Datasheet MAX912C-D, MAX912CPE, MAX913ESA, MAX913MJA, MAX912MJE Datasheet (Maxim)

19-0157; Rev 1; 1/94

Single/Dual, Ultra-Fast, Low-Power,

Precision TTL Comparators

_______________General Description

The MAX913 single and MAX912 dual high-speed,
low-power comparators have differential inputs and
complementary TTL outputs. Fast propagation delay
(10ns typ), extremely low supply current, and a wide
common-mode input range that includes the negative
rail make the MAX912/MAX913 ideal for low-power,
high-speed, single +5V (or ±5V) applications such as
V/F converters or switching regulators.

The MAX912/MAX913 outputs remain stable through
the linear region. This feature eliminates output instability
common to high-speed comparators when driven with a
slow-moving input signal.

The MAX912/MAX913 can be powered from a single
+5V supply or a ±5V split supply. The MAX913 is an
improved plug-in replacement for the LT1016. It pro­vides significantly wider input voltage range and equiva-
lent speed at a fraction of the power. The MAX912 dual
comparator has equal performance to the MAX913 and
includes independent latch controls.

________________________Applications

Zero-Crossing Detectors
Ethernet Line Receivers
Switching Regulators
High-Speed Sampling Circuits
High-Speed Triggers
Extended Range V/F Converters
Fast Pulse Width/Height Discriminators

____________________________Features

♦ Ultra Fast (10ns)
♦ Single +5V or Dual ±5V Supply Operation
♦ Input Range Extends Below Negative Supply
♦ Low Power: 6mA (+5V) Per Comparator
♦ No Minimum Input Signal Slew-Rate Requirement
♦ No Power-Supply Current Spiking
♦ Stable in the Linear Region
♦ Inputs Can Exceed Either Supply
♦ Low Offset Voltage: 0.8mV

______________Ordering Information

PART TEMP. RANGE PIN-PACKAGE

MAX912CPE

MAX912CSE 0°C to +70°C 16 Narrow SO
MAX912C/D 0°C to +70°C Dice*
MAX912EPE -40°C to +85°C 16 Plastic DIP
MAX912ESE -40°C to +85°C 16 Narrow SO
MAX912MJE -55°C to +125°C 16 CERDIP
MAX913CPA
MAX913CSA 0°C to +70°C 8 SO
MAX913C/D 0°C to +70°C Dice*
MAX913EPA -40°C to +85°C 8 Plastic DIP
MAX913ESA -40°C to +85°C 8 SO
MAX913MJA -55°C to +125°C 8 CERDIP

* Dice are specified at TA= +25°C, DC parameters only.

0°C to +70°C 16 Plastic DIP

0°C to +70°C 8 Plastic DIP

MAX912/MAX913

___________________________________________________________Pin Configurations

TOP VIEW

1

V+

2

IN+
IN-

V-

+

-

3
4

MAX913

8

Q

7

Q

6

GND

5

LE

DIP/SO

________________________________________________________________

116QA

QA QB

GND

LEA

N.C.

V-

INA-

MAX912

2
3
4
5

AB

+

-

6
7
89INA+ INB+

15
14
13
12

-

+

11
10

DIP/Narrow SO

Maxim Integrated Products

QB

GND
LEB
N.C.
V+
INB-

1

Call toll free 1-800-998-8800 for free samples or literature.

Single/Dual, Ultra-Fast, Low-Power,
Precision TTL Comparators

ABSOLUTE MAXIMUM RATINGS

Positive Supply Voltage............................................................7V

Negative Supply Voltage ........................................................-7V

Differential Input Voltage .....................................................±15V

Input Voltage (Referred to V-)..................................- 0.3V to 15V

Latch Pin Voltage.............................................Equal to Supplies

Continuous Output Current...............................................±20mA

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

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

MAX912/MAX913

(V+ = +5V, V- = -5V, VQ= 1.4V, VLE= 0V, TA= T

PARAMETER

Input Offset Voltage (Note 1) V

Offset Drift TCV
Input Offset Current (Note 1) I

Input Bias Current I

Input Voltage Range V

Common-Mode Rejection Ratio CMRR
Power-Supply Rejection Ratio PSRR
Small-Signal Voltage Gain A

Output Voltage

Positive Supply Current Per
Comparator

Negative Supply Current Per
Comparator

Latch-Pin High Input Voltage V
Latch-Pin Low Input Voltage V
Latch-Pin Current I

SYMBOL MIN TYP MAX

OS

OS

OS

B

CM

V

V

OH

V

OL

I+

I- 0.4 2 mA

IH
IL

IL

to T

MIN

MAX

RS≤ 100Ω

C, E temp. ranges 8
M temp. range 10
C, E temp. ranges
M temp. range

Single +5V

-5.0V ≤ VCM≤ +3.5V
Positive supply: 4.5V ≤ V+ ≤ 5.5V 60 85
Negative supply: -2V ≥ V- ≥ -7V
1V ≤ VQ≤ 2V, TA= +25°C 1500 3500 V/V

V+ ≥ 4.5V
I

= 4mA 0.3 0.5

SINK

TA= +25°C, I
C, E temp. ranges 610
M temp. range 12

VLE= 0V

16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ...696mW

16-Pin CERDIP (derate 10.00mW/°C above +70°C)....800mW

Operating Temperature Ranges:

MAX91_ C_ _ ......................................................0°C to +70°C

MAX91_ E_ _....................................................-40°C to +85°C

MAX91_ MJ_ .................................................-55°C to +125°C

Storage Temperature Range.............................-65°C to +150°C

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

, unless otherwise noted. Typical values are at TA= +25°C.)

CONDITIONS

TA= +25°C

TA= T

TA= +25°C

TA= T

TA= +25°C

C, E temp. ranges

M temp. range

I

OUT

I

OUT

= 10mA 0.4

SINK

MIN

MIN

= 1mA
= 10mA

to T

to T

MAX

MAX

-5.2 +3.5

-5.0 +3.5

-0.2 +3.5

0.8 2
3

2 µV/°C

0.3 0.5

0.8

35

0 +3.5

80 110

80 100

2.7 3.4

2.4 3.0

12

2.0 V

0.8 V

-20 µA

UNITS

mV

µA

µA

V

dB
dB

V

mA

2 _______________________________________________________________________________________

Single/Dual, Ultra-Fast, Low-Power,

Precision TTL Comparators

ELECTRICAL CHARACTERISTICS (continued)

(V+ = +5V, V- = -5V, VQ= 1.4V, VLE= 0V, TA= T

PARAMETER SYMBOL UNITSMIN TYP MAX

Propagation Delay (Note 2) t

Differential Propagation Delay
(Note 2)

PD+

, t

PD-

∆t

PD

Channel-to-Channel
Propagation Delay
(Note 2)

Latch Setup Time (Note 3) ns
Latch Hold Time (Note 3) ns
Latch Propagation Delay (Note 4) ns

SU

H

LPD

Note 1: Input Offset Voltage (VOS) is defined as the average of the two input offset voltages, measured by forcing first one output,

then the other to 1.4V. Input Offset Current (I

Note 2: Propagation Delay (tPD) and Differential Propagation Delay (∆tPD) cannot be measured in automatic handling equipment

with low input overdrive values. The MAX912/MAX913 are sample tested to 0.1% AQL with a 1V step and 500mV overdrive
at +25°C only. Correlation tests show that t
formed to guarantee that all internal bias conditions are correct. For low overdrive conditions, VOSis added to the over­drive. Differential Propagation Delay is defined as: ∆tPD= t

Note 3: Input latch setup time (tSU) is the interval in which the input signal must be stable prior to asserting the latch signal.

The hold time (t
guaranteed by design.

Note 4: Latch Propagation Delay (t

See Timing Diagram.

) is the interval after the latch is asserted in which the input signal must be stable. These parameters are

H

) is the delay time for the output to respond when the latch-enable pin is deasserted.

LPD

to T

MIN

, unless otherwise noted).

MAX

CONDITIONS

∆VIN= 100mV,
VOD= 5mV

∆VIN= 100mV,
VOD= 20mV

∆VIN= 100mV,
VOD= 5mV

∆VIN= 100mV,
VOD= 5mV
(MAX912 only)

) is defined the same way.

OS

and ∆t

PD

can be guaranteed with this test, if additional DC tests are per-

PD

T

A

TA= T
TA = +25°C
TA= T

TA=
+25°C

TA= +25°C

– tPD-.

PD+

= +25°C

MIN

MIN

to T

MAX

to T

MAX

MAX913

10 14

912

23
35MAX912

500 ps

20t
32t

7t

16

ns

15

ns

MAX912/MAX913

__________________________________________Typical Operating Characteristics

(V+ = 5V, V- = -5V, VLE= 0V, CL= 15pF, TA = +25°C, unless otherwise noted.)

PROPAGATION DELAY

10

9

8

7

PROPAGATION DELAY (ns)

6

5

vs. INPUT OVERDRIVE

VOD = 10mV

t

PD(-)

t

PD(+)

1 10 100

INPUT OVERDRIVE (mV)

_______________________________________________________________________________________ 3

PROPAGATION DELAY

vs. SOURCE RESISTANCE

50

MAX912-01

VOD = 10mV

40

30

20

PROPAGATION DEALY (ns)

10

0

1 100 10,000

10 1000

SOURCE RESISTANCE (Ω)

11

MAX912-02

10

9

t

PD(-)

t

PD(+)

8

PROPAGATION DELAY (ns)

7

6

PROPAGATION DELAY

vs. LOAD CAPACITANCE

VOD = 10mV

t

PD(-)

t

PD(+)

10 20 30 40 50

LOAD CAPACITANCE (pF)

MAX912-03

Single/Dual, Ultra-Fast, Low-Power,
Precision TTL Comparators

____________________________Typical Operating Characteristics (continued)

(V+ = 5V, V- = -5V, VLE= 0V, CL= 15pF, TA = +25°C, unless otherwise noted.)

PROPAGATION DELAY

vs. TEMPERATURE

11

VOD = 10mV

10

9

8

PROPAGATION DELAY (ns)

MAX912/MAX913

7

6

Q OUTPUT

-55

-15 25 105 12565

vs. TEMPERATURE

1000

800

600

(µV)

OS

V

400

200

0

-55

-15 25 65 105 125

Q OUTPUT

Q OUTPUT

t

PD(-)

t

PD(+)

TEMPERATURE (°C)

OFFSET VOLTAGE

TEMPERATURE (°C)

t

PD(-)

Q OUTPUT
t

PD(+)

POSITIVE SUPPLY CURRENT

(PER COMPARATOR)

vs. POSTIVE SUPPLY VOLTAGE

10

MAX912-04

MAX912-11

V- = 0V TO -5V

8

6

I+ (PER COMPARATOR)

4

2

34567

6

5

4

(µA)

B

I

3

2

-55 -15 25 65 105 125

TA = +125°C

TA = +25°C

TA = -55°C

V+ (V)

INPUT BIAS CURRENT

vs. TEMPERATURE

VCM = -5.2V

VCM = 0V

VCM = +3.5V

TEMPERATURE (°C)

1.2

MAX912-07

1.0

0.8

0.6

I- (PER COMPARATOR)

0.4

0.2

MA912-12

OUTPUT VOLTAGE (V)

NEGATIVE SUPPLY CURRENT

(PER COMPARATOR)

vs. NEGATIVE SUPPLY VOLTAGE

TA = +125°C

0

1234567

vs. DIFFERENTIAL INPUT VOLTAGE

5

4

3

2

1

0

-3

-2 -1 1 2 30

DIFFERENTIAL INPUT VOLTAGE (mV)

V- (V)

OUTPUT VOLTAGE

TA = +125°C

TA = +25°C

MAX912-08

TA = +25°C

TA = -55°C

MAX912-14

TA = -55°C

4 _______________________________________________________________________________________

Single/Dual, Ultra-Fast, Low-Power,

Precision TTL Comparators

____________________________Typical Operating Characteristics (continued)

(V+ = 5V, V- = -5V, VLE= 0V, CL= 15pF, TA = +25°C, unless otherwise noted.)

POSITIVE-TO-NEGATIVE PROPAGATION DELAY



5ns/div

INPUT
100mV/div

OUTPUT
Q

1V/div

Q

MAX912/MAX913 RESPONSE TO

+

50MHz (



10mV

) SINE WAVE

P-P

NEGATIVE-TO-POSITIVE PROPAGATION DELAY



5ns/div

INPUT
10mV/div

OUTPUT
Q
2V/div

INPUT
100mV/div

OUTPUT
Q

1V/div

Q

MAX912/MAX913

10ns/div

MAX912/MAX913 RESPONSE TO SLOW-MOVING TRIANGLE WAVE

MAX912/MAX913 RESPONSE



INPUT
20mV/div



20µs/div

OUTPUT
Q

1V/div

Q
1V/div



INDUSTRY STANDARD

686 RESPONSE

20µs/div

INPUT
20mV/div

OUTPUT
Q

1V/div
Q

1V/div

_______________________________________________________________________________________ 5

Single/Dual, Ultra-Fast, Low-Power,
Precision TTL Comparators

____________________________________________________________Pin Descriptions

PIN

MAX912

1 QA Comparator A TTL output
2

3, 14 GND

4 LEA

5, 12 N.C. Not internally connected

6 V-

MAX912/MAX913

7 INA- Comparator A inverting input
8 INA+ Comparator A noninverting input

9 INB+ Comparator B noninverting input
10 INB- Comparator B inverting input
11 V+ Positive power supply, +5V. Bypass to GND with a 0.1µF capacitor.

13 LEB
15

16 QB Comparator B TTL output

PIN

MAX913

1 V+ Positive power supply. Bypass to GND with a 0.1µF capacitor.

2 IN+ Noninverting input

3 IN- Inverting input

4 V-

5 LE

6 GND Logic ground

7 Q TTL output

8

NAME FUNCTION

–Q–

A

Comparator A complementary TTL output
Logic ground. Connect both GND pins to ground.

Comparator A latch enable. QA and –Q–A are latched when LEA is high or floating.
Comparator A latch is transparent when LEA is low.

Negative power supply: -5V for dual supplies (bypass to GND with a 0.1µF capacitor), or GND for a
single supply

Comparator B latch enable. QB and –Q–B are latched when LEB is high or floating.

–Q–

NAME FUNCTION

Comparator B latch is transparent when LEB is low.

B

Comparator B complementary TTL output

Negative power supply: -5V for dual supplies (bypass to GND with a 0.1µF capacitor), or GND for a
single supply

Latch enable. Q and –Q–are latched when LE is TTL high or floating. The comparator latch is
transparent when LE is low.

–Q–

Complementary TTL output

6 _______________________________________________________________________________________

Single/Dual, Ultra-Fast, Low-Power,

Precision TTL Comparators

_______________Detailed Description

The MAX913 (single) and MAX912 (dual) high-speed
comparators have a unique design that prevents oscil­lation when the comparator is in its linear region. No
minimum input slew rate is required.

Many high-speed comparators oscillate in the linear
region, as shown in the

Characteristics’

industry-standard 686 response graph.
One way to overcome this oscillation is to sample the
output after it has passed through the unstable region.
Another practical solution is to add hysteresis. Either
solution results in a loss of resolution and bandwidth.

Because the MAX912/MAX913 do not need hysteresis,
they offer high resolution to all signals—including low­frequency signals.

The MAX912/MAX913 provide a TTL-compatible latch
function that holds the comparator output state (Figure 1).
As long as Latch Enable (LE) is high or floating, the input
signal has no effect on the output state. With LE low, the
outputs are controlled by the input differential voltage and
the latch is transparent.

A comparator can be thought of as having two sec­tions: an input amplifier and a logic interface. The
MAX912/MAX913’s input amplifier is fully differential,
with input offset voltage trimmed to below 2.0mV at
+25°C. Input common-mode range extends from
200mV below the negative supply rail to 1.5V below the
positive power supply. The total common-mode range
is 8.7V when operating from ±5VDC supplies.

The MAX912/MAX913’s amplifier has no built-in hys­teresis. For highest accuracy, do not add hysteresis.
Figure 2 shows how hysteresis degrades resolution.

Typical Operating

Input Amplifier

A comparator’s ability to resolve small signal differ-

Resolution

ences—its resolution—is affected by various factors.
As with most amplifiers, the most significant factors are
the input offset voltage (VOS) and the common-mode
and power-supply rejection ratios (CMRR, PSRR). If
source impedance is high, input offset current can be
significant. If source impedance is unbalanced, the
input bias current can introduce another error.

For high-speed comparators, an additional factor in reso­lution is the comparator’s stability in its linear region. Many
high-speed comparators are useless in their linear region
because they oscillate. This makes the differential input
voltage region around 0V unusable, as does a high V

OS.

Hysteresis does not cure the problem, but acts to keep
the input away from its linear range (Figure 2).

The MAX912/MAX913 do not oscillate in the linear region,
which greatly enhances the comparator’s resolution.

__________Applications Information

The MAX912/MAX913 are tested with ±5V power sup­plies that provide an input common-mode range (VCM)
of 8.7V (-5.2V to +3.5V). Operation from a single +5V
supply provides a common-mode input range of 3.7V
(-0.2V to +3.5V). Connect V- to GND for single-supply
operation. The MAX912/MAX913 will operate from a
minimum single-supply voltage of +4.5V.

The V+ supply provides power to both the analog input
stage and digital output circuits, whereas the V- supply
only powers the analog section. Bypass V+ and V- to
ground with 0.1µF to 1.0µF ceramic capacitors in parallel
with 10µF or greater tantalum capacitors. Connect the
ceramic capacitors very close to the MAX912/MAX913’s

Power Supplies and Bypassing

MAX912/MAX913

(DIFFERENTIAL)

Figure 1. Timing Diagram

_______________________________________________________________________________________ 7

LATCH
ENABLE (LE)

t

SU

V

IN

t

H

t

PD+

Q

∆t

PD

Q

t

PD-

t

LPDR

Single/Dual, Ultra-Fast, Low-Power,
Precision TTL Comparators

supply pins, keeping leads short to minimize lead
inductance. For particularly noisy applications, use fer­rite beads on the power-supply lines.

Board Layout

As with all high-speed components, careful attention to
layout is essential for best performance.

1) Use a printed circuit board with an unbroken

ground plane.

2) Pay close attention to the bandwidth of bypass

components and keep leads short.

3) Avoid sockets; solder the comparator and other

components directly to the board to minimize

The MAX912/MAX913 design eliminates the input slew­rate requirement imposed on many standard compara­tors. As long as LE is high after the maximum propaga­tion delay and the input is greater than the compara­tor’s total DC error, the output will be valid without oscil­lations.

Maximum Clock (LE) and Signal Rate

The maximum clock and signal rate is 70MHz, based
on the comparator’s rise and fall time with a 5mV over­drive at +25°C (Figure 1). With a 20mV overdrive, the
maximum propagation delay is 12ns and the clock and
signal rate is 85MHz.

Input Slew Rate

unwanted parasitic inductance and capacitance.

MAX912/MAX913

Figure 2. Effect of Hysteresis on Input Resolution

IN+

IN-

Q

WITH HYSTERESIS
IDEAL (WITHOUT HYSTERESIS)

WHEN HYSTERESIS IS ADDED, A COMPARATOR CANNOT RESOLVE ANY INPUT SIGNAL WITHIN THE HYSTERESIS BAND.

*

.
.
.
.
.
.

..

HYSTERESIS

BAND

*

.
.
.
.
.
.

__________________________________________________________Chip Topographies

INB-

MAX912

INB+

INA+

INA-

MAX913

IN-

IN+

V+

V-

0.071"

(1.80mm)

LEA

GND

LEB
GND

V+

QA

QB QA

QB

0.080"

(2.03mm)

TRANSISTOR COUNT: 197;
SUBSTRATE CONNECTED TO V-.

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.

8

___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

© 1994 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

V-

0.056"

V+

(1.42mm)

LE

Q

GND

0.058"

(1.47mm)

Q

TRANSISTOR COUNT: 100;
SUBSTRATE CONNECTED TO V-.