Rainbow Electronics MAX149 - Manual (Page 3)

MAX148/MAX149
+2.7V to +5.25V, Low-Power, 8-Channel,
Serial 10-Bit ADCs
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Multiplexer Leakage Current
µA 0.01 10 Shutdown VREF Input Current
k
Ω
18 25 VREF Input Resistance
µA 100 150 VREF Input Current
V 1.0
V
DD
+
50mV
VREF Input Voltage Range
(Note 9)
pF 16 Input Capacitance
1.8
MHz
0.225
Internal Clock Frequency
µA ±0.01 ±1
UNITS MIN TYP MAX SYMBOL PARAMETER
SHDN = FLOAT
VREF = 2.500V
SHDN = V
DD
On/off leakage current, V CH_ = 0V or V DD
CONDITIONS
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.)
V 2.470 2.500 2.530 VREF Output Voltage T A = +25°C (Note 7)
mA 30 VREF Short-Circuit Current
±30 MAX149
mV 0.35 Load Regulation (Note 8) 0mA to 0.2mA output load
0 Internal compensation mode
µF
4.7
Capacitive Bypass at VREF
External compensation mode
µF 0.01 Capacitive Bypass at REFADJ
% ±1.5 REFADJ Adjustment Range
V
V DD -
0.5
REFADJ Buffer-Disable Threshold
µF
0
Capacitive Bypass at VREF
Internal compensation mode
2.00
V/V
2.06
Reference Buffer Gain
4.7
MAX148
MAX149
External compensation mode
±10
µA
±50
REFADJ Input Current
MAX148
MAX149
ppm/°C VREF Temperature Coefficient
0 to VREF
V
±VREF / 2
Input Voltage Range, Single-
Ended and Differential (Note 6) Unipolar, COM = 0V
Bipolar, COM = VREF / 2
0.1 2.0
MHz
0 2.0
External Clock Frequency
Data transfer only
CONVERSION RATE (continued)
ANALOG/COM INPUTS
INTERNAL REFERENCE (MAX149 only, reference buffer enabled)
EXTERNAL REFERENCE AT VREF (Buffer disabled)
EXTERNAL REFERENCE AT REFADJ