserted by an
external push button through the manual reset input pin.

The ADM13305 is available in an 8-lead, narrow body SOIC
package. The device operates over the extended industrial
temperature range of −40°C to +85°C.

ADM13305-25
ADM13305-33

RESET

LOGIC + TIMER

OSCILLATOR

ADM13305-4
ADM13305-5

RESET

LOGIC + TIMER

OSCILLATOR

RESET

RESET

RESET

RESET

06922-002

06922-001

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2007 Analog Devices, Inc. All rights reserved.

ADM13305

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TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1 

General Description ......................................................................... 1

Functional Block Diagrams ............................................................. 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Timing Requirements .................................................................. 5

Switching Characteristics ............................................................ 5

Functional Truth Table ................................................................ 5

Absolute Maximum Ratings ............................................................ 6

Thermal Resistance ...................................................................... 6

REVISION HISTORY

8/07—Revision 0: Initial Version

ESD Caution...................................................................................6

Pin Configuration and Function Descriptions ..............................7

Typical Performance Characteristics ..............................................8

Theory of Operation ...................................................................... 10

Input Configuration ................................................................... 10

Reset Output ............................................................................... 10

Watchdog Timer ......................................................................... 10

Manual Reset (MR) .................................................................... 11

Outline Dimensions ....................................................................... 12

Ordering Guide .......................................................................... 12

Rev. 0 | Page 2 of 12

ADM13305

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SPECIFICATIONS

VDD = 2.7 V to 5.5 V, −40°C ≤ TA ≤ +85°C, unless otherwise noted.

Table 1. ADM13305-18, ADM13305-25, and ADM13305-33

Parameter Min Typ Max Unit Test Conditions/Comments

OPERATING VOLTAGE RANGE, VDD 2.7 5.5 V
SUPPLY CURRENT, IDD 40 µA
INPUT CAPACITANCE, CI 10 pF VI = 0 V to VDD
RESET, RESET OUTPUT

High Level Output Voltage, VOH V
V
V
Low Level Output Voltage, VOL 0.2 V IOL = 20 µA

0.4 V IOL = 2 mA, VDD = 3.3 V

0.4 V IOL = 3 mA, VDD = 5.5 V
Power-Up Reset Voltage

1

SENSE INPUTS

Falling Threshold Voltage, V

1.64 1.68 1.72 V TA = 0°C to 85°C

IT−

2.20 2.25 2.30 V TA = 0°C to 85°C

2.86 2.93 3.00 V TA = 0°C to 85°C

4.46 4.55 4.64 V TA = 0°C to 85°C

1.64 1.68 1.73 V TA = −40°C to +85°C

2.20 2.25 2.32 V TA = −40°C to +85°C

2.86 2.93 3.02 V TA = −40°C to +85°C

4.46 4.55 4.67 V TA = −40°C to +85°C
Hysteresis at SENSEv Inputs, V

15 mV V

HYS

20 mV V
30 mV V
40 mV V

WDI

Average High Level Input Current, I
Average Low Level Input Current, I

100 150 µA WDI = VDD = 5.5 V

H(AV)

−15 −20 µA WDI = 0 V, VDD = 5.5 V

L(AV)

INPUT VOLTAGE AT MR AND WDI

High Level, VIH 0.7 × VDD V

Low Level, VIL 0.3 × VDD V
INPUT TRANSITION RISE AND FALL RATE AT MR

HIGH LEVEL INPUT CURRENT, IH

WDI 120 170 µA WDI = VDD = 5.5 V

MR

SENSE1 5 8 µA SENSE1 = VDD = 5.5 V

SENSE2 6 9 µA SENSE2 = VDD = 5.5 V
LOW LEVEL INPUT CURRENT, IL

WDI −120 −170 µA WDI = 0 V, VDD = 5.5 V

MR

SENSEv −1 +1 µA SENSE1, SENSE2 = 0 V

1

The lowest supply voltage at which

RESET

becomes active. t

− 0.2 V IOH = −20 µA

DD

− 0.4 V IOH = −2 mA, VDD = 3.3 V

DD

− 0.4 V IOH = −3 mA, VDD = 5.5 V

DD

0.4 V IOL = 20 µA, VDD ≥ 1.1 V

= 1.68 V

IT−

= 2.25 V

IT−

= 2.93 V

IT−

= 4.55 V

IT−

50 ns/V

−130 −180 µA

−430 −600 µA

, VDD ≥ 15 s/V.

r

= 0.7 × VDD, VDD = 5.5 V

MR

= 0 V, VDD = 5.5 V

MR

Rev. 0 | Page 3 of 12

ADM13305

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VDD = 2.7 V to 5.5 V, −40°C ≤ TA ≤ +85°C, unless otherwise noted.

Table 2. ADM13305-4 and ADM13305-5

Parameter Min Typ Max Unit Test Conditions/Comments

OPERATING VOLTAGE RANGE, VDD 2.7 5.5 V
SUPPLY CURRENT, IDD 40 µA
INPUT CAPACITANCE, CI 10 pF VI = 0 V to VDD
RESET, RESET OUTPUT

High-Level Output Voltage, VOH V
V
V
Low-Level Output Voltage, VOL 0.2 V IOH = 20 µA

0.4 V IOH = 2 mA, VDD = 3.3 V

0.4 V IOH = 3 mA, VDD = 5.5 V
Power-Up Reset Voltage

1

SENSEv INPUTS

Falling Input Threshold Voltage, V

0.5952 0.6 0.6048 V TA = −40°C to +85°C

IT−

2.23 2.25 2.29 V TA = −40°C to +85°C

2.90 2.93 2.98 V TA = −40°C to +85°C
Hysteresis at SENSEv Inputs, V

0 mV V

HYS

20 mV V
30 mV V

WDI

Average High Level Input Current, I
Average Low Level Input Current, I

100 150 µA WDI = VDD = 5.5 V

H(AV)

−15 −20 µA WDI = 0 V, VDD = 5.5 V

L(AV)

INPUT VOLTAGE AT MR AND WDI

High Level, VIH 0.7 × VDD V

Low Level, VIL 0.3 × VDD V
INPUT TRANSITION RISE AND FALL RATE AT MR

HIGH LEVEL INPUT CURRENT, IH

WDI 120 170 µA WDI = VDD = 5.5 V

MR

SENSE1 5 8 µA SENSE1 = VDD = 5.5 V

SENSE2 −50 +50 nA SENSE2 = VDD = 5.5 V
LOW LEVEL INPUT CURRENT, IL

WDI −120 −170 µA WDI = 0 V, VDD = 5.5 V

MR

SENSEv −1 +1 µA SENSE1, SENSE2 = 0 V

1

The lowest supply voltage at which

RESET

becomes active. tr, VDD ≥ 15 µs/V.

− 0.2 V IOH = −20 µA

DD

− 0.4 V IOH = −2 mA, VDD = 3.3 V

DD

− 0.4 V IOH = −3 mA, VDD = 5.5 V

DD

0.4 V IOH = 20 µA, VDD ≥ 1.1 V

= 0.6 V

IT−

= 2.25 V

IT−

= 2.93 V

IT−

50 ns/V

−130 −180 µA

−430 −600 µA

= 0.7 × VDD, VDD = 5.5 V

MR

= 0 V, VDD = 5.5 V

MR

Rev. 0 | Page 4 of 12