MAX1258BETM+ Maxim Integrated Products, MAX1258BETM+ Datasheet - Page 33

• Manufacturer Part Number: MAX1258BETM+
• Description: IC ADC/DAC 12BIT 48-TQFN
• Manufacturer: Maxim Integrated Products
• Type: ADC, DACr

Specifications of MAX1258BETM+

• Resolution (bits): 12 b
• Sampling Rate (per Second): 225k
• Data Interface: Serial
• Voltage Supply Source: Analog and Digital
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 21. DAC Power-Up and Power-Down Commands
If CS goes high prior to completing 16 SCLK cycles, the
command is discarded. To initiate a new transfer, drive
CS low again.
For example, writing the DAC serial interface word 1111
0000 and 1111 0100 disconnects DAC outputs 4
through 7 and forces them to a high-impedance state.
DAC outputs 0 through 3 remain in their previous state.
Figures 6–9 illustrate the conversion timing for the
MAX1220/MAX1257/MAX1258. All 12-bit conversion
results are output in 2-byte format, MSB first, with four
leading zeros. Data appears on DOUT on the falling
edges of SCLK. Data is binary for unipolar mode and
C3 C2 C1 C0
1
1
1
1
1
CONTROL
BITS
1
1
1
1
1
1
1
1
1
1
1 — — — — — — — — 0
1 — — — — — — — — 0
1 — — — — — — — — 1
1 — — — — — — — — 0
1 — — — — — — — — 1
12-Bit, Multichannel ADCs/DACs with FIFO,
______________________________________________________________________________________
Temperature Sensing, and GPIO Ports
DATA BITS
Output-Data Format
D3 D2 D1 D0
0
1
0
0
1
1
0
0
0
1
X
X
X
X
X
DESCRIPTION
Power-Down 1
Power-Down 2
Power-Down 3
Power-Down 4
Power-Up
two’s complement for bipolar mode and temperature
results. See Figures 3, 4, and 5 for input/output and
temperature-transfer functions.
Figure 3 shows the unipolar transfer function for single-
ended or differential inputs. Figure 4 shows the bipolar
transfer function for differential inputs. Code transitions
occur halfway between successive-integer LSB values.
Output coding is binary, with 1 LSB = V
(MAX1257)
(MAX1220/MAX1258) for unipolar and bipolar opera-
tion, and 1 LSB = +0.125°C for temperature measure-
ments.
Power up individual DAC buffers indicated by data
in DAC0 through DAC7. A one indicates the DAC
output is connected and active. A zero does not
affect the DAC’s present state.
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and high impedance.
A zero does not affect the DAC’s present state.
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and pulled to AGND
with a 1kΩ resistor. A zero does not affect the DAC’s
present state.
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and pulled to AGND
with a 100kΩ resistor. A zero does not affect the
DAC’s present state.
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and pulled to REF1 with
a 100kΩ resistor. A zero does not affect the DAC’s
present state.
Bipolar
and
true-differential
1
ADC Transfer Functions
LSB
FUNCTION
=
V
REF1
results
REF1
/
/ 4096
4096
and
33