ADC1415S_SER 5 © IDT 2012. All rights reserved.
Product data sheet Rev. 05 — 2 July 2012 28 of 40
Integrated Device Technology
ADC1415S series
Single 14-bit ADC; input buffer; CMOS or LVDS DDR digital outputs
11.5.7 Output codes versus input voltage
11.6 Serial Peripheral Interface (SPI)
11.6.1 Register description
The ADC1415S serial interface is a synchronous serial communications port that allows
easy interfacing with many commonly-used microprocessors. It provides access to the
registers that control the operation of the chip.
This interface is configured as a 3-wire type (SDIO as bidirectional pin)
Pin SCLK is the serial clock input and CS
is the chip select pin.
Each read/write operation is initiated by a LOW level on CS. A minimum of three bytes is
transmitted (two instruction bytes and at least one data byte). The number of data bytes is
determined by the value of bits W1 and W2 (see Table 17).
[1] Bit R/W indicates whether it is a read (logic 1) or a write (logic 0) operation.
[2] Bits W1 and W0 indicate the number of bytes to be transferred after the instruction byte (see Table 17).
Table 15. Output codes
V
INP
V
INM
Offset binary Two’s complement OTR pin
< 1 00 0000 0000 0000 10 0000 0000 0000 1
1 00 0000 0000 0000 10 0000 0000 0000 0
0.9998779 00 0000 0000 0001 10 0000 0000 0001 0
0.9997559 00 0000 0000 0010 10 0000 0000 0010 0
0.9996338 00 0000 0000 0011 10 0000 0000 0011 0
0.9995117 00 0000 0000 0100 10 0000 0000 0100 0
.... .... .... 0
0.0002441 01 1111 1111 1110 11 1111 1111 1110 0
0.0001221 01 1111 1111 1111 11 1111 1111 1111 0
0 10 0000 0000 0000 00 0000 0000 0000 0
+0.0001221 10 0000 0000 0001 00 0000 0000 0001 0
+0.0002441 10 0000 0000 0010 00 0000 0000 0010 0
.... .... .... 0
+0.9995117 11 1111 1111 1011 01 1111 1111 1011 0
+0.9996338 11 1111 1111 1100 01 1111 1111 1100 0
+0.9997559 11 1111 1111 1101 01 1111 1111 1101 0
+0.9998779 11 1111 1111 1110 01 1111 1111 1110 0
+1 11 1111 1111 1111 01 1111 1111 1111 0
> +1 11 1111 1111 1111 01 1111 1111 1111 1
Table 16. Instruction bytes for the SPI
MSB LSB
Bit 76543210
Description R/W
[1]
W1
[2]
W0
[2]
A12 A11 A10 A9 A8
A7 A6 A5 A4 A3 A2 A1 A0