2645L8 Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

производитель

2645L8

Quad 12-/10-/8-Bit PWM to VOUT DACs with 10ppm/°C Reference

Linear Technology 

LTC2645

Operation

Another technique for minimizing errors is to use a sepa-

rate power ground return trace on another board layer.

The trace should run between the point where the power

supply is connected to the board and the DAC ground pin.

Thus the DAC ground pin becomes the common point for

analog ground, digital ground, and power ground. When

the LTC2645 is sinking large currents, this current flows

out of the ground pin and directly into the power ground

trace without affecting the analog ground plane voltage.

It is sometimes necessary to interrupt the ground plane

to confine digital ground currents to the digital portion of

the plane. When doing this, make the gap in the plane only

as long as it needs to be to serve its purpose and ensure

that no traces cross over the gap.

OUTPUT

VOLTAGE

0V

NEGATIVE

OFFSET

INPUT CODE

(b)

OUTPUT

VOLTAGE

0V

0

VREF = VCC

2048

INPUT CODE

(a)

4095

VREF = VCC

INPUT CODE

(c)

Figure 2. Effects of Rail-to-Rail Operation on a DAC Transfer Curve (Shown for 12 Bits).

(a) Overall Transfer Function

(b) Effect of Negative Offset for Codes Near Zero

(c) Effect of Positive Full-Scale Error for Codes Near Full-Scale

POSITIVE

FSE

OUTPUT

VOLTAGE

2645 F02

For more information www.linear.com/LTC2645

2645f

17

Share Link: