MAX148 Datasheet, PDF (3/24 Pages) Maxim Integrated Products – +2.7V to +5.25V, Low-Power, 8-Channel, Serial 10-Bit ADCs

+2.7V to +5.25V, Low-Power, 8-Channel,
Serial 10-Bit ADCs
ELECTRICAL CHARACTERISTICS (continued)
V_DD = +2.7V to +5.25V; COM = 0V; f_SCLK = 2.0MHz; external clock (50% duty cycle); 15 clocks/conversion cycle (133ksps);
MAX149—4.7µF capacitor at VREF pin; MAX148—external reference, VREF = 2.500 V applied to VREF pin; T_A = T_MIN to T_MAX; unless
otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
CONVERSION RATE (continued)
Internal Clock Frequency
SHDN = FLOAT
SHDN = V_DD
External Clock Frequency
Data transfer only
ANALOG/COM INPUTS
Input Voltage Range, Single-
Ended and Differential (Note 6)
Unipolar, COM = 0V
Bipolar, COM = VREF / 2
Multiplexer Leakage Current
Input Capacitance
On/off leakage current, V_{CH_} = 0V or V_DD
INTERNAL REFERENCE (MAX149 only, reference buffer enabled)
VREF Output Voltage
VREF Short-Circuit Current
T_A = +25°C (Note 7)
VREF Temperature Coefficient
MAX149
Load Regulation (Note 8)
0mA to 0.2mA output load
Capacitive Bypass at VREF
Internal compensation mode
External compensation mode
Capacitive Bypass at REFADJ
REFADJ Adjustment Range
EXTERNAL REFERENCE AT VREF (Buffer disabled)
MIN TYP MAX UNITS
1.8
0.225
MHz
0.1
2.0
MHz
0
2.0
0 to VREF
V
±VREF / 2
±0.01 ±1
µA
16
pF
2.470
0
4.7
0.01
2.500
±30
0.35
±1.5
2.530
30
V
mA
ppm/°C
mV
µF
µF
%
VREF Input Voltage Range
(Note 9)
1.0
V_DD +
50mV
V
VREF Input Current
VREF Input Resistance
Shutdown VREF Input Current
VREF = 2.500V
100
150
µA
18
25
kΩ
0.01
10
µA
REFADJ Buffer-Disable Threshold
V_DD -
0.5
V
EXTERNAL REFERENCE AT REFADJ
Capacitive Bypass at VREF
Reference Buffer Gain
REFADJ Input Current
Internal compensation mode
External compensation mode
MAX149
MAX148
MAX149
MAX148
0
µF
4.7
2.06
V/V
2.00
±50
µA
±10
_______________________________________________________________________________________ 3