MAX1178AEUP Maxim Integrated, MAX1178AEUP Datasheet - Page 9

• Manufacturer Part Number: MAX1178AEUP
• Description: Analog to Digital Converters - ADC
• Manufacturer: Maxim Integrated

Specifications of MAX1178AEUP

• Number Of Channels: 1
• Architecture: SAR
• Conversion Rate: 135 KSPs
• Resolution: 16 bit
• Input Type: Single-Ended
• Snr: 91 dB
• Interface Type: Parallel
• Operating Supply Voltage: 4.75 V to 5.25 V
• Maximum Operating Temperature: + 85 C
• Package / Case: TSSOP-20
• Maximum Power Dissipation: 879 mW
• Minimum Operating Temperature: - 40 C
• Number Of Converters: 1
• Voltage Reference: 4.096 V

The MAX1178/MAX1188 have a selectable standby or
low-power shutdown mode. In standby mode, the ADC’s
internal reference and reference buffer do not power
down between conversions, eliminating the need to wait
for the reference to power up before performing the next
conversion. Shutdown mode powers down the reference
and reference buffer after completing a conversion. The
reference and reference buffer require a minimum of
12ms to power up and settle from shutdown (C
0.1µF, C
The state of R/C at the second falling edge of CS
selects which power-down mode the MAX1178/
MAX1188 enter upon conversion completion. Holding
R/C low causes the MAX1178/MAX1188 to enter stand-
by mode. The reference and buffer are left on after the
conversion completes. R/C high causes the
MAX1178/MAX1188 to enter shutdown mode and
power-down the reference and buffer after conversion
(Figures 5 and 6). Set the voltage at R/C high during
the second falling edge of CS to realize the lowest cur-
rent operation.
While in standby mode, the supply current is less than
3.7mA (typ). The next falling edge of CS with R/C low
causes the MAX1178/MAX1188 to exit standby mode
and begin acquisition. The reference and reference
buffer remain active to allow quick turn-on time.
In shutdown mode, the reference and reference buffer
are shut down between conversions. Shutdown mode
reduces supply current to 0.5µA (typ) immediately after
the conversion. The next falling edge of CS with R/C low
causes the reference and buffer to wake up and enter
acquisition mode. To achieve 16-bit accuracy, allow
12ms for the internal reference to wake up (C
0.1µF, C
The internal reference of the MAX1178/MAX1188 is
internally buffered to provide +4.096V output at REF.
Bypass REF to AGND and REFADJ to AGND with 10µF
and 0.1µF, respectively. Sink or source current at
REFADJ to make fine adjustments to the internal refer-
ence. The input impedance of REFADJ is nominally
5kΩ. Use the circuit in Figure 7 to adjust the internal
reference to ±1.5%.
Selecting Standby or Shutdown Mode
REF
REF
= 10µF).
= 10µF).
Internal and External Reference
16-Bit, 135ksps, Single-Supply ADCs with
_______________________________________________________________________________________
Internal Reference
Shutdown Mode
Standby Mode
REFADJ
REFADJ
Bipolar Analog Input Range
=
=
Figure 4. Equivalent Input Circuit
Figure 5. Selecting Standby Mode
Figure 6. Selecting Shutdown Mode
REF AND
REF AND
BUFFER
BUFFER
POWER
POWER
AIN
R2 = 7.85kΩ (MAX1188) OR 3.92kΩ (MAX1178)
R3 = 5.45kΩ (MAX1188) OR 17.79kΩ (MAX1178)
EOC
EOC
R/C
MAX1178/MAX1188
R/C
CS
CS
R2
ACQUISITION
ACQUISITION
R3
161Ω
POWER-
DOWN
S3
R1
3.4kΩ
TRACK
CONVERSION
CONVERSION
HOLD
S1
REF
C
30pF
HOLD
TRACK
S1, S2 = T/H SWITCH
S3 = POWER-DOWN
S2
DATA
HOLD
OUT
DATA
OUT
T/H OUT
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