etc. SNR is computed by taking the ratio of the RMS
signal to the RMS noise, which includes all spectral
components minus the fundamental, the first five har-
monics, and the DC offset.
Signal-to-Noise Plus Distortion
Signal-to-noise plus distortion (SINAD) is the ratio of the
fundamental input frequency’s RMS amplitude to the
RMS equivalent of all the other ADC output signals.
Effective Number of Bits
Effective number of bits (ENOB) indicates the global
accuracy of an ADC at a specific input frequency and
sampling rate. An ideal ADC’s error consists of quanti-
zation noise only. With an input range equal to the full-
scale range of the ADC, calculate the effective number
of bits as follows:
Total Harmonic Distortion
Total harmonic distortion (THD) is the ratio of the RMS
sum of the first five harmonics of the input signal to the
fundamental itself. This is expressed as:
where V
1
is the fundamental amplitude and V
2
through
V
5
are the 2nd- through 5th-order harmonics.
Spurious-Free Dynamic Range
Spurious-free dynamic range (SFDR) is the ratio of the
RMS amplitude of the fundamental (maximum signal
component) to the RMS value of the next largest fre-
quency component.
Chip Information
TRANSISTOR COUNT: 15,383
PROCESS: BiCMOS
THD
=
×
20 log
V+V+V+V
V
2
2
3
2
4
2
5
2
1
E
SINAD - 1.76
NOB
=
602.
SINAD db
Signal
Noise Distortion
RMS
RMS
()
()
=×
+
20 log
MAX1179/MAX1187/MAX1189
16-Bit, 135ksps, Single-Supply ADCs with
Bipolar Analog Input Range
______________________________________________________________________________________ 13
Ordering Information (continued)
PART TEMP RANGE PIN-PACKAGE
INPUT VOLTAGE
RANGE
INL (LSB)
MAX1179CCUI 0°C to +70°C 28 TSSOP ±5V ±4
MAX1179AEUI -40°C to +85°C 28 TSSOP ±5V ±2
MAX1179BEUI -40°C to +85°C 28 TSSOP ±5V ±2
MAX1179CEUI -40°C to +85°C 28 TSSOP ±5V ±4
MAX1187ACUI 0°C to +70°C 28 TSSOP 0 to +10V ±2
MAX1187BCUI 0°C to +70°C 28 TSSOP 0 to +10V ±2
MAX1187CCUI 0°C to +70°C 28 TSSOP 0 to +10V ±4
MAX1187AEUI -40°C to +85°C 28 TSSOP 0 to +10V ±2
MAX1187BEUI -40°C to +85°C 28 TSSOP 0 to +10V ±2
MAX1187CEUI -40°C to +85°C 28 TSSOP 0 to +10V ±4
MAX1189ACUI 0°C to +70°C 28 TSSOP ±10V ±2
MAX1189BCUI 0°C to +70°C 28 TSSOP ±10V ±2
MAX1189CCUI 0°C to +70°C 28 TSSOP ±10V ±4
MAX1189AEUI* -40°C to +85°C 28 TSSOP ±10V ±2
MAX1189BEUI* -40°C to +85°C 28 TSSOP ±10V ±2
MAX1189CEUI* -40°C to +85°C 28 TSSOP ±10V ±4
*Future product—contact factory for availability.
