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 (408) 737-7600

© 1994 Maxim Integrated Products

Printed USA

is a registered trademark of Maxim Integrated Products.

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

Precision TTL Comparators

HYSTERESIS

BAND*

IN+

IN-

Q

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

WITH HYSTERESIS

IDEAL (WITHOUT HYSTERESIS)

.

.

.

.

.

.

.

.

.

.

.

.

..

Figure 2. Effect of Hysteresis on Input Resolution

supply pins, keeping leads short to minimize lead

inductance. For particularly noisy applications, use fer-

rite 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

unwanted parasitic inductance and capacitance.

Input Slew Rate

The MAX912/MAX913 design eliminates the input slew-

rate requirement imposed on many standard compara-

tors. As long as LE is high after the maximum propaga-

tion delay and the input is greater than the compara-

tor’s total DC error, the output will be valid without oscil-

lations.

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 over-

drive at +25°C (Figure 1). With a 20mV overdrive, the

maximum propagation delay is 12ns and the clock and

signal rate is 85MHz.

__________________________________________________________Chip Topographies

V-

LEA

LEB

GND

INB-

QB

0.071"

(1.80mm)

0.080"

(2.03mm)

INB+

INA+

INA-

GND

QB

QA QA

V+

V+

V-

LE

IN-

0.056"

(1.42mm)

0.058"

(1.47mm)

IN+

V+

Q

GND

Q

MAX913

MAX912

TRANSISTOR COUNT: 100;

SUBSTRATE CONNECTED TO V-.

TRANSISTOR COUNT: 197;

SUBSTRATE CONNECTED TO V-.