Datasheet ADM6348 Datasheet (ANALOG DEVICES)

Ultralow Power, 3-Lead, SOT-23

ADM6326/ADM6328/ADM6346/ADM6348

FEATURES

Ultralow supply current of 1 μA maximum (ADM6326/ADM6328)
Accurate monitoring of 2.5 V, 3 V, 3.3 V, and 5 V rails
Reset thresholds available in increments from 2.2 V to 4.63 V
Glitch immunity from negative-going V

transients

CC

2 reset output options

Push-pull
Open-drain

RESET

(ADM6326/ADM6346)

RESET

(ADM6328/ADM6348)
Minimum reset timeout of 100 ms
Operating temperature range of −40°C to +85°C
3-lead SOT-23 package

APPLICATIONS

Telecommunications
Microprocessor systems
Desktop and notebook computers
Portable equipment

GENERAL DESCRIPTION

The ADM6326/ADM6328/ADM6346/ADM6348 devices provide
low cost solutions for protecting sensitive circuitry, such as micro­processor and telecommunications circuitry.

With built-in glitch immunity, ultralow supply currents, and
24 reset threshold voltage options, the ADM6326/ADM6328/
ADM6346/ADM6348 not only ensure that systems are immune
to fast transients on V
for monitoring a variety of supply voltages in low power,
portable equipment.

These devices provide a reset output during power-up, power­down, and brownout conditions. On power-up, an internal
timer holds

RESET

, but also that the devices are suitable

CC

asserted for at least 100 ms. This holds the

Microprocessor Reset Circuits

FUNCTIONAL BLOCK DIAGRAMS

ADM6326/ADM6346

V

CC

V

REF

ADM6328/ADM6348

V

CC

V

REF

microprocessor in a reset state until conditions have stabilized.
The reset output remains operational with V

The ADM6326 and ADM6346 have an active low push-pull reset
output. The ADM6328 and ADM6348 have an active low open­drain reset output, which requires an external pull-up resistor.
The ADM6326 and ADM6328 offer a choice of ten reset thresholds
in increments between 2.2 V and 3.08 V, whereas the ADM6346
and ADM6348 offer a choice of 14 reset thresholds between 3.3 V
and 4.63 V.

These devices are available in a 3-lead SOT-23 package and
operate over the extended temperature range of −40°C to +85°C.

GND

Figure 1.

GND

Figure 2.

RESET

GENERATOR

(100ms)

RESET

GENERATOR

(100ms)

as low as 1 V.

CC

RESET

RESET

08052-001

08052-002

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] ©2009 Analog Devices, Inc. All rights reserved.

ADM6326/ADM6328/ADM6346/ADM6348

TABLE OF CONTENTS

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

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

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

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

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

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

Absolute Maximum Ratings ............................................................ 4

Thermal Resistance ...................................................................... 4

ESD Caution .................................................................................. 4

REVISION HISTORY

9/09—Revision 0: Initial Version

Pin Configuration and Function Descriptions ..............................5

Typical Performance Characteristics ..............................................6

Theory of Operation .........................................................................7

Reset Output ..................................................................................7

Interfacing to Other Devices .......................................................7

Transient Immunity ......................................................................7

Outline Dimensions ..........................................................................8

Ordering Guide .............................................................................9

Rev. 0 | Page 2 of 12

ADM6326/ADM6328/ADM6346/ADM6348

SPECIFICATIONS

TA = −40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C and VCC = 3 V. Overtemperature limits are guaranteed by design.

Table 1.

Parameter Min Typ Max Unit Test Conditions/Comments

OPERATING VOLTAGE RANGE, VCC 1.0 5.5 V
INPUT CURRENT, ICC 0.5 1.0 µA ADM6326/ADM6328 only, VCC = 3.0 V for VTH ≤

2.93 V, V

1.0 1.75 µA VCC = 5.5 V, no load
RESET THRESHOLD

Threshold Voltage, VTH (See Table 2) VTH − 2.5% VTH V
V

− 1.5% VTH V

TH

Temperature Coefficient 40 ppm/°C

+ 2.5% V

TH

+ 1.5% V TA = 25°C

TH

Hysteresis

ADM6326/ADM6328 6.3 mV
ADM6346/ADM6348 9.5 mV

TIMING CHARACTERISTICS

VCC to Reset Delay (tRD) 20 µs VCC = VTH to (VTH − 100 mV)
Reset Active Timeout Period (tRP) 100 185 280 ms

RESET

OUTPUT VOLTAGE LOW, VOL

RESET

OUTPUT VOLTAGE HIGH, VOH

0.3 V V

0.4 V V

0.8 × V

CC

V ADM6326 only, VCC = 3.2 V, I

0.8 × VCC V ADM6326/ADM6346 only, VCC = 4.5 V,
I

0.8 × VCC V ADM6326/ADM6346 only, VCC = V
I

OPEN-DRAIN

RESET

OUTPUT LEAKAGE CURRENT

0.1 µA

= 3.2 V for VTH > 2.93 V, no load

CC

> 2.1 V, I

CC

≥ 1.2 V, I

CC

= 800 µA, VTH ≤ 4.38 V

SOURCE

= 800 µA, VTH ≥ 4.5 V

SOURCE

= 1.6 mA, reset asserted

SINK

= 100 A, reset asserted

SINK

SOURCE

= 500 µA

TH(MAX)

,

Table 2. Reset Threshold Voltage

Parameter

Min Typ Max Min Max

= 25°C

T

A

RESET THRESHOLD VOLTAGE (VTH)

ADM632x-22 2.167 2.2 2.233 2.145 2.25 V
ADM632x-23 2.285 2.32 2.355 2.262 2.375 V
ADM632x-24 2.364 2.4 2.436 2.34 2.46 V
ADM632x-25 2.462 2.5 2.537 2.437 2.562 V
ADM632x-26 2.591 2.63 2.669 2.564 2.696 V
ADM632x-27 2.66 2.7 2.741 2.633 2.768 V
ADM632x-28 2.758 2.8 2.842 2.73 2.87 V
ADM632x-29 2.886 2.93 2.974 2.857 3.0 V
ADM632x-30 2.955 3.00 3.045 2.925 3.075 V
ADM632x-31 3.034 3.08 3.126 3.003 3.15 V
ADM634x-33 3.25 3.3 3.35 3.217 3.383 V
ADM634x-34 3.349 3.4 3.451 3.315 3.485 V
ADM634x-35 3.447 3.5 3.552 3.412 3.587 V
ADM634x-36 3.546 3.6 3.654 3.51 3.69 V
ADM634x-37 3.644 3.7 3.755 3.607 3.792 V
ADM634x-38 3.743 3.8 3.857 3.705 3.895 V
ADM634x-39 3.841 3.9 3.958 3.802 3.997 V
ADM634x-40 3.94 4.0 4.06 3.9 4.1 V
ADM634x-41 4.038 4.1 4.161 3.997 4.202 V
ADM634x-42 4.137 4.2 4.263 4.095 4.305 V
ADM634x-43 4.235 4.3 4.364 4.192 4.407 V
ADM634x-44 4.314 4.38 4.446 4.27 4.489 V
ADM634x-45 4.432 4.5 4.567 4.387 4.612 V
ADM634x-46 4.56 4.63 4.699 4.514 4.746 V

T

= −40°C to +85°C

A

Unit

Rev. 0 | Page 3 of 12

ADM6326/ADM6328/ADM6346/ADM6348

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating
Supply Voltage, VCC −0.3 V to +6 V
Input Current, ICC 20 mA
Output Voltage

Push-Pull
Open-Drain

Output Current (
Rate of Rise of VCC
Temperature

Storage −65°C to +155°C
Operating −40°C to +85°C
Soldering (10 sec) 300°C

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

RESET

RESET

RESET

)

−0.3 V to (VCC + 0.3 V)

−0.3 V to +6 V
20 mA

100 V/μs

THERMAL RESISTANCE

θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.

Table 4. Thermal Resistance

Package Type θJA Unit
3-Lead SOT-23 270 °C/W

ESD CAUTION

Rev. 0 | Page 4 of 12

ADM6326/ADM6328/ADM6346/ADM6348

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

ADM6326/

GND

1

ADM6328/

2

RESET

Figure 3. ADM6326/ADM6328/ADM6346/ADM6348 Pin Configuration

Table 5. Pin Function Descriptions

Pin No. Mnemonic Description

1 GND Ground Reference for All Signals; 0 V.
2

RESET

Active Low Logic Output. This pin is low when VCC is less than the reset threshold; it remains low for 185 ms
(typical) after V

becomes greater than the reset threshold.

CC

3 VCC Supply Voltage Being Monitored.

ADM6346/

ADM6348

TOP VIEW

(Not to Scale)

V

3

CC

08052-003

Rev. 0 | Page 5 of 12

ADM6326/ADM6328/ADM6346/ADM6348

(

A

A

(

TYPICAL PERFORMANCE CHARACTERISTICS

1.0

0.9
= 5V

0.8

0.7

µA)

0.6

0.5

0.4

0.3

SUPPLY CURRENT

0.2

0.1

0

–40 –20 0 20 40 60 80

V

CC

VCC = 3.3V

VCC = 1.4V

TEMPERAT URE (°C)

Figure 4. Supply Current vs. Temperature

08052-004

280

260

240

220

200

180

160

140

POWER-UP RES ET TIME OUT (ms)

120

100

–40 –20 0 20 40 60 80

TEMPERATURE (°C)

Figure 6. Power-Up Reset Timeout vs. Temperature

08052-007

800

700

600

TION (µs)

500

400

300

200

MAXIMUM TRANSIENT DUR

100

0

1 10 100 1000

RESET THRESHOLD OVERDRI VE, VTH – VCC (mV)

Figure 5. Maximum Transient Duration vs. Reset Threshold Overdrive

250

200

µs)
Y

150

100

VOD = 10mV

= 20mV

V

OD

50

POWER-DOWN RESET DEL

0

–40 –20 0 20 40 8060

08052-006

V

= 200mV

OD

TEMPERATURE (°C)

V

OD

= 100mV

8052-005

Figure 7. Power-Down Reset Delay vs. Temperature

Rev. 0 | Page 6 of 12

ADM6326/ADM6328/ADM6346/ADM6348

V

THEORY OF OPERATION

The ADM6326/ADM6328/ADM6346/ADM6348 are designed
to protect the integrity of a system’s operation by ensuring the
proper operation of the system during power-up, power-down,
and brownout conditions. Ultralow supply currents make these
devices particularly suitable for use in low power, portable
equipment.

RESET OUTPUT

The ADM6326 and ADM6346 have an active low, push-pull
reset output, whereas the ADM6328 and ADM6348 have an
active low, open-drain reset output, which requires an external
pull-up resistor. The

down to 1 V.

V

CC

When the ADM6326/ADM6328/ADM6346/ADM6348 are
powered up, the
equal to the

RESET
allows adequate time for the system to power up correctly and
for the power supply to stabilize before any devices are brought out
of reset and are allowed to begin executing instructions. Initializing
a system in this way provides a more reliable startup for micro-

processor systems.

When the monitored voltage falls below its associated threshold

RESET

(V

),

TH

this quickly means that the entire system can be reset at once
before any part of the system’s voltage falls below its recommended
operating voltage. This system reset can avoid dangerous and/or
erroneous operation of a microprocessor based system.

RESET

signal is guaranteed to be valid for

RESET

output remains low for a period typically

active timeout period of 185 ms. This feature

is asserted within 20 μs (typical). Asserting

RESET

INTERFACING TO OTHER DEVICES

The active low, open-drain reset output of the ADM6328 and
ADM6348 makes these devices ideal for integration with devices
such as microprocessors with bidirectional reset pins. Simply
connect the

RESET

the

RESET

output of the ADM6328 or ADM6348 to

input of the microprocessor using a single pull-up

resistor to allow either device to initiate a system reset (see

). Figure 8

CC

V

CC

ADM6328/ADM6348

RESET

GND

Figure 8. Interfacing to a Microprocessor with a Bidirectional Reset Pin

R

PULL-UP

RESET
INPUT

V

CC

MICROPROCESSOR

SYSTEM

GND

TRANSIENT IMMUNITY

To avoid unnecessary resets caused by fast power supply transients,
the ADM6326/ADM6328/ADM6346/ADM6348 provide glitch
immunity from negative-going V

Figure 5 shows the

RESET

comparator overdrive (that is, the
maximum magnitude of negative-going pulses with respect to
the typical threshold) vs. the pulse duration without a reset.

transients.

CC

08052-008

V

CC

RESET

V

CC

1V
0V

V

CC

0V

V

TH

t

RP

RESET

Figure 9.

Timing

V

TH

t

RD

8052-009

Rev. 0 | Page 7 of 12

ADM6326/ADM6328/ADM6346/ADM6348

OUTLINE DIMENSIONS

3.04

2.90

2.80

1.40

1.30

1.20

3

1

2.64

2.10

2

1.02

0.95

0.88

0.100

0.013

SEATING

PLANE

0.60

0.45

2.05

1.78

COMPLIANT TO JEDEC STANDARDS TO-236-AB

1.03

0.89

0.51

0.37

1.12

0.89

GAUGE

PLANE

0.180

0.085

0.25

0.54

REF

0.60 MAX

0.30 MIN

011909-C

Figure 10. 3-Lead Small Outline Transistor Package [SOT-23-3]

(RT-3)

Dimensions shown in millimeters

Rev. 0 | Page 8 of 12

ADM6326/ADM6328/ADM6346/ADM6348

ORDERING GUIDE

1

Model

ADM6326-22ARTZ-R7
ADM6326-23ARTZ-R7
ADM6326-24ARTZ-R7
ADM6326-25ARTZ-R7
ADM6326-26ARTZ-R7
ADM6326-27ARTZ-R7
ADM6326-28ARTZ-R7
ADM6326-29ARTZ-R7
ADM6326-30ARTZ-R7
ADM6326-31ARTZ-R7
ADM6328-22ARTZ-R7
ADM6328-23ARTZ-R7
ADM6328-24ARTZ-R7
ADM6328-25ARTZ-R7
ADM6328-26ARTZ-R7
ADM6328-27ARTZ-R7
ADM6328-28ARTZ-R7
ADM6328-29ARTZ-R7
ADM6328-30ARTZ-R7
ADM6328-31ARTZ-R7
ADM6346-33ARTZ-R7
ADM6346-34ARTZ-R7
ADM6346-35ARTZ-R7
ADM6346-36ARTZ-R7
ADM6346-37ARTZ-R7
ADM6346-38ARTZ-R7
ADM6346-39ARTZ-R7
ADM6346-40ARTZ-R7
ADM6346-41ARTZ-R7
ADM6346-42ARTZ-R7
ADM6346-43ARTZ-R7
ADM6346-44ARTZ-R7
ADM6346-45ARTZ-R7
ADM6346-46ARTZ-R7
ADM6348-33ARTZ-R7
ADM6348-34ARTZ-R7
ADM6348-35ARTZ-R7
ADM6348-36ARTZ-R7
ADM6348-37ARTZ-R7
ADM6348-38ARTZ-R7
ADM6348-39ARTZ-R7
ADM6348-40ARTZ-R7
ADM6348-41ARTZ-R7
ADM6348-42ARTZ-R7
ADM6348-43ARTZ-R7
ADM6348-44ARTZ-R7
ADM6348-45ARTZ-R7
ADM6348-46ARTZ-R7

1

Contact sales for the availability of nonstandard models.

2

Z = RoHS Compliant Part.

3

Standard model.

`

2, 3

2

2.32 V Push-Pull 3-Lead SOT-23 RT-3 LAR

2

2.4 V Push-Pull 3-Lead SOT-23 RT-3 LAS

2

2.5 V Push-Pull 3-Lead SOT-23 RT-3 LAT

2

2.63 V Push-Pull 3-Lead SOT-23 RT-3 LAU

2

2.7 V Push-Pull 3-Lead SOT-23 RT-3 LAV

2

2.8 V Push-Pull 3-Lead SOT-23 RT-3 LAW

2

2.93 V Push-Pull 3-Lead SOT-23 RT-3 LAX

2

3.0 V Push-Pull 3-Lead SOT-23 RT-3 LAY

2

3.08 V Push-Pull 3-Lead SOT-23 RT-3 LAZ

2

2.2 V Open-Drain 3-Lead SOT-23 RT-3 LB0

2

2.32 V Open-Drain 3-Lead SOT-23 RT-3 LB1

2

2.4 V Open-Drain 3-Lead SOT-23 RT-3 LB2

2

2.5 V Open-Drain 3-Lead SOT-23 RT-3 LB3

2

2.63 V Open-Drain 3-Lead SOT-23 RT-3 LB4

2

2.7 V Open-Drain 3-Lead SOT-23 RT-3 LB5

2, 3

2

2.93 V Open-Drain 3-Lead SOT-23 RT-3 LB7

2

3.0 V Open-Drain 3-Lead SOT-23 RT-3 LB8

2

3.08 V Open-Drain 3-Lead SOT-23 RT-3 LB9

2, 3

2

3.4 V Push-Pull 3-Lead SOT-23 RT-3 LBC

2

3.5 V Push-Pull 3-Lead SOT-23 RT-3 LBD

2

3.6 V Push-Pull 3-Lead SOT-23 RT-3 LBE

2

3.7 V Push-Pull 3-Lead SOT-23 RT-3 LBF

2

3.8 V Push-Pull 3-Lead SOT-23 RT-3 LBG

2

3.9 V Push-Pull 3-Lead SOT-23 RT-3 LBH

2

3.0 V Push-Pull 3-Lead SOT-23 RT-3 LCN

2

4.1 V Push-Pull 3-Lead SOT-23 RT-3 LCP

2

4.2 V Push-Pull 3-Lead SOT-23 RT-3 LCQ

2

4.3 V Push-Pull 3-Lead SOT-23 RT-3 LCR

2

4.38 V Push-Pull 3-Lead SOT-23 RT-3 LCS

2

4.5 V Push-Pull 3-Lead SOT-23 RT-3 LCT

2

4.63 V Push-Pull 3-Lead SOT-23 RT-3 LCU

2

3.3 V Open-Drain 3-Lead SOT-23 RT-3 LCV

2

3.4 V Open-Drain 3-Lead SOT-23 RT-3 LCW

2

3.5 V Open-Drain 3-Lead SOT-23 RT-3 LCX

2

3.6 V Open-Drain 3-Lead SOT-23 RT-3 LCY

2

3.7 V Open-Drain 3-Lead SOT-23 RT-3 LCZ

2

3.8 V Open-Drain 3-Lead SOT-23 RT-3 LD0

2

3.9 V Open-Drain 3-Lead SOT-23 RT-3 LD1

2

3.0 V Open-Drain 3-Lead SOT-23 RT-3 LD2

2

4.1 V Open-Drain 3-Lead SOT-23 RT-3 LD3

2

4.2 V Open-Drain 3-Lead SOT-23 RT-3 LD4

2

4.3 V Open-Drain 3-Lead SOT-23 RT-3 LD5

2

4.38 V Open-Drain 3-Lead SOT-23 RT-3 LD6

2

4.5 V Open-Drain 3-Lead SOT-23 RT-3 LD7

2, 3

Typ ica l Th res hol d
Voltage (T

2.2 V Push-Pull 3-Lead SOT-23 RT-3 LAQ

2.8 V Open-Drain 3-Lead SOT-23 RT-3 LB6

3.3 V Push-Pull 3-Lead SOT-23 RT-3 LBA

4.63 V Open-Drain 3-Lead SOT-23 RT-3 LD8

= 25°C)

A

RESET

Output

Structure Package Description Package Option Branding

Rev. 0 | Page 9 of 12

ADM6326/ADM6328/ADM6346/ADM6348

NOTES

Rev. 0 | Page 10 of 12

ADM6326/ADM6328/ADM6346/ADM6348

NOTES

Rev. 0 | Page 11 of 12

ADM6326/ADM6328/ADM6346/ADM6348

NOTES

©2009 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D08052-0-9/09(0)

Rev. 0 | Page 12 of 12