Rainbow Electronics MAX16055 User Manual

General Description

The MAX16055 precision hex voltage microprocessor
(µP) supervisory circuit monitors up to six system-sup­ply voltages and asserts a single reset when any one
supply voltage drops below its preset threshold. The
device significantly reduces system size and compo­nent count while improving reliability compared to multi­ple ICs or discrete components.

A variety of factory-trimmed threshold voltages are avail­able to accommodate different supply voltages and tol­erance with minimal external components. The
MAX16055 includes internally fixed threshold options for
monitoring 3.3V, 3.0V, 2.5V, 1.8V, 1.5V, 1.2V, 1.1V, 1.0V,
and 0.9V supplies with -5% or -10% tolerance. The
MAX16055 is also available with one to five adjustable
threshold inputs to monitor voltages down to 0.5V.

A single active-low, open-drain output asserts when
any monitored input falls below its associated thresh­old. The reset output features a weak internal pullup
(typically 70µA) to supply input IN1. The reset output
remains low for the reset timeout period (140ms, min)
after all voltages rise above the selected thresholds.
The reset output remains valid as long as either IN1 or
IN2 input voltage is above 1V. The MAX16055 is avail­able in a small 10-pin µMAX®(3mm x 3mm) package.
The MAX16055 operates over the -40°C to +125°C
automotive temperature range.

Applications

Features

o Precision Factory-Set Reset Threshold Options

3.3V, 3.0V, 2.5V, 1.8V, 1.5V, 1.2V, 1.1V, 1.0V, and

0.9V

o Adjustable Voltage Threshold Monitors Down to

0.5V with 1.5% Accuracy

o Open-Drain RESET Output with 70µA Internal

Pullup

o Fixed 140ms (min) Reset Timeout Period

o Manual Reset Input

o Reset Valid for IN1 ≥ 1V or IN2 ≥ 1V

o Tolerance Select (5%/10%) Input

o Immune to Short Supply Transients

MAX16055

Ultra-Small, Hex Voltage,

Microprocessor Supervisor

________________________________________________________________

Maxim Integrated Products

1

Pin Configuration

Ordering Information

MAX16055

µP

RESET

V

CC

10kΩ

IN2

MR

GND

TOL

MONITORED

SUPPLIES

IN1

0.1µF

IN3
IN4

IN5
IN6

Typical Operating Circuit

19-4411; Rev 0; 1/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

+

Denotes a lead(Pb)-free/RoHS-compliant package.

*

Insert the desired threshold option letter from the Selector
Guide into the blank to complete the part number. Contact factory
for availability.

PART TEMP RANGE

PIN-PACKAGE

-40°C to +125°C 10 µMAX

Telecommunications

High-End Printers

Desktop and Notebook
Computers

Data Storage Equipment

Networking Equipment

Industrial Equipment

Set-Top Boxes

Servers/Workstations

µMAX is a registered trademark of Maxim Integrated Products, Inc.

MAX16055_AUB+*

TOP VIEW

IN1

1 +

2

3

4

5

MAX16055

µMAX

IN2

IN3

GND

10

RESET

9

MR

8

TOLIN4

7

6

IN6IN5

MAX16055

Ultra-Small, Hex Voltage,
Microprocessor Supervisor

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V

IN1

= 1V to 5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at V

IN1

= 3.3V, TA= +25°C.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

RESET, TOL, MR, IN_ to GND ..................................-0.3V to +6V

Input/Output Current (all pins) ............................................20mA

Continuous Power Dissipation (TA= +70°C)

10-Pin µMAX (derate 5.6mW/°C above +70°C) ...........444mW

Operating Temperature Range .........................-40°C to +125°C

Storage Temperature Range .............................-65°C to +150°C

Junction Temperature......................................................+150°C

Lead Temperature (soldering, 10s) .................................+300°C

Operating Voltage Range V

Input Current (Note 3) I

Threshold Voltage V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT

IN1

IN_

TH

(Note 2) 1.0 5.5 V

V

= nominal input voltage (for IN2–IN6;

IN_

3.3V, 3.0V, 2.5V, 1.8V, 1.5V, 1.2V, 1.1V,

1.0V, 0.9V supplies)

V

= nominal input voltage (for +3.3V IN1

IN1

supply)

V

= 0 to 0.5V or V

IN_

thresholds)

V

decreasing

IN_

(for adjustable

ADJ

3.3V, TOL = GND 3.00 3.08 3.15

3.3V, TOL = V

3.0V, TOL = GND 2.70 2.78 2.85

3.0V , TOL = V

2.5V, TOL = GND 2.25 2.32 2.38

2.5V, TOL = V

1.8V, TOL = GND 1.62 1.67 1.71

1.8V, TOL = V

1.5V, TOL = GND 1.355 1.389 1.425

1.5V, TOL = V

1.2V, TOL = GND 1.084 1.112 1.140

1.2V, TOL = V

1.1V, TOL = GND 0.993 1.019 1.045

1.1V, TOL = V

1.0V, TOL = GND 0.903 0.926 0.95

1.0V, TOL = V

0.9V , TOL = GND 0.813 0.834 0.855

0.9V, TOL = V

25 40

55 115

-0.1 +0.1

IN1

IN1

IN1

IN1

IN1

IN1

IN1

IN1

2.85 2.93 3.00

2.55 2.63 2.70

IN1

2.13 2.19 2.25

1.53 1.58 1.62

1.283 1.316 1.350

1.027 1.053 1.08

0.941 0.965 0.99

0.856 0.878 0.90

0.770 0.790 0.810

µA

V

MAX16055

Ultra-Small, Hex Voltage,

Microprocessor Supervisor

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Note 1: 100% production tested at TA= +25°C. Limits over temperature guaranteed by design.
Note 2: The devices are powered from IN1.
Note 3: Monitored IN1 voltage is also the device power supply.
Note 4: RESET output is guaranteed to be in the correct state for IN1 or IN2 falling down to 1V.

ELECTRICAL CHARACTERISTICS (continued)

(V

IN1

= 1V to 5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at V

IN1

= 3.3V, TA= +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT

Adjustable Threshold V

Reset Threshold Hysteresis V

Reset Threshold Temperature
Coefficient

IN_ to Reset Delay t

Reset Timeout Period t

RESET Output Low (Note 4) V

RESET Output High V

RESET Output High Source

Current

TOL Input Current TOL = IN1 100 nA

MR, TOL Input Voltage Low V

MR, TOL Input Voltage High V

MR Minimum Pulse Width 1µs
MR Glitch Rejection 100 ns
MR-to-RESET Delay 200 ns
MR Pullup Resistance 10 20 33 kΩ

TH

HYST

RD

RP

OL

OH

I

OH

IL

IH

V

decreasing

IN_

V

increasing relative to V

IN_

V

falling at 10mV/µs from (VTH + 50mV)

IN_

- 50mV)

to (V

TH

V

= 5V, I

IN1

V

= 2.5V, I

IN1

V

= 1.0V, I

IN1

V

> 2.55V, I

IN1

not asserted

V

> 2.55V, RESET not asserted 70 µA

IN1

= 2mA 0.3

SINK

SINK

SINK

SOURCE

TOL = GND 0.491 0.5 0.506

TOL = V

= 1.2mA 0.4

= 50µA 0.3

= 6µA (min), RESET

CC

decreasing 0.3 %V

IN_

0.465 0.472 0.479

60 ppm/°C

20 µs

140 200 280 ms

0.8 x
V

IN1

0.7 x
V

IN1

0.3 x
V

IN1

V

V

V

V

V

TH

MAX16055

Ultra-Small, Hex Voltage,
Microprocessor Supervisor

4 _______________________________________________________________________________________

Typical Operating Characteristics

(V

IN1

= 3.3V, TA= +25°C, unless otherwise noted.)

IN1 INPUT CURRENT

vs. TEMPERATURE

MAX16055 toc01

TEMPERATURE (°C)

IN1 INPUT CURRENT (µA)

1109565 80-10 5 20 35 50-25

44
42

46

48

50

52

54

56

58

60

62

64

66

68

70

40

-40 125

IN1 INPUT CURRENT

vs. IN1 VOLTAGE

MAX16055 toc02

IN1 VOLTAGE (V)

IN1 INPUT CURRENT (µA)

5.04.50.5 1.0 1.5 2.5 3.0 3.52.0 4.0

10

20

30

40

50

60

70

80

0

0 5.5

NORMALIZED THRESHOLD ERROR

vs. TEMPERATURE

MAX16055 toc03

TEMPERATURE (°C)

NORMALIZED THRESHOLD ERROR (%)

95805065

-10 5 20 35-25

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1.0

-1.0

-40

125

110

MAXIMUM IN_ TRANSIENT DURATION

vs. RESET THRESHOLD OVERDRIVE

MAX16055 toc04

IN_ OVERDRIVE (mV)

MAXIMUM IN_ TRANSIENT DURATION (µs)

900800100 200 300 500 600400 700

10

20

30

40

50

60

70

80

0

0 1000

RESET
ASSERTS ABOVE THIS LINE

RESET PROPAGATION DELAY

vs. RESET THRESHOLD OVERDRIVE

(IN_ DECREASING)

MAX16055 toc05

IN_ OVERDRIVE (mV)

RESET PROPAGATION DELAY (µs)

900800600 700200 300 400 500100

10

20

30

40

50

60

70

80

90

100

0

0 1000

RESET PULLUP AND PULLDOWN

RESPONSE (C

L

= 47pF)

MAX16055 toc06

IN_
100mV/div
AC-COUPLED

RESET
2V/div

20µs/div

RESET TIMEOUT PERIOD

vs. TEMPERATURE

MAX16055 toc07

RESET THRESHOLD (ms)

192

194

196

198

200

202

204

206

208

210

190

TEMPERATURE (°C)

1109580655035205-10-25-40 125

V

IN_

= 3.3V

MR-TO-RESET PROPAGATION DELAY

vs. TEMPERATURE

MAX16055 toc08

TEMPERATURE (°C)

MR-TO-RESET DELAY (ns)

120

110

150

140

130

170

160

200

190

180

210

100

1109580655035205-10-25-40 125

V

IN_

= 3.3V

RESET TIMEOUT DELAY

MAX16055 toc09

IN_
1V/div

RESET
1V/div

40ms/div

MR-TO-RESET PROPAGATION DELAY

MAX16055 toc10

MR
2V/div

RESET
2V/div

40ns/div

VIN = 3.3V

MAX16055

Ultra-Small, Hex Voltage,

Microprocessor Supervisor

_______________________________________________________________________________________ 5

Typical Operating Characteristics (continued)

(V

IN1

= 3.3V, TA= +25°C, unless otherwise noted.)

Pin Description

PIN NAME FUNCTION

1 IN1

2 IN2 Voltage Input 2. See the Selector Guide for voltage threshold. Keep IN1 or IN2 > 1V to ensure RESET is valid.

3 IN3 Voltage Input 3. See the Selector Guide for voltage threshold.

4 IN4 Voltage Input 4. See the Selector Guide for voltage threshold.

5 IN5 Voltage Input 5. See the Selector Guide for voltage threshold.

6 IN6 Voltage Input 6. See the Selector Guide for voltage threshold.

7 TOL

8 MR

9 RESET

10 GND Ground

Voltage Input 1. IN1 is the power-supply input and voltage monitoring input for the device. Connect a 0.1µF
bypass capacitor from IN1 to GND. Keep IN1 or IN2 > 1V to ensure RESET is valid.

Threshold Tolerance Input. Connect TOL to GND to select thresholds 5% below nominal. Connect TOL to IN1
to select thresholds 10% below nominal.

Active-Low Manual-Reset Input. When MR is low, RESET goes low and remains asserted for the reset timeout
period after MR is pulled high. MR is internally pulled high by a 20kΩ pullup resistor to IN1.

Active-Low Reset Output. RESET goes low when any input (IN_) goes below the specified threshold. After all
inputs rise above the specified threshold voltages, RESET remains low for 140ms (min) before going high.
The open-drain RESET output features a weak (70µA) internal pullup to IN1.

MAX16055

Ultra-Small, Hex Voltage,
Microprocessor Supervisor

6 _______________________________________________________________________________________

Detailed Description

The MAX16055 hex voltage µP supervisory circuit main­tains system integrity in multisupply systems (Figure 1).
The MAX16055 offers accurate, factory-fixed undervolt­age threshold options for monitoring very low voltages.
The MAX16055 also offers one to five adjustable thresh­olds for monitoring voltages down to 0.5V. See the

Selector Guide

for the available threshold options.

The MAX16055 includes an accurate voltage reference,
precision comparators, and a series of accurate internal
resistor-divider networks to set the factory-fixed reset
threshold options for monitoring 3.3V, 3.0V, 2.5V, 1.8V,

1.5V, 1.2V, 1.1V, 1.0V, or 0.9V supplies. The resistor
networks scale the specified IN_ threshold voltages to
match the internal reference voltage. Adjustable thresh­old options allow the monitored voltage to be connected
to the input of the internal comparator. Use an external
voltage-divider to set the threshold voltage.

Figure 1. Functional Diagram

IN1

3.3V

IN2

ADJ

IN3

ADJ

IN4

1.8V

IN5

ADJ

ALL DEVICES ARE POWERED FROM IN1 (3.3V/2.5V); RESET IS VALID IF V

IN1

OR V

TIMEOUT

(200ms)

UVLO

IS GREATER THAN 1V

IN2

PULLUP

IN2

IN1

70µA

RESET

IN6

ADJ

IN1

TOL

MR

REF

MAX16055C

The MAX16055 is immune to short IN_ transients. Each
of the internal comparators provides a typical hystere­sis of 0.3% with respect to the reset threshold. This
built-in hysteresis improves the monitor’s immunity to
ambient noise without significantly reducing threshold
accuracy. See the

Typical Operating Characteristics

for
a glitch immunity graph labeled Maximum IN_ Transient
Duration vs. Reset Threshold Overdrive.

Reset Output

The MAX16055 RESET output asserts low when any
monitored IN_ voltage drops below the specified reset
threshold. RESET remains low for the reset timeout peri­od of 140ms (min) after all inputs rise above the
respective thresholds (Figure 2). The RESET output is
open drain with a weak internal pullup to the monitored
IN1 supply (70µA typ). For many applications, no exter­nal pullup resistor is required to interface with other
logic devices. Apply an external pullup resistor to any
voltage from 0 to 5.5V when interfacing to different
logic-supply voltages (Figure 3). Internal circuitry pre­vents reverse current flow from the external pullup volt­age into the RESET output when RESET is not asserted.
RESET asserts low upon power-up. After all IN_ inputs
rise above the respective threshold voltages, RESET

remains low for the reset timeout period (Figure 4)
before going high.

IN1 powers the MAX16055 and is also a monitored volt­age. When any monitored supply drops below the
threshold voltage, RESET asserts low and remains low
while either IN1 or IN2 is above 1.0V.

Adjustable Thresholds

The MAX16055 includes monitor options with
adjustable reset thresholds. The threshold voltage at
each adjustable IN_ input is typically 0.5V. To monitor a
voltage higher than 0.5V, connect a resistor-divider net­work to the circuit as shown in Figure 5:

V

INTH

= 0.5V x (R1 + R2)/R2

Therefore:

R1 = R2 ((V

INTH

/0.5V) - 1)

Use high valued resistors (~ 100kΩ) to minimize current
through the external resistors. Use lower valued resis­tors for greater accuracy. The MAX16055 includes an
internal voltage clamp (1.5V typ) at each of the
adjustable voltage inputs. An input voltage higher than

1.5V induces a higher input current.

MAX16055

Ultra-Small, Hex Voltage,

Microprocessor Supervisor

_______________________________________________________________________________________ 7

Figure 2. RESET Output Timing Diagram

Figure 3. Interfacing with External Logic-Supply Voltage

IN_

V

TH_

RESET

10%

t

RD

RESET

+5V

V

CC

µP

GND

+3.3V

V

+ V

HYST

90%

IN1

10kΩ

RESET

MAX16055

GND

TH_

t

RP

Manual-Reset Input (MR)

Many µP-based products require manual-reset capabil­ity. A logic-low on MR asserts RESET low. RESET
remains asserted while MR is low, and during the reset
timeout period (140ms, min) after MR returns high. The
MR input has an internal 20kΩ pullup resistor to IN1.
Connect a normally open momentary switch from MR to
GND to create a manual-reset function. Connect a

0.1µF capacitor from MR to GND to provide additional
noise immunity when driving MR from long cables or
when the device is used in a noisy environment.

Tolerance (TOL)

The MAX16055 features an adjustable threshold toler­ance. Connect TOL to GND to set the threshold volt­ages 5% below the nominal value. Connect TOL to IN1
to set the threshold voltages 10% below the nominal
value. See the

Electrical Characteristics

table. Do not

leave TOL unconnected.

Applications Information

Unused Inputs

Connect unused monitor inputs to a supply voltage
higher than the specified threshold voltage. Connect a
100kΩ resistor between an unused adjustable input
and IN1 to limit the bias current. Use IN1 for normal
operation (device power supply). Do not connect
unused monitor inputs to ground. Do not leave unused
monitor inputs unconnected.

Reset Output Pullup Resistor

When connecting a pullup resistor from RESET to a
voltage rail lower than the voltage on IN1, the internal
70µA pullup current flows through the pullup resistor,
causing the voltage at RESET to be higher than the volt­age rail when RESET is deasserted. Ensure that the
value of the pullup resistor is low enough that the volt­age rise does not cause problems.

Power-Supply Bypassing and Grounding

IN1 powers the MAX16055. Connect a 0.1µF bypass
capacitor from IN1 to ground. All monitored inputs are
immune to short supply transients. Add bypass capaci­tors from IN2–IN6 to GND to improve noise immunity.

MAX16055

Ultra-Small, Hex Voltage,
Microprocessor Supervisor

8 _______________________________________________________________________________________

Figure 4. RESET Output with Various Input Voltages

Figure 5. Setting the Adjustable Threshold

V

IN1

V

IN2

V

IN3

V

IN4

V

IN5

V

IN6

t

BEGINS

RP

WHEN THE LAST
SUPPLY EXCEEDS

+ V

ITS V

TH

HYST

RESET

V

+ V

TH

HYST

t

RP

V

INTH

MAX16055

R1

R2

V

TH

R1 = R2

V

INTH

(

-1

V

TH

)

MAX16055

Ultra-Small, Hex Voltage,

Microprocessor Supervisor

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________

9

© 2009 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

Chip Information

PROCESS: BiCMOS

Selector Guide

Package Information

For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages

.

PACKAGE TYPE PACKAGE CODE DOCUMENT NO.

10 µMAX U10+2

21-0061

*

Adjustable voltage is based on the 0.5V internal threshold. External threshold voltage can be set using an external resistor-divider.

(V

ADJ

= 0.500V typ).

PART*

(SUFFIX IN BOLD)

MAX16055A 3.3 2.5 1.5 1.8 1.2 0.9

MAX16055B 3.3 3.0 1.8 1.5 1.1 1.0

MAX16055C 3.3 ADJ ADJ 1.8 ADJ ADJ

MAX16055D 3.3 ADJ 1.5 ADJ ADJ ADJ

MAX16055E 3.3 2.5 ADJ 1.8 ADJ ADJ

MAX16055F 3.3 2.5 1.5 ADJ ADJ ADJ

MAX16055G 3.3 2.5 ADJ ADJ ADJ ADJ

MAX16055H 3.3 ADJ ADJ ADJ ADJ ADJ

MAX16055I 2.5 ADJ ADJ ADJ ADJ ADJ

MAX16055J 3.3 3.3 2.5 1.2 1.5 1.2

IN1 IN2 IN3 IN4 IN5 IN6

NOMINAL INPUT VOLTAGE (V)