LTC2400CS8 datasheet(26/40 Pages) LINER

26 / 40 page

LTC2400

TYPICAL APPLICATIONS

SYNCHRONIZATION OF MULTIPLE LTC2400s

Since the LTC2400’s absolute accuracy (total unadjusted

error) is 10ppm, applications utilizing multiple matched

ADCs are possible.

Simultaneous Sampling with Two LTC2400s

One such application is synchronizing multiple LTC2400s,

see Figure 27. The start of conversion is synchronized to

the rising edge of CS. In order to synchronize multiple

LTC2400s, CS is a common input to all the ADCs.

To prevent the converters from autostarting a new con-

version at the end of data output read, 31 or fewer SCK

clock signals are applied to the LTC2400 instead of 32 (the

32nd falling edge would start a conversion). The exact

timing and frequency for the SCK signal is not critical

since it is only shifting out the data. In this case, two

LTC2400’s simultaneously start and end their conversion

cycles under the external control of CS.

Increasing the Output Rate Using Multiple LTC2400s

A second application uses multiple LTC2400s to increase

the effective output rate by 4

×, see Figure 28. In this case,

four LTC2400s are interleaved under the control of sepa-

rate CS signals. This increases the effective output rate

from 7.5Hz to 30Hz (up to a maximum of 60Hz). Addition-

ally, the one-shot output spectrum is unfolded allowing

further digital signal processing of the conversion results.

SCK and SDO may be common to all four LTC2400s. The

four CS rising edges equally divide one LTC2400 conver-

sion cycle (7.5Hz for 60Hz notch frequency). In order to

synchronize the start of conversion to CS, 31 or less SCK

clock pulses must be applied to each ADC.

Both the synchronous and 4

× output rate applications use

the external serial clock and single cycle operation with

reduced data output length (see Serial Interface Timing

Modes section and Figure 6). An external oscillator clock

is applied commonly to the FO pin of each LTC2400 in

order to synchronize the sampling times. Both circuits

may be extended to include more LTC2400s.

31 OR LESS CLOCK CYCLES

SCK1

SCK2

2400 F27

SDO1

SDO2

31 OR LESS CLOCK CYCLES

LTC2400

VCC

VREF

VIN

GND

SCK

SDO

SCK2

SCK1

SDO1

SDO2

LTC2400

VCC

VREF

VIN

GND

SCK

SDO

µCONTROLLER

EXTERNAL OSCILLATOR

(153,600HZ)

VREF

(0.1V TO VCC)

Figure 27. Synchronous Conversion—Extendable

LTC2400CS8 数据表(PDF) 26 Page - Linear Technology

LTC2400CS8 数据表(HTML) 26 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

数据表下载

链接网址

LTC2400CS8 数据表(PDF) 26 Page - Linear Technology

LTC2400CS8 数据表(HTML) 26 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

数据表 下载

链接网址

数据表下载