Datasheet
13Maxim Integrated
14-/16-Bit, Low-Power, Buffered Output,
Rail-to-Rail DACs with SPI Interface
MAX5214/MAX5216
Table 1. Operating Mode Truth Table (MAX5214)
Serial Interface
The MAX5214/MAX5216 3-wire serial interface is com-
patible with MICROWIRE, SPI, QSPI, and DSP. The
interface provides three inputs: SCLK, CS, and DIN. The
chip-select input (CS) frames the serial data loading at
DIN. Following a chip-select input high-to-low transition,
the data is shifted synchronously and latched into the
input register on each falling edge of the serial-clock
input (SCLK). Each serial word is 16-bit for the MAX5214
and 24-bit for the MAX5216. The first 2 bits are the
control bits followed by 14 data bits (MSB first) for the
MAX5214 and 22 data bits (MSB first) for the MAX5216
as shown in Tables 1 and 2. The serial input register
transfers its contents to the input registers after loading
16/24 bits of data and updates the DAC output immedi-
ately after the data is received on the 16-/24-bit falling
edge of the clock. To initiate a new data transfer, drive
CS high and keep CS high for a minimum of 20ns before
the next write sequence. The SCLK can be either high or
low between CS write pulses. Figures 1 and 2 show the
timing diagram for the complete 3-wire serial interface
transmission. The MAX5216 DAC code is unipolar binary
with V
OUT
= (code/65,535) x V
REF
. The MAX5214 DAC
code is unipolar binary with V
OUT
= (code/16,383) x
V
REF
. See Tables 1 and 2.
Table 2. Operating Mode Truth Table (MAX5216)
16-BIT WORD
FUNCTION
CONTROL
BITS
DATA BITS
MSB LSB
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
0 0 X X X X X X X X X X X X X X No operation
1 0 0 X A1 A0 X X X X X X X X X X
Power-down
(see Table 3)
0 1 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 Write through
1 1 Reserved, Do Not Use
24-BIT WORD
FUNCTION
CONTROL
BITS
DATA BITS
MSB LSB
D23 D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6
D5–
D0
0 0 X X X X X X X X X X X X X X X X X No operation
1 0 0 X A1 A0 X X X X X X X X X X X X X
Power-down
(see Table 3)
0 1 B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 X Write through
1 1 Reserved, Do Not Use