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19-0291; Rev 2; 2/10
Hex/Quad, Power-Supply Supervisory Circuits
General Description
The MAX6887/MAX6888 multivoltage supply supervi-
sors provide several voltage-detector inputs, one watch-
dog input, and three outputs. Each voltage-detector
input offers a factory-set undervoltage and overvoltage
threshold. Manual reset and margin disable inputs offer
additional flexibility.
The MAX6887 offers six voltage-detector inputs, while
the MAX6888 offers four inputs. Output
RESET
asserts
when any input voltage drops below its respective
undervoltage threshold or manual reset
MR
is asserted.
Output
OV
asserts when any input voltage exceeds its
respective overvoltage threshold. Monitor standard
supply voltages listed in the
Selector Guide.
The MAX6887/MAX6888 offer a watchdog timer with an
initial and normal timeout periods of 102.4s and 1.6s,
respectively. Watchdog output
WDO
asserts when the
watchdog timer expires. Connect
WDO
to manual reset
input
MR
to generate resets when the watchdog timer
expires.
RESET, OV,
and
WDO
are active-low, open-
drain outputs.
The MAX6887/MAX6888 are available in a 5mm x 5mm
x 0.8mm, 16-pin thin QFN package and operate over
the extended -40°C to +85°C temperature range.
o
Hex/Quad Voltage Detectors
o
Undervoltage and Overvoltage Thresholds
o
1% Threshold Accuracy
o
Margining Disable and Manual Reset Input
o
Watchdog Timer
o
Open-Drain
RESET, OV,
and
WDO
Outputs
o
180ms (min) Reset Timeout Period
o
Few External Components
o
Small 5mm x 5mm, 16-Pin Thin QFN Packages
Features
MAX6887/MAX6888
Ordering Information
PART
MAX6887_ETE+
MAX6888_ETE+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 Thin QFN-EP*
16 Thin QFN-EP*
Applications
Multivoltage Systems
Telecom
Networking
Servers/Workstations/Storage Systems
Note:
Insert the desired letter from the Selector Guide into the
blank to complete the part number.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
Pin Configurations and Typical Operating Circuit appear at
end of data sheet.
Selector Guide
PART
MAX6887AETE
MAX6887BETE
NOMINAL INPUT VOLTAGE (V)*
IN1
5.0
5.0
IN2
3.3
3.3
3.3
2.5
2.5
2.5
2.5
1.8
Adj
IN3
2.5
2.5
1.8
1.8
1.8
1.5
Adj
Adj
Adj
IN4
1.8
Adj
Adj
1.5
Adj
Adj
Adj
Adj
Adj
IN5
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
IN6
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
TOL
(%)
5
5
5
5
5
5
5
5
5
PART
MAX6887IETE
MAX6887JETE
MAX6887KETE
MAX6887LETE
NOMINAL INPUT VOLTAGE (V)*
IN1
5.0
5.0
5.0
3.3
IN2
3.3
3.3
3.3
2.5
2.5
2.5
2.5
1.8
Adj
IN3
2.5
2.5
1.8
1.8
1.8
1.5
Adj
Adj
Adj
IN4
1.8
Adj
Adj
1.5
Adj
Adj
Adj
Adj
Adj
IN5
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
IN6
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
Adj
TOL
(%)
10
10
10
10
10
10
10
10
10
MAX6887CETE 5.0
MAX6887DETE 3.3
MAX6887EETE
MAX6887FETE
3.3
3.3
MAX6887METE 3.3
MAX6887NETE 3.3
MAX6887OETE 3.3
MAX6887PETE
MAX6887RETE
3.3
Adj
MAX6887GETE 3.3
MAX6887HETE 3.3
MAX6887QETE
Adj
*See
thresholds options tables (Tables 1 and 2) for actual undervoltage and overvoltage thresholds.
Selector Guides continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
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.
Hex/Quad, Power-Supply Supervisory Circuits
MAX6887/MAX6888
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
IN1–IN6, V
CC
,
RESET, OV, WDO
.............................-0.3V to +6V
WDI,
MR, MARGIN
...................................................-0.3V to +6V
BP .............................................................................-0.3V to +3V
Input/Output Current (all pins)..........................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin 5mm x 5mm Thin QFN
(derate 20.8mW/°C above +70°C) ..............................1667mW
Maximum Junction Temperature .....................................+150°C
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +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
IN1
–V
IN4
or V
CC
= 2.7V to 5.8V, WDI = GND,
MARGIN
=
MR
= BP, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are
at T
A
= +25°C.) (Notes 1, 2)
PARAMETER
Operating Voltage Range
(Note 3)
Supply Current
Threshold Accuracy
(See the
Selector Guide)
Threshold Hysteresis
Threshold Tempco
IN_ Input Impedance
I
CC
V
TH
V
TH-HYST
∆V
TH
/°C
R
IN
For V
IN_
< highest V
IN1
–
IN4
and
V
IN_
< V
CC
(not ADJ), thresholds are not set
as adjustable
IN5, IN6 (MAX6887 only)
IN1–IN4 set as adjustable thresholds
V
CC
≥
2.5V
IN_ falling/rising, 100mV overdrive
180
20
200
25
I
SINK
= 4mA, output asserted
Output high impedance
-1
0.4
+1
220
130
SYMBOL
CONDITIONS
Voltage on either one of IN1–IN4 or V
CC
to
guarantee the part is fully operational
V
IN1
= 5.8V, IN2–IN6 = GND, no load
IN1–IN6, IN_ falling, T
A
= +25°C to +85°C
IN1–IN6, IN_ falling, T
A
= -40°C to +85°C
-1
-1.5
0.3
10
200
300
MIN
2.7
0.9
TYP
MAX
5.8
1.2
+1
+1.5
UNITS
V
mA
% V
TH
% V
TH
ppm/°C
kΩ
IN_ Input Leakage Current
Power-Up Delay
IN_ to
RESET
or
OV
Delay
RESET
Timeout Period
OV
Timeout Period
RESET, OV,
and
WDO
Output
Low
RESET, OV,
and
WDO
Output
Open-Drain Leakage Current
I
IN
t
D-PO
t
D-R
t
RP
t
OP
V
OL
I
LKG
-150
+150
2.5
nA
ms
µs
ms
µs
V
µA
2
_______________________________________________________________________________________
Hex/Quad, Power-Supply Supervisory Circuits
ELECTRICAL CHARACTERISTICS (continued)
(V
IN1
–V
IN4
or V
CC
= 2.7V to 5.8V, WDI = GND,
MARGIN
=
MR
= BP, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are
at T
A
= +25°C.) (Notes 1, 2)
PARAMETER
MR, MARGIN,
WDI Input Voltage
MR
Input Pulse Width
MR
Glitch Rejection
MR
to
RESET
or
OV
Delay
MR
to Internal BP Pullup Current
MARGIN
to Internal BP Pullup
Current
WDI Pulldown Current
WDI Input Pulse Width
Watchdog Timeout Period
t
WDI
t
WD
Initial
Normal
t
D-MR
I
MR
I
MARGIN
I
WDI
V
MR
= 1.4V
V
MARGIN
= 1.4V
V
WDI
= 0.6V
5
5
5
50
92.16
1.44
102.4
1.6
112.64
1.76
SYMBOL
V
IL
V
IH
t
MR
1.4
1
100
200
10
10
10
15
15
15
CONDITIONS
MIN
TYP
MAX
0.6
UNITS
V
µs
ns
ns
µA
µA
µA
ns
s
MAX6887/MAX6888
Note 1:
Note 2:
Note 3:
Note 4:
100% production tested at T
A
= +25°C and T
A
= +85°C. Specifications at T
A
= -40°C are guaranteed by design.
Device may be supplied from any one of IN1–IN4 or V
CC
.
The internal supply voltage, measured at V
CC
, equals the maximum of IN1–IN4.
Versions Q and R require that power be applied through V
CC
.
Typical Operating Characteristics
(V
IN1
–V
IN4
or V
CC
= 5V, WDI = GND,
MARGIN
=
MR
= BP, T
A
= +25°C, unless otherwise noted.)
IN1–IN4 SUPPLY CURRENT
vs. IN1–IN4 SUPPLY VOLTAGE
MAX6887 toc01
V
CC
SUPPLY CURRENT
vs. V
CC
SUPPLY VOLTAGE
MAX6887 toc02
RESET TIMEOUT PERIOD
vs. TEMPERATURE
215
TIMEOUT PERIOD (ms)
210
205
200
195
190
185
180
MAX6887 toc03
1.00
0.95
SUPPLY CURRENT (mA)
0.90
0.85
0.80
0.75
0.70
2.6
3.6
4.6
5.6
SUPPLY VOLTAGE (V)
T
A
= -40°C
T
A
= +25°C
1.00
0.95
SUPPLY CURRENT (mA)
T
A
= +85°C
0.90
0.85
0.80
0.75
0.70
2.6
3.6
4.6
5.6
SUPPLY VOLTAGE (V)
T
A
= -40°C
T
A
= +25°C
220
T
A
= +85°C
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
3
Hex/Quad, Power-Supply Supervisory Circuits
MAX6887/MAX6888
Typical Operating Characteristics (continued)
(V
IN1
–V
IN4
or V
CC
= 5V, WDI = GND,
MARGIN
=
MR
= BP, T
A
= +25°C, unless otherwise noted.)
IN_ TO RESET OR OV
PROPAGATION DELAY vs. TEMPERATURE
MAX6887 toc04
WATCHDOG TIMEOUT PERIOD
vs. TEMPERATURE
MAX6887 toc05
NORMALIZED IN_ THRESHOLD
vs. TEMPERATURE
1.004
NORMALIZED IN_ THRESHOLD
1.003
1.002
1.001
1.000
0.999
0.998
0.997
0.996
0.995
MAX6887 toc06
30
29
PROPAGATION DELAY (µs)
28
27
26
25
24
23
22
21
20
-40
-15
10
35
60
100mV OVERDRIVE
1.700
1.675
TIMEOUT PERIOD (s)
1.650
1.625
1.600
1.575
1.550
1.525
1.500
1.005
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
MAXIMUM IN_ TRANSIENT
vs. IN_THRESHOLD OVERDRIVE
MAX6887 toc07
OUTPUT-VOLTAGE LOW vs. SINK CURRENT
MAX8667 toc08
MR TO RESET OUTPUT PROPAGATION
DELAY vs. TEMPERATURE
2.75
PROPAGATION DELAY (µs)
2.50
2.25
2.00
1.75
1.50
1.25
1.00
MAX6887 toc09
200
MAXIMUM TRANSIENT DURATION (µs)
175
150
125
100
75
50
25
0
1
10
100
PO_ ASSERTION OCCURS
ABOVE THIS LINE
400
350
OUTPUT-VOLTAGE LOW (mV)
300
250
200
150
100
50
0
3.00
1000
0
2
4
6
8
10
12
14
-40
-15
10
35
60
85
IN_ THRESHOLD OVERDRIVE (mV)
SINK CURRENT (mA)
TEMPERATURE (°C)
Pin Description
PIN
MAX6887
1
MAX6888
1
NAME
FUNCTION
Open-Drain, Active-Low Reset Output.
RESET
asserts when any input voltage falls below its
undervoltage threshold or when
MR
is pulled low.
RESET
remains low for 200ms after all
assertion-causing conditions are cleared. An external pullup resister is required.
Open-Drain, Active-Low Watchdog Timer Output. Logic output for the watchdog timer function.
WDO
goes low when
WDI
is not strobed high-to-low or low-to-high within the watchdog timeout
period.
Open-Drain Active-Low Overvoltage Output.
OV
asserts when any input voltage exceeds its
overvoltage threshold.
OV
remains low for 25µs after all overvoltage conditions are cleared.
An external pullup resistor is required.
Ground
RESET
2
2
WDO
3
4
3
4
OV
GND
4
_______________________________________________________________________________________
PCB Design
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