Rainbow Electronics MAX6338 User Manual

General Description

The MAX6338 quad voltage monitor is capable of moni­toring up to four supplies without any external compo­nents. A variety of factory-trimmed threshold voltages
and supply tolerances are available to optimize the
MAX6338 for specific applications. The selection
includes input options for monitoring +5.0V, +3.3V,
+3.0V, +2.5V, +1.8V, and -5.0V voltages. An additional
high-input impedance comparator option can be used
as an adjustable voltage monitor, general-purpose com­parator, or digital level translator.

Each of the monitored voltages is available with trip
thresholds to support power-supply tolerances of either
5% or 10% below the nominal voltage. An internal
bandgap reference ensures accurate trip thresholds
across the extended (-40°C to +85°C) operating temper­ature range.

The MAX6338 consumes 25µA (typ) supply current and
operates with supply voltages from +2.5V to +5.5V. An
internal undervoltage lockout circuit forces all four digital
outputs low when VCCdrops below the minimum operat­ing voltage. The four digital outputs all have weak inter­nal pull-ups to VCC, allowing wire-ORed connection.
Each input threshold voltage has an independent output.

The MAX6338 is available in a 10-pin µMAX package.

________________________Applications

Telecommunications

High-End Printers

Desktop and Notebook Computers

Data Storage Equipment

Networking Equipment

Industrial Equipment

Set-Top Boxes

Features

♦ Monitors Four Voltages (Factory Programmed or

User Adjustable)

+5.0V, +3.3V, +3.0V, +2.5V, +1.8V, -5.0V
(nominal) or User-Adjustable Settings

♦ Low 25µA Supply Current

♦ Four Independent, Open-Drain, Active-Low

Outputs

♦ +2.5V to +5.5V Supply Voltage Range

♦ Guaranteed from -40°C to +85°C

♦ No External Components Required

♦ Small 10-Pin µMAX Package

MAX6338

Quad Voltage Monitor in µMAX Package

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

NOMINAL INPUT VOLTAGE

PART

SUPPLY

TOLERANCE

(%)

MAX6338AUB

5

10

MAX6338BUB

5

5

MAX6338CUB

5

10

MAX6338DUB

5

5

MAX6338EUB

5

10

MAX6338FUB

5

5

MAX6338GUB

5

10

MAX6338HUB

5

5

MAX6338IUB

5

10

MAX6338JUB

5

5

MAX6338KUB

10

MAX6338LUB

5

MAX6338MUB

5

-5 10

MAX6338NUB

5

-5 5

MAX6338OUB

5

-5 10

MAX6338PUB

5

-5 5

19-1695; Rev 1; 7/01

Ordering Information

Selector Guide

*Insert the desired letter from the Selector Guide into the blank
to complete the part number.

*Adjustable voltage based on +1.23V internal threshold. External
threshold voltage can be set using an external resistor-divider.
† Nominal input voltages for 1.8V and 2.5V are specified for 10%
tolerances

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

PART TEMP. RANGE PIN-PACKAGE

MAX6338_UB* -40°C to +85°C 10 µMAX

IN1

IN2

IN3

TOP VIEW

1

IN1

2

IN2

3

IN3

4

5

10

V

CC

9

MAX6338

µMAX

OUT1

8

OUT2

7

OUT3IN4

OUT4GND

6

(V)

(V)

3.3 2.5 Adj*

3.3 2.5† Adj*

3.3 1.8 Adj*

3.3 1.8† Adj*

3.0 2.5 Adj*

3.0 2.5† Adj*

3.0 1.8 Adj*

3.0 1.8† Adj*

3.3 2.5 1.8

3.3 2.5† 1.8†

Adj* 3.3 2.5 Adj*

Adj* 3.3 2.5† Adj*

3.0 Adj*

3.0 Adj*

3.3 Adj*

3.3 Adj*

(V)

IN4

(V)

MAX6338

Quad Voltage Monitor in µMAX Package

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +2.5V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C and VCC= +5V, unless other­wise noted.) (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.

Terminal Voltage (with respect to GND)

V

CC

......................................................................-0.3V to +6V

Output Voltages (OUT_) ...........................................-0.3V to +6V

Input Voltages (IN_) (except -5V).............................-0.3V to +6V

Input Voltage (-5V input) ..........................................-6V to +0.3V

Continuous OUT_ Current...................................................20mA

Continuous Power Dissipation (T

A

= +70°C)

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

Operating Temperature Range ...........................-40°C to +85°C

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

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

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

Note 1: 100% production tested at +25°C. Overtemperature limits guaranteed by design.
Note 2: Guaranteed by design.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range V

Supply Current I

Input Current (Note 2) I

+5.0V (-5%) Threshold V

+5.0V (-10%) Threshold V

+3.3V (-5%) Threshold V

+3.3V (-10%) Threshold V

+3.0V (-5%) Threshold V

+3.0V (-10%) Threshold V

+2.5V (-10%) Threshold V

+1.8V (-10%) Threshold V

-5.0V (+5%) Threshold V

-5.0V (+10%) Threshold V

Adjustable Threshold V

Threshold Voltage Temperature
Coefficient

Threshold Hysteresis V

Propagation Delay t

Output Low Voltage V

Output High Voltage V

CC

CC

IN_

TH

TH

TH

TH

TH

TH

TH

TH

TH

TH

TH

THYST

pd

OL

OH

VCC = +3V 25 50

VCC = +5V 35 65

V

= input threshold voltage

IN_

(+1.8V, +2.5V, +3.0V, +3.3V, +5.0V)

V

= 0 to V

IN_

CC

(input threshold voltage =1.23V)

V

= -5V

IN_

(input threshold voltage = -5V)

VIN decreasing 4.5 4.63 4.75 V

VIN decreasing 4.25 4.38 4.50 V

VIN decreasing 3.0 3.08 3.15 V

VIN decreasing 2.85 2.93 3.00 V

VIN decreasing 2.7 2.78 2.85 V

VIN decreasing 2.55 2.63 2.70 V

VIN decreasing 2.13 2.19 2.25 V

VIN decreasing 1.53 1.58 1.62 V

VIN increasing -4.75 -4.63 -4.50 V

VIN increasing -4.5 -4.38 -4.25 V

VIN decreasing 1.20 1.23 1.26 V

V

= VTH to (VTH - 50mV) or

IN_

to (VTH - 50mV)

V

TH

VCC = 5V, I

VCC = 2.5V, I

VCC = 1V, I

VCC > 2.5V, I

= 2mA 0.4

SINK

= 1.2mA 0.4

SINK

= 50µA0.4

SINK

SOURCE

= 6µA (minimum) 0.8 x V

+2.5 +5.5 V

25 40

-0.1 +0.1

-10 -20

60 ppm/°C

0.3 %

20 µ s

CC

µA

µA

V

V

MAX6338

Quad Voltage Monitor in µMAX Package

_______________________________________________________________________________________ 3

Typical Operating Characteristics

(VCC= +5V, TA= +25°C, unless otherwise noted.)

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

45

TA = -40°C

TA = +25°C

MAX6338-01

NORMALIZED THRESHOLD ERROR (%)

40

35

30

25

SUPPLY CURRENT (µA)

20

15

10

TA = +85°C

2.5 3.5 4.03.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)

OUTPUT VOLTAGE LOW

vs. SINK CURRENT

0.6

0.5

0.4

0.3

0.2

OUTPUT VOLTAGE LOW (V)

0.1

TA = +25°C

TA = +85°C

VCC = 5V

TA = -40°C

MAX6338-04

50mV/div

NORMALIZED THRESHOLD ERROR

0.10

0.08

0.06

0.04

0.02

0

-0.02

-0.04

-0.06

2.5 3.53.0 4.0 4.5 5.0 5.5

IN_

OUT_

2V/div

vs. SUPPLY VOLTAGE

NORMALIZED TO +5V

SUPPLY VOLTAGE (V)

PROPAGATION DELAY

(WITH 100mV OVERDRIVE)

0.1

MAX6338-02

0

-0.1

-0.2

NORMALIZED THRESHOLD (%)

-0.3

-40 20 40-20 0

MAX6338-05

IN_

20mV/div

OUT_

2V/div

NORMALIZE THRESHOLD

vs. TEMPERATURE

VCC = +5V

TEMPERATURE (°C)

PROPAGATION DELAY

(WITH 20mV OVERDRIVE)

MAX6338-03

60

80

MAX6338-06

0

04312 5678910

SINK CURRENT (mA)

10µs/div

10µs/div

_______________Detailed Description

The MAX6338 is a low-power (25µA), quad voltage
monitor designed for multivoltage systems. Preset volt­age options for +5.0V, +3.3V, +3.0V, +2.5V, +1.8V, and

-5.0V make these quad monitors ideal for applications
such as telecommunications, desktop and notebook
computers, high-end printers, data storage equipment,
and networking equipment.

The MAX6338 has an internally trimmed threshold that
minimizes or eliminates the need for external compo­nents. The four open-drain outputs have weak (10µA)
internal pullups to VCC, allowing them to interface easily
with other logic devices. The MAX6338 can monitor
power supplies with either 5% or 10% tolerance specifi­cations, depending on the selected version. An addi­tional high-input-impedance comparator option can be
used as an adjustable voltage monitor, general-pur­pose comparator, or digital level translator.

The weak internal pullups can be overdriven by external
pullups to any voltage from 0 to +5.5V. Internal circuitry
prevents current flow from the external pullup voltage to
V

CC

. The outputs can be wire-ORed for a single “power

good” signal.

The MAX6338 has either one or two auxiliary inputs and
two or three factory-programmed threshold voltages, or
four fixed voltages. The inverting input of all compara-

tors is connected to a 1.23V bandgap reference for all
positive voltages. The noninverting terminals are acces­sible through internal resistive voltage-dividers with
preset factory threshold voltages. In the case of auxil­iary (AUX) input, the positive terminal of the comparator
is accessible directly for setting the threshold for the
monitored voltage.

When any of the inputs (IN1–IN4) are higher than the
threshold level, the output is high. The output goes low
as the input drops below the threshold voltage monitor.
The undervoltage lockout circuitry remains active and
the outputs remain low with VCCdown to 1V (Figure 1).

Applications Information

Hysteresis

When the voltage on one comparator input is at or near
the voltage on the other input, ambient noise generally
causes the comparator output to oscillate. The most
common way to eliminate this problem is through hys­teresis. When the two comparator input voltages are
equal, hysteresis causes one comparator input voltage
to move quickly past the other, thus taking the input out
of the region where oscillation occurs. Standard com­parators require hysteresis to be added through the
use of external resistors. The external resistive network
usually provides a positive feedback to the input in
order to cause a jump in the threshold voltage when

MAX6338

Quad Voltage Monitor in µMAX Package

4 _______________________________________________________________________________________

Pin Description

PIN NAME FUNCTION

1 IN1 Input Voltage 1. See Selector Guide for monitored voltages.

2 IN2 Input Voltage 2. See Selector Guide for monitored voltages.

3 IN3 Input Voltage 3. See Selector Guide for monitored voltages.

4 IN4 Input Voltage 4. See Selector Guide for monitored voltages.

5 GND Ground

6 OUT4

7 OUT3

8 OUT2

9 OUT1

10 V

CC

Output 4. OUT4 goes low when V
internal pullup to V

Output 3. OUT3 goes low when V
internal pullup to V

Output 2. OUT2 goes low when V
internal pullup to V

Output 1. OUT1 goes low when V
internal pullup to V

Power Supply. Connect VCC to a +2.5V to +5.5V supply. An undervoltage lockout circuit forces all OUT_
pins low when V

.

CC

.

CC

.

CC

.

CC

drops below 2.5V.

CC

falls below its absolute threshold. OUT4 is open drain with a 10µA

IN4

falls below its absolute threshold. OUT3 is open drain with a 10µA

IN3

falls below its absolute threshold. OUT2 is open drain with a 10µA

IN2

falls below its absolute threshold. OUT1 is open drain with a 10µA

IN1

MAX6338

Quad Voltage Monitor in µMAX Package

_______________________________________________________________________________________ 5

Figure 1. MAX6338 Functional Diagram

V

CC

MAX6338M/N/O/P

IN1

IN2

IN3*

(AUX)*

IN4

(-5V)

OUT1

V

CC

OUT2

V

CC

OUT3

V

CC

OUT4

*SEE AUXILIARY INPUT SECTION.

V

REF

REFERENCE

V

CC

UNDERVOLTAGE LOCKOUT

MAX6338

output toggles in one direction or the other. These
resistors are not required when using the MAX6338
because hysteresis is built into the device. MAX6338
hysteresis is typically 0.3%.

Undervoltage Detection Circuit

The open-drain outputs of the MAX6338 can be config­ured to detect an undervoltage condition. Figure 2
shows a configuration where a low at a comparator out­put indicates an undervoltage condition, which in turn
causes an LED to light.

The MAX6338 can also be used in applications such as
system supervisory monitoring, multivoltage level
detection, and VCCbar graph monitoring (Figure 3).

Window Detection

A window detector circuit uses two auxiliary inputs in a
configuration such as the one shown in Figure 4.
External resistors R1–R4 set the two threshold voltages
(V

TH1

and V

TH4

) of the window detector circuit. Window
width (∆VTH) is the difference between the threshold
voltages (Figure 5).

Quad Voltage Monitor in µMAX Package

6 _______________________________________________________________________________________

Figure 2. Quad Undervoltage Detector with LED Indicators Figure 3. VCCBar Graph Monitoring

Figure 4. Window Detection Figure 5. Output Response of Window Detector Circuit

+5V

IN1

V1

IN2

V2

V3

V4

MAX6338

IN3

IN4

*OPTIONAL

V

GND

CC

OUT1

OUT2

OUT3

OUT4

0.1µF*

(+5V)

V

IN

IN1

IN2

IN3

IN4

+5V

V

MAX6338

GND

IN1

IN2

IN3

IN4

+5V

V

CC

MAX6338HUB

GND

OUT1

OUT2

OUT3

OUT4

OUT1

OUT1

OUT4

OUT

V

TH4

V

= (1 + ) V

TH1

V

= 1.23V

REF

INPUT

V

= (1 + ) V

TH4

R2

REF

R1

R2

R1

R4

R3

R4

REF

R3

CC

OUT1

OUT2

OUT3

OUT4

V

TH1

∆V

TH

D1

D2

D3

D4

Auxiliary Input

The adjustable voltage monitor is comparable to an
internal reference of 1.23V as shown in Figure 6. To set
the desired trip level of monitored supply, V

INTH

,

choose: R1 = R2 [(V

INTH

/ 1.23) - 1)]. For example, for a
voltage detection at 4.5V (assume R2 = 100kΩ), R1 =
265kΩ.

Unused Inputs

The unused inputs (except the auxiliary) are internally
connected to ground through the lower resistors of the
threshold-setting resistor pairs. The auxiliary (AUX)
input, however, must be connected to either ground or
VCCif unused.

Power-Supply Bypassing and Grounding

The MAX6338 operates from a single +2.5V to +5.5V
supply. In noisy applications, connect a 0.1µF capaci­tor on the supply voltage line close to VCCpin for
bypassing.

Chip Information

TRANSISTOR COUNT: 620

PROCESS: BiCMOS

MAX6338

Quad Voltage Monitor in µMAX Package

_______________________________________________________________________________________ 7

Figure 6. Setting the Auxiliary Monitor

Typical Operating Circuit

V

INTH

R1

R2

V

= 1.23V

REF

V

R1 = R2 ( - 1

INTH

1.23

)

(MAY BE ONE OF THE MONITORED VOLTAGES)

SUPPLIES

TO BE

MONITORED

+2.5V TO +5.5V

V

MAX6338

IN1

IN2

IN3

IN4

GND

CC

OUT1

OUT2

OUT3

OUT4

SYSTEM

LOGIC

µP

MAX6338

Quad Voltage Monitor in µMAX Package

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.

8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Package Information

10LUMAX.EPS