19-1695; Rev 2; 12/05
Quad Voltage Monitor in µMAX Package
General Description
The MAX6338 quad voltage monitor is capable of moni-
toring up to four supplies without any external compo-
nents. 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 com-
parator, 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 temper-
ature 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 V
CC
drops below the minimum operat-
ing voltage. The four digital outputs all have weak inter-
nal pull-ups to V
CC
, allowing wire-ORed connection.
Each input threshold voltage has an independent output.
The MAX6338 is available in a 10-pin µMAX
®
package.
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
Ordering Information
PART
MAX6338_UB*
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
10 µMAX
*Insert
the desired letter from the Selector Guide into the blank
to complete the part number.
Devices are available in both leaded and lead-free packaging.
Specify lead free by adding the + symbol at the end of the part
number when ordering.
NOMINAL INPUT VOLTAGE
PART
IN1
(V)
5
5
5
5
5
5
5
5
5
5
Adj*
Adj*
5
5
5
5
IN2
(V)
3.3
3.3
3.3
3.3
3.0
3.0
3.0
3.0
3.3
3.3
3.3
3.3
3.0
3.0
3.3
3.3
IN3
(V)
2.5
2.5†
1.8
1.8†
2.5
2.5†
1.8
1.8†
2.5
2.5†
2.5
2.5†
Adj*
Adj*
Adj*
Adj*
IN4
(V)
Adj*
Adj*
Adj*
Adj*
Adj*
Adj*
Adj*
Adj*
1.8
1.8†
Adj*
Adj*
-5
-5
-5
-5
SUPPLY
TOLERANCE
(%)
10
5
10
5
10
5
10
5
10
5
10
5
10
5
10
5
Selector Guide
________________________Applications
Telecommunications
High-End Printers
Desktop and Notebook Computers
Data Storage Equipment
Networking Equipment
Industrial Equipment
Set-Top Boxes
MAX6338AUB
MAX6338BUB
MAX6338CUB
MAX6338DUB
MAX6338EUB
MAX6338FUB
MAX6338GUB
MAX6338HUB
MAX6338IUB
MAX6338JUB
MAX6338KUB
Pin Configuration
TOP VIEW
IN1
1
IN2
IN3
IN4
GND
2
3
4
5
10
V
CC
9
OUT1
OUT2
OUT3
OUT4
MAX6338LUB
MAX6338MUB
MAX6338NUB
MAX6338OUB
MAX6338PUB
MAX6338
8
7
6
µMAX
µMAX is a registered trademark of Maxim Integrated Products, Inc.
*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
1
________________________________________________________________
Maxim Integrated Products
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.
Quad Voltage Monitor in µMAX Package
MAX6338
ABSOLUTE MAXIMUM RATINGS
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
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.
ELECTRICAL CHARACTERISTICS
(V
CC
= +2.5V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C and V
CC
= +5V, unless other-
wise noted.) (Note 1)
PARAMETER
Supply Voltage Range
Supply Current
SYMBOL
V
CC
I
CC
V
CC
= +3V
V
CC
= +5V
V
IN_
= input threshold voltage
(+1.8V, +2.5V, +3.0V, +3.3V, +5.0V)
Input Current (Note 2)
I
IN_
V
IN_
= 0 to V
CC
(input threshold voltage =1.23V)
V
IN_
= -5V
(input threshold voltage = -5V)
+5.0V (-5%) Threshold
+5.0V (-10%) Threshold
+3.3V (-5%) Threshold
+3.3V (-10%) Threshold
+3.0V (-5%) Threshold
+3.0V (-10%) Threshold
+2.5V (-10%) Threshold
+1.8V (-10%) Threshold
-5.0V (+5%) Threshold
-5.0V (+10%) Threshold
Adjustable Threshold
Threshold Voltage Temperature
Coefficient
Threshold Hysteresis
Propagation Delay
V
THYST
t
pd
V
IN_
= V
TH
to (V
TH
- 50mV) or
V
TH
to (V
TH
- 50mV)
V
CC
= 5V, I
SINK
= 2mA
Output Low Voltage
Output High Voltage
V
OL
V
OH
V
CC
= 2.5V, I
SINK
= 1.2mA
V
CC
= 1V, I
SINK
= 50µA
V
CC
> 2.5V, I
SOURCE
= 6µA (minimum)
0.8 x V
CC
V
TH
V
TH
V
TH
V
TH
V
TH
V
TH
V
TH
V
TH
V
TH
V
TH
V
TH
V
IN
decreasing
V
IN
decreasing
V
IN
decreasing
V
IN
decreasing
V
IN
decreasing
V
IN
decreasing
V
IN
decreasing
V
IN
decreasing
V
IN
increasing
V
IN
increasing
V
IN
decreasing
4.5
4.25
3.0
2.85
2.7
2.55
2.13
1.53
-4.75
-4.5
1.20
-0.1
-10
4.63
4.38
3.08
2.93
2.78
2.63
2.19
1.58
-4.63
-4.38
1.23
60
0.3
20
0.4
0.4
0.4
V
V
CONDITIONS
MIN
+2.5
25
35
25
TYP
MAX
+5.5
50
65
40
+0.1
-20
4.75
4.50
3.15
3.00
2.85
2.70
2.25
1.62
-4.50
-4.25
1.26
V
V
V
V
V
V
V
V
V
V
V
ppm/°C
%
µs
µA
UNITS
V
µA
Note 1:
100% production tested at +25°C. Overtemperature limits guaranteed by design.
Note 2:
Guaranteed by design.
2
_______________________________________________________________________________________
Quad Voltage Monitor in µMAX Package
MAX6338
Typical Operating Characteristics
(V
CC
= +5V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6338-01
NORMALIZED THRESHOLD ERROR
vs. SUPPLY VOLTAGE
MAX6338-02
NORMALIZE THRESHOLD
vs. TEMPERATURE
V
CC
= +5V
NORMALIZED THRESHOLD (%)
0
MAX6338-03
45
40
SUPPLY CURRENT (µA)
35
30
25
20
15
10
2.5
3.0
3.5
4.0
4.5
5.0
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
0.10
NORMALIZED THRESHOLD ERROR (%)
0.08
0.06
0.04
0.02
0
-0.02
-0.04
-0.06
2.5
3.0
3.5
4.0
NORMALIZED TO +5V
0.1
-0.1
-0.2
-0.3
4.5
5.0
5.5
-40
-20
0
20
40
60
80
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
5.5
SUPPLY VOLTAGE (V)
OUTPUT-VOLTAGE LOW
vs. SINK CURRENT
MAX6338-04
PROPAGATION DELAY
(WITH 100mV OVERDRIVE)
MAX6338-05
PROPAGATION DELAY
(WITH 20mV OVERDRIVE)
MAX6338-06
0.6
V
CC
= 5V
OUTPUT-VOLTAGE LOW (V)
0.5
0.4
0.3
T
A
= +85°C
0.2
0.1
0
0
1
2
3
4
5
6
7
8
9
T
A
= -40°C
T
A
= +25°C
IN_
50mV/div
IN_
20mV/div
OUT_
2V/div
OUT_
2V/div
10
10µs/div
10µs/div
SINK CURRENT (mA)
_______________________________________________________________________________________
3
Quad Voltage Monitor in µMAX Package
MAX6338
Pin Description
PIN
1
2
3
4
5
6
7
8
9
10
NAME
IN1
IN2
IN3
IN4
GND
OUT4
OUT3
OUT2
OUT1
V
CC
FUNCTION
Input Voltage 1. See the
Selector Guide
for monitored voltages.
Input Voltage 2. See the
Selector Guide
for monitored voltages.
Input Voltage 3. See the
Selector Guide
for monitored voltages.
Input Voltage 4. See the
Selector Guide
for monitored voltages.
Ground
Output 4. OUT4 goes low when V
IN4
falls below its absolute threshold. OUT4 is open drain with a 10µA
internal pullup to V
CC
.
Output 3. OUT3 goes low when V
IN3
falls below its absolute threshold. OUT3 is open drain with a 10µA
internal pullup to V
CC
.
Output 2. OUT2 goes low when V
IN2
falls below its absolute threshold. OUT2 is open drain with a 10µA
internal pullup to V
CC
.
Output 1. OUT1 goes low when V
IN1
falls below its absolute threshold. OUT1 is open drain with a 10µA
internal pullup to V
CC
.
Power Supply. Connect V
CC
to a +2.5V to +5.5V supply. An undervoltage lockout circuit forces all OUT_
pins low when V
CC
drops below 2.5V.
_______________Detailed Description
The MAX6338 is a low-power (25µA), quad voltage
monitor designed for multivoltage systems. Preset volt-
age 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 compo-
nents. The four open-drain outputs have weak (10µA)
internal pullups to V
CC
, allowing them to interface easily
with other logic devices. The MAX6338 can monitor
power supplies with either 5% or 10% tolerance specifi-
cations, depending on the selected version. An addi-
tional high-input-impedance comparator option can be
used as an adjustable voltage monitor, general-pur-
pose 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-
4
tors is connected to a 1.23V bandgap reference for all
positive voltages. The noninverting terminals are acces-
sible through internal resistive voltage-dividers with
preset factory threshold voltages. In the case of auxil-
iary (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 V
CC
down 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 hys-
teresis. 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 com-
parators 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
_______________________________________________________________________________________
Quad Voltage Monitor in µMAX Package
MAX6338
V
CC
MAX6338M/N/O/P
IN1
OUT1
V
CC
IN2
OUT2
V
CC
IN3*
(AUX)*
OUT3
V
CC
IN4
(-5V)
OUT4
V
REF
REFERENCE
V
CC
UNDERVOLTAGE LOCKOUT
*SEE
AUXILIARY INPUT
SECTION.
Figure 1. Functional Diagram
_______________________________________________________________________________________
5
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