ALD2321A/ALD2321B/ALD2321

Advanced Linear Devices

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Sink Output, can be connected together to form a push-pull output

which has the combined output capabilities of both channels.

In the dual complementary output mode, each comparator can be

used to drive separate loads. Due to the complementary nature of

the two outputs, only one output is active at any a given time, except

for a limited crossover time. When OUT (sink output) is active ON,

current, OUT pin is OFF. To configure push-pull output, simply

Since each voltage comparator has its own complementary out-

puts, each comparator can be configured to have a different output

type. For example, one comparator output can be connected as

Open Drain output while the other comparator can be wired as

push-pull output. If used to drive capacitive loads, the output DC

current levels are at a very low level, at essentially leakage current

levels, which can be a power saving feature.

The ALD2321A/ALD2321B/ALD2321 can detect and resolve very

low voltage levels at high speed, with little or no overdrive voltage.

Compared with other voltage comparator devices that require 100

mV overdrive voltages, or multiple stage circuits that include input

preamp, etc., the ALD2321A/ALD2321B/ALD2321 can perform all

input to output functions in one device with minimal delay time and

with as low as a 1mV signal.

The ALD2321A/ALD2321B/ALD2321 is supplied with 4 external e-

trim pins, VE11, VE12, VE21, and VE22. These pins are used for

trimming of the voltage comparator offset voltages at the factory,

and normally should be left open unconnected. However, in some

cases these pins can be used as positive/negative feedback pins,

since these pins have a positive/negative factor on the offset

voltage. For example, see TYPICAL APPLICATIONS section

titled "Voltage Comparator With Output Feedback to Provide

Hysteresis."

GENERAL DESCRIPTION (cont'd)

In a printed circuit board layout, it is suggested that

these pins, along with no connect (N/C) pins 8 and 9,

be surrounded with ground traces to prevent any

possible crosstalk and noise coupling from other signal

sources.

Although not required for most applications, if neces-

sary, small valued capacitors of approximately 1000pF

can be mounted at these pins to ground to further

reduce noise. For information on customized trimming

under different biasing and power supply conditions,

please contact factory.

1

OUT1

COMPARATOR 1 SINK OUTPUT

OUTPUT

2

OUT1H

COMPARATOR 1 SOURCE OUTPUT

OUTPUT

3

-IN1

COMPARATOR 1 INVERTING INPUT

INPUT

4

+IN1

COMPARATOR 1 NON-INVERTING INPUT

INPUT

5

GND

GROUND / V- SUPPLY

-

6VE11

- VOS E-Trim COMPARATOR 1

INPUT

7VE12

+ VOS E-Trim COMPARATOR 1

INPUT

8

N/C

No Connect/Do Not connect externally

-

9

N/C

No Connect/Do Not connect externally

-

10

VE22

+VOS E-Trim COMPARATOR 2

INPUT

11

VE21

- VOS E-Trim COMPARATOR 2

INPUT

12

+IN2

COMPARATOR 2 NON-INVERTING INPUT

INPUT

13

-IN2

COMPARATOR 2 INVERTING INPUT

INPUT

14

OUT2H

COMPARATOR 2 SOURCE OUTPUT

OUTPUT

15

OUT2

COMPARATOR 2 SINK OUTPUT

OUTPUT

16

V+

V+ SUPPLY

-

ALD2321 PIN IDENTIFICATION

PIN #

SYMBOL

FUNCTION

SIGNAL PROPAGATION

BLOCK DIAGRAM

NONINVERTING INPUT

INVERTING INPUT

GND

(6)

(5)

INVERTING INPUT

(11)

(10)

N/C

(8)

(9)

N/C

NONINVERTING INPUT

-

+

-

+