Datasheet

Operating Modes and Serial Interfaces
The MAX1132/MAX1133 are fully compatible with
MICROWIRE and SPI/QSPI devices. MICROWIRE and
SPI/QSPI both transmit a byte and receive a byte at the
same time. The simplest software interface requires
only three 8-bit transfers to perform a conversion (one
8-bit transfer to configure the ADC, and two more 8-bit
transfers to clock out the 16-bit conversion result).
Short Acquisition Mode (24 SCLK)
Configure short acquisition by setting M1 = 0 and M0 =
0. In short acquisition mode, the acquisition time is 5.5
clock cycles. The total period is 24 clock cycles per
conversion.
Mode 2 Long Acquisition Mode (32 SCLK)
Configure long acquisition by setting M1 = 1 and M0 =
1. In long acquisition mode, the acquisition time is 13.5
clock cycles. The total period is 32 clock cycles per
conversion.
Calibration Mode
A calibration is initiated through the serial interface by
setting M1 = 0, M0 = 1. Calibration can be done in
either internal or external clock mode, though it is desir-
able that the part be calibrated in the same mode in
which it will be used to do conversions. The part will
remain in calibration mode for approximately 80,000
clock cycles unless the calibration is aborted.
Calibration is halted if RST or SHDN goes low, or if a
valid start condition occurs.
Software Shutdown
A software power-down is initiated by setting M1 = 1,
M0 = 0. After the conversion completes, the part shuts
down. It reawakens upon receiving a new start bit.
Conversions initiated with M1 = 1 and M0 = 0 (shut-
down) use the acquisition mode selected for the previ-
ous conversion.
Shutdown Mode
The MAX1132/MAX1133 may be shut down by pulling
SHDN low or by asserting software shutdown. In addi-
tion to lowering power dissipation to 13µW, consider-
able power can be saved by shutting down the
converter for short periods (duration will be affected by
REF startup time with internal reference) between con-
versions. There is no need to perform a calibration after
the converter has been shut down, unless the time in
MAX1132/MAX1133
16-Bit ADC, 200ksps, 5V Single-Supply
with Reference
______________________________________________________________________________________ 15
4
7
6
2
3
IN
+15V
-15V
0.0033
µ
F
0.1
µ
F
0.1
µ
F
100pF
1k
Ω
20
Ω
AIN
MAX427
ELANTEC
EL2003
Figure 8. AIN Buffer for AC/DC Use
4
7
6
2
3
IN
+5V
-5V
AIN
0.1
µ
F
0.1
µ
F
0.1
µ
F
22
Ω
510
Ω
MAX410
Figure 9. ±5V Buffer for AC/DC Use Has ±3.5V Swing