LTC2190 View Datasheet(PDF) - Linear Technology

Part Name

Description

MFG CO.

LTC2190

16-Bit, 65Msps/40Msps/ 25Msps Low Power Dual ADCs

Linear Technology 

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LTC2192

LTC2191/LTC2190

APPLICATIONS INFORMATION

GROUNDING AND BYPASSING

The LTC2192/LTC2191/LTC2190 require a printed circuit

board with a clean unbroken ground plane. A multilayer

board with an internal ground plane in the first layer be-

neath the ADC is recommended. Layout for the printed

circuit board should ensure that digital and analog signal

lines are separated as much as possible. In particular, care

should be taken not to run any digital track alongside an

analog signal track or underneath the ADC.

High quality ceramic bypass capacitors should be used at

the VDD, OVDD, VCM, VREF, REFH and REFL pins. Bypass

capacitors must be located as close to the pins as possible.

Size 0402 ceramic capacitors are recommended. The traces

connecting the pins and bypass capacitors must be kept

short and should be made as wide as possible.

Of particular importance is the capacitor between REFH

and REFL. This capacitor should be on the same side of

the circuit board as the A/D, and as close to the device

as possible.

The analog inputs, encode signals, and digital outputs

should not be routed next to each other. Ground fill and

grounded vias should be used as barriers to isolate these

signals from each other.

HEAT TRANSFER

Most of the heat generated by the LTC2192/LTC2191/

LTC2190 is transferred from the die through the bottom-

side exposed pad and package leads onto the printed circuit

board. For good electrical and thermal performance, the

exposed pad must be soldered to a large grounded pad

on the PC board. This pad should be connected to the

internal ground planes by an array of vias.

TYPICAL APPLICATIONS

C3 0.1µF

C2 0.1µF

C4

2.2µF

SDO

SENSE

VDD C5

0.1µF

C29

0.1µF

AIN1+

AIN1–

–

+

+

–

–

+

CN1

+

–

PAR/SER

AIN2+

AIN2–

C37

1

VCM1

2

GND

3

4 AIN1+

AIN1–

5

GND

6

REFH

7

REFL

8

REFH

9

REFL

10

PAR/SER

11

AIN2+

12

13 AIN2–

GND

14

VCM2

0.1µF

LTC2192

VDD

C7

0.1µF

ENCODE

INPUT

SPI

PORT

OUT1C+ 40

OUT1C– 39

OUT1D+ 38

OUT1D– 37

DCO+ 36

DCO– 35

34

OVDD

33

OGND

FR+ 32

31

FR–

OUT2A+ 30

OUT2A– 29

OUT2B+ 28

OUT2B– 27

OVDD

DIGITAL

OUTPUTS

C16 0.1µF

219210 TA02

219210p

25

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