MAXIM MAX8211, MAX8212 User Manual
________________General Description
Maxim’s MAX8211 and MAX8212 are CMOS micropower
voltage detectors that warn microprocessors (µPs) of
power failures. Each contains a comparator, a 1.5V
bandgap reference, and an open-drain N-channel output
driver. Two external resistors are used in conjunction with
the internal reference to set the trip voltage to the desired
level. A hysteresis output is also included, allowing the user
to apply positive feedback for noise-free output switching.
The MAX8211 provides a 7mA current-limited output sink
whenever the voltage applied to the threshold pin is less
than the 1.5V internal reference. In the MAX8212, a voltage
greater than 1.5V at the threshold pin turns the output
stage on (no current limit).
The CMOS MAX8211/MAX8212 are plug-in replacements
for the bipolar ICL8211/ICL8212 in applications where the
maximum supply voltage is less than 16.5V. They offer several performance advantages, including reduced supply
current, a more tightly controlled bandgap reference, and
more available current from the hysteresis output.
________________________Applications
µP Voltage Monitoring
Undervoltage Detection
Overvoltage Detection
Battery-Backup Switching
Power-Supply Fault Monitoring
Low-Battery Detection
____________________________Features
♦ µP Power-Fail Warning
♦ Improved 2nd Source for ICL8211/ICL8212
♦ Low-Power CMOS Design
♦ 5µA Quiescent Current
♦ On-Board Hysteresis Output
♦ ±40mV Threshold Accuracy (±3.5%)
♦ 2.0V to 16.5V Supply-Voltage Range
♦ Define Output Current Limit (MAX8211)
♦ High Output Current Capability (MAX8212)
_______________Ordering Information
MAX8211/MAX8212
Microprocessor Voltage Monitors
with Programmable Voltage Detection
________________________________________________________________ Maxim Integrated Products 1
___________________Pin Configuration
TOP VIEW
V+
MAX8211
MAX8212
N.C.
N.C.
GND
8
7
6
5
2
3
4
N.C.
1
HYST
THRESH
OUT
DIP/SO
___________Typical Operating Circuit
PART TEMP RANGE PIN-PACKAGE
MAX8211CPA
0°C to +70°C 8 Plastic DIP
MAX8211CSA 0°C to +70°C 8 SO
MAX8211CUA 0°C to +70°C 8 µMAX
MAX8211CTY 0°C to +70°C 8 TO-99
MAX8211EPA -40°C to +85°C 8 Plastic DIP
MAX8211ESA -40°C to +85°C 8 SO
MAX8211EJA -40°C to +85°C 8 CERDIP
MAX8211MJA -55°C to +125°C 8 CERDIP
MAX8211MTV -55°C to +125°C 8 TO-99
MAX8211ETY -40°C to +85°C 8 TO-99
19-0539; Rev 4; 9/02
Ordering Information continued on last page.
*Contact factory for dice specifications.
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.
Pin Configurations continued at end of data sheet.
R3
R2
R1
LOGIC-SUPPLY UNDERVOLTAGE DETECTOR
(DETAILED CIRCUIT DIAGRAM—FIGURE 5)
HYST
THRESH
V+
V+
OUT
MAX8211
GND
µP
NMI
MAX8211/MAX8212
Microprocessor Voltage Monitors
with Programmable Voltage Detection
2 _______________________________________________________________________________________
Supply Voltage .......................................................-0.5V to +18V
Output Voltage .......................................................-0.5V to +18V
Hysteresis...................+0.5V to -18V with respect to (V+ + 0.5V)
Threshold Input Voltage ...............................-0.5V to (V+ + 0.5V)
Current into Any Terminal .................................................±50mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) .....727mW
8-Pin SO (derate 5.88mW/°C above +70°C)..................471mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C)..........640mW
8-Pin TO-99 (derate 6.67mW/°C above +70°C).............533mW
Operating Temperature Ranges
MAX821_C_ _ .......................................................0°C to +70°C
MAX821_E_ _.....................................................-40°C to +85°C
MAX821_M_ _..................................................-55°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.
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V+ = 5V, TA= +25°C, unless otherwise noted.)
PARAMETER
SYMBOL CONDITIONS UNITS
TA= +25°C 515 515
Supply Current I+
2V ≤ V+ ≤ 16.5V,
GND ≤ V
TH
≤ V+
TA= T
MIN
to T
MAX
20 20
µA
Threshold Voltage
Disparity between Output
and Hysteresis Output
V
THP
±0.1 ±0.1 mV
2.0 16.5 2.0 16.5
Guaranteed Operating
Supply Voltage Range
V
SUPP
2.2 16.5 2.2 16.5
V
Typical Operating
Supply Voltage Range
V
SUPP
1.5 16.5 1.5 16.5 V
Threshold Voltage
Temperature Coefficient
∆V
TH/∆T
-200 -200 ppm/°C
Variation of Threshold
Voltage with Supply Voltage
∆V
TH
V+ = 4.5V to 5.5V 1.0 0.2 mV
0.01 10 0.01 10
Threshold Input Current I
TH
20 20
nA
Output Leakage Current I
LOUT
V
OUT
= 16.5V, VTH= 1.0V 10
V
OUT
= 16.5V, VTH= 1.3V 10
V
OUT
= 5V, VTH= 1.0V 1
TA= T
MIN
to T
MAX
,
C/E temp. ranges
V
OUT
= 5V, VTH= 1.3V 1
V
OUT
= 16.5V, VTH= 0.9V 30
V
OUT
= 16.5V, VTH= 1.3V 30
V
OUT
= 5V, VTH= 0.9V 10
TA= T
MIN
to T
MAX
,
M temp. range
V
OUT
= 5V, VTH= 1.3V 10
µA
MAX8212
MIN TYP MAX
MAX8211
MIN TYP MAX
TA= T
MIN
to T
MAX
0V ≤ VTH≤ V+, TA= +25°C
I
OUT
= 4mA,
I
HYST
= 1mA
TA= +25°C
TA= T
MIN
to T
MAX
See Figure 4
V+ = 16.5V, I
OUT
= 3mA
1.05 1.25 1.05 1.25
V+ = 16.5V, I
OUT
= 4mA
1.11 1.19 1.11 1.19
Threshold Trip Voltage V
TH
TA= +25°C
V+ = 2V, I
OUT
= 500µA
V
TA= T
MIN
to T
MAX
V+ = 2.2V, I
OUT
= 500µA
MAX8211/MAX8212
Microprocessor Voltage Monitors
with Programmable Voltage Detection
________________________________________________________________________________________ 3
Note 1: The maximum output current of the MAX8211 is limited by design to 30mA under any operating condition. The output voltage
may be sustained at any voltage up to +16.5V as long as the maximum power dissipation of the device is not exceeded.
Note 2: The maximum output current of the MAX8212 is not defined, and systems using the MAX8212 must therefore ensure that the
output current does not exceed 50mA and that the maximum power dissipation of the device is not exceeded.
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, TA= +25°C, unless otherwise noted.)
PARAMETER
SYMBOL CONDITIONS UNITS
I
OUT
= 2mA, VTH= 1.0V 0.17 0.4
Output Saturation Voltage V
OL
I
OUT
= 2mA, VTH= 1.3V 0.17 0.4
V
VTH= 1.0V (Note 1) 47.0
Maximum Available
Output Current
I
OH
C temp. range,
V
OUT
= 5V
VTH= 1.3V (Note 2) 12 35
mA
TA= T
MIN
to T
MAX
, C/E temp. ranges,
V+ = 16.5V, VTH= 1.0V,
V
HYST
= -16.5V with respect to V+
0.1 0.1
Hysteresis Leakage
Current
I
LHYS
TA= T
MIN
to T
MAX
, M temp. range,
V+ = 16.5V, V
TH
= 0.9V,
V
HYST
= -16.5V with respect to V+
3 3
µA
Hysteresis Saturation
Voltage
V
HYS
(MAX)
I
HYST
= 0.5mA, VTH= 1.3V,
measured with respect to V+
-0.1 -0.2 -0.1 -0.2 V
Maximum Available
Hysteresis Current
V
HYS
(MAX)
VTH= 1.3V, V
HYS
= 0V 210 210 mA
MAX8212
MIN TYP MAX
MAX8211
MIN TYP MAX
_______________Detailed Description
As shown in the block diagrams of Figures 1 and 2, the
MAX8211 and MAX8212 each contain a 1.15V reference, a comparator, an open-drain N-channel output
transistor, and an open-drain P-channel hysteresis output. The MAX8211 output N-channel turns on when the
voltage applied to the THRESH pin is less than the
internal reference (1.15V). The sink current is limited to
7mA (typical), allowing direct drive of an LED without a
series resistor. The MAX8212 output turns on when the
voltage applied to THRESH is greater than the internal
reference. It is not current limited, and will typically sink
35mA.
Compatibility with ICL8211/ICL8212
The CMOS MAX8211/MAX8212 are plug-in replacements
for the bipolar ICL8211/ICL8212 in most applications.
The use of CMOS technology has several advantages.
The quiescent supply current is much less than in the
bipolar parts. Higher-value resistors can also be used
Figure 1. MAX8211 Block Diagram
THRESH
1.15V
REFERENCE
V+
P
HYST
OUT
N
Loading...