Rainbow Electronics MAX998 User Manual

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________________General Description

The MAX976/MAX978/MAX998 dual/quad/single, highspeed, low-power comparators are optimized for +3V/+5V single-supply applications. They achieve a 20ns propagation delay while consuming only 225µA supply current per comparator. The MAX998 features a low-power shutdown mode that places the output in a high-impedance state and reduces supply current to 1nA.

The MAX976/MAX978/MAX998 inputs have a commonmode voltage range that extends 200mV below ground. Their outputs are capable of Rail-to-Rail®operation without external pull-up circuitry, making these devices ideal for interface with CMOS/TTL logic. All inputs and outputs can tolerate a continuous short-circuit fault condition to either rail. The comparators’ internal hysteresis ensures clean output switching, even with slow-moving input signals.

For space-critical applications, the single MAX998 is available in a 6-pin SOT23 package, the dual MAX976 is available in an 8-pin µMAX package, and the quad MAX978 is available in a 16-pin QSOP package.

________________________Applications

Battery-Powered Systems Threshold Detectors/Discriminators 3V Systems IR Receivers Digital Line Receivers

____________________________Features

♦ Single-Supply Operation Down to 2.7V ♦ 20ns Propagation Delay ♦ 225µA Supply Current ♦ 1nA Shutdown Supply Current ♦ Rail-to-Rail Outputs ♦ Ground-Sensing Inputs ♦ Internal Hysteresis Ensures Clean Switching ♦ Available in Space-Saving Packages:

SOT23-6 (MAX998) µMAX (MAX976) QSOP-16 (MAX978)

MAX976/MAX978/MAX998

Single/Dual/Quad, SOT23, Single-Supply,

High-Speed, Low-Power Comparators

________________________________________________________________

Maxim Integrated Products

TOP VIEW

GND

IN-IN+

16V

5 SHDN

OUT

MAX998

SOT23-6

__________________Pin Configurations

SHDN

R1 R2

IR RECEIVER

OUT

0.1µF

MAX998

GND

___________Typical Operating Circuit

19-1299; Rev 1; 1/98

PART

MAX976ESA

MAX976EUA MAX978ESE

-40°C to +85°C

TEMP. RANGE PIN-PACKAGE

8 SO 8 µMAX 16 Narrow SO

_______________Ordering Information

Pin Configurations continued at end of data sheet

Rail-to-Rail is a registered trademark of Nippon Motorola Ltd.

MAX978EEE MAX998ESA MAX998EUT-T -40°C to +85°C

-40°C to +85°C

-40°C to +85°C 16 QSOP 8 SO 6 SOT23-6

SOT

TOP MARK

— — — — —

AAAO

MAX976/MAX978/MAX998

Single/Dual/Quad, SOT23, Single-Supply, High-Speed, Low-Power Comparators

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +2.7V to +5.5V, VCM= 0V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)

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.

Supply Voltage (VCC).............................................................+6V

SHDN (MAX998).........................................................-0.3V to 6V

All Other Pins..............................................-0.3V to (V

+ 0.3V)

Duration of Output Short Circuit to GND or V

........Continuous

Continuous Power Dissipation (T

= +70°C)

6-Pin SOT23-6 (derate 7.1mW/°C above +70°C) .........571mW

8-Pin µMAX (derate 4.10mW/°C above +70°C)............330mW

8-Pin SO (derate 5.88mW/°C above +70°C).................471mW

16-Pin Narrow SO (derate 8.70mW/°C above +70°C)..696mW

16-Pin QSOP (derate 8.33mW/°C above +70°C)..........667mW

Operating Temperature Range ..........................-40°C to +85°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

VCC= 5.5V

MAX998 only, SHDN = GND

SINK

= 2mA

VCC= 5.5V

Inferred from PSRR test

VCC= 5V (Note 4)

2.7V < VCC< 5.5V

CONDITIONS

OUT Short-Circuit Current

V0.1 0.4V

OUT Output Voltage Low

nA±5 ±100I

Input Offset Current

mVV

HYS

0.5 1.5 4

Input-Referred Hysteresis

nA1 500I

Shutdown Supply Current

300 650

V2.7 5.5V

Supply Voltage Range

dB63 100PSRRPower-Supply Rejection Ratio

UNITSMIN TYP MAXSYMBOLPARAMETER

LOAD

=10pF (Note 6) ns2t

SKEW

Propagation-Delay Skew

MAX976/MAX978 only ns1∆t

Propagation-Delay Matching Between Channels

Sinking Sourcing

Overdrive = 50mV

20 40

Propagation Delay

SOURCE

= 2mA, VCC- V

V0.1 0.4V

OUT Output Voltage High

(Note 2) V-0.2 VCC- 1.2V

CMR

Common-Mode Voltage Range

-0.2V ≤ VCM≤ (VCC- 1.2V) dB66 95CMRRCommon-Mode Rejection Ratio VCC= 5V (Note 3) mV

0.2 ±2

Input Offset Voltage

TA= +25°C TA= T

MIN

to T

MAX

±3

pFInput Capacitance 3C

LOAD

=10pF,

VCC= 5V (Note 5)

Overdrive = 5mV

MAX998 only V

SHDN Input Voltage High

0.65 x V

MAX998 only V

SHDN Input Voltage Low

0.2 x V

MAX998 only, SHDN = GND, V

OUT

= 0V to V

nAOUT Leakage Current 1 200I

OUT

MAX998 only nA

SHDN Input Current

1 200I

SHDN

LOAD

=10pF ns1.6tR/t

Output Rise/Fall Time

MAX998 only, VCC= 5V, ICC= 10% of typical µs5t

Shutdown Delay Time

VCC= 2.7V

µA

225

Supply Current per Comparator

0.3 1.5 5

nAI

75 300Input Bias Current

All others

MAX976EUA, MAX998EUT

MAX976/MAX978/MAX998

Single/Dual/Quad, SOT23, Single-Supply,

High-Speed, Low-Power Comparators

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +2.7V to +5.5V, VCM= 0V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)

Note 1: The MAX998EUT specifications are 100% tested at T

= +25°C. Limits over the extended temperature range are guaran-

teed by design, not production tested.

Note 2: Inferred from CMRR test. Either input can be driven to the absolute maximum limit without false output inversion, as long as

the other input is within the common-mode voltage range.

Note 3: V

is defined as the mean of trip points. The trip points are the extremities of the differential input voltage required to make

the comparator output change state (Figure 1).

Note 4: The difference between the upper and lower trip points is equal to the width of the input-referred hysteresis zone (Figure 1). Note 5: Propagation Delay is guaranteed by design. For low overdrive conditions, V

TRIP

(Figure 1) is added to the overdrive.

Note 6: Propagation-Delay Skew is the difference between the positive-going and the negative-going propagation delay. Note 7: For design purposes, the t

can be as high as 60µs.

CONDITIONS

MAX998 only, VCC= 5V, ICC= 90% of typical (Note 7)

µs15t

Wake-Up from Shutdown

UNITSMIN TYP MAXSYMBOLPARAMETER

VCC= 0V to 5V step, output valid µs3t

Power-Up Delay

__________________________________________Typical Operating Characteristics

(VCC= +5V, VCM= 0V, TA= +25°C, unless otherwise noted.)

125

175

275

225

325

375

-60 -20 0-40 20 40 60 80 100

SUPPLY CURRENT PER COMPARATOR

vs. TEMPERATURE

MAX976 TOC01

TEMPERATURE (°C)

SUPPLY CURRENT PER COMPARATOR (µA)

VCC = 5.5V, V

OUT

= LOW

VCC = 5.5V, V

OUT

= HIGH

VCC = 2.7V, V

OUT

= HIGH

VCC = 2.7V, V

OUT

= LOW

30 20

50 40

70 60

100

110

-60 -20 0-40 20 40 60 80 100

SHORT-CIRCUIT OUTPUT CURRENT

vs. TEMPERATURE

MAZX976 TOC2

TEMPERATURE (°C)

OUTPUT CURRENT (mA)

VCC = 5.5V, SOURCING

VCC = 2.7V, SOURCING

VCC = 5.5V, SINKING

VCC = 2.7V, SINKING

1.6

0.1 1 10 100

OUTPUT LOW VOLTAGE vs.

OUTPUT SINK CURRENT

0.4

0.8

0.6

0.2

1.0

1.2

1.4

MAX976 TOC03

OUTPUT CURRENT (mA)

OUTPUT LOW VOLTAGE (V)

VCC = 5.5V

VCC = 2.7V

0.1 1 10 100

OUTPUT HIGH VOLTAGE vs. OUTPUT SOURCE CURRENT

MAX976 TOC04

OUTPUT CURRENT (mA)

OUTPUT HIGH VOLTAGE (V)

VCC = 5.5V

VCC = 2.7V

19 18

21 20

24 23

-60 -20 0-40 20 40 60 80 100

PROPAGATION DELAY

vs. TEMPERATURE

MAZX976 TOC5

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

VCC = 5.5V

VCC = 2.7V

VOD = 50mV C

LOAD

= 15pF

10 100 1000

PROPAGATION DELAY vs. CAPACITIVE LOAD

MAX976 TOC06

CAPACITIVE LOAD (pF)

PROPAGATION DELAY (ns)

VOD = 50mV

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