Datasheet
SLAS251A − DECEMBER 1999 − REVISED JANUARY 2003
23
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range, V
CC
= V
REFP
=
2.7 V to 5.5 V, V
REFM
= 0 V, SCLK frequency = 20 MHz at 5 V, 15 MHz at 3 V (unless otherwise noted)
(continued)
ac specifications
†
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SINAD Signal-to-noise ratio + distortion f
I
= 12 kHz at 200 KSPS I suffix 59 60 dB
THD Total harmonic distortion f
I
= 12 kHz at 200 KSPS −82 −74 dB
ENOB Effective number of bits f
I
= 12 kHz at 200 KSPS 9.6 Bits
SFDR Spurious free dynamic range f
I
= 12 kHz at 200 KSPS −83 −72 dB
Analog input
Full-power bandwidth, −3 dB 1 MHz
Full-power bandwidth, −1 dB 500 kHz
†
Best AC performance can be measured with a 100-nF to 200-nF capacitor added between the analog input and analog ground. This circuit is
to be inserted between the driving opamp (OPA627) and the analog input AIN.
reference specifications
‡
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Positive reference input voltage, REFP V
CC
= 2.7 V to 5.5 V 2 V
CC
V
Negative reference input voltage, REFM V
CC
= 2.7 V to 5.5 V 0 2 V
V
CC
= 5.5 V
CS = 1, SCLK = 0, (off) 100 MΩ
Reference input impedance
V
CC
= 5.5 V
CS = 0, SCLK = 20 MHz (on) 20 25 kΩ
Reference input impedance
V
CC
= 2.7 V
CS = 1, SCLK = 0 (off) 100 MΩ
V
CC
= 2.7 V
CS = 0, SCLK = 15 MHz (on) 20 25 kΩ
Reference Input voltage difference, REFP − REFM V
CC
= 2.7 V to 5.5 V 2 V
CC
V
V
CC
= 5.5 V VREF SELECT = 4 V 3.85 4 4.15 V
Internal reference voltage, REFP − REFM
V
CC
= 5.5 V VREF SELECT = 2 V 1.925 2 2.075 V
Internal reference voltage, REFP − REFM
V
CC
= 2.7 V VREF SELECT = 2 V 1.925 2 2.075 V
Internal reference start-up time V
CC
= 5.5 V, 2.7 V with 10-µF compensation cap 20 ms
Internal reference temperature coefficient V
CC
= 2.7 V to 5.5 V 16 40
§
PPM/°C
‡
Add 0.1-µF and 10-µF capacitors between the REFP and REFM pins
§
Not assured