LTC1283 Datasheet, PDF (13/24 Pages) Linear Technology – 3V Single Chip 10-Bit Data Acquisition System

LTC1283
APPLICATI S I FOR ATIO
CS
SCLK
D_IN
D_OUT
SHIFT
MUX ADDRESS
IN
t_SMPL
SAMPLE ANALOG
INPUT
40 TO 44
ACLK CYCLES
SHIFT RESULT OUT
AND NEW ADDRESS IN
SGL/
SEL SEL
DIFF ODD/ 1 0 UNI MSBF WL1 WL0
SIGN
DON’T CARE
SGL/
SEL
DIFF ODD/ 1 SEL UNI MSBF WL1 WL0
SIGN
0
B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Figure 3. CS High During Conversion
LTC1283 • F03
CS
SCLK
D_IN
D_OUT
SHIFT
MUX ADDRESS
IN
t_SMPL
SAMPLE ANALOG
INPUT
40 TO 44
ACLK CYCLES
SHIFT RESULT OUT
AND NEW ADDRESS IN
SCLK MUST REMAIN LOW
SGL/
SEL SEL
DIFF ODD/ 1 0 UNI MSBF WL1 WL0
SIGN
DON’T CARE
SGL/
SEL
DIFF ODD/ 1 SEL UNI MSBF WL1 WL0
SIGN
0
B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Figure 4. CS Low During Conversion
LTC1283 • F04
Table 2. 3V Microprocessor with Hardware Serial Interfaces
Compatible with the LTC1283*
PART NUMBER
Motorola
MC68HC11
MC68HC05
RCA
CDP68HC05
National Semiconductor
COP800 Family
HPC16000 Family
Texas Instruments
TMS70C02
TMS70C42
TYPE OF INTERFACE
SPI
SPI
SPI
MICROWIRE/PLUS^†
MICROWIRE/PLUS^†
Serial Port
Serial Port
*Contact factory for interface information for processors not on this list
†_{MICROWIRE/PLUS is a trademark of National Semiconductor Corp.}
Serial Port Microprocessors
Most synchronous serial formats contain a shift clock
(SCLK) and two data lines, one for transmitting and one for
receiving. In most cases data bits are transmitted on the
falling edge of the clock (SCLK) and captured on the rising
edge. However, serial port formats vary among MPU
manufacturers as to the smallest number of bits that can
be sent in one group (e.g., 4-bit, 8-bit or 16-bit transfers).
They also vary as to the order in which the bits are
transmitted (LSB- or MSB-first). The following examples
show how the LTC1283 accommodates these differences.
National MICROWIRE (COP820C)
The COP820C transfers data MSB-first and in 8-bit incre-
ments. This is easily accommodated by setting the LTC1283
to MSB-first format and 10-bit word length. The data
output word is then received by the COP820C in one 8-bit
block and one 2-bit block.
13