Datasheet
www.ti.com
TIMING REQUIREMENTS (see Figure 1 )
ADS7887
ADS7888
SLAS468 – JUNE 2005
ADS7888 SPECIFICATIONS (continued)
+V
DD
= 2.35 V to 5.25 V, T
A
= –40 ° C to 125 ° C, f
sample
= 1.25 MHz
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
DD
= 5 V 5.5 7.5
Power dissipation in static state mW
V
DD
= 3 V 3 4.5
Power down time 0.1 µs
Power up time 0.8 µs
Invalid conversions after power up 1
TEMPERATURE RANGE
Specified performance –40 125 ° C
All specifications typical at T
A
= –40 ° C to 125 ° C, V
DD
= 2.35 V to 5.25 V, unless otherwise specified.
PARAMETER TEST CONDITIONS
(1)
MIN TYP MAX UNIT
V
DD
= 3 V 14 × t
SCLK
ADS7887
V
DD
= 5 V 14 × t
SCLK
t
conv
Conversion time ns
V
DD
= 3 V 12 × t
SCLK
ADS7888
V
DD
= 5V 12 × t
SCLK
V
DD
= 3 V 40
Minimum quiet time needed from bus 3-state to start
t
q
ns
of next conversion
V
DD
= 5 V 40
V
DD
= 3 V 15 25
t
d1
Delay time, CS low to first data (0) out ns
V
DD
= 5 V 13 25
V
DD
= 3 V 10
t
su1
Setup time, CS low to SCLK low ns
V
DD
= 5 V 10
V
DD
= 3 V 15 25
t
d2
Delay time, SCLK falling to SDO ns
V
DD
= 5 V 13 25
V
DD
< 3 V 7
t
h1
Hold time, SCLK falling to data valid
(2)
ns
V
DD
> 5 V 5.5
V
DD
= 3 V 10 25
t
d3
Delay time, 16th SCLK falling edge to SDO 3-state ns
V
DD
= 5 V 8 20
V
DD
= 3 V 25 40
t
w1
Pulse duration, CS ns
V
DD
= 5 V 25 40
V
DD
= 3 V 17 30
t
d4
Delay time, CS high to SDO 3-state, Figure 3 ns
V
DD
= 5 V 15 25
V
DD
= 3 V 0.4 × t
SCLK
t
wH
Pulse duration, SCLK high ns
V
DD
= 5 V 0.4 × t
SCLK
V
DD
= 3 V 0.4 × t
SCLK
t
wL
Pulse duration, SCLK low ns
V
DD
= 5 V 0.4 × t
SCLK
V
DD
= 3 V 25
Frequency, SCLK MHz
V
DD
= 5 V 25
Delay time, second falling edge of clock and CS to V
DD
= 3 V -2 5
t
d5
enter in powerdown (use min spec not to accidently ns
V
DD
= 5 V -2 5
enter in powerdown) Figure 4
Delay time, CS and 10th falling edge of clock to V
DD
= 3 V 2 -5
t
d6
enter in powerdown (use max spec not to accidently ns
V
DD
= 5 V 2 -5
enter in powerdown) Figure 4
(1) 3-V Specifications apply from 2.35 V to 3.6 V, and 5-V specifications apply from 4.75 V to 5.25 V.
(2) With 50-pf load.
7