19-3596; Rev 0; 2/05
Pin-Selectable, Octal/Hex/Quad, Power-Supply
Sequencers/Supervisors
General Description
The MAX6892/MAX6893/MAX6894 pin-selectable, mul-
tivoltage supply sequencers/supervisors monitor sever-
al voltage-detector inputs and one watchdog input,
asserting the respective voltage detector or watchdog
output when the inputs drop below the configured volt-
age thresholds or the watchdog timer expires. The
MAX6892 features eight voltage detector inputs and 10
outputs. The MAX6893 features six voltage-detector
inputs and eight outputs, while the MAX6894 features
four voltage detector inputs and six outputs. A
RESET
output ensures all monitored inputs are above the set
thresholds. The voltage detector outputs are configured
as open drain. Manual reset and margin disable inputs
offer additional flexibility.
The thresholds of the MAX6892/MAX6893/MAX6894 are
selected through five logic inputs (TH0–TH4). The logic on
these five inputs selects the supply voltage tolerance (5%
or 10%) and one of 32 factory-set thresholds settings.
Watchdog and reset timeout periods can use factory
default settings or are independently adjustable by con-
necting external capacitors.
When any of the monitored voltages falls below its
threshold, the respective output asserts and remains
asserted for 6.25ms (typ) after the monitored voltage
exceeds the threshold. The outputs can be connected
to the shutdown or enable inputs of DC-DC regulators
to provide turn-on power sequencing to ensure proper
system initialization.
The MAX6892 is available in a 5mm x 5mm x 0.8mm,
32-pin, thin QFN package, while the MAX6893/
MAX6894 are available in a 5mm x 5mm x 0.8mm, 28-
pin, thin QFN package. The MAX6892/MAX6893/
MAX6894 are specified to operate over the extended
temperature range (-40°C to +85°C)
♦
Dedicated
RESET
and
WDO
Outputs
♦
Capacitor-Adjustable Reset and Watchdog
Timeout Periods
♦
Factory-Default Reset and Watchdog Timeout
Periods
♦
Up to Eight Independent, Open-Drain Power-Good
Outputs
♦
Enable Margining Disable and Manual Reset
Controls
♦
-40°C to +85°C Operating Temperature Range
♦
Small 5mm x 5mm Thin QFN Package
♦
Few External Components
♦
±1% Threshold Accuracy
Features
♦
Pin-Selectable or User-Adjustable Voltage
Detector Thresholds
MAX6892/MAX6893/MAX6894
Ordering Information
PART
MAX6892ETJ
MAX6893ETI
MAX6894ETI
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
32 Thin QFN
28 Thin QFN
28 Thin QFN
PKG
CODE
T3255-4
T2855-8
T2855-8
Pin Configurations
PG1
WDI
TOP VIEW
IN1
IN2
IN3
IN4
32
PG2
PG3
PG4
GND
PG5
PG6
PG7
PG8
1
2
3
4
5
6
7
8
9
31
30
29
28
27
26
IN5
25
24
23
22
21
IN7
IN8
DBP
VCC
ENABLE
SRT
SWT
TH4
Applications
Telecommunication/Central Office Systems
Networking Systems
Servers/Workstations
Base Stations
Storage Equipment
Multimicroprocessor/Voltage Systems
MAX6892
IN6
20
19
18
17
16
*EXPOSED PADDLE
10
11
12
13
14
15
RESET
WDO
MARGIN
TH0
MR
TH1
TH2
Typical Operating Circuit appears at end of data sheet.
THIN QFN
*EXPOSED PAD INTERNALLY CONNECTED TO GND.
Pin Configurations continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
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.
TH3
Pin-Selectable, Octal/Hex/Quad, Power-Supply
Sequencers/Supervisors
MAX6892/MAX6893/MAX6894
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
PG_,
RESET, WDO
.................................................-0.3V to +14V
IN1–IN8, TH0–TH4,
ENABLE,
WDI,
MR, MARGIN,
SRT, SWT, V
CC
.....................................................-0.3V to +6V
DBP ..........................................................................-0.3V to +3V
Input/Output Current (all pins)..........................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
28-Pin Thin QFN (derate 21.3mW/°C
above +70°C).............................................................1702mW
32-Pin Thin QFN (derate 21.3mW/°C
above +70°C)............................................................1702mW
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
IN6
–V
IN8
= GND, V
IN2
–V
IN5
= 2.7V to 5.5V, WDI =
ENABLE
= GND, TH0–TH4 =
MARGIN
=
MR
= DBP, T
A
= -40°C to
+85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1 and 2)
PARAMETER
Operating Voltage Range
(Note 3)
Undervoltage Lockout
Digital Bypass Voltage
Supply Current
V
UVLO
V
DBP
I
CC
V
TH
V
TH-HYS
∆V
TH
/°C
IN1, IN6–IN8
Input Leakage Current
I
IN
-50
IN2–IN5 set as adjustable thresholds
For IN_ voltages < the highest IN_ supply or
< V
CC
and thresholds are not set as
adjustable
V
CC
≥
V
UVLO
IN_ falling/rising, 100mV overdrive
5.625
V
SRT
= V
CC
C
SRT
= 47nF
V
SRT
= GND
180
135
180
25
6.25
200
207
230
6.875
220
280
280
290
400
555
3
kΩ
ms
µs
ms
ms
ms
nA
+50
nA
SYMBOL
CONDITIONS
Voltage on either one of IN2–IN5 or V
CC
that
guarantees the part is fully operational
For 1V < (V
IN2–
V
IN5
or V
CC
) < V
UVLO
,
PG_ are pulled down to GND with a 10µA
current
No load
V
IN2
= 5.5V, V
IN1
, V
IN3–
V
IN8
= GND, no
load
IN1–IN8,
IN_ falling
T
A
= +25°C to +85°C
T
A
= -40°C to +85°C
-1
-2
0.3
10
MIN
2.7
TYP
MAX
5.5
UNITS
V
2.5
2.48
2.55
0.9
2.67
1.1
+1
V
V
mA
Threshold Accuracy (Table 2)
Threshold Hysteresis
Threshold Tempco
% V
TH
+2
% V
TH
ppm/°C
IN2–IN5 Input Impedance
Power-Up Delay
IN_ to PG_ Delay
PG_ Timeout Period
RESET
Default Timeout Period
RESET
Adjustable Timeout Period
SRT Adjustable Timeout Current
R
IN2–IN5
t
D-PO
t
D-R
t
PG
t
RP
t
RP-ADJ
I
SRT
2
_______________________________________________________________________________________
Pin-Selectable, Octal/Hex/Quad, Power-Supply
Sequencers/Supervisors
ELECTRICAL CHARACTERISTICS (continued)
(V
IN1
= V
IN6
–V
IN8
= GND, V
IN2
–V
IN5
= 2.7V to 5.5V, WDI =
ENABLE
= GND, TH0–TH4 =
MARGIN
=
MR
= DBP, T
A
= -40°C to
+85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1 and 2)
PARAMETER
SRT Default Timeout Threshold
SRT Adjustable Timeout
Threshold
SRT Adjustable Timeout
Discharge Threshold
SRT Adjustable Timeout Output
Low Discharge Current
PG_,
RESET, WDO
Output Low
PG_,
RESET, WDO
Output Initial
Pulldown Current
PG_,
RESET, WDO
Output Open-
Drain Leakage Current
MR, MARGIN, ENABLE,
TH0–TH4, WDI Input Voltage
MR
Input Pulse Width
MR
Glitch Rejection
MR
to
RESET
Delay
MR
to DBP Pullup Current
MARGIN
to DBP Pullup Current
ENABLE
to PG_ Delay
ENABLE
Pulldown Current
t
D-MR
I
MR
I
MARGIN
t
D-ENPG
V
ENABLE
= 0.6V
5
V
MR
= 1.4V
V
MARGIN
= 1.4V
5
5
SYMBOL
V
SRT-DEF
V
SRT-ADJ
V
SRT-DIS
CONDITIONS
V
SRT
≥
V
SRT-DEF
, selects reset default
timeout
(Note 4)
(Note 5)
MIN
1.1
0.95
TYP
1.25
1.0
100
MAX
1.5
1.05
UNITS
V
V
mV
MAX6892/MAX6893/MAX6894
I
SRT-DIS
V
OL
I
UV
V
SRT
= 0.3V
I
SINK
= 4mA, output asserted
V
CC
< V
UVLO
, V
PG
_
,
RESET, WDO
= 0.8V
0.7
0.4
10
40
mA
V
µA
I
LKG
V
IL
V
IH
T
MR
Output high impedance
-1
+1
0.6
µA
1.4
1
100
2
10
10
200
10
15
15
15
V
µs
ns
µs
µA
µA
ns
µA
_______________________________________________________________________________________
3
Pin-Selectable, Octal/Hex/Quad, Power-Supply
Sequencers/Supervisors
MAX6892/MAX6893/MAX6894
ELECTRICAL CHARACTERISTICS (continued)
(V
IN1
= V
IN6
–V
IN8
= GND, V
IN2
–V
IN5
= 2.7V to 5.5V, WDI =
ENABLE
= GND, TH0–TH4 =
MARGIN
=
MR
= DBP, T
A
= -40°C to
+85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1 and 2)
PARAMETER
TH0–TH4 Input Current
WDI Pulldown Current
WDI Input Pulse Width
Watchdog Default Timeout Period
Watchdog Adjustable Timeout
Period
SWT Adjustable Timeout Current
SWT Default Timeout Threshold
SWT Adjustable Timeout
Threshold
SWT Adjustable Timeout
Discharge Threshold
SWT Adjustable Timeout Output
Low Discharge Current
t
WD
t
WD-ADJ
I
SWT
V
SWT-DEF
V
SWT-ADJ
V
SWT-DIS
I
SWT-DIS
V
SWT
= V
CC
C
SWT
= 0.33µF
V
SWT
= GND
V
SWT
≥
V
SWT-DEF
, selects watchdog default
timeout period
(Note 4)
(Note 5)
V
SWT
= 0.3V
0.7
Initial mode
Normal mode
Initial mode
Normal mode
I
WDI
V
WDI
= 0.6V
SYMBOL
CONDITIONS
MIN
-1
5
50
92.16
1.44
53.7
0.93
180
1.1
0.95
102.4
1.6
82.5
1.43
230
1.25
1.0
100
112.64
1.76
111.9
1.94
280
1.5
1.05
s
nA
V
V
mV
mA
10
TYP
MAX
+1
15
UNITS
µA
µA
ns
s
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
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 IN2–IN5, or V
CC
.
The internal supply voltage, measured at V
CC
, equals the maximum of IN2–IN5.
External capacitor is charged by I
S_T
when V
S_T-DIS
< V
S_T
< V
S_T-ADJ
.
External capacitor is discharged by I
S_T-DIS
down to V
S_T-DIS
after V
S_T
reaches V
S_T-ADJ
.
4
_______________________________________________________________________________________
Pin-Selectable, Octal/Hex/Quad, Power-Supply
Sequencers/Supervisors
MAX6892/MAX6893/MAX6894
Typical Operating Characteristics
(V
IN1
= V
IN6
–V
IN8
= GND, V
IN2
–V
IN5
= 2.7V to 5.5V, WDI = GND, TH0–TH4 =
MARGIN
=
MR
= DBP. Typical values are at T
A
= +25°C.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE (IN2–IN5)
MAX6892 toc01
SUPPLY CURRENT
vs. SUPPLY VOLTAGE (V
CC
)
MAX6892 toc02
NORMALIZED PG_ TIMEOUT PERIOD
vs. TEMPERATURE
NORMALIZED PG_ TIMEOUT PERIOD
MAX6892 toc03
1.1
1.0
SUPPLY CURRENT (mA)
0.9
0.8
0.7
0.6
0.5
2.5
3.0
3.5
4.0
4.5
5.0
T
A
= -40°C
T
A
= +25°C
1.1
1.0
SUPPLY CURRENT (mA)
0.9
T
A
= +85°C
0.8
0.7
0.6
0.5
T
A
= +25°C
1.3
1.2
1.1
1.0
0.9
0.8
0.7
T
A
= +85°C
T
A
= -40°C
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
-40
-15
10
35
60
85
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
IN_TO PG_ PROPAGATION DELAY
vs. TEMPERATURE
MAX6892 toc04
NORMALIZED DEFAULT RESET
TIMEOUT PERIOD vs. TEMPERATURE
MAX6892 toc05
NORMALIZED ADJUSTABLE RESET
TIMEOUT PERIOD vs. TEMPERATURE
NORMALIZED RESET TIMEOUT PERIOD
1.08
1.06
1.04
1.02
1.00
0.98
0.96
0.94
0.92
0.90
85
-40
-15
10
35
t
RP
= 200ms
C
SRT
= 47nF
60
85
MAX6892 toc06
30
IN_TO PG_ PROPAGATION DELAY (µs)
28
26
24
22
20
18
16
14
12
10
-40
-15
10
35
60
100mV OVERDRIVE
1.020
NORMALIZED RESET TIMEOUT PERIOD
1.015
1.010
1.005
1.000
0.995
0.990
0.985
0.980
-40
-15
10
35
t
RP
= 200ms
V
SRT
= V
CC
60
1.10
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
NORMALIZED DEFAULT WATCHDOG
TIMEOUT PERIOD vs. TEMPERATURE
MAX6892 toc07
NORMALIZED ADJUSTABLE WATCHDOG
TIMEOUT PERIOD vs. TEMPERATURE
NORMALIZED WATCHDOG TIMEOUT PERIOD
MAX6892 toc08
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
MAX6892 toc09
1.04
NORMALIZED WATCHDOG TIMEOUT PERIOD
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
-40
-15
10
35
60
t
RP
= 1.6s
V
SWT
= V
CC
1.20
1.15
1.10
1.05
1.00
0.95
0.90
0.85
0.80
-40
-15
10
35
t
RP
= 1.6s
C
SWT
= 0.33µF
60
1.005
85
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
