LTC1407CMSE#TR Linear Technology, LTC1407CMSE#TR Datasheet - Page 17

• Manufacturer Part Number: LTC1407CMSE#TR
• Description: IC ADC 12BIT 3MSPS SAMPLE 10MSOP
• Manufacturer: Linear Technology

Specifications of LTC1407CMSE#TR

• Number Of Bits: 12
• Sampling Rate (per Second): 3M
• Data Interface: Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 14mW
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIONS INFORMATION
HARDWARE INTERFACE TO TMS320C54x
The LTC1407/LTC1407A are serial output ADCs whose inter-
face has been designed for high speed buffered serial ports
in fast digital signal processors (DSPs). Figure 6 shows
an example of this interface using a TMS320C54X.
The buffered serial port in the TMS320C54x has direct
access to a 2kB segment of memory. The ADC’s serial data
can be collected in two alternating 1kB segments, in real
time, at the full 3Msps conversion rate of the LTC1407/
LTC1407A. The DSP assembly code sets frame sync mode
at the BFSR pin to accept an external positive going pulse
LTC1407A
LTC1407/
CONV
SDO
GND
V
SCK
DD
7
10
9
8
6
3V
Figure 6. DSP Serial Interface to TMS320C54x
CONV
CLK
0V TO 3V LOGIC SWING
INTERFACELINK
3-WIRE SERIAL
and the serial clock at the BCLKR pin to accept an external
positive edge clock. Buffers near the LTC1407/LTC1407A
may be added to drive long tracks to the DSP to prevent
corruption of the signal to LTC1407/LTC1407A. This con-
fi guration is adequate to traverse a typical system board,
but source resistors at the buffer outputs and termination
resistors at the DSP , may be needed to match the char-
acteristic impedance of very long transmission lines. If
you need to terminate the SDO transmission line, buffer
it fi rst with one or two 74ACxx gates. The TTL threshold
inputs of the DSP port respond properly to the 3V swing
used with the LTC1407/LTC1407A.
5V
B13
LTC1407/LTC1407A
B12
V
BFSR
BCLKR
BDR
TMS320C54x
CC
1407 F06
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