MAX6457UKD-T [MAXIM]

High-Voltage, Low-Current Voltage Monitors in SOT Packages;


型号：	MAX6457UKD-T
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	High-Voltage, Low-Current Voltage Monitors in SOT Packages
文件：	总15页 (文件大小：184K)
中文：	中文翻译
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MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

General Description

Features

o Wide Supply Voltage Range, 4V to 28V

o Internal 2.25V 2.5ꢀ Reference

o Low Current (3.5µA, typ at 12V)

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.

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

o Internal Threshold Hysteresis Options

(0.5ꢀ, 5ꢀ, 8.3ꢀ)

o Two IN-to-OUT Timeout Period Options

(50µs, 150ms)

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.

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

Ordering Information

PART

TEMP RANGE

-40°C to +125°C

PIN-PACKAGE

5 SOT23

MAX6457UKD_ _-T

MAX6458UKD_ _-T

MAX6459UT_-T

MAX6459UT_/V+

MAX6460UT-T

5 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.

/V denotes an automotive qualified part.

Pin Configurations appear at end of data sheet.

Typical Operating Circuit

Applications

Undervoltage Monitoring/Shutdown

Overvoltage Monitoring/Protection

Window Voltage Detection Circuitry

Multicell Battery-Stack Powered Equipment

Notebooks, eBooks

+21V (NOMINAL)

OUT

BATTERY

CHARGER

DC-DC

CONVERTER

SHDN

MAX6457

PULLUP

LOAD

5-CELL

Li+

BATTERY

STACK

Automotive

IN+

OUT

Industrial

Telecom

GND

CLEAR

Networking

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

19-2048; Rev 6; 12/12

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

ABSOLUTE MAXIMUM RATINGS

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)

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

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

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

+ 0.3V)

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

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

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

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

Continuous Power Dissipation (T = +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

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

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

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Operating Voltage Range

(Note 2)

= 5V, no load

Supply Current

= 12V, no load

= 24V, no load

3.5

7.5

µA

6.5

12.5

1.255

1.194

1.151

= -40°C to +85°C, V ≥ 4V

1.195

1.170

1.180

1.228

rising

TH+

= +85°C to +125°C, V

≥ 4V

= -40°C to +85°C

MAX645_U_D_A

MAX645_U_D_B

MAX645_U_D_C

= +85°C to +125°C 1.155

= -40°C to +85°C 1.133

= +85°C to +125°C 1.111

= -40°C to +85°C 1.093

Threshold Voltage

TH-

falling

= +85°C to +125°C 1.071

MAX64_ _U_D_A

MAX64_ _U_D_B

MAX64_ _U_D_C

(Note 2)

0.5

Threshold Voltage Hysteresis

TH+

8.3

IN Operating Voltage Range

IN Leakage Current

= 1.25V, V

= +28V

-55

+55

MAX645_UKD0_

MAX6459UT_

MAX6460UT

µs

OUT Timeout Period

MAX6457 and MAX6458 only,

D3 option

150

210

0.4

rising from GND to V

≥ 4V in less than

Startup Time

1µs (Note 3)

CLEAR Input Logic Voltage

(MAX6457)

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

ELECTRICAL CHARACTERISTICS (continued)

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

PARAMETER

SYMBOL

CONDITIONS

= 250µA, OUT asserted,

MIN

TYP

MAX

UNITS

≥ 1.5V, I

SINK

0.4

= -40°C to +85°C

Output Voltage Low

≥ 4.0V, I

= 1mA, OUT asserted,

SINK

0.4

= -40°C to +125°C

Output Leakage Current

Output Short-Circuit Sink

= 5V, V = 28V (Note 4)

OUT

500

LKG

OUT asserted, OUT = V

MAX6460

Reference Short-Circuit Current

REF = GND

= -40°C to +85°C

2.183

2.171

2.25

2.303

Reference Output Voltage

Load Regulation

REF

= +85°C to +125°C

Sourcing: 0 ≤ I

sinking: 0 ≤ |I

≤ 100µA,

| ≤ 300nA

REF

µV/µA

REF

Input Offset Voltage

-4.5

-25

+4.5

+25

1.4

OFFSET

Input Hysteresis

Input Bias Current

+ = 1.4V, V - = 1V

BIAS

Input Offset Current

OFFSET

CMVR

CMRR

Common-Mode Voltage Range

Common-Mode Rejection Ratio

Comparator Power-Supply

Rejection Ratio

PSRR

+ = V - = 1.4V

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

Note 2: IN voltage monitoring requires that V

≥ 4V, but OUT remains asserted in the correct undervoltage lockout state for V

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

but cannot exceed +28V.

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Typical Operating Characteristics

(GND = 0, R

= 10kΩ, and T = +25°C, unless otherwise noted.)

PULLUP

TRIP THRESHOLD VOLTAGE

vs. TEMPERATURE (0.5% HYSTERESIS)

TRIP THRESHOLD VOLTAGE

vs. TEMPERATURE (5% HYSTERESIS)

SUPPLY CURRENT vs. SUPPLY VOLTAGE

1.25

1.23

1.21

1.19

1.17

1.15

1.13

1.11

1.25

1.23

1.21

1.19

1.17

1.15

1.13

1.11

+ (RISING)

= +125°C

- (FALLING)

= +25°C

- (FALLING)

= -40°C

-40 -25 -10

20 35 50 65 80 95 110 125

-40 -25 -10

20 35 50 65 80 95 110 125

(V)

TEMPERATURE (°C)

TRIP THRESHOLD VOLTAGE

vs. TEMPERATURE (8.3% HYSTERESIS)

OUTPUT LOW VOLTAGE

vs. OUTPUT SINK CURRENT

1.25

1.23

1.21

1.19

1.17

1.15

1.13

1.11

100,000

10,000

1000

100

= +125°C

+ (RISING)

= +25°C

= -40°C

- (FALLING)

= 12V

0.1

-40 -25 -10

20 35 50 65 80 95 110 125

0.01

0.1

100

TEMPERATURE (°C)

(mA)

SINK

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Typical Operating Characteristics (continued)

(GND = 0, R

= 10kΩ, and T = +25°C, unless otherwise noted.)

PULLUP

OUTPUT SHORT-CIRCUIT SINK CURRENT

vs. TEMPERATURE

OUTPUT FALL TIME

vs. SUPPLY VOLTAGE

TIMEOUT PERIOD vs. TEMPERATURE

1000

100

2000

1800

1600

1400

1200

1000

800

= 12V

= +125°C

MAX6457UKD3

MAX6457UKD0

= 5V

600

= +25°C

= 24V

0.1

0.01

400

= -40°C

200

-40 -25 -10

20 35 50 65 80 95 110 125

(V)

-40 -25 -10

20 35 50 65 80 95 110 125

TEMPERATURE (

TEMPERATURE (°C)

MAXIMUM TRANSIENT DURATION

vs. INPUT OVERDRIVE

INPUT LEAKAGE CURRENT

vs. TEMPERATURE

300

250

200

150

100

= 1.25V

OUT ASSERTED LOW

ABOVE THIS LINE

-2

100

1000

-40 -25 -10

20 35 50 65 80 95 110 125

INPUT OVERDRIVE (V - V +) (mV)

TEMPERATURE (°C)

TH-

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Pin Description

NAME

FUNCTION

MAX6457 MAX6458 MAX6459 MAX6460

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

resistor. OUT asserts low for V

between 1.5V and 4V. OUT asserts low

when V

drops below V

and goes high after the timeout period (t

)

IN+

TH-

exceeds V

TH+

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

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

—

OUT

when V

drops below V

or when V exceeds V

. OUT goes

TH+

IN+

TH-

IN-

high after the timeout period (t ) when V

exceeds V

and V

TH+ IN-

IN+

drops below V

TH-

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

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

when V

drops below V . OUT goes high when V

is above V

IN+

IN-

IN+

IN-

Open-Drain Monitor A Undervoltage Output. OUTA requires an external

pullup resistor. OUTA goes low when V

drops below V

and goes

between

IN+

TH-

—

OUTA

OUTB

high when V

exceeds V

. OUTA also goes low for V

TH+

IN+

1.5V and 4V.

Open-Drain Monitor B Overvoltage Output. OUTB requires an external

pullup resistor. OUTB goes low when V exceeds V and goes high

IN-

TH+

when V drops below V . OUTB also goes low when V drops

IN-

TH-

below 4V.

GND

IN+

Ground

Adjustable Undervoltage Monitor Threshold Input. Noninverting input for

MAX6460.

Adjustable Overvoltage Monitor Threshold Input. Inverting input for

MAX6460.

—

IN-

Clear Input. For V

> V

, drive CLEAR high to latch OUT high.

TH+

IN+

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.

—

CLEAR

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 floating when not used. REF output is

stable with capacitive loads from 0 to 50pF or greater than 1µF.

—

REF

Supply Voltage

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Functional Diagrams

IN+

IN-

MAX6458

MAX6457

TIMEOUT

OPTION

IN+

OUT

TIMEOUT

OPTION

LATCH

OUT

HYSTERESIS

OPTION

HYSTERESIS

OPTION

1.228V

CLEAR

1.228V

"UV": UNDERVOLTAGE

"OV": OVERVOLTAGE

GND

Figure 2. MAX6458 Functional Diagram

Figure 1. MAX6457 Functional Diagram

IN+

IN-

MAX6459

OUTA

IN+

OUT

IN-

OUTB

REF

MAX6460

HYSTERESIS

OPTION

2.25V

1.228V

"UV": UNDERVOLTAGE

"OV": OVERVOLTAGE

GND

Figure 3. MAX6459 Functional Diagram

Figure 4. MAX6460 Functional Diagram

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Detailed Description

⎛

⎞

R3+R4

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.

= V

REF

REFD

⎜

⎟

⎝

⎠

⎛

⎞

TRIP

R1=R2

−1

⎜

⎟

⎝

⎠

REFD

Programming the Trip Voltage (V

)

TRIP

Two external resistors set the trip voltage, V

(Figure 5).

TRIP

where V

REFD

= reference output voltage (2.25V, typ),

= divided reference, V

REF

is the point at which the applied voltage (typically

) toggles OUT. The MAX6457/MAX6458/MAX6459/

TRIP

= desired trip thresh-

TRIP

old in (in volts).

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:

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.

⎛

⎞

TRIP

R1=R2

- 1

⎜

⎟

⎝

⎠

TRIP

PULLUP

OUT

PULLUP

OUT

MAX6457–

MAX6460

IN+

REF

IN+

OUT

(OUTA FOR

MAX6459)

(OUTA)

OUT

MAX6460

GND

REFD

IN-

GND

R1 + R2

TRIP

= V

Figure 5a. Programming the Trip Voltage

Figure 5b. Programming the MAX6460 Trip Voltage

where V

= desired trip voltage (in volts), V

TRIP

threshold trip voltage (V + for overvoltage detection

HYST

or V - for undervoltage detection).

TH+

Use the MAX6460 voltage reference (REF) to set the

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

age 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 determine the resistor values

when connecting REF to IN-:

IN+

TH-

OUT

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

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

TH+

IN+

TH-

CLEAR

OUT

Figure 7. Timing Diagram (MAX6457)

Hysteresis

+21V

OUT

Hysteresis adds noise immunity to the voltage monitors

and prevents oscillation due to repeated triggering

BATTERY

CHARGER

DC-DC

CONVERTER

SHDN

when V is near the threshold trip voltage. The hystere-

sis in a comparator creates two trip points: one for the

rising input voltage (V +) and one for the falling input

voltage (V -). These thresholds are shown in Figure 6.

MAX6457–

MAX6460

PULLUP

LOAD

5-CELL

Li+

BATTERY

STACK

The internal hysteresis options of the MAX6457/

MAX6458/MAX6459 are designed to eliminate the need

for adding an external hysteresis circuit.

IN+

OUT

(OUTA FOR

MAX6459)

GND

Timeout Period

The timeout period (t ) for the MAX6457 is the time

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

threshold (V +) to when the output goes high (see

Figure 8. Undervoltage Lockout Typical Application Circuit

Figures 6 and 7). For the MAX6458, the monitored volt-

age 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 overvoltage protection applications requir-

ing transient immunity to avoid false output assertion

due to noise spikes.

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

Drive CLEAR high to latch OUT high when V + exceeds

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

V + drops back below V -. 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

Latched-Output Operation

pullup resistor from CLEAR to V

and a 1µF capacitor

The MAX6457 features a digital latch input (CLEAR) to

from CLEAR to GND to hold CLEAR low. Connect

CLEAR to GND when not used. See Figure 9.

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

is below the internal threshold (V -), or if V

is below

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

FUSE

SUPPLY

LOAD

IN+

MAX6457–

MAX6460

MAX6457–

MAX6460

100kΩ

PULLUP

LOAD

SCR

OUT

(OUTA FOR

MAX6459)

CLEAR

OUT

(OUTA FOR

MAX6459)

IN+

1µF

GND

Figure 9. Overvoltage Shutdown Circuit (with External Pass

MOSFET)

Figure 10. Overvoltage Shutdown Circuit (with SCR Fuse)

Window Detection

The MAX6458/MAX6459 include undervoltage and

overvoltage comparators for window detection (Figures

2 and 3). The circuit in Figure 11 shows the typical con-

figuration for this application. For the MAX6458, OUT

Applications Information

Undervoltage Lockout

Figure 8 shows the typical application circuit for detecting

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 DC-

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

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

asserts high when V

is within the selected “window.”

When V

TRIPLOW

OUT asserts low.

falls below the lower limit of the window

) or exceeds the upper limit (V

TRIPHIGH

The MAX6459 features two independent open-drain

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

age (see the Programming the Trip Voltage (V

) sec-

TRIP

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

that V + drops below V - of the MAX6457–MAX6460,

overvoltage events). When V

is within the selected

window, OUTA and OUTB assert high. When V

falls

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

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

below V

, OUTA asserts low while OUTB

TRIPLOW

age of the 5-cell stack so that V + > V +, 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 volt-

PULLUP

OUT

MAX6458

ONLY

OUT

age (see the Programming the Trip Voltage (V

)

TRIP

IN+

IN-

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.

MAX6458

MAX6459

PULLUP

OUTA

OUTB

MAX6459

ONLY

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.

GND

Figure 11. Window Detection

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

remains high. When V

exceeds V

, OUTB

and

Example Calculations for Window

Detection

TRIPHIGH

asserts low while OUTA remains high. V

TRIPLOW

are given by the following equations:

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

R3 of Figure 11 for window detection. Select the upper

TRIPHIGH

⎛

⎞

and lower trip points (V

and V

TRIPLOW

TOTAL

TRIPHIGH

V_TRIPLOW= V_TH-

⎜

⎝

⎟

⎠

R2+R3

= 21V

⎛

⎞

⎠

= 23.1V

= 18.9V

TRIPHIGH

TRIPLOW

TOTAL

V_TRIPHIGH= V_TH+

⎜

⎝

⎟

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

where R

= R1 + R2 + R3.

TOTAL

1) Choose R

= 4.2MΩ = R1 + R2 + R3

TOTAL

Use the following steps to determine the values for R1,

R2, and R3.

2) Calculate R3

1) Choose a value for R

, the sum of R1, R2, and

TOTAL

× R

(1.228V) (4.2MΩ)

TH+

TOTAL

R3. Because the MAX6458/MAX6459 have very

high input impedance, R can be up to 5MΩ.

R3 =

23.1V

TRIPHIGH

TOTAL

= 223.273kΩ

3) Calculate R2

2) Calculate R3 based on R

upper trip point:

and the desired

TOTAL

V_TH+× R_TOTAL

R3 =

V_TRIPHIGH

OUT

(UP TO 28V)

(4V TO 28V)

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

TOTAL

lower trip point:

PULLUP

× R

TOTAL

TH-

MAX6457–

MAX6460

OUT/

OUTA/

OUTB

OUT/

OUTA/

OUTB

R2 =

- R3

TRIPLOW

4) Calculate R1 based on R

, R3, and R2:

TOTAL

R1 = R

- R2 - R3

TOTAL

GND

Figure 13. Interfacing to Voltages Other than V

MON

IN-

PULLUP

MAX6457–

MAX6460

OUT

(OUTA)

OUT

IN+

REF

IN+

(OUTA FOR

MAX6459)

GND

NEG

Figure 14. Monitoring Negative Voltages

Figure 12. Monitoring Voltages Other than V

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

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

PART

SUFFIX

TIMEOUT OPTION

50µs

HYSTERESIS OPTION (%)

0.5

50µs

8.3

0.5

MAX6457UKD_ _ -T

MAX6458UKD_ _ -T

150ms

50µs

8.3

0.5

MAX6459UT_ -T

MAX6460UT-T

50µs

8.3

0.5

N/A

50µs

Selector Guide

COUNT

LATCHED NUMBER OF HYSTERESIS

TIMEOUT

PERIOD

PART

TOP MARK

COMPARATORS

OUTPUT

OUTPUTS

(%V

)

TH+

MAX6457UKD0A-T

MAX6457UKD3A-T

MAX6457UKD0B-T

MAX6457UKD3B-T

MAX6457UKD0C-T

MAX6457UKD3C-T

MAX6458UKD0A-T

MAX6458UKD3A-T

MAX6458UKD0B-T

MAX6458UKD3B-T

MAX6458UKD0C-T

MAX6458UKD3C-T

MAX6459UTA-T

✓

0.5

50µs

150ms

50µs

AEAA

AANN

AANL

AANO

AANM

ADZZ

AANP

AANS

AANQ

AEAB

AANR

AANT

ABML

ABEJ

0.5

✓

150ms

50µs

✓

8.3

0.5

✓

150ms

50µs

—

150ms

50µs

150ms

50µs

8.3

0.5

150ms

50µs

MAX6459UTB-T

50µs

MAX6459UTC-T

8.3

0.5

50µs

ABMM

ABEG

MAX6460UT-T

50µs

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Interfacing to Voltages Other than V

× R

TOTAL

TH-

The open-drain outputs of the MAX6457–MAX6460

allow the output voltage to be selected independent of

R2 =

- R3

TRIPLOW

. For systems requiring an output voltage other than

, connect the pullup resistor between OUT, OUTA, or

(1.167V) (4.2MΩ)

- 223.273kΩ

18.9V

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

= 36.06kΩ

Monitoring Negative Voltages

4) Calculate R1

Figure 14 shows the typical application circuit for moni-

toring negative voltages (V

) using the MAX6460.

NEG

R1 = R

- R2 - R3

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

TOTAL

following equation to select R2:

= 4.2MΩ - 223.273kΩ - 36.06kΩ

= 3.94067MΩ

-V_NEG

R2 = R1 ×

V_REF

Monitoring Voltages Other than V

The MAX6457–MAX6460 can monitor voltages other than

(Figure 12). Calculate V

Programming the Trip Voltage (V

where V

= 2.25V and V

< 0. V + must always

REF

NEG IN

as shown in the

TRIP

be within the specified operating range: 0 to V

) section. The moni-

TRIP

tored voltage (V

) is independent of V . V + must

MON

CC IN

be within the specified operating range: 0 to V

Pin Configurations

TOP VIEW

OUT

GND

IN+

OUT

GND

IN+

MAX6457

SOT23

MAX6459

SOT23

MAX6458

SOT23

MAX6460

SOT23

CLEAR

IN-

OUTA

GND

IN+

OUT

GND

IN+

OUTB

IN-

REF

IN-

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Package Information

Chip Information

For the latest package outline information and land patterns (foot-

prints), go to www.maxim-integrated.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.

PROCESS: BiCMOS

LAND

PATTERN NO.

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE NO.

90-0174

90-0175

5 SOT23

6 SOT23

U5+1

U6+1

21-0057

21-0058

Maxim Integrated

MAX6457–MAX6460

High-Voltage, Low-Current Voltage Monitors in

SOT Packages

Revision History

REVISION REVISION

PAGES

CHANGED

DESCRIPTION

NUMBER

DATE

7/02

6/03

Initial release

—

Updated the Pin Description and Detailed Description sections.

Added lead-free notation to Ordering Information.

6, 8

12/05

1/07

Updated the Pin Description and Figures 5a, 9, 12.

6, 8, 10, 11, 13-16

3/09

Updated the Programming the Trip Voltage (V

Updated the Package Information table.

) section.

TRIP

7/12

12/12

Added MAX6459UT_/V+ to Ordering Information

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 specifications 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.

Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 ________________________________ 15

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.

MAX6457UKD-T [MAXIM]

相关型号：

MAX6457UKD0A+

MAX6457UKD0A-T

MAX6457UKD0A/GG8

MAX6457UKD0B+

MAX6457UKD0B-T

MAX6457UKD0C+

MAX6457UKD0C+T

MAX6457UKD0C-T

MAX6457UKD3A-T

MAX6457UKD3B+

MAX6457UKD3B-T

MAX6457UKD3C+