General Description
The MAX6710 precision quad-voltage monitor with micro-
processor (µP) supervisory reset timing monitors up to
four system-supply voltages 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, and 1.8V supplies with -5% or
-10% tolerances. The device is also available with one to
three adjustable threshold options to monitor voltages
down to 0.62V.
A single active-low reset output asserts when any moni-
tored 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 volt-
age remains >1V.
The MAX6710 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, 3.0V, 2.5V, and 1.8V Supplies
♦Adjustable Voltage Threshold Monitors Down to
0.62V with 1.5% Accuracy
♦Low 35µA 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
♦Guaranteed from -40°C to +85°C
♦Small 6-Pin SOT23 Package
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT Package
________________________________________________________________ Maxim Integrated Products 1
19-2324; Rev 0; 1/02
Ordering Information
*Insert the desired suffix letter from the Selector Guide into the
blank to complete the part number. There is a 2500 piece mini-
mum order increment requirement on the SOT package and
these devices are available in tape-and-reel only.
Pin Configuration appears at end of data sheet.
PART TEMP RANGE
PIN-PACKAGE
MAX6710_UT-T* -40°C to +85°C 6 SOT23-6
MAX6710
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.
Selector Guide appears at end of data sheet.
MAX6710
Low-Voltage, High-Accuracy, 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_ ).................................................-0.3V to +6V
RESET.......................................................................-0.3V to +6V
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
SYM BOL
CONDITIONS
MIN
TYP
UNITS
VCC MAX6710Q
2.0 5.5
TA = 0oC to +85oC
1.0 5.5
Operating Voltage Range
(Notes 2, 3) VIN2 All others
TA = -40oC to +85oC 1.2 5.5
V
IN_ = nominal input voltage (for 1.8V, 2.5V,
and 5.0V supplies)
25
40
IN2 = nominal input voltage (for 3.0V and
3.3V supplies) (Note 4)
55 115
VIN1 = 0 to 0.85V (for adjustable thresholds)
0.4
IIN_
VIN3,V
IN4 = 0 to 0.85V
(for adjustable thresholds)
0.2
Input Current
ICC MAX6710Q only, VCC = 5.5V
35
50
µA
5V (-5%)
4.50 4.63 4.75
5V (-10%)
4.25 4.38 4.50
3.3V (-5%)
3.00 3.08 3.15
3.3V (-10%)
2.85 2.93 3.00
3.0V (-5%)
2.70 2.78 2.85
3.0V (-10%)
2.55 2.63 2.70
2.5V (-5%)
2.25 2.32 2.38
2.5V (-10%)
2.13 2.19 2.25
1.8V (-5%)
1.62 1.67 1.71
Threshold Voltage VTH IN_ decreasing
1.8V (-10%)
1.53 1.58 1.62
V
Adjustable Threshold VTH IN_ decreasing
0.611 0.620 0.624
V
Reset Threshold Hysteresis
VHYST
IN_ increasing relative to IN_ decreasing
0.3
%VTH
Reset Threshold Temperature
Coefficient
TCVTH 60
ppm/oC
IN_ to Reset Delay tRD VIN _fal ling at 10m V/µs fr om V
TH
to ( VTH
- 50m V)
30
µs
Reset 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.) (Note 1)
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT Package
_______________________________________________________________________________________ 3
Note 1: 100% production tested at TA= +25°C. Limits over temperature guaranteed by design.
Note 2: The device is powered from input IN2 or VCC (for MAX6710Q).
Note 3: The RESET output is guaranteed to be in the correct state for IN1 or IN2 down to 1V.
Note 4: Monitored IN2 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.
40
46
44
42
48
50
52
54
56
58
60
-40 -15 10 35 60 85
IN2 INPUT CURRENT vs. TEMPERATURE
MAX6710 toc01
TEMPERATURE (°C)
IN2 INPUT CURRENT (µA)
VIN2 = 3.3V
VIN2 = 3V
0
20
10
50
40
30
60
70
80
90
0 1.0 1.50.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
IN2 INPUT CURRENT vs. IN2 VOLTAGE
MAX6710 toc02
IN2 VOLTAGE (V)
IN2 INPUT CURRENT (µA)
-0.10
-0.04
-0.06
-0.08
-0.02
0
0.02
0.04
0.06
0.08
0.10
-40 -15 10 35 60 85
NORMALIZED THRESHOLD ERROR
vs. TEMPERATURE
MAX6710 toc03
TEMPERATURE (°C)
NORMALIZED THRESHOLD ERROR (%)
VTH = 1.8V
VIN2 = 3.3V
Typical Operating Characteristics
(VIN2 = 3.0V, TA= +25°C)
PARAMETER
SYM BOL
CONDITIONS
MIN
TYP
UNITS
VIN2, VCC = 5V, ISINK = 2mA
0.3
VIN2, VCC = 2.5V, ISINK = 1.2mA
0.4
RESET Output Low VOL
VIN2 = 1.0V, ISINK = 50µA, TA = 0oC to +85oC
0.3
V
VCC ≥ 2.0V, ISOURCE = 6µA, RESET
deasserted (MAX6710Q)
0.8 ✕ VCC
RESET Output High VOH VIN2 ≥ 2.0V, ISOURCE = 6µA, RESET
deasserted
0.8 ✕ VIN2
V
RESET Output High Source
Current IOH VIN2 ≥ 2.0V, RESET deasserted
10
µA
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.) (Note 1)
Pin Description
PIN NAME FUNCTION
1 IN1 Input Voltage 1. See Selector Guide for monitored voltages.
IN2
2VCC
Inp ut V ol tag e 2. S ee Sel ector G ui de for m oni tor ed vol tag es. IN 2 i s the p ow er -sup ply i np ut for the
devi ce. V
CC i s the p ow er -sup ply i np ut for the d evi ce and i s not a m oni tor ed vol tag e ( MAX 6710Q onl y) .
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
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, VCC.
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT Package
4 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VIN2 = 3.0V, TA= +25°C)
220
222
221
223
224
225
226
227
228
229
230
231
232
MAX6710 toc07
TEMPERATURE (°C)
-40 10-15 35 60 85
RESET TIMEOUT DELAY
vs. TEMPERATURE
RESET TIMEOUT DELAY (ms)
40ms/div
MAX6710 toc08
RESET
2V/div
RESET TIMEOUT DELAY
IN_
2V/div
0
20
10
40
30
60
50
70
90
80
100
0 200 300 400100 500 600 700 900800 1000
MAX6710 toc04
MAXIMUM IN_ TRANSIENT DURATION (µs)
RESET ASSERTED
ABOVE THIS LINE
RESET THRESHOLD OVERDRIVE (mV)
MAXIMUM IN_ TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
0
20
10
40
30
60
50
70
90
80
100
0 200 300 400100 500 600 700 900800 1000
MAX6710 toc05
RESET THRESHOLD OVERDRIVE (mV)
RESET DELAY vs. RESET THRESHOLD
OVERDRIVE (IN_ DECREASING)
RESET DELAY (µs)
IN_
100mV/div
AC-COUPLED
10µs/div
MAX6710 toc06
RESET PULLUP AND PULLDOWN
RESPONSE (CL = 47pF)
RESET
2V/div
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT Package
_______________________________________________________________________________________ 5
Detailed Description
The MAX6710 is a very small, low-power, quad-voltage
µP supervisory circuit designed to maintain system
integrity in multisupply systems (Figure 1). The device
offers several internally trimmed undervoltage threshold
options that minimize the need for external compo-
nents. Preset voltage monitoring options for 5.0V, 3.3V,
3.0V, 2.5V, and 1.8V make the device ideal for telecom-
munications, desktop and notebook computers, high-
end printers, data storage equipment, and networking
equipment applications.
The quad-voltage reset includes an accurate bandgap
reference, four precision comparators, and a series of
internally 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 inter-
IN1
(ADJ)
IN2, VCC
(3.3V/3V)
IN3
(2.5V/1.8V)
IN4
(ADJ)
0.62V
REFERENCE
NOR
GATE
TIME-
OUT
(200ms)
IN2, VCC
RESET
MAX6710
ALL DEVICES ARE POWERED FROM IN2, VCC (3.0V/3.3V). RESET IS VALID IF VIN1 OR VIN2 IS GREATER THAN 1V, OR IF VCC IS GREATER THAN 2V (MAX6710Q ONLY)
UVLO
Figure 1. MAX6710 Functional Diagram
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT Package
6 _______________________________________________________________________________________
nal bandgap reference/comparator voltage. Adjustable
threshold options bypass the internal resistor networks
and connect directly to one of the comparator inputs (an
external resistor-divider network is required for threshold
matching). The MAX6710Q provides a separate unmoni-
tored power-supply input (VCC) and three adjustable volt-
age inputs.
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 MAX6710 is also designed to ignore short IN_
transients. See Typical Operating Characteristics for a
glitch immunity graph.
Applications Information
Reset Output
The MAX6710 RESET output asserts low when any
monitored IN_ voltage drops below its specified reset
threshold and remains low for the reset timeout period
(140ms minimum) after all inputs exceed their thresh-
olds (Figure 2). The output is open drain with a weak
internal pullup to the monitored IN2 or VCC 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 differ-
ent logic-supply voltages (Figure 3). Internal circuitry
prevents reverse current flow from the external pullup
voltage to IN2.
The MAX6710 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.
Adjustable Thresholds
The MAX6710 offers several monitor options with
adjustable reset thresholds. The threshold voltage at
each adjustable IN_ input is typically 0.62V. To monitor a
voltage >0.62V, connect a resistor-divider network to the
circuit as shown in Figure 4.
VINTH = 0.62V x (R1 + R2) / R2
or, solved in terms of R1:
R1 = R2 ((VINTH / 0.62V) - 1)
Figure 2.
RESET
Output Timing Diagram
Figure 4. Setting the Auxiliary Monitor
VTH_
90%
10%
IN_
VTH_
RESET
tRP
tRD
VREF = 0.62V
R2
R1
VINTH
R1 = R2 ( - 1)
VINTH
0.62V
Figure 3. Interfacing to Different Logic-Supply Voltage
IN2
GND
IN2 = +3.3V +5V
MAX6710
VCC
GND
RESET
RESET
100kΩ
Because the MAX6710 has a guaranteed input current
of ±0.2µA (±0.4µA for IN1) on its adjustable inputs,
resistor values up to 100kΩcan be used for R2 with
<1% error. The MAX6710Q 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.
Unused Inputs
Connect unused monitor inputs to a supply voltage
greater in magnitude than their specified threshold volt-
ages. For unused IN_ adjustable inputs, connect a
1MΩseries resistor between the unused input and IN2
(or VCC) to limit the bias current. The IN2 input must
always be used for normal operation (device power-
supply pin). Unused monitor inputs cannot be connect-
ed to ground or allowed to float.
Adding Manual Reset Capability
Figure 5 shows an application circuit adding manual
reset to the MAX6710 quad-voltage supervisor.
Depressing the pushbutton switch short-circuits the ana-
log input to ground and initiates a RESET pulse. The
switch must be open for 200ms (typ) in order to deassert
the RESET output. No external switch debounce is
required. Use a small capacitor to improve noise immuni-
ty when using long leads from the pushbutton switch to
the adjustable input.
Power-Supply Bypassing and Grounding
The MAX6710 is normally powered from the monitored
IN2 or from the VCC supply input. All monitored inputs
are immune to short supply transients. If higher immuni-
ty is desired in noisy applications, connect a 0.1µF
bypass capacitor 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: 699
PROCESS: BiCMOS
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT Package
_______________________________________________________________________________________ 7
Pin Configuration
Figure 5. Adding Manual Reset Capability
IN1
IN2
IN3 MAX6710
GND
RESET
IN4
(ADJUSTABLE
INPUT)
R1
R2
(VCC) IN2
IN4IN3
16
5GND
IN1
( ) ARE FOR MAX6710Q ONLY
MAX6710
SOT23
TOP VIEW
2
34
RESET
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT Package
8 _______________________________________________________________________________________
NOMINAL INPUT VOLTAGE
PART
(SUFFIX IN BOLD) IN1
(V)
IN2
(V)
IN3
(V)
IN4
(V)
SUPPLY
TOLERANCE
(%)
TOP
MARK
MAX6710AUT 5 3.3 2.5 Adj* 10 AAZA
MAX6710BUT 5 3.3 2.5 Adj* 5 AAZB
MAX6710CUT 5 3.3 1.8 Adj* 10 AAZC
MAX6710DUT 5 3.3 1.8 Adj* 5 AAZD
MAX6710EUT Adj* 3.3 2.5 1.8 10 AAZE
MAX6710FUT Adj* 3.3 2.5 1.8 5 AAZF
MAX6710GUT 5 3.3 Adj* Adj* 10 AAZG
MAX6710HUT 5 3.3 Adj* Adj* 5 AAZH
MAX6710IUT Adj* 3.3 2.5 Adj* 10 AAZI
MAX6710JUT Adj* 3.3 2.5 Adj* 5 AAZJ
MAX6710KUT Adj* 3.3 1.8 Adj* 10 AAZK
MAX6710LUT Adj* 3.3 1.8 Adj* 5 AAZL
MAX6710MUT Adj* 3 2.5 Adj* 10 AAZM
MAX6710NUT Adj* 3 2.5 Adj* 5 AAZN
MAX6710OUT Adj* 3 1.8 Adj* 10 AAZO
MAX6710PUT Adj* 3 1.8 Adj* 5 AAZP
MAX6710QUT Adj* VCC Adj* Adj* N/A AAZQ
Selector Guide
*Adjustable voltage based on 0.62V internal threshold. External threshold voltage can be set using an external resistor-divider.
MAX6710
Low-Voltage, High-Accuracy, Quad-Voltage
µP Supervisory Circuit in SOT 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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 9
© 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
6LSOT.EPS
Package Information