19-2534; Rev 4; 3/09
High-Voltage, Low-Current Voltage Monitors in
SOT Packages
General Description
The MAX6457–MAX6460 high supply voltage, low-power
voltage monitors operate over a 4V to 28V supply voltage
range. Each device includes a precision bandgap refer-
ence, one or two low-offset voltage comparators, internal
threshold hysteresis, power-good or reset timeout
options, and one or two high-voltage open-drain outputs.
Two external resistors (three for window detection) set the
trip threshold voltages.
The MAX6457 is a single voltage monitor for undervoltage
or overvoltage detection. A logic-based clear input either
latches the output for overvoltage applications or allows
the device to operate in transparent mode. The MAX6458
includes two comparators (one overvoltage and one
undervoltage) for window detection and a single output to
indicate if the monitored input is within an adjustable volt-
age window. The MAX6459 includes dual overvoltage/
undervoltage comparators with two independent com-
parator outputs. Use the MAX6459 as a window com-
parator with separate undervoltage and overvoltage
outputs or as two independent, single voltage monitors.
The MAX6460 includes a single comparator and an inter-
nal reference, and can also accept an external reference.
The inverting and noninverting inputs of the comparator
are externally accessible to support positive or negative
voltage monitors and to configure the device for active-
high or active-low output logic.
The MAX6457/MAX6458 offer fixed timing options as a
voltage detector with a 50µs typical delay or as a reset cir-
cuit with a 90ms minimum reset timeout delay. The moni-
tored input must be above the adjusted trip threshold (or
within the adjusted voltage window for the MAX6458) for
the selected timeout period before the output changes
state. The MAX6459/MAX6460 offer only a fixed 50µs
timeout period. Internal threshold hysteresis options (0.5%,
5%, and 8.3% for the MAX6457/MAX6458/MAX6459, and
0.5% for the MAX6460) reduce output chatter in noise-
sensitive applications. Each device is available in a small
SOT23 package and specified over the extended temper-
ature range of -40°C to +125°C.
Features
o
Wide Supply Voltage Range, 4V to 28V
o
Internal 2.25V ±2.5% Reference
o
Low Current (3.5µA, typ at 12V)
o
Open-Drain n-Channel Output (28V Compliant)
o
Internal Threshold Hysteresis Options
(0.5%, 5%, 8.3%)
o
Two IN-to-OUT Timeout Period Options
(50µs, 150ms)
o
Internal Undervoltage Lockout
o
Immune to Short Voltage Transients
o
Small SOT23 Packages
o
Few External Components
o
Fully Specified from -40°C to +125°C
MAX6457–MAX6460
Ordering Information
PART
MAX6457UKD_
_-T
MAX6458UKD_
_-T
MAX6459UT_-T
MAX6460UT-T
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
5 SOT23
5 SOT23
6 SOT23
6 SOT23
Note:
The MAX6457/MAX6458/MAX6459 are available with
factory-trimmed internal hysteresis options. The MAX6457 and
MAX6458 offer two fixed timing options. Select the desired hys-
teresis and timing options using Table 1 or the Selector Guide at
the end of the data sheet, and enter the corresponding letters
and numbers in the part number by replacing “_ _” or “_”. These
devices are offered in tape-and-reel only and must be ordered in
2500-piece increments.
Devices are available in both leaded and lead(Pb)-free/RoHS-
compliant packaging. Specify lead(Pb)-free by replacing “-T”
with “+T” when ordering.
Pin Configurations appear at end of data sheet.
Applications
Undervoltage Monitoring/Shutdown
Overvoltage Monitoring/Protection
Window Voltage Detection Circuitry
Multicell Battery-Stack Powered Equipment
Notebooks, eBooks
Automotive
Industrial
Telecom
Networking
BATTERY
CHARGER
Typical Operating Circuit
+21V (NOMINAL)
IN
OUT
DC-DC
CONVERTER
SHDN
V
CC
R1
5-CELL
Li+
BATTERY
STACK
IN+
R2
GND
MAX6457
OUT
R
PULLUP
LOAD
CLEAR
________________________________________________________________
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.
High-Voltage, Low-Current Voltage Monitors in
SOT Packages
MAX6457–MAX6460
ABSOLUTE MAXIMUM RATINGS
V
CC
, OUT, OUTA, OUTB,
CLEAR
to GND ..........-0.3V to +30.0V
IN+, IN- to GND..........................................-0.3V to (V
CC
+ 0.3V)
REF to GND..............-0.3V to the lower of +6V and (V
CC
+ 0.3V)
Input Currents (V
CC
, IN+, IN-) ............................................20mA
Sink Current (OUT, OUTA, OUTB) ......................................20mA
Continuous Power Dissipation (T
A
= +70°C)
5-Pin SOT23 (derate 7.1 mW/°C above +70°C)............571mW
6-Pin SOT23 (derate 8.7 mW/°C above +70°C)............696mW
Junction Temperature ......................................................+150°C
Operating Temperature Range .........................-40°C to +125°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
= 4V to 28V, T
A
= -40°C to +125°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Operating Voltage Range
Supply Current
SYMBOL
V
CC
I
CC
(Note 2)
V
CC
= 5V, no load
V
CC
= 12V, no load
V
CC
= 24V, no load
V
TH+
T
A
= -40°C to +85°C, V
CC
≥
4V
V
IN
rising T
A
= +85°C to +125°C, V
CC
≥
4V
MAX645_U_D_A
Threshold Voltage
V
TH-
T
A
= -40°C to +85°C
T
A
= +85°C to +125°C
1.195
1.170
1.180
1.155
1.133
1.111
1.093
1.071
0.5
5
8.3
0
-55
50
V
CC
+55
V
nA
µs
%V
TH+
CONDITIONS
MIN
4
2
3.5
6.5
1.228
TYP
MAX
28
5
7.5
12.5
1.255
1.255
1.255
1.255
1.194
1.194
1.151
1.151
V
µA
UNITS
V
T
A
= -40°C to +85°C
V
IN
MAX645_U_D_B
falling
T
A
= +85°C to +125°C
MAX645_U_D_C
MAX64_ _U_D_A
T
A
= -40°C to +85°C
T
A
= +85°C to +125°C
Threshold Voltage Hysteresis
IN Operating Voltage Range
IN Leakage Current
V
IN
I
IN
MAX64_ _U_D_B
MAX64_ _U_D_C
(Note 2)
V
IN
= 1.25V, V
CC
= +28V
MAX645_UKD0_
MAX6459UT_
MAX6460UT
MAX6457 and MAX6458 only,
D3 option
90
OUT Timeout Period
t
TP
150
2
210
ms
ms
Startup Time
CLEAR
Input Logic Voltage
(MAX6457)
V
IL
V
IH
V
CC
rising from GND to V
CC
≥
4V in less than
1µs (Note 3)
2
0.4
V
2
_______________________________________________________________________________________
High-Voltage, Low-Current Voltage Monitors in
SOT Packages
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 4V to 28V, T
A
= -40°C to +125°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
V
CC
≥
1.5V, I
SINK
= 250µA, OUT asserted,
T
A
= -40°C to +85°C
V
CC
≥
4.0V, I
SINK
= 1mA, OUT asserted,
T
A
= -40°C to +125°C
V
CC
= 5V, V
OUT
= 28V (Note 4)
OUT asserted, OUT = V
CC
REF = GND
V
REF
T
A
= -40°C to +85°C
T
A
= +85°C to +125°C
Sourcing: 0
≤
I
REF
≤
100µA,
sinking: 0
≤
|I
REF
|
≤
300nA
V
OFFSET
I
BIAS
I
OFFSET
CMVR
CMRR
PSRR
V
IN
+ = V
IN
- = 1.4V
0
80
80
V
IN
+ = 1.4V, V
IN
- = 1V
-4.5
6
-25
2
1.4
+25
2.183
2.171
10
7
2.25
2.25
50
+4.5
2.303
2.303
MIN
TYP
MAX
0.4
V
0.4
500
nA
mA
mA
V
µV/µA
mV
mV
nA
pA
V
dB
dB
UNITS
MAX6457–MAX6460
Output Voltage Low
V
OL
Output Leakage Current
Output Short-Circuit Sink
MAX6460
Reference Short-Circuit Current
Reference Output Voltage
Load Regulation
Input Offset Voltage
Input Hysteresis
Input Bias Current
Input Offset Current
Common-Mode Voltage Range
Common-Mode Rejection Ratio
Comparator Power-Supply
Rejection Ratio
I
LKG
I
SC
Note 1:
Devices are production tested at T
A
= +25°C. Overtemperature limits are guaranteed by design.
Note 2:
IN voltage monitoring requires that V
CC
≥
4V, but OUT remains asserted in the correct undervoltage lockout state for V
CC
down to 1.5V.
Note 3:
Startup time is the time required for the internal regulator and reference to reach specified accuracy after the monitor is
powered up from GND.
Note 4:
The open-drain output can be pulled up to a voltage greater than V
CC
but cannot exceed +28V.
_______________________________________________________________________________________
3
High-Voltage, Low-Current Voltage Monitors in
SOT Packages
MAX6457–MAX6460
Typical Operating Characteristics
(GND = 0, R
PULLUP
= 10kΩ, and T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX6457-60 toc01
TRIP THRESHOLD VOLTAGE
vs. TEMPERATURE (0.5% HYSTERESIS)
V
TH
+ (RISING)
TRIP THRESHOLD VOLTAGE (V)
1.23
1.21
1.19
1.17
1.15
1.13
1.11
V
TH
- (FALLING)
MAX6457-60 toc02
TRIP THRESHOLD VOLTAGE
vs. TEMPERATURE (5% HYSTERESIS)
MAX6457-60 toc03
12
10
8
I
CC
(µA)
6
4
T
A
= -40°C
2
0
4
10
16
V
CC
(V)
22
T
A
= +125°C
T
A
= +25°C
1.25
1.25
TRIP THRESHOLD VOLTAGE (V)
1.23
1.21
1.19
1.17
1.15
1.13
1.11
V
TH
- (FALLING)
V
TH
+ (RISING)
28
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
TRIP THRESHOLD VOLTAGE
vs. TEMPERATURE (8.3% HYSTERESIS)
MAX6457-60 toc04
OUTPUT LOW VOLTAGE
vs. OUTPUT SINK CURRENT
MAX6457-60 toc05
1.25
TRIP THRESHOLD VOLTAGE (V)
1.23
1.21
1.19
1.17
1.15
1.13
1.11
V
TH
- (FALLING)
V
TH
+ (RISING)
100,000
10,000
T
A
= +125°C
1000
V
OL
(mV)
100
10
1
V
CC
= 12V
0.1
T
A
= +25°C
T
A
= -40°C
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
0.01
0.1
1
I
SINK
(mA)
10
100
4
_______________________________________________________________________________________
电源技术
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
