ANALOG DEVICES ADM6348 Service Manual

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

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rights of third parties that may result from its use. Specifications subject to change without notice. No
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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