![](http://datasheet.mmic.net.cn/110000/LM12438CIWMX_datasheet_3495887/LM12438CIWMX_7.png)
20 Electrical Specifications (Continued)
222 Converter Dynamic Characteristics
The following specifications apply only to the LM12434 and LM12438 for VAa e
VDa e 5V AGND e DGND e 0V VREFa e 4096V VREFb e 0V 12-bit a sign conversion mode fCLK e 80 MHz
throughput rate e 1333 kHz RS e 25X source impedance for VREFa and VREFb s 25X fully-differential input with fixed
2048V common-mode voltage and minimum acquisition time unless otherwise specified Boldface limits apply for TA e
TJ e TMIN to TMAX all other limits TA e TJ e 25 C (Notes 6 7 8 and 9) (Continued)
Symbol
Parameter
Conditions
Typical
Limits
Units
(Note 10)
(Note 11)
(Limit)
tZ
Auto-Zero Time
Sequencer State S2
(Figure 10)
76 (tCLK)
76 (tCLK) a 50 ns
(max)
tCAL
Full Calibration Time
Sequencer State S2
(Figure 10)
4944 (tCLK) 4944 (tCLK) a 50 ns
(max)
Throughput Rate
(Note 18)
142
140
kHz
(min)
tWD
‘‘Watchdog’’ Mode Comparison Time
Sequencer States S6 S4
11 (tCLK)
11 (tCLK) a 50 ns
(max)
and S5
(Figure 10)
SNR
Signal-to-Noise Ratio
VIN e g4096V (Note 20)
Differential Input
fIN e 1 kHz
79
dB
fIN e 10 kHz
79
dB
fIN e 62 kHz
70
dB
SNR
Signal-to-Noise Ratio
VIN e 4096 Vp-p
Single-Ended Input
fIN e 1 kHz
71
dB
fIN e 10 kHz
71
dB
fIN e 62 kHz
67
dB
SINAD
Signal-to-Noise a Distortion Ratio
VIN e g4096V (Note 20)
Differential Input
fIN e 1 kHz
79
dB
fIN e 10 kHz
78
dB
fIN e 62 kHz
67
dB
SINAD
Signal-to-Noise a Distortion Ratio
VIN e 4096 Vp-p
Single-Ended Input
fIN e 1 kHz
71
dB
fIN e 10 kHz
70
dB
fIN e 62 kHz
64
dB
THD
Total Harmonic Distortion
VIN e g4096V (Note 20)
Differential Input
fIN e 1 kHz
b
90
dBc
fIN e 10 kHz
b
85
dBc
fIN e 62 kHz
b
71
dBc
THD
Total Harmonic Distortion
VIN e 4096 Vp-p
Distortion Single-Ended Input
fIN e 1 kHz
b
88
dBc
fIN e 10 kHz
b
82
dBc
fIN e 62 kHz
b
67
dBc
ENOB
Effective Number of Bits
VIN e g4096V (Note 20)
Differential Input
fIN e 1 kHz
126
Bits
fIN e 10 kHz
122
Bits
fIN e 62 kHz
121
Bits
ENOB
Effective Number of Bits
VIN e 4096 Vp-p
Single-Ended Input
fIN e 1 kHz
113
Bits
fIN e 10 kHz
112
Bits
fIN e 62 kHz
108
Bits
SFDR
Spurious Free Dynamic Range
VIN e g4096V (Note 20)
Differential Input
fIN e 1 kHz
90
dBc
fIN e 10 kHz
86
dBc
fIN e 62 kHz
76
dBc
SFDR
Spurious Free Dynamic Range
VIN e 4096V Vp-p
Single-Ended Input
fIN e 1 kHz
90
dBc
fIN e 10 kHz
85
dBc
fIN e 62 kHz
72
dBc
7