Multirange, +5V, 8-Channel,

Serial 12-Bit ADCs

4

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ELECTRICAL CHARACTERISTICS (continued)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

INTERNAL REFERENCE

REF Output Voltage

4.076

4.096

4.116

V

MAX1270_C/MAX1271_C

±15

REF Output Tempco

MAX1270_E/MAX1271_E

±30

ppm/

°C

Output Short-Circuit Current

30

mA

Load Regulation

0 to 0.5mA output current (Note 5)

10

mV

Capacitive Bypass at REF

4.7

µF

Capacitive Bypass at REFADJ

0.01

µF

REFADJ Output Voltage

2.465

2.500

2.535

V

REFADJ Adjustment Range

Figure 1

±1.5

%

Buffer Voltage Gain

1.638

V/V

REFERENCE INPUT (Reference buffer disabled, reference input applied to REF)

Input Voltage Range

2.40

4.18

V

Normal or STBYPD

400

Input Current

FULLPD

1

µA

Normal or STBYPD

10

k

Ω

Input Resistance

FULLPD

4.18

M

Ω

REFADJ Threshold for Buffer

Disable

0.5

V

POWER REQUIREMENT

Supply Voltage

4.75

5.25

V

Bipolar range

18

Normal

Unipolar range

6

10

mA

STBYPD power-down mode (Note 6)

700

850

Supply Current

FULLPD power-down mode

120

220

µA

External reference = 4.096V

±0.1

±0.5

Power-Supply Rejection

Ratio (Note 7)

PSRR

Internal reference

±0.5

LSB

TIMING

MAX127_A

0.1

1.8

External Clock Frequency Range

MAX127_B

0.1

2.0

MHz

MAX127_A

3.3

External clock mode

(Note 8)

MAX127_B

3.0

Acquisition Phase

Internal clock mode, Figure 9

3

5

µs