General Description
The MAX6339 is a precision quad voltage monitor with
microprocessor (µP) supervisory reset timing. The device
can monitor up to four system supply voltages without
any external components and asserts a single reset if any
supply voltage drops below its preset threshold. The
device significantly reduces system size and component
count while improving reliability compared to separate
ICs or discrete components.
A variety of factory-trimmed threshold voltages are avail-
able to accommodate different supply voltages and toler-
ances with minimal external component requirements.
The selection includes internally fixed options for monitor-
ing +5.0V, +3.3V, +3.0V, +2.5V, +1.8V, and -5.0V sup-
plies with -5% and/or -10% tolerances. The device is also
available with one or two user-adjustable threshold
options if non-standard thresholds are desired (use exter-
nal resistor-divider network).
The quad monitor provides a single active-low reset out-
put that is asserted when any monitored input is below its
associated threshold. The output is open drain with a
weak internal pullup (10µA) to IN2. Reset remains low for
a reset timeout period (140ms min) after all voltages are
above the selected thresholds. The output is valid as long
as either the IN1 or IN2 input voltage remains > 1V.
The MAX6339 is available in a small 6-pin SOT23 pack-
age and operates over the extended (-40°C to +85°C)
temperature range.
________________________Applications
Telecommunications
High-End Printers
Desktop and Network Computers
Data Storage Equipment
Networking Equipment
Industrial Equipment
Set-Top Boxes
Features
♦Monitors Four Power-Supply Voltages
♦Precision Factory-Set Reset Threshold Options
for +5.0V, +3.3V, +3.0, +2.5V, +1.8V, and -5.0V
Supplies
♦User-Adjustable Voltage Monitoring Threshold
Options
♦Low 55µA Supply Current
♦Open-Drain RESET Output with 10µA Internal
Pullup
♦140ms (min) Reset Timeout Period
♦RESET Valid to IN1 = 1V or IN2 = 1V
♦Immune to Short Monitored Supply Transients
♦No External Components Required
♦Guaranteed from -40°C to +85°C
♦Small 6-Pin SOT23 Package
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
________________________________________________________________ Maxim Integrated Products 1
19-1756; Rev 3; 12/05
Ordering Information
*Insert the desired letter from the Selector Guide into the blank
to complete the part number. There is a 2500 piece minimum
order increment requirement on the SOT package and these
devices are available in tape-and-reel only.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
Pin Configuration appears at end of data sheet.
PART TEMP. RANGE
PIN-PACKAGE
MAX6339_UT-T*
-40°C TO +85°C
6 SOT23-6
MAX6339
IN1
IN2
IN3
IN4
RESET
GND
SUPPLIES
TO BE
MONITORED µP
Typical Operating Circuit
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.
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
2_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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)
Input Voltages (IN_ ) (except -5V)............................-0.3V to +6V
RESET.......................................................................-0.3V to +6V
Input Voltage (-5V Input) ..........................................-6V to +0.3V
Continuous RESET Current .................................................20mA
Continuous Power Dissipation (TA= +70°C)
6-pin SOT23 (derate 8.7mW/°C above +70°C).........695.7mW
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
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
UNITS
Supply Voltage Range
(Notes 2, 3) VIN2 1.0 5.5 V
VIN_ = input threshold voltage (input threshold
voltage of 1.8V, 2.5V, 5V) 25 40
VIN2 = input threshold voltage (input threshold
voltage of 3.0V, 3.3V) (Note 4) 55
115
VIN_ = 0 to VIN2
(input threshold voltage = +1.23V)
-0.1 +0.1
VIN1 = 1.5V (MAX6339 K/L only) 0.4 1.5
Input Current
IIN_
VIN_ = -5V (input threshold voltage = -5V) -15 -20
µA
+5V (-5%) threshold
4.50 4.63 4.75
+5V (-10%) threshold
4.25 4.38 4.50
+3.3V (-5%) threshold
3.00 3.08 3.15
+3.3V (-10%) threshold
2.85 2.93 3.00
+3.0V (-5%) threshold
2.70 2.78 2.85
+3.0V (-10%) threshold
2.55 2.63 2.70
+2.5V (-10% ) threshold
2.13 2.19 2.25
VIN_
decreasing
+1.8V (-10%) threshold
1.53 1.58 1.62
-5V (+5%) threshold
-4.75 -4.63 -4.50
Reset
Threshold Voltage VTH
VIN_
increasing
-5V (+10%) threshold
-4.50 -4.38 -4.25
V
Adjustable Threshold VTH VIN decreasing
1.20 1.23 1.26
V
Threshold Voltage
Temperature Coefficient 60
ppm/°C
Threshold Hysteresis VHYST 0.3 %
Reset Delay tRD VIN = VTH to (VTH - 50mV) (all inputs except –5V)
or VIN_ = VTH to (VTH + 50mV) (-5V input only) 20 µs
Reset Active Timeout
Period tRP
140 200 280
ms
ELECTRICAL CHARACTERISTICS
(VIN2 = +1V to +5.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VIN2 = +3.0V to +3.3V, TA= +25°C, unless
otherwise noted.) (Note 1)
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VIN2 = +1V to +5.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VIN2 = +3.0V to +3.3V, TA= +25°C, unless
otherwise noted.) (Note 1)
Note 1: 100% production tested at TA= +25°C. Limits over temperature guaranteed by design.
Note 2: The device is powered from input IN2.
Note 3: The RESET output is guaranteed to be in the correct state for IN1 or IN2 down to 1V.
Note 4: Monitored voltage (+3.3V, +3.0V) is also the device power supply. Supply current splits as follows: 25µA for the resistor-
divider (for the monitored voltage) and 30µA for other circuits.
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
VIN2 = 5V, ISINK = 2mA 0.4
VIN2 = 2.5V, ISINK = 1.2mA 0.4Output Low Voltage VOL
VIN1 = VIN2 = 1V, ISINK = 50µA 0.4
V
Output High Voltage VOH VIN2 > 2.55V, ISOURCE = 6µA
(RESET unasserted)
0.8 ✕
VIN2 V
Output High Source
Current IOH VIN2 > 2.55V (RESET unasserted) 6 10 µA
35
50
45
40
55
60
65
70
75
80
85
-40 0-20 20 406080
IIN2 INPUT CURRENT vs. TEMPERATURE
MAX6339toc01
TEMPERATURE (°C)
IIN2 INPUT CURRENT (µA)
VIN2 = +3.3V
VIN2 = +3.0V
50
60
55
70
65
80
75
85
3.0 4.03.5 4.5 5.0 5.5
IIN2 INPUT CURRENT
vs. IIN2 VOLTAGE
MAX6339toc02
INPUT VOLTAGE (V)
IIN2 INPUT CURRENT ( µA)
-0.30
-0.15
-0.20
-0.25
-0.10
-0.5
0
0.05
0.10
0.15
-40 0-20 20 406080
NORMALIZED THRESHOLD ERROR
vs. TEMPERATURE
MAX6339toc03
TEMPERATURE (°C)
NORMALIZED THRESHOLD ERROR (%)
VTH = +5V
VTH = 1.8V
VIN2 = +3.0V
Typical Operating Characteristics
(VIN2 = +3.0V, TA= +25°C)
Pin Description
PIN NAME FUNCTION
1IN1 Input Voltage 1. See the Selector Guide for monitored voltages.
2 IN2 Input Voltage 2. See the Selector Guide for monitored voltages. IN2 is the power-supply input for
the device.
3IN3 Input Voltage 3. See the Selector Guide for monitored voltages.
4IN4 Input Voltage 4. See the Selector Guide for monitored voltages.
5GND Ground
6RESET
Reset Output, Active Low. RESET goes low when any input goes below its specified threshold. After
all inputs are above their threshold voltage, RESET remains low for at least 140ms (minimum) before
going high. RESET output is open drain with a weak internal pullup to IN2.
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
4_______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VIN2 = +3.0V, TA= +25°C)
180
190
185
195
200
205
210
215
-40 0-20 20 406080
RESET TIMEOUT DELAY
vs. TEMPERATURE
MAX6339toc07
TEMPERATURE (°C)
RESET TIMEOUT DELAY (ms)
RESET
2V/div
IN_
2V/div
200ms/div
RESET TIMEOUT DELAY
MAX6339toc08
2V/div
0
20
10
30
60
70
50
40
80
0200 300 400 500100 600 700 800 900 1000
MAXIMUM IN_ TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
MAX6339toc04
RESET THRESHOLD OVERDRIVE (mV)
MAXIMUM IN_ TRANSIENT DURATION (µs)
RESET ASSERTED
ABOVE THIS LINE
0
20
10
30
60
70
50
40
80
0200300 400 500100 600 700 800 900 1000
RESET DELAY vs. RESET THRESHOLD
OVERDRIVE (IN_ decreasing)
MAX6339toc05
RESET THRESHOLD OVERDRIVE (mV)
RESET DELAY (µs)
RESET
2V/div
IN_
100mV/div
10µs/div
RESET PULLUP AND PULLDOWN
RESPONSE (CL = 47pF)
MAX6339toc06
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
_______________________________________________________________________________________ 5
Detailed Description
The MAX6339 is a very small, low-power, quad voltage
µP supervisory circuit designed to maintain system
integrity in multi-supply systems (Figure 1). The device
offers several internally trimmed undervoltage threshold
options that minimize or eliminate the need for external
components. Preset voltage monitoring options for
+5.0V, +3.3V, +3.0V, +2.5V, +1.8V, and -5.0V make it
ideal for telecommunications, desktop and notebook
computers, high-end printers, data storage equipment,
and networking equipment applications.
The quad monitor/reset includes an accurate bandgap
reference, four precision comparators, and a series of
internal trimmed resistor-divider networks to set the fac-
tory-fixed reset threshold options. The resistor networks
scale the specified IN_ reset voltages to match the
internal bandgap reference/comparator voltage. User-
adjustable threshold options bypass the internal resis-
tor networks and connect directly to one of the
comparator inputs (an external resistor-divider network
is required for threshold matching). All threshold volt-
age options, fixed and adjustable, are indicated
through a single-letter code in the product number (see
the Selector Guide).
Each of the internal comparators has a typical hystere-
sis of 0.3% with respect to its reset threshold. This built-
in hysteresis improves the monitor’s immunity to
ambient noise without significantly reducing threshold
accuracy when an input sits at its specified reset volt-
age. The MAX6339 is also designed to ignore short IN_
transients. See the Typical Operating Characteristics for
a glitch immunity graph.
Applications Information
Reset Output
The MAX6339 RESET output is asserted low when any
of the monitored IN_ voltages drop below its specified
reset threshold (or above for -5V option) and remain
low for the reset timeout period (140ms minimum) after
all inputs exceed their thresholds (Figure 2). The output
is open drain with a weak internal pullup to the moni-
tored IN2 supply (10µA typ). For many applications no
external pullup resistor is required to interface with
other logic devices. An external pullup resistor to any
voltage from 0 to +5.5V can overdrive the internal
pullup if interfacing to different logic supply voltages
(Figure 3). Internal circuitry prevents reverse current
flow from the external pullup voltage to IN2.
The MAX6339 is normally powered from the monitored
IN2 supply when all input voltages are above their
specified thresholds. When any supply drops below its
threshold, the reset output is asserted and guaranteed
to remain low while either IN1 or IN2 is above +1.0V.
User-Adjustable Thresholds
The MAX6339 offers several monitor options with user-
adjustable reset thresholds. The threshold voltage at
each adjustable IN_ input is typically 1.23V. To monitor
a voltage > 1.23V, connect a resistor-divider network to
the circuit as shown in Figure 4.
VINTH = 1.23V x (R1 + R2) / R2
or, solved in terms of R1:
R1 = R2 ((VINTH / 1.23V) - 1)
Because the MAX6339 has a guaranteed input current
of ±0.1µA on its adjustable inputs, resistor values up to
100kΩcan be used for R2 with < 1% error.
Unused Inputs
If some monitor inputs are to be unused, they must be
tied to a supply voltage greater in magnitude than their
specified threshold voltages. For unused IN3 or IN4
options with positive thresholds (fixed or adjustable),
the inputs can be connected directly to the IN2 supply.
For unused IN4 options with negative thresholds, the
input must be tied to a more negative supply. The IN2
input must always be used for normal operation (device
power-supply pin). Unused pins cannot be connected
to ground or allowed to float.
Negative Voltage Monitoring Beyond -5V
The MAX6339 is offered with options to monitor -5V sup-
plies with internally fixed thresholds. To monitor supplies
more negative than -5V, a low-impedance resistor-
divider network can be used external to the MAX6339 as
shown in Figure 5. The current through the external resis-
tor-divider should be greater than the input current for
the -5V monitor options. For an input monitor current
error of < 1%, the resistor-divider current should ≥ 2mA
(for IIN4 = 20µA max). Set R2 = 2.5kΩ. Calculate R1
based on the desired VIN_ reset threshold voltage, using
the following formula:
R1 = R2 ✕[(VINTH / VTH ) -1]
where R2 ≤2.49kΩ, VINTH = desired threshold voltage
and VTH is the internal threshold voltage.
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
6_______________________________________________________________________________________
IN1
(5V)
IN2
(3.3/3V)
IN3
(AUX)
IN4
(-5V)
IN2
IN1
REFERENCE
NOR
GATE
IN1 (5V)
PULLUP
TIME
OUT
(200ms)
VREF
RESET
MAX6339
ALL DEVICES ARE POWERED FROM IN2 (3.0V/3.3V). RESET IS VALID IF VIN1 OR VIN2 IS GREATER THAN 1V.
Figure 1. Functional Diagram
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
_______________________________________________________________________________________ 7
For -VIN = -12V nominal, VINTH = -11.1V, VTH = -4.63V,
and R2 = 2.49kΩ,
R1 = 2.49kΩ✕[(-11.1 / -4.63) -1]
R1 = 3.48kΩ
Power-Supply Bypassing and Grounding
The MAX6339 is normally powered from the monitored
IN2 supply input. All monitor inputs are immune to short
supply transients. If higher immunity is desired in noisy
applications, connect 0.1µF bypass capacitors from the
IN2 input to ground. Additionally, capacitance can be
added to IN1, IN3, and IN4 to increase their noise
immunity.
Chip Information
TRANSISTOR COUNT: 896
PROCESS: BiCMOS
Figure 2.
RESET
Output Timing Diagram
Figure 4. Setting the Auxiliary Monitor
VTH_
90%
10%
IN_
VTH_
RESET
tRP
tRD
R1 = R2 ( - 1)
VINTH
1.23
VREF = 1.23V
R2
R1
VINTH
Figure 3. Interfacing to Different Logic Supply Voltage
IN2
GND
IN2 = +3.3V +5V
MAX6339
VCC
GND
RESET
RESET
100kΩ
Pin Configuration
Figure 5. Negative Voltage Monitoring Beyond -5V
R1 = R2 × [( )-1]
VINTH
VTH
VREF = 1.23V
R1
R2
-5V
VINTH
IN2
IN4IN3
16RESET
5GND
IN1
MAX6339
SOT23
TOP VIEW
2
34
NOMINAL INPUT VOLTAGE
PART IN1
(V)
IN2
(V)
IN3
(V)
IN4
(V)
SUPPLY
TOLERANCE
(%)
TOP
MARK
MAX6339AUT 5 3.3 2.5 Adj* 10 AAJU
MAX6339BUT 5 3.3 2.5† Adj* 5 AAJV
MAX6339CUT 5 3.3 1.8 Adj* 10 AAJW
MAX6339DUT 5 3.3 1.8† Adj* 5 AAJX
MAX6339EUT 5 3.0 2.5 Adj* 10 AAJY
MAX6339FUT 5 3.0 2.5† Adj* 5 AAJZ
MAX6339GUT 5 3.0 1.8 Adj* 10 AAKA
MAX6339HUT 5 3.0 1.8† Adj* 5 AAKB
MAX6339IUT 5 3.3 2.5 1.8 10 AAKC
MAX6339JUT 5 3.3 2.5† 1.8† 5 AAKD
MAX6339KUT Adj* 3.3 2.5 Adj* 10 AAKE
MAX6339LUT Adj* 3.3 2.5 Adj* 5 AAKF
MAX6339MUT 5 3.0 Adj* -5 10 AAKG
MAX6339NUT 5 3.0 Adj* -5 5 AAKH
MAX6339OUT 5 3.3 Adj* -5 10 AAKI
MAX6339PUT 5 3.3 Adj* -5 5 AAKJ
Selector Guide
*Adjustable voltage based on +1.23V internal threshold. External threshold voltage can be set using an external resistor-divider.
†Normal input voltages for 1.8V and 2.5V are specified for 10% tolerances.
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
8_______________________________________________________________________________________
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
©2005 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
6LSOT.EPS
PACKAGE OUTLINE, SOT 6L BODY
21-0058
1
1
G
MAX6339
Quad Voltage µP Supervisory Circuit
in SOT Package
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
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