LTC1863/LTC1867

14

18637f

APPLICATIO S I FOR ATIO

Figure 7. Example 2, CS/CONV Starts a Conversion with Short Active HIGH Pulse.

With CS/CONV Returning LOW Before the Conversion, the ADC Remains Powered Up.

INPUT VOLTAGE (V)

1867 F09

111...111

111...110

100...001

100...000

000...000

000...001

011...110

011...111

FS – 1LSB

0V

UNIPOLAR

ZERO

FS = 4.096

1LSB = (LTC1863) = 1mV

1LSB = (LTC1867) = 62.5

µV

Figure 8. LTC1863/LTC1867 Bipolar Transfer

Characteristics (Two’s Complement)

Figure 9. LTC1863/LTC1867 Unipolar Transfer

Characteristics (Straight Binary)

S0

SD

0S

S1

COM UNI

SLP

MSB = D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

CS/CONV

SCK

SDI

SDO

(LTC1867)

Hi-Z

123456789

10

11

12

13

14

15

16

D12

MSB = D15

D14

D13

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

Hi-Z

1867 F07

DON'T CARE

DON'T CARE

NOT NEEDED FOR LTC1863

SDO

(LTC1863)

INPUT VOLTAGE (V)

0V

–1

LSB

1867 F08

011...111

011...110

000...001

000...000

100...000

100...001

111...110

1

LSB

BIPOLAR

ZERO

111...111

FS/2 – 1LSB

–FS/2

FS = 4.096

1LSB = (LTC1863) = 1mV

1LSB = (LTC1867) = 62.5

µV