MSB

LSB

puts become high impedance, and the serial inter-

saved, allowing the MAX5150/MAX5151 to recall the

output state prior to entering shutdown when returning

to normal mode. Exit shutdown by recalling the previ-

ous condition or by updating the DAC with new infor-

mation. When returning to normal operation (exiting

shutdown), wait 20µs for output stabilization.

Serial Interface

The MAX5150/MAX5151 3-wire serial interface is com-

patible with both Microwire (Figure 2) and SPI/QSPI

(Figure 3) serial-interface standards. The 16-bit serial

input word consists of an address bit, two control bits,

and 13 bits of data (MSB to LSB) as shown in Figure 4.

Low-Power, Dual, 13-Bit Voltage-Output DACs

with Serial Interface

10

______________________________________________________________________________________

16-BIT SERIAL WORD

FUNCTION

A0

C1

C0

D12.......................D0

(MSB)

(LSB)

0

0

1

13-bit DAC data

Load input register A; DAC registers are unchanged.

0

1

1

13-bit DAC data

Load all DAC registers from the shift register

(start up both DACs with new data.).

1

1

0

13-bit DAC data

Load input register B; all DAC registers are updated.

0

1

0

13-bit DAC data

Load input register A; all DAC registers are updated.

1

0

1

13-bit DAC data

Load input register B; DAC registers are unchanged.

0

0

0

1 1 0 x xxxxxxxxx

Shut down DAC A (provided PDL = 1).

0

0

0

1 0 1 x xxxxxxxxx

Update DAC register B from input register B

(start up DAC B with data previously stored in input register B).

0

0

0

0 0 1 x xxxxxxxxx

Update DAC register A from input register A

(start up DAC A with data previously stored in input register A).

1

1

1

xxxxxxxxxxxxx

Shut down both DACs (provided PDL = 1).

1

0

0

xxxxxxxxxxxxx

Update both DAC registers from their respective input registers

(start up both DACs with data previously stored in the input registers).

0

0

0

1 1 1 x xxxxxxxxx

Shut down DAC B (provided PDL = 1).

0

0

0

0 1 0 x xxxxxxxxx

UPO goes low (default).

0

0

0

0 1 1 x xxxxxxxxx

UPO goes high.

0

0

0

1 0 0 1 xxxxxxxxx

Mode 1, DOUT clocked out on SCLK’s rising edge.

0

0

0

1 0 0 0 xxxxxxxxx

Mode 0, DOUT clocked out on SCLK’s falling edge (default).

0

0

0

0 0 0 x xxxxxxxxx

No operation (NOP).

Table 1. Serial-Interface Programming Commands

x = Don’t care

Note: When A0, C1, and C0 = 0, then D12, D11, D10, and D9 become control bits.

SCLK

DIN

CS

SK

SO

I/O

MAX5150

MAX5151

MICROWIRE

PORT

Figure 2. Connections for Microwire