MAX1281BEUP-T Maxim Integrated, MAX1281BEUP-T Datasheet - Page 18

• Manufacturer Part Number: MAX1281BEUP-T
• Description: Analog to Digital Converters - ADC
• Manufacturer: Maxim Integrated

Specifications of MAX1281BEUP-T

• Number Of Channels: 8/4
• Architecture: SAR
• Conversion Rate: 300 KSPs
• Resolution: 12 bit
• Input Type: Single-Ended/Pseudo-Differential
• Snr: 70 dB
• Interface Type: 4-Wire (SPI, Microwire, QSPI, TMS320)
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-20
• Maximum Power Dissipation: 559 mW
• Minimum Operating Temperature: - 40 C
• Number Of Converters: 1
• Voltage Reference: 2.5 V

power consumption using the specified power-down
mode, with the internal reference and the maximum
clock speed. The clock speed in FASTPD or REDP
should be limited to 4.8MHz for the MAX1280/
MAX1281. FULLPD mode may provide increased power
Serial 12-Bit ADCs with Internal Reference
Figure 11. Average Supply Current vs. Sampling Rate (Using
REPD, FASTPD, and Normal Operation and Internal Reference)
Figure 12a. Full Power-Down Timing
Figure 12b. Reduced-Power/Fast Power-Down Timing
18
400ksps/300ksps, Single-Supply, Low-Power, 8-Channel,
______________________________________________________________________________________
I
VDD1
RE FADJ
+ I
2.5
2.0
1.5
1.0
0.5
VDD2
DIN
REF
I
VDD1
0
MAX1281, V
C
CODE = 101010000000
+ I
LOAD
NORMAL OPERATION
50
VDD2
1
DIN
REF
= 20pF
REDP
FULLPD
100
SAMPLING RATE (sps)
DD1
1
= V
150
2.5mA
1.22V
DD2
2.5V
FASTPD
0 0
REDPD
2.5mA
= 3.0V
200
2.5V (ALWAYS ON)
250
1 0
300
0mA
0V
0V
350
1.3mA
1
γ = RC = 17kΩ x 0.01µF
REDP
DUMMY CONVERSION
2.5mA
WAIT 2ms (10 x RC)
1
1 0
REDP
2.5mA
1.3mA OR 0.9mA
savings in applications where the MAX1280/
MAX1281 are inactive for long periods of time, but
where intermittent bursts of high-speed conversions are
required.
The MAX1280/MAX1281 can be used with an internal
or external reference. An external reference can be
connected directly at REF or at the REFADJ pin.
An internal buffer is designed to provide 2.5V at REF for
both the MAX1280/MAX1281. The internally trimmed
1.22V reference is buffered with a gain of +2.05V/V.
The MAX1280/MAX1281’s full-scale range with the inter-
nal reference is 2.5V for unipolar inputs and ±1.25V for
bipolar inputs. The internal reference voltage is
adjustable to ±100mV with the circuit of Figure 13.
An external reference can be placed at either the input
(REFADJ) or the output (REF) of the internal reference-
buffer amplifier. The REFADJ input impedance is typical-
ly 17kΩ. At REF, the DC input resistance is a minimum of
1 0
1
1.3mA
Internal and External References
FULLPD
1.22V
2.5mA
2.5V
1
0 0
FASTPD
0mA
2.5mA
0
1
External Reference
0.9mA
Internal Reference
1