MAX1245ACAP Maxim Integrated, MAX1245ACAP Datasheet - Page 19

• Manufacturer Part Number: MAX1245ACAP
• Description: Analog to Digital Converters - ADC Integrated Circuits (ICs)
• Manufacturer: Maxim Integrated

Specifications of MAX1245ACAP

• Number Of Channels: 8/4
• Architecture: SAR
• Conversion Rate: 100 KSPs
• Resolution: 12 bit
• Input Type: Single-Ended/Differential
• Snr: 70 dB
• Interface Type: 4-Wire (SPI, Microwire, QSPI, TMS320)
• Operating Supply Voltage: 2.375 V to 3.3 V
• Maximum Operating Temperature: + 70 C
• Package / Case: SSOP-20
• Maximum Power Dissipation: 640 mW
• Minimum Operating Temperature: 0 C
• Number Of Converters: 1
• Factory Pack Quantity: 66
• Voltage Reference: 2.048 V

Figure 18 shows an application circuit to interface the
MAX1245 to the TMS320 in external clock mode. The tim-
ing diagram for this interface circuit is shown in Figure 19.
Use the following steps to initiate a conversion in the
MAX1245 and to read the results:
1) The TMS320 should be configured with CLKX
2) The MAX1245’s CS pin is driven low by the TMS320’s
3) An 8-bit word (1XXXXX11) should be written to the
4) The MAX1245’s SSTRB output is monitored via the
5) The TMS320 reads in one data bit on each of the
6) Pull CS high to disable the MAX1245 until the next
Figure 19. TMS320 Serial-Interface Timing Diagram
(transmit clock) as an active-high output clock and
CLKR (TMS320 receive clock) as an active-high
input clock. CLKX and CLKR on the TMS320 are
tied together with the MAX1245’s SCLK input.
XF_ I/O port, to enable data to be clocked into the
MAX1245’s DIN.
MAX1245 to initiate a conversion and place the
device into external clock mode. Refer to Table 1 to
select the proper XXXXX bit values for your specific
application.
TMS320’s FSR input. A falling edge on the SSTRB
output indicates that the conversion is in progress
and data is ready to be received from the
MAX1245.
next 16 rising edges of SCLK. These data bits rep-
resent the 12-bit conversion result followed by four
trailing bits, which should be ignored.
conversion is initiated.
SSTRB
DOUT
SCLK
DIN
CS
START
TMS320LC3x-to-MAX1245 Interface
______________________________________________________________________________________
SEL2
SEL1
SEL0
+2.375V, Low-Power, 8-Channel,
UNI/BIP SGL/DIF
PD1
Figure 18. MAX1245-to-TMS320 Serial Interface
PD0
TMS320LC3x
Serial 12-Bit ADC
MSB
CLKX
CLKR
FSR
DX
DR
XF
B10
B1
LSB
CS
SCLK
DIN
DOUT
SSTRB
MAX1245
HIGH
IMPEDANCE
HIGH
IMPEDANCE
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