max5307 Maxim Integrated Products, Inc., max5307 Datasheet - Page 11

• Manufacturer Part Number: max5307
• Description: Low-power, Low-glitch, Octal 12-bit Voltage-output Dacs With Serial Interface
• Manufacturer: Maxim Integrated Products, Inc.

Figure 2. Connections for MICROWIRE
The MAX5307 has an active low CLR input. Drive CLR
low to clear all internal registers, shutdown all DACs,
and terminate all DAC outputs to GND through 100kΩ
resistors. CLR is asynchronous and can be applied at
any time. If CLR is toggled low during loading of a seri-
al word, that word will terminate and must be reloaded.
The external reference input has a typical input imped-
ance of 200kΩ. The input voltage range is from 800mV
to V
MAX5306/MAX5307. The DAC outputs are then ratio-
metric to V
The rail-to-rail buffer amplifier is stable with any combi-
nation of resistive loads greater than 2kΩ and capaci-
tive loads less than 500pF. With a capacitive load of
200pF the output buffers have a slew rate of 1V/µs. For
a 1/4 FS to 3/4 FS output transition, the amplifier output
typically settles to 1/2 LSB in less than 10µs when
loaded with 2kΩ in parallel with 200pF.
The MAX5306/MAX5307 have a POR circuit to set the
DACs output to zero when V
ensures that unwanted DAC output voltages will not
occur immediately following a system startup, such as
after a loss of power. Upon initial power-up the POR cir-
cuit ensures that all DAC registers are cleared, the
DACs are powered-down, and their outputs are termi-
nated to GND through a 100kΩ resistor.
*THE DOUT-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX5306,
BUT MAY BE USED FOR TRANSMISSION VERIFICATION PURPOSES.
DD
Low-Power, Low-Glitch, Octal 12-Bit Voltage-
. V
MAX5306
DD
DD
.
can be used as the reference for the
DOUT*
SCLK
DIN
______________________________________________________________________________________
CS
Hardware Clear (CLR)
DD
Output DACs with Serial Interface
SK
SO
SI*
I/O
is first applied. This
Reference Input
Power-On Reset
Output Buffer
MICROWIRE
PORT
Any number of MAX5306 can be daisy-chained by con-
necting the DOUT pin of one device to the DIN pin of
the following device in the chain (Figure 5). To write to
the chain, drive CS low until all n x 16 clock cycles
(where n is the number of devices in the chain) and
associated data have been applied to the first device.
When CS is driven high, each device in the chain acts
on the 16 bits in its input register. To adjust a single
device in the chain, a No-Operation (NOP) command
must be loaded for all other devices.
Figure 6 shows an alternate method of connecting sev-
eral MAX5306s or MAX5307s. In this configuration, the
data bus is common to all devices; data is not shifted
through a daisy chain. More I/O lines are required in
this configuration because a dedicated chip-select
input (CS) is required for each IC.
The MAX5306/MAX5307 are normally configured for
unipolar output. Table 3 lists the unipolar output volt-
ages vs. digital codes.
The MAX5306/MAX5307 outputs can be configured for
bipolar operation using Figure 7’s circuit.
where D is the decimal value of the DACs binary input
code. Table 4 shows digital codes (offset binary) and
corresponding output voltages for the Figure 7 circuit.
Figure 3. Connections for SPI/QSPI
*THE DOUT-MISO CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX5307,
BUT MAY BE USED FOR TRANSMISSION VERIFICATION PURPOSES.
MAX5307
V
OUT
DOUT*
SCLK
DIN
CS
Application Information
= V
REF
Daisy-Chaining Devices
[(2D / 4096 -1)]
CPOL = 0, CPHA = 0
MISO*
MOSI
SCK
I/O
Unipolar Output
Bipolar Output
SPI/QSPI
PORT
+5V
SS
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