MAX6458UKD0C+T - Maxim Integrated

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 reference,

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

voltage window. The MAX6459 includes dual overvoltage/

undervoltage comparators with two independent compar-

ator outputs. Use the MAX6459 as a window comparator

with separate undervoltage and overvoltage outputs or as

two independent, single voltage monitors. The MAX6460

includes a single comparator and an internal 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 moni-

tors 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 circuit with a 90ms minimum reset timeout delay.

The monitored 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 temperature range of -40°C to +125°C.

Applications

●Undervoltage Monitoring/Shutdown

●Overvoltage Monitoring/Protection

●Window Voltage Detection Circuitry

●Multicell Battery-Stack Powered Equipment

●Notebooks, eBooks

●Automotive

● Industrial

●Telecom

●Networking

Benets and Features

●Wide Supply Voltage Range, 4V to 28V

● Internal 2.25V ±2.5% Reference

● Low Current (3.5μA, typ at 12V)

●Open-Drain n-Channel Output (28V Compliant)

● Internal Threshold Hysteresis Options

(0.5%, 5%, 8.3%)

● Two IN-to-OUT Timeout Period Options

(50μs, 150ms)

● Internal Undervoltage Lockout

● Immune to Short Voltage Transients

●Small SOT23 Packages

●Few External Components

●Fully Specified from -40°C to +125°C

●AEC-Q100 Qualified (MAX6459UTA/V+ only)

19-2048; Rev 7; 7/17

Pin Configurations appears at end of data sheet.

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 let-

ters 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.

/V denotes an automotive qualified part.

PART TEMP RANGE PIN-PACKAGE

MAX6457UKD_ _-T -40°C to +125°C 5 SOT23

MAX6458UKD_ _-T -40°C to +125°C 5 SOT23

MAX6459UTA/V-T -40°C to +125°C 6 SOT23

MAX6459UT_/V+ -40°C to +125°C 6 SOT23

MAX6460UT-T -40°C to +125°C 6 SOT23

5-CELL

Li+

BATTERY

STACK

BATTERY

CHARGER

DC-DC

CONVERTER

LOAD

RPULLUP

SHDN

+21V (NOMINAL)

VCC

GND CLEAR

IN+ OUT

MAX6457

IN OUT

MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

in SOT Packages

Ordering Information

Typical Operating Circuit

VCC, OUT, OUTA, OUTB, CLEAR to GND ........-0.3V to +30.0V

IN+, IN- to GND ........................................ -0.3V to (VCC + 0.3V)

REF to GND ...........-0.3V to the lower of +6V and (VCC + 0.3V)

Input Currents (VCC, IN+, IN-) ...........................................20mA

Sink Current (OUT, OUTA, OUTB) ..................................... 20mA

Continuous Power Dissipation (TA = +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

Soldering Temperature (reflow)

Lead(Pb)-free...............................................................+260°C

Containing lead (Pb) ....................................................+240°C

(VCC = 4V to 28V, TA = -40°C to +125°C, unless otherwise specified. Typical values are at TA = +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Operating Voltage Range VCC (Note 2) 4 28 V

Supply Current ICC

VCC = 5V, no load 2 5

µAVCC = 12V, no load 3.5 7.5

VCC = 24V, no load 6.5 12.5

Threshold Voltage

VTH+ VIN

rising

TA = -40°C to +85°C, VCC ≥ 4V 1.195 1.228 1.255

TA = +85°C to +125°C, VCC ≥ 4V 1.170 1.255

VTH- VIN

falling

MAX645_U_D_A TA = -40°C to +85°C 1.180 1.255

TA = +85°C to +125°C 1.155 1.255

MAX645_U_D_B TA = -40°C to +85°C 1.133 1.194

TA = +85°C to +125°C 1.111 1.194

MAX645_U_D_C TA = -40°C to +85°C 1.093 1.151

TA = +85°C to +125°C 1.071 1.151

Threshold Voltage

Hysteresis

MAX64_ _U_D_A 0.5

%VTH+

MAX64_ _U_D_B 5

MAX64_ _U_D_C 8.3

IN Operating Voltage Range VIN (Note 2) 0 VCC V

IN Leakage Current IIN VIN = 1.25V, VCC = +28V -55 +55 nA

OUT Timeout Period tTP

MAX645_UKD0_

MAX6459UT_

MAX6460UT

50 µs

MAX6457 and MAX6458 only,

D3 option 90 150 210 ms

Startup Time VCC rising from GND to VCC ≥ 4V in less than 1µs

(Note 3) 2 ms

CLEAR Input Logic Voltage

(MAX6457)

VIL 0.4 V

VIH 2

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MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

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Absolute Maximum Ratings

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

Note 1: Devices are production tested at TA = +25°C. Overtemperature limits are guaranteed by design.

Note 2: IN voltage monitoring requires that VCC ≥ 4V, but OUT remains asserted in the correct undervoltage lockout state for VCC

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 VCC but cannot exceed +28V.

(VCC = 4V to 28V, TA = -40°C to +125°C, unless otherwise specified. Typical values are at TA = +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Output Voltage Low VOL

VCC ≥ 1.5V, ISINK = 250µA, OUT asserted,

TA = -40°C to +85°C 0.4

VCC ≥ 4.0V, ISINK = 1mA, OUT asserted,

TA = -40°C to +125°C 0.4

Output Leakage Current ILKG VCC = 5V, VOUT = 28V (Note 4) 500 nA

Output Short-Circuit Sink ISC OUT asserted, OUT = VCC 10 mA

MAX6460

Reference Short-Circuit

Current REF = GND 7 mA

Reference Output Voltage VREF

TA = -40°C to +85°C 2.183 2.25 2.303 V

TA = +85°C to +125°C 2.171 2.25 2.303

Load Regulation Sourcing: 0 ≤ IREF ≤ 100µA,

sinking: 0 ≤ |IREF| ≤ 300nA 50 µV/µA

Input Offset Voltage VOFFSET -4.5 +4.5 mV

Input Hysteresis 6 mV

Input Bias Current IBIAS VIN+ = 1.4V, VIN- = 1V -25 +25 nA

Input Offset Current IOFFSET 2 pA

Common-Mode Voltage

Range CMVR 0 1.4 V

Common-Mode Rejection

Ratio CMRR 80 dB

Comparator Power-Supply

Rejection Ratio PSRR VIN+ = VIN- = 1.4V 80 dB

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MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

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Electrical Characteristics (continued)

(GND = 0, RPULLUP = 10kΩ, and TA = +25°C, unless otherwise noted.)

TRIP THRESHOLD VOLTAGE

vs. TEMPERATURE (0.5% HYSTERESIS)

MAX6457-60 toc02

TEMPERATURE (°C)

TRIP THRESHOLD VOLTAGE (V)

1109580655035205-10-25

1.13

1.15

1.17

1.19

1.21

1.23

1.25

1.11

-40 125

VTH+ (RISING)

VTH- (FALLING)

TRIP THRESHOLD VOLTAGE

vs. TEMPERATURE (5% HYSTERESIS)

MAX6457-60 toc03

TEMPERATURE (°C)

TRIP THRESHOLD VOLTAGE (V)

1109580655035205-10-25

1.13

1.15

1.17

1.19

1.21

1.23

1.25

1.11

-40 125

VTH+ (RISING)

VTH- (FALLING)

TRIP THRESHOLD VOLTAGE

vs. TEMPERATURE (8.3% HYSTERESIS)

MAX6457-60 toc04

TEMPERATURE (°C)

TRIP THRESHOLD VOLTAGE (V)

1109580655035205-10-25

1.13

1.15

1.17

1.19

1.21

1.23

1.25

1.11

-40 125

VTH+ (RISING)

VTH- (FALLING)

OUTPUT LOW VOLTAGE

vs. OUTPUT SINK CURRENT

MAX6457-60 toc05

ISINK (mA)

VOL (mV)

1010.1

100

1000

10,000

100,000

0.1

0.01 100

TA = +125°C

TA = +25°C

TA = -40°C

VCC = 12V

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX6457-60 toc01

VCC (V)

(µA)

221610

4 28

TA = +25°C

TA = +125°C

TA = -40°C

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MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

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Typical Operating Characteristics

(GND = 0, RPULLUP = 10kΩ, and TA = +25°C, unless otherwise noted.)

TIMEOUT PERIOD vs. TEMPERATURE

MAX6457-60 toc07

TEMPERATURE (°C)

(ms)

1109580655035205-10-25

0.1

100

1000

0.01

-40 125

MAX6457UKD3

MAX6457UKD0

OUTPUT FALL TIME

vs. SUPPLY VOLTAGE

MAX6457-60 toc08

VCC (V)

OUTPUT FALL TIME (ns)

242016128

200

400

600

800

1000

1200

1400

1600

1800

2000

4 28

TA = +125°C

TA = -40°C

TA = +25°C

MAXIMUM TRANSIENT DURATION

vs. INPUT OVERDRIVE

MAX6457-60 toc09

INPUT OVERDRIVE (VTH- - VIN+) (mV)

MAXIMUM TRANSIENT DURATION (µs)

10010

100

150

200

250

300

1 1000

OUT ASSERTED LOW

ABOVE THIS LINE

MAX6457-60 toc10

TEMPERATURE (°C)

IIN (nA)

1109580655035205-10-25

-2

-40 125

VIN = 1.25V

INPUT LEAKAGE CURRENT

vs. TEMPERATURE

OUTPUT SHORT-CIRCUIT SINK CURRENT

vs. TEMPERATURE

MAX6457-60 toc06

TEMPERATURE (°C)

(mA)

1109580655035205-10-25

-40 125

VCC = 12V

VCC = 5V

VCC = 24V

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MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

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Typical Operating Characteristics (continued)

PIN NAME FUNCTION

MAX6457 MAX6458 MAX6459 MAX6460

1 1 — 1 OUT

MAX6457: Open-Drain Monitor Output. OUT requires an external

pullup resistor. OUT asserts low for VCC between 1.5V and 4V. OUT

asserts low when VIN+ drops below VTH- and goes high after the

timeout period (tTP) when VIN+ exceeds VTH+.

MAX6458: Open-Drain Monitor Output. OUT requires an external

pullup resistor. OUT asserts low for VCC between 1.5V and 4V. OUT

asserts low when VIN+ drops below VTH- or when VIN- exceeds

VTH+. OUT goes high after the timeout period (tTP) when VIN+

exceeds VTH+ and VIN- drops below VTH-.

MAX6460: Open-Drain Monitor Output. OUT requires an external

pullup resistor. OUT asserts low for VCC between 1.5V and 4V. OUT

asserts low when VIN+ drops below VIN-. OUT goes high when VIN+

is above VIN-.

— — 1 — OUTA

Open-Drain Monitor A Undervoltage Output. OUTA requires an

external pullup resistor. OUTA goes low when VIN+ drops below

VTH- and goes high when VIN+ exceeds VTH+. OUTA also goes low

for VCC between 1.5V and 4V.

— — 5 — OUTB

Open-Drain Monitor B Overvoltage Output. OUTB requires an

external pullup resistor. OUTB goes low when VIN- exceeds VTH+

and goes high when VIN- drops below VTH-. OUTB also goes low

when VCC drops below 4V.

2 2 2 2 GND Ground

3 3 3 3 IN+ Adjustable Undervoltage Monitor Threshold Input. Noninverting input

for MAX6460.

— 4 4 4 IN- Adjustable Overvoltage Monitor Threshold Input. Inverting input for

MAX6460.

4 — — — CLEAR

Clear Input. For VIN+ > VTH+, drive CLEAR high to latch OUT high.

Connect CLEAR to GND to make the latch transparent. CLEAR

must be low when powering up the device. Connect CLEAR to GND

when not used.

— — — 5 REF

Reference. Internal 2.25V reference output. Connect REF to IN+

through a voltage divider for active-low output. Connect REF to IN-

through a voltage divider for active-high output. REF can source up

to 100µA and sink up to 300nA. Leave REF oating when not used.

REF output is stable with capacitive loads from 0 to 50pF or greater

than 1µF.

5 5 6 6 VCC Supply Voltage

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Pin Description

Figure 1. MAX6457 Functional Diagram Figure 2. MAX6458 Functional Diagram

Figure 3. MAX6459 Functional Diagram Figure 4. MAX6460 Functional Diagram

MAX6457

HYSTERESIS

OPTION

TIMEOUT

OPTION LATCH

VCC

IN+

GND

OUT

1.228V CLEAR

MAX6458

VCC

IN+

IN-

GND

OUT

1.228V

HYSTERESIS

OPTION

TIMEOUT

OPTION

"UV": UNDERVOLTAGE

"OV": OVERVOLTAGE

MAX6459

VCC

IN+

IN-

GND

1.228V

HYSTERESIS

OPTION

"UV": UNDERVOLTAGE

"OV": OVERVOLTAGE

OUTA

OUTB

MAX6460

VCC

IN+

IN-

REF

GND

2.25V

OUT

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Functional Diagrams

Detailed Description

Each of the MAX6457–MAX6460 high-voltage (4V to

28V), low-power voltage monitors include a precision

bandgap reference, one or two low-offset-voltage com-

parators, internal threshold hysteresis, internal timeout

period, and one or two high-voltage open-drain outputs.

Programming the Trip Voltage (VTRIP)

Two external resistors set the trip voltage, VTRIP (Figure 5).

VTRIP is the point at which the applied voltage (typically

VCC) toggles OUT. The MAX6457/MAX6458/MAX6459/

MAX6460’s high input impedance allows large-value

resistors without compromising trip-voltage accuracy.

To minimize current consumption, select a value for R2

between 10kΩ and 1MΩ, then calculate R1 as follows:

TRIP

R1 R2 - 1



=



REFD REF

R3 R4



=



TRIP

REFD

R1 R2 1



= −





where VREF = reference output voltage (2.25V, typ),

VREFD = divided reference, VTRIP = desired trip threshold

in (in volts).

For an active-low power-good output, connect the

resistor divider R1 and R2 to the inverting input and

the reference-divider network to the noninverting input.

Alternatively, connect an external reference less than

1.4V to either input.

where VTRIP = desired trip voltage (in volts), VTH =

threshold trip voltage (VTH+ for overvoltage detection or

VTH- for undervoltage detection).

Use the MAX6460 voltage reference (REF) to set the

trip threshold by connecting IN+ or IN- through a voltage

divider (within the inputs common-mode voltage range)

to REF. Do not connect REF directly to IN+ or IN- since

this violates the input common-mode voltage range. Small

leakage currents into the comparators inputs allows use

of large value resistors to prevent loading the reference

and affecting its accuracy. Figure 5b shows an active-high

power-good output. Use the following equation to deter-

mine the resistor values when connecting REF to IN-:

Figure 5a. Programming the Trip Voltage Figure 5b. Programming the MAX6460 Trip Voltage

Figure 6. Input and Output Waveforms (Noninverting Input Varied)

VCC

IN+

GND

OUT

(OUTA FOR

MAX6459)

VCC

RPULLUP

OUT

(OUTA)

MAX6457–

MAX6460

VTRIP = VTH R1 + R2

VCC

IN+

REF

IN-

GND

VTRIP

VREFD

RPULLUP

OUTOUT

MAX6460

VTH+

VTH-

VIN+

VOUT

VCC

VHYST

tTP tTP

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Hysteresis

Hysteresis adds noise immunity to the voltage monitors

and prevents oscillation due to repeated triggering when

VIN is near the threshold trip voltage. The hysteresis in a

comparator creates two trip points: one for the rising input

voltage (VTH+) and one for the falling input voltage (VTH-).

These thresholds are shown in Figure 6.

The internal hysteresis options of the MAX6457/MAX6458/

MAX6459 are designed to eliminate the need for adding

an external hysteresis circuit.

Timeout Period

The timeout period (tTP) for the MAX6457 is the time from

when the input (IN+) crosses the rising input threshold

(VTH+) to when the output goes high (see Figures 6 and

7). For the MAX6458, the monitored voltage must be in

the “window” before the timeout starts. The MAX6459

and MAX6460 do not offer the extended timeout option

(150ms). The extended timeout period is suitable for over-

voltage protection applications requiring transient immu-

nity to avoid false output assertion due to noise spikes.

Latched-Output Operation

The MAX6457 features a digital latch input (CLEAR) to

latch any overvoltage event. If the voltage on IN+ (VIN+)

is below the internal threshold (VTH-), or if VCC is below

4V, OUT remains low regardless of the state of CLEAR.

Drive CLEAR high to latch OUT high when VIN+ exceeds

VTH+. When CLEAR is high, OUT does not deassert if

VIN+ drops back below VIN-. Toggle CLEAR to deassert

OUT. Drive CLEAR low to make the latch transparent

(Figure 7). CLEAR must be low when powering up the

MAX6457. To initiate self-clear at power-up, add a 100kΩ

pullup resistor from CLEAR to VCC and a 1μF capacitor

from CLEAR to GND to hold CLEAR low. Connect CLEAR

to GND when not used. See Figure 9.

Figure 7. Timing Diagram (MAX6457)

Figure 8. Undervoltage Lockout Typical Application Circuit

IN+

OUT

>VTH+

<VTH-

VCC

tTP tTP tTP

CLEAR

5-CELL

Li+

BATTERY

STACK

BATTERY

CHARGER

DC-DC

CONVERTER

LOAD

RPULLUP

IN OUT

+21V

VCC

GND

IN+ OUT

(OUTA FOR

MAX6459)

MAX6457–

MAX6460

SHDN

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Applications Information

Undervoltage Lockout

Figure 8 shows the typical application circuit for detect-

ing an undervoltage event of a 5-cell Li+ battery stack.

Connect OUT of the MAX6457/MAX6458/MAX6460

(OUTA of the MAX6459) to the shutdown input of the

DCDC converter to cut off power to the load in case of an

undervoltage event. Select R1 and R2 to set the trip volt-

age (see the Programming the Trip Voltage (VTRIP) sec-

tion). When the voltage of the battery stack decreases so

that VIN+ drops below VTH- of the MAX6457–MAX6460,

then OUT (OUTA) goes low and disables the power sup-

ply to the load. When the battery charger restores the volt-

age of the 5-cell stack so that VIN+ > VTH+, OUT (OUTA)

goes high and the power supply resumes driving the load.

Overvoltage Shutdown

The MAX6457–MAX6460 are ideal for overvoltage shut-

down applications. Figure 9 shows a typical circuit for

this application using a pass P-channel MOSFET. The

MAX6457–MAX6460 are powered directly from the sys-

tem voltage supply. Select R1 and R2 to set the trip

voltage (see the Programming the Trip Voltage (VTRIP)

section). When the supply voltage remains below the

selected threshold, a low logic level on OUT (OUTB for

MAX6459) turns on the p-channel MOSFET. In the case

of an overvoltage event, OUT (OUTB) asserts high, turns

off the MOSFET, and shuts down the power to the load.

Figure 10 shows a similar application using a fuse and

a silicon-controlled rectifier (SCR). An overvoltage event

turns on the SCR and shorts the supply to ground. The

surge of current through the short circuit blows the fuse

and terminates the current to the load. Select R3 so that

the gate of the SCR is properly biased when OUT (OUTB)

goes high impedance.

Window Detection

The MAX6458/MAX6459 include undervoltage and over-

voltage comparators for window detection (Figures 2 and 3).

The circuit in Figure 11 shows the typical configuration

for this application. For the MAX6458, OUT asserts high

when VCC is within the selected “window.” When VCC

falls below the lower limit of the window (VTRIPLOW) or

exceeds the upper limit (VTRIPHIGH), OUT asserts low.

The MAX6459 features two independent open-drain

outputs: OUTA (for undervoltage events) and OUTB (for

overvoltage events). When VCC is within the selected

window, OUTA and OUTB assert high. When VCC falls

below VTRIPLOW, OUTA asserts low while OUTB remains

Figure 9. Overvoltage Shutdown Circuit (with External Pass

MOSFET)

Figure 10. Overvoltage Shutdown Circuit (with SCR Fuse)

Figure 11. Window Detection

LOAD

100kΩ

1µF

R2 RPULLUP

VCC

GND

IN+

OUT

(OUTA FOR

MAX6459)

MAX6457–

MAX6460

VSUPPLY

CLEAR

LOAD

VCC

FUSE

GND

IN+ OUT

(OUTA FOR

MAX6459)

MAX6457–

MAX6460

VSUPPLY

SCR

VCC

GND

VCC

MAX6458

MAX6459

IN+

IN-

OUT

MAX6458

ONLY

OUTB

MAX6459

ONLY

RPULLUP

OUTA OUTA

OUTB

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high. When VCC exceeds VTRIPHIGH, OUTB asserts low

while OUTA remains high. VTRIPLOW and VTRIPHIGH are

given by the following equations:

TOTAL

TRIPLOW TH-

TOTAL

TRIPHIGH TH

R2 R3



=





=



where RTOTAL = R1 + R2 + R3.

Use the following steps to determine the values for R1,

R2, and R3.

1) Choose a value for RTOTAL, the sum of R1, R2, and

R3. Because the MAX6458/MAX6459 have very high

input impedance, RTOTAL can be up to 5MΩ.

2) Calculate R3 based on RTOTAL and the desired upper

trip point:

TH TOTAL

TRIPHIGH

V R

R3 V

3) Calculate R2 based on RTOTAL, R3, and the desired

lower trip point:

TH- TOTAL

TRIPLOW

V R

R2 - R3

4) Calculate R1 based on RTOTAL, R3, and R2:

R1 = RTOTAL - R2 - R3

Example Calculations for Window

Detection

The following is an example for calculating R1, R2, and

R3 of Figure 11 for window detection. Select the upper

and lower trip points (VTRIPHIGH and VTRIPLOW).

VCC = 21V

VTRIPHIGH = 23.1V

VTRIPLOW = 18.9V

For 5% hysteresis, VTH+ = 1.228 and VTH- = 1.167.

1) Choose RTOTAL = 4.2MΩ = R1 + R2 + R3

2) Calculate R3

TH+ TOTAL

TRIPHIGH

V R (1.228V)(4.2M )

R3 V 23.1V

223.273k

×Ω

= =

= Ω

3) Calculate R2

Figure 12. Monitoring Voltages Other than VCC

Figure 13. Interfacing to Voltages Other than VCC

Figure 14. Monitoring Negative Voltages

MAX6457–

MAX6460

VMON

VCC

GND

RPULLUP

IN+ OUT

(OUTA FOR

MAX6459)

OUT

(OUTA)

MAX6457–

MAX6460

VCC

GND

RPULLUP

OUT/

OUTA/

OUTB

OUT/

OUTA/

OUTB

VCC (4V TO 28V) VOUT (UP TO 28V)

MAX6460

VCC

GND

VNEG

RPULLUP

IN+

REF

IN-

OUT OUT

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│

MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

in SOT Packages

PART SUFFIX TIMEOUT OPTION HYSTERESIS OPTION (%)

MAX6457UKD_ _ -T

MAX6458UKD_ _ -T

0A 50µs 0.5

0B 50µs

0C 50µs 8.3

3A 150ms 0.5

3B 150ms

3C 150ms 8.3

MAX6459UT_ -T

50µs 0.5

50µs

50µs 8.3

MAX6460UT-T

N/A 50µs 0.5

PART PIN

COUNT

LATCHED

OUTPUT

NUMBER OF

OUTPUTS

HYSTERESIS

(%VTH+)

TIMEOUT

PERIOD TOP MARK COMPARATORS

MAX6457UKD0A-T 5 ü1 0.5 50µs AEAA 1

MAX6457UKD3A-T 5 ü1 0.5 150ms AANN 1

MAX6457UKD0B-T 5 ü1 5 50µs AANL 1

MAX6457UKD3B-T 5 ü1 5 150ms AANO 1

MAX6457UKD0C-T 5 ü1 8.3 50µs AANM 1

MAX6457UKD3C-T 5 ü1 8.3 150ms ADZZ 1

MAX6458UKD0A-T 5 — 1 0.5 50µs AANP 2

MAX6458UKD3A-T 5 — 1 0.5 150ms AANS 2

MAX6458UKD0B-T 5 — 1 5 50µs AANQ 2

MAX6458UKD3B-T 5 — 1 5 150ms AEAB 2

MAX6458UKD0C-T 5 — 1 8.3 50µs AANR 2

MAX6458UKD3C-T 5 — 1 8.3 150ms AANT 2

MAX6459UTA-T 6 — 2 0.5 50µs ABML 2

MAX6459UTB-T 6 — 2 5 50µs ABEJ 2

MAX6459UTC-T 6 — 2 8.3 50µs ABMM 2

MAX6460UT-T 6 — 1 0.5 50µs ABEG 1

MAX6459UTA/V-T 6 — 2 0.5 50µs ACRY 2

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MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

in SOT Packages

Table 1. Factory-Trimmed Internal Hysteresis and Timeout Period Options

Selector Guide

TH- TOTAL

TRIPLOW

R2 - R3

(1.167V) (4.2M ) - 223.273k

18.9V

36.06k

Ω

= Ω

4) Calculate R1

TOTAL

R1 R - R2 - R3

4.2M - 223.273 k - 36.06k

3.94067M

=Ω ΩΩ

= Ω

Monitoring Voltages Other than VCC

The MAX6457–MAX6460 can monitor voltages other

than VCC (Figure 12). Calculate VTRIP as shown in the

Programming the Trip Voltage (VTRIP) section. The moni-

tored voltage (VMON) is independent of VCC. VIN+ must

be within the specified operating range: 0 to VCC.

Interfacing to Voltages Other than VCC

The open-drain outputs of the MAX6457–MAX6460 allow

the output voltage to be selected independent of VCC. For

systems requiring an output voltage other than VCC, con-

nect the pullup resistor between OUT, OUTA, or OUTB

and any desired voltage up to 28V (see Figure 13).

Monitoring Negative Voltages

Figure 14 shows the typical application circuit for monitor-

ing negative voltages (VNEG) using the MAX6460. Select

a value for R1 between 25kΩ and 1MΩ. Use the following

equation to select R2:

NEG

REF

-V

R 2 R1 V

= ×

where VREF = 2.25V and VNEG < 0. VIN+ must always be

within the specified operating range: 0 to VCC.

GND

IN+

1 5 VCC

OUT

MAX6457

SOT23

TOP VIEW

3 4

GND

IN-IN+

1 6 VCC

5 OUTB

OUTA

MAX6459

SOT23

3 4

GND

IN-IN+

1 5 VCC

OUT

MAX6458

SOT23

3 4

GND

IN-IN+

1 6 VCC

5 REF

OUT

MAX6460

SOT23

3 4

CLEAR

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│

MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

in SOT Packages

Pin Congurations

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

5 SOT23 U5+1 21-0057 90-0174

6 SOT23 U6+1 21-0058 90-0175

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│

MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

in SOT Packages

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maximintegrated.com/packages. Note

that a “+”, “#”, or “-” in the package code indicates RoHS status

only. Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

Chip Information

PROCESS: BiCMOS

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 7/02 Initial release —

1 6/03 Updated the Pin Description and Detailed Description sections. 6, 8

2 12/05 Added lead-free notation to Ordering Information. 1

3 1/07 Updated the Pin Description and Figures 5a, 9, 12. 6, 8, 10, 11, 13-16

4 3/09 Updated the Programming the Trip Voltage (VTRIP) section. 8

5 7/12 Updated the Package Information table. 14

6 12/12 Added MAX6459UT_/V+ to Ordering Information 1

7 7/17 Added AEC-Q100 to Benets and Features section and /V part to Ordering

Information and Selector Guide 1, 12

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

are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)

shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

│

MAX6457–MAX6460 High-Voltage, Low-Current Voltage Monitors

in SOT Packages

Revision History

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

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Maxim Integrated:

MAX6457UKD3C+T MAX6457UKD0A+T MAX6457UKD0B+T MAX6457UKD0C+T MAX6457UKD3A+T

MAX6457UKD3B+T MAX6458UKD0A+T MAX6458UKD0B+T MAX6458UKD0C+T MAX6458UKD3A+T

MAX6458UKD3B+T MAX6458UKD3C+T MAX6459UTA+T MAX6459UTB+T MAX6459UTC+T MAX6460UT+T

MAX6459UTA/V+T MAX6458UKD0B