MAX8212CSA - Maxim Integrated Products, Inc.

________________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 sev-

eral 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

oµP Power-Fail Warning

oImproved 2nd Source for ICL8211/ICL8212

oLow-Power CMOS Design

o5µA Quiescent Current

oOn-Board Hysteresis Output

o±40mV Threshold Accuracy (±3.5%)

o2.0V to 16.5V Supply-Voltage Range

oDefine Output Current Limit (MAX8211)

oHigh Output Current Capability (MAX8212)

_______________Ordering Information

MAX8211/MAX8212

Microprocessor Voltage Monitors

with Programmable Voltage Detection

________________________________________________________________

Maxim Integrated Products

V+

HYST

THRESH

MAX8211

OUT

GND

V+

LOGIC-SUPPLY UNDERVOLTAGE DETECTOR

(DETAILED CIRCUIT DIAGRAM—FIGURE 5)

µP

NMI

_________________Pin Configurations

TOP VIEW

V+

MAX8211

MAX8212

N.C.

GND

N.C. 1

HYST

THRESH

OUT

DIP/SO

___________Typical Operating Circuit

19-0539; Rev 5; 9/08

Ordering Information continued on last page.

Contact factory for dice specifications.

Contact factory for availability and processing to MIL-STD-883.

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.

Pin Configurations continued at end of data sheet.

PART TEMP RANGE PIN -

PA C K A G E

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

MAX8211ETY -40°C to +85°C 8 TO-99

MAX8211MJA -55°C to +125°C 8 CERDIP**

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 (TA = +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 ≤VTH ≤V+ TA= TMIN to TMAX 20 20 µA

Threshold Voltage

Disparity between Output

and Hysteresis Output

VTHP ±0.1 ±0.1 mV

2.0 16.5 2.0 16.5

Guaranteed Operating

Supply Voltage Range VSUPP 2.2 16.5 2.2 16.5 V

Typical Operating

Supply Voltage Range VSUPP 1.5 16.5 1.5 16.5 V

Threshold Voltage

Temperature Coefficient ∆VTH/∆T-200 -200 ppm/°C

Variation of Threshold

Voltage with Supply Voltage ∆VTH V+ = 4.5V to 5.5V 1.0 0.2 mV

0.01 10 0.01 10

Threshold Input Current ITH 20 20 nA

Output Leakage Current ILOUT

VOUT = 16.5V, VTH = 1.0V 10

VOUT = 16.5V, VTH = 1.3V 10

VOUT = 5V, VTH = 1.0V 1

TA= TMIN to TMAX,

C/E temp. ranges

VOUT = 5V, VTH = 1.3V 1

VOUT = 16.5V, VTH = 0.9V 30

VOUT = 16.5V, VTH = 1.3V 30

VOUT = 5V, VTH = 0.9V 10

TA= TMIN to TMAX,

M temp. range

VOUT = 5V, VTH = 1.3V 10

µA

MAX8212

MIN TYP MAX

MAX8211

MIN TYP MAX

TA= TMIN to TMAX

0V ≤VTH ≤V+, TA= +25°C

IOUT = 4mA,

IHYST = 1mA

TA= +25°C

TA= TMIN to TMAX

See Figure 4

V+ = 16.5V, IOUT = 3mA 1.05 1.25 1.05 1.25

V+ = 16.5V, IOUT = 4mA 1.11 1.19 1.11 1.19

Threshold Trip Voltage VTH

TA= +25°C V+ = 2V, IOUT = 500µA V

TA= TMIN to TMAX V+ = 2.2V, IOUT = 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

IOUT = 2mA, VTH = 1.0V 0.17 0.4

Output Saturation Voltage VOL IOUT = 2mA, VTH = 1.3V 0.17 0.4 V

VTH = 1.0V (Note 1) 4 7.0

Maximum Available

Output Current IOH C temp. range,

VOUT = 5V VTH = 1.3V (Note 2) 12 35 mA

TA= TMIN to TMAX, C/E temp. ranges,

V+ = 16.5V, VTH = 1.0V,

VHYST = -16.5V with respect to V+

0.1 0.1

Hysteresis Leakage

Current ILHYS

TA= TMIN to TMAX, M temp. range,

V+ = 16.5V, VTH = 0.9V,

VHYST = -16.5V with respect to V+

3 3

µA

Hysteresis Saturation

Voltage

VHYS

(MAX)

IHYST = 0.5mA, VTH = 1.3V,

measured with respect to V+ -0.1 -0.2 -0.1 -0.2 V

Maximum Available

Hysteresis Current

VHYS

(MAX) VTH = 1.3V, VHYS = 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 refer-

ence, a comparator, an open-drain n-channel output

transistor, and an open-drain p-channel hysteresis out-

put. 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

1.15V

REFERENCE

HYST

OUT

THRESH

V+

Figure 1. MAX8211 Block Diagram

MAX8211/MAX8212

Microprocessor Voltage Monitors

with Programmable Voltage Detection

4 ________________________________________________________________________________________

V+

HYST

THRESH

MAX8211

MAX8212

OUT

GND

V+

VOUT

VIN

Figure 3. Basic Overvoltage/Undervoltage Circuit

in the networks that set up the trip voltage, since the

comparator input (THRESH pin) is a low-leakage

MOSFET transistor. This further reduces system current

drain. The tolerance of the internal reference has also

been significantly improved, allowing for more precise

voltage detection without the use of potentiometers.

The available current from the HYST output has been

increased from 21µA to 10mA, making the hysteresis

feature easier to use. The disparity between the HYST

output and the voltage required at THRESH to switch

the OUT pin has also been reduced in the MAX8211

from 8mV to 0.1mV to eliminate output “chatter” or

oscillation.

Most voltage detection circuits operate with supplies of

15V or less; in these applications, the MAX8211/

MAX8212 will replace ICL8211/ICL8212s with the per-

formance advantages described above. However, note

that the CMOS parts have an absolute maximum sup-

ply-voltage rating of 18V, and should never be used in

applications where this rating could be exceeded.

Exercise caution when replacing ICL8211/ICL8212s in

closed-loop applications such as programmable

zeners. Although neither the ICL8211/ICL8212 nor the

MAX8211/MAX8212 are internally compensated, the

CMOS parts have higher gain and may not be stable

for the external compensation-capacitor values used in

lower-gain ICL8211/ICL8212 circuits.

__________Applications Information

Basic Voltage Detectors

Figure 3 shows the basic circuit for both undervoltage

detection (MAX8211) and overvoltage detection

(MAX8212). For applications where no hysteresis is

needed, R3 should be omitted. The ratio of R1 to R2 is

then chosen such that, for the desired trip voltage at VIN,

1.15V is applied to the THRESH pin. Since the com-

parator inputs are very low-leakage MOSFET transis-

tors, the MAX8211/MAX8212 can use much higher

resistors values in the attenuator network than can the

bipolar ICL8211/ICL8212. See Table 1 for switching

delays.

Table 1. Switching Delays

Voltage Detectors with Hysteresis

To ensure noise-free output switching, hysteresis is

frequently used in voltage detectors. For both the

MAX8211 and MAX8212 the HYST output is on for

threshold voltages greater than 1.15V. R3 (Figure 3)

controls the amount of current (positive feedback) sup-

plied from the HYST output to the mid-point of the resis-

tor divider, and hence the magnitude of the hysteresis,

or dead-band.

Figure 2. MAX8212 Block Diagram

1.15V

REFERENCE

HYST

OUT

THRESH

V+

TYPICAL DELAYS MAX8211 MAX8212

t(on) 40µs 250µs

t(off) 1.5ms 3ms

Calculate resistor values for Figure 3 as follows:

1) Choose a value for R1. Typical values are in

the 10kΩ to 10MΩ range.

2) Calculate R2 for the desired upper trip point

VUusing the formula:

3) Calculate R3 for the desired amount of

hysteresis, where VL is the lower trip point:

or, if V+ = VIN:

Figure 5 shows an alternate circuit, suitable only when the

voltage being detected is also the power-supply voltage

for the MAX8211 or MAX8212.

Calculate resistor values for Figure 5 as follows:

1) Choose a value for R1. Typical values are in

the 10kΩ to 10MΩ range.

2) Calculate R2:

3) Calculate R3:

Low-Voltage Detector for Logic Supply

The circuit of Figure 5 will detect when a 5.0V (nominal)

supply goes below 4.5V, which is the VMIN normally

specified in logic systems. The selected resistor values

ensure that false undervoltage alarms will not be gener-

ated, even with worst-case threshold trip values and

resistor tolerances. R3 provides approximately 75mV of

hysteresis.

R3 R1 (VUVL)

1.15V

=× −

R2 R1 (VLVTH)

VTH

R1 (VL1.15V)

1.15V

=×−=×−

R3 R2 (VLVTH)

(VUVL)R2 (VL1.15V)

(VUVL)

=×−

−=×−

−

R3 R2 (V VTH)

(VUVL)R2 (V + 1.15V)

(VUVL)

=×

+−

−=× −

−

R2 = R1 (VUVTH)

VTH

R1 (VU1.15V)

1.15V

×−=× −

MAX8211/MAX8212

Microprocessor Voltage Monitors

with Programmable Voltage Detection

________________________________________________________________________________________ 5

-55

TA (°C)

VTH (V)

1.250

1.230

1.210

1.190

1.170

1.150

1.130

1.110

1.090

1.070

1.050

MAX8211,8212-FIG 4

-25 25 75 125

V+ = 16.5V

V+ = 2V

Figure 4. MAX8211/MAX8212 Threshold Trip Voltage vs.

Ambient Temperature

VIN

HYST MAX8211

OUT

GND

V+

48.7kΩ

2.2MΩ

750kΩ

VOUT

(LOW FOR

VIN < 4.5V)

THRESH

Figure 5. MAX8211 Logic-Supply Low-Voltage Detector

MAX8211/MAX8212

Microprocessor Voltage Monitors

with Programmable Voltage Detection

6 _______________________________________________________________________________________

_Ordering Information (continued)

_____________________________________________Pin Configurations (continued)

THRESH

HYST

N.C.

V+

GND

N.C.

OUT

MAX8211

MAX8212

µMAX

TOP VIEW TOP VIEW

HYST

V+

N.C.

GND

N.C.

THRESH

OUT

TO-99*

CASE IS CONNECTED TO PIN 7 ON TV PACKAGE.

CASE IS CONNECTED TO PIN 4 ON TY PACKAGE.

Contact factory for dice specifications.

Contact factory for availability and processing to MIL-STD-883.

PART TEMP RANGE PIN -

PA C K A G E

MAX8211MSA/PR -55°C to +125°C 8 SO**

MAX8211MSA/PR-T -55°C to +125°C 8 SO**

MAX8211MTV -55°C to +125°C 8 TO-99**

MAX8212CPA -0°C to +70°C 8 Plastic DIP

MAX8212CSA -0°C to +70°C 8 SO

MAX8212CUA -0°C to +70°C 8 µMAX

MAX8212CTY -0°C to +70°C 8 TO-99

MAX8212EPA -40°C to +85°C 8 Plastic DIP

MAX8212ESA -40°C to +85°C 8 SO

MAX8212EJA -40°C to +85°C 8 CERDIP

MAX8212ETY -40°C to +85°C 8 TO-99

MAX8212MJA -55°C to +125°C 8 CERDIP**

MAX8212MSA/PR -55°C to +125°C 8 SO**

MAX8212MSA/PR-T -55°C to +125°C 8 SO**

MAX8212MTV -55°C to +125°C 8 TO-99**

Package Information

For the latest package outline information and land patterns, go

to www.maxim-ic.com/packages.

PACKAGE TYPE PACKAGE CODE DOCUMENT NO.

8 CERDIP J8-2 21-0045

8 Plastic DIP P8-1 21-0043

8 SO S8-2 21-0041

8 TO-99 T99-8 21-0022

8 µMAX U8-1 21-0036

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600

MAX8211/MAX8212

Microprocessor Voltage Monitors

with Programmable Voltage Detection

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 1/91 Initial release —

4 9/02 Updated Figure 5. 5

5 9/08 Updated Ordering Information. 1, 6