19-0882; Rev 0; 7/07
Low-Power Battery Backup
Circuits in Small µDFN Packages
General Description
The MAX16033–MAX16040 supervisory circuits reduce
the complexity and number of components required for
power-supply monitoring and battery control functions
in microprocessor (µP) systems. The devices signifi-
cantly improve system reliability and accuracy com-
pared to other ICs or discrete components. The
MAX16033–MAX16040 provide µP reset, backup-bat-
tery switchover, power-fail warning, watchdog, and
chip-enable gating features.
The MAX16033–MAX16040 operate from supply volt-
ages up to 5.5V. The factory-set reset threshold voltage
ranges from 2.32V to 4.63V. The devices feature a man-
ual-reset input (MAX16033/MAX16037), a watchdog
timer input (MAX16034/MAX16038), a battery-on output
(MAX16035/MAX16039), an auxiliary adjustable reset
input (MAX16036/MAX16040), and chip-enable gating
(MAX16033–MAX16036). Each device includes a
power-fail comparator and offers an active-low push-
pull reset or an active-low open-drain reset.
The MAX16033–MAX16040 are available in 2mm x
2mm, 8-pin or 10-pin µDFN packages and are fully
specified from -40°C to +85°C.
Features
o
Low 1.2V Operating Supply Voltage
o
Precision Monitoring of 5.0V, 3.3V, 3.0V, and 2.5V
Power-Supply Voltages
o
Independent Power-Fail Comparator
o
Debounced Manual-Reset Input
o
Watchdog Timer, 1.6s Timeout
o
Battery-On Output Indicator
o
Auxiliary User-Adjustable RESETIN
o
Low 13µA Quiescent Supply Current
o
Two Available Output Structures:
Active-Low Push-Pull Reset
Active-Low Open-Drain Reset
o
Active-Low Reset Valid Down to 1.2V
o
Power-Supply Transient Immunity
o
140ms (min) Reset Timeout Period
o
Small 2mm x 2mm, 8-Pin and 10-Pin
µDFN
Packages
MAX16033–MAX16040
Ordering Information
PART*
MAX16033LLB_
_+T
MAX16033PLB_ _+T
MAX16034LLB_
_+T
MAX16034PLB_ _+T
TEMP RANGE
PIN-
PACKAGE
PKG
CODE
Applications
Portable/Battery-
Powered Equipment
POS Equipment
Critical µP/µC Power
Monitoring
Set-Top Boxes
Controllers
Computers
Fax Machines
Industrial Control
Real-Time Clocks
Intelligent Instrument
-40°C to +85°C 10 µDFN-10 L1022-1
-40°C to +85°C 10 µDFN-10 L1022-1
-40°C to +85°C 10 µDFN-10 L1022-1
-40°C to +85°C 10 µDFN-10 L1022-1
Pin Configurations and Typical Operating Circuit appear at
end of data sheet.
Ordering Information continued on last page.
*These
parts offer a choice of reset threshold voltages. From the
Reset Threshold Ranges table, insert the desired threshold volt-
age code in the blank to complete the part number. See Selector
Guide for a listing of device features.
+Denotes
a lead-free package.
T
= Tape and reel.
Selector Guide
PART
MAX16033_
MAX16034_
MAX16035_
MAX16036_
MAX16037_
MAX16038_
MAX16039_
MAX16040_
✓
✓
✓
✓
MR
✓
✓
✓
✓
WATCHDOG
BATTON
RESETIN
CEIN/CEOUT
✓
✓
✓
✓
PFI,
PFO
✓
✓
✓
✓
✓
✓
✓
✓
PIN-PACKAGE
10 µDFN-10
10 µDFN-10
10 µDFN-10
10 µDFN-10
8 µDFN-8
8 µDFN-8
8 µDFN-8
8 µDFN-8
Note:
Replace “_” with L for push-pull or P for open-drain
RESET
and
PFO
outputs.
________________________________________________________________
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.
Low-Power Battery Backup
Circuits in Small µDFN Packages
MAX16033–MAX16040
ABSOLUTE MAXIMUM RATINGS
Terminal Voltages (with respect to GND)
V
CC,
BATT, OUT .......................................................-0.3V to +6V
RESET
(open drain),
PFO
(open drain) ....................-0.3V to +6V
RESET
(push-pull),
PFO
(push-pull), BATTON, RESETIN, WDI
MR, CEIN, CEOUT,
PFI ............................-0.3V to (V
OUT
+ 0.3V)
Input Current
V
CC
Peak..............................................................................1A
V
CC
Continuous ............................................................250mA
BATT Peak ....................................................................250mA
BATT Continuous ............................................................40mA
GND ................................................................................75mA
Output Current
OUT ..................................Short-Circuit Protected for up to 5s
RESET,
BATTON .............................................................20mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µDFN (derate 4.8mW/°C above +70°C) ..........380.6mW
10-Pin µDFN (derate 5mW/°C above +70°C) ...........402.8mW
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
CC
= 2.25V to 5.5V, V
BATT
= 3V,
RESET
not asserted, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
=
+25°C.) (Note 1)
PARAMETER
Operating Voltage Range
Supply Current
SYMBOL
V
CC
, V
BATT
I
CC
CONDITIONS
No load (Note 2)
V
CC
= 2.8V
No load, V
CC
> V
TH
V
BATT
= 2.8V,
V
CC
= 0V,
excluding I
OUT
I
BATT
(V
BATT
+ 0.2V) < V
CC
< 5.5V
V
CC
= 3.6V
V
CC
= 5.5V
Supply Current in Battery
Backup Mode
BATT Standby Current (Note 3)
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
-0.1
-0.3
MIN
0
13
16
22
TYP
MAX
5.5
30
35
50
1
µA
2
+0.02
+0.02
3.1
3.7
4.6
V
BATT
- 0.2
V
BATT
- 0.15
V
BATT
- 0.15
0
-40
mV
V
Ω
µA
µA
UNITS
V
V
CC
= 4.75V, V
CC
> V
TH
, I
OUT
= 150mA
V
CC
to OUT On-Resistance
R
ON
V
CC
= 3.15V, V
CC
> V
TH
, I
OUT
= 65mA
V
CC
= 2.5V, V
CC
> V
TH
, I
OUT
= 25mA
V
BATT
= 4.50V, V
CC
= 0V, I
OUT
= 20mA
Output Voltage in Battery
Backup Mode
V
OUT
V
BATT
= 3.15V, V
CC
= 0V, I
OUT
= 10mA
V
BATT
= 2.5V, V
CC
= 0V, I
OUT
= 5mA
Battery-Switchover Threshold
V
SW
V
CC
- V
BATT
, V
CC
< V
TH
V
CC
rising
V
CC
falling
2
_______________________________________________________________________________________
Low-Power Battery Backup
Circuits in Small µDFN Packages
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 2.25V to 5.5V, V
BATT
= 3V,
RESET
not asserted, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
=
+25°C.) (Note 1)
PARAMETER
RESET OUTPUT
MAX160_ _ _L_46
MAX160_ _ _L_44
Reset Threshold
V
TH
MAX160_ _ _L_31
MAX160_ _ _L_29
MAX160_ _ _L_26
MAX160_ _ _L_23
V
CC
Falling Reset Delay
Reset Active Timeout Period
RESET
Output Low Voltage
RESET
Output High Voltage
RESET
Output Leakage
Current
POWER-FAIL COMPARATOR
PFI Input Threshold
PFI Hysteresis
PFI Input Current
PFO
Output Low Voltage
PFO
Output High Voltage
PFO
Leakage Current
PFO
Delay Time
MANUAL RESET (MAX16033/MAX16037)
V
IL
MR
Input Voltage
V
IH
Pullup Resistance to V
CC
Minimum Pulse Width
Glitch Immunity
MR
to Reset Delay
V
CC
= 3.3V
0.7 x
V
CC
20
1
100
120
165
kΩ
µs
ns
ns
0.3 x
V
CC
V
OL
V
OH
V
PFI
= 0V or V
CC
Output asserted
V
CC
> 2.1V, I
SINK
= 1.6mA
V
CC
> 1.2V, I
SINK
= 100µA
0.8 x
V
CC
1
4
-100
V
PFI
V
PFI
falling
1.185
1.235
1
+100
0.3
0.4
1.285
V
%
nA
V
V
µA
µs
t
RP
V
OL
V
OH
I
LKG
RESET
asserted
I
SINK
= 1.6mA, V
CC
> 2.1V
I
SINK
= 100µA, V
CC
> 1.2V
0.8 x
V
CC
1
V
CC
falling at 10V/ms
140
4.50
4.25
3.00
2.85
2.55
2.25
4.63
4.38
3.08
2.93
2.63
2.32
25
280
0.3
0.4
4.75
4.50
3.15
3.00
2.70
2.38
µs
ms
V
V
µA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX16033–MAX16040
MAX160_ _L only (push-pull),
RESET
not
asserted, I
SOURCE
= 500µA, V
CC
> V
TH(MAX)
MAX160_ _P only (open drain), not asserted
MAX160_ _L only (push-pull), V
CC
> V
TH(MAX)
,
I
SOURCE
= 500µA, output not asserted
MAX160_ _P only (open drain), V
PFO
= 5.5V,
not asserted
V
PFI
+ 100mV to V
PFI
- 100mV
V
_______________________________________________________________________________________
3
Low-Power Battery Backup
Circuits in Small µDFN Packages
MAX16033–MAX16040
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 2.25V to 5.5V, V
BATT
= 3V,
RESET
not asserted, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
=
+25°C.) (Note 1)
PARAMETER
Watchdog Timeout Period
Minimum WDI Input Pulse Width
SYMBOL
t
WD
t
WDI
V
IL
WDI Input Voltage
V
IH
WDI Input Current
BATTON (MAX16035/MAX16039)
Output Voltage
Output Short-Circuit Current
RESETIN (MAX16036/MAX16040)
RESETIN Threshold
RESETIN Input Current
RESETIN to Reset Delay
CEIN
Leakage Current
CEIN
to
CEOUT
Resistance
CEOUT
Short-Circuit Current
CEIN
to
CEOUT
Propagation
Delay (Note 4)
(V
RTH
+ 100mV) to (V
RTH
- 100mV)
RESET
asserted
RESET
not asserted, V
CC
= V
TH(MAX),
V
CEIN
= V
CC
/ 2, I
SINK
= 10mA
RESET
asserted, V
CEOUT
= 0V
50Ω source impedance driver,
C
LOAD
= 50pF
V
CC
= 4.75V
V
CC
= 3.15V
0.7 x
V
CC
V
BATT
- 0.1
1
µs
1
1.5
2
CHIP-ENABLE GATING (MAX16033–MAX16036)
±1
100
2.0
7
9
µA
Ω
mA
ns
V
RTH
1.185
1.235
0.01
1.5
1.285
25
V
nA
µs
V
OL
I
SINK
= 3.2mA, V
BATT
= 2.1V
Sink current, V
CC
= 5V
Source current, V
BATT
> 2V
10
60
30
120
0.4
V
mA
µA
0.7 x
V
CC
-1.0
+1.0
µA
(Note 4)
CONDITIONS
MIN
1.00
100
0.3 x
V
CC
TYP
1.65
MAX
2.25
UNITS
s
ns
WATCHDOG (MAX16034/MAX16038)
V
V
CC
= 5V, V
CC
> V
BATT
, I
SOURCE
= 100µA
CEOUT
Output-Voltage High
V
CC
= 0V, V
BATT
> 2.2V, I
SOURCE
= 1µA
RESET
to
CEOUT
Delay
V
Note 1:
Note 2:
Note 3:
Note 4:
All devices are 100% production tested at T
A
= +25°C. All overtemperature limits are guaranteed by design.
V
BATT
can be 0V any time, or V
CC
can go down to 0V if V
BATT
is active (except at startup).
Positive current flows into BATT.
Guaranteed by design.
4
_______________________________________________________________________________________
Low-Power Battery Backup
Circuits in Small µDFN Packages
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. TEMPERATURE
MAX16033 toc01
MAX16033–MAX16040
BATTERY SUPPLY CURRENT
(BACKUP MODE) vs. TEMPERATURE
MAX16033 toc02
BATT-TO-OUT ON-RESISTANCE
vs. TEMPERATURE
BATTERY-TO-OUT ON-RESISTANCE (Ω)
9
8
7
6
5
4
3
2
1
0
-40
-15
V
BATT
= 3V
V
BATT
= 5V
V
CC
= 0V
V
BATT
= 2V
MAX16033 toc03
20
19
18
SUPPLY CURRENT (µA)
17
16
15
14
13
12
11
10
-40
V
CC
= 5V
1.0
0.9
BATTERY SUPPLY CURRENT (µA)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
V
BATT
= 3V
V
CC
= 0V
1.0
-15
10
35
60
85
-40
-15
10
35
60
85
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
V
CC
-TO-OUT ON-RESISTANCE
vs. TEMPERATURE
MAX16033 toc04
RESET TIMEOUT PERIOD
vs. TEMPERATURE
MAX16033 toc05
V
CC
-TO-RESET PROPAGATION DELAY
vs. TEMPERATURE
V
CC
-TO-RESET PROPAGATION DELAY (µs)
V
CC
FALLING
0.25V/ms
90
75
60
1V/ms
45
30
15
10V/ms
0
-40
-20
0
20
40
60
80
105
MAX16033 toc06
MAX16033 toc08
230
225
RESET TIMEOUT PERIOD (ms)
220
215
210
205
200
195
190
185
180
1.4
V
CC
-TO-OUT ON-RESISTANCE (Ω)
1.2
1.0
0.8
0.6
0.4
0.2
0
V
CC
= 5V
120
V
CC
= 2.5V
I
OUT
= 25mA
V
CC
= 3V
I
OUT
= 65mA
V
CC
= 4.5V
I
OUT
= 150mA
-40 -25 -10
5
20
35
50
65
80
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
NORMALIZED RESET THRESHOLD
vs. TEMPERATURE
1.003
1.002
1.001
1.000
0.999
0.998
0.997
0.996
0.995
0.994
0.993
0.992
0.991
0.990
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
MAX16033 toc07
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
300
MAXIMUM TRANSIENT DURATION (µs)
250
200
150
100
50
0
1
10
100
1000
10,000
RESET THRESHOLD OVERDRIVE (V
TH
- V
CC
) (mV)
MAX160_ _-29
(V
TH
= 2.93V)
MAX160_ _-46
(V
TH
= 4.63V)
RESET OCCURS
ABOVE CURVE
NORMALIZED RESET THRESHOLD
_______________________________________________________________________________________
5
