Datasheet
www.ti.com
www.ti.com
ADS7826
ADS7827
ADS7829
SLAS388–JUNE 2003
SPECIFICATIONS
At -40°C to 85°C, V
CC
= 2.7 V, V
ref
= 2.5 V, unless otherwise specified.
ADS7829IB ADS7829 ADS7826I ADS7827I
TEST
PARAMETER UNIT
CONDITIONS
MIN TYP MAX MIN TYP MAX MIN TYP MAX MIN TYP MAX
ANALOG INPUT
Full-scale input +In - (-In) 0 V
ref
0 V
ref
0 V
ref
0 V
ref
V
span
Absolute input +In -0.2 V
CC
+0.2 -0.2 V
CC
+0.2 -0.2 V
CC
+0.2 -0.2 V
CC
+0.2 V
range
-IN -0.2 1.0 -0.2 1.0 -0.2 1.0 -0.2 1.0 V
Capacitance 25 25 25 25 pF
Leakage current ±1 ±1 ±1 ±1 µA
SYSTEM PERFORMANCE
Resolution 12 12 10 8 Bits
No missing codes 12 11 10 8 Bits
Integral linearity error -1.25 ±0.4 1.25 -2 ±0.8 2 -1 ±0.3 1 -1 ±0.2 1 LSB
(1)
Differential linearity error -1 ±0.4 1.25 -2 ±0.8 2 -1 ±0.3 1 -1 ±0.2 1 LSB
Offset error -3 ±0.3 3 -3 ±0.6 3 -2 ±0.4 2 -1 ±0.4 1 LSB
Gain error -2 ±0.3 2 -2 ±0.6 2 -1 ±0.3 1 -1 ±0.2 1 LSB
Noise 33 33 33 33 µVrms
Power supply rejection 82 82 94 98 dB
SAMPLING DYNAMICS
Conversion time 12 12 10 8 DCLOCK
Cycles
Acquisition time 1.5 1.5 1.5 1.5 DCLOCK
Cycles
f
DCLOCK
16 x fsample 16 x fsample 14 x fsample 12 x fsample kHz
Throughput 2.7 V ≤ V
CC
125 125 200 250 kHz
(sample rate) ≤ 5.25 V
(2)
fsample
2.0 V ≤ V
CC
75 75 85 100 kHz
< 2.7 V
(3) (2)
DYNAMIC CHARACTERISTICS
Total harmonic distortion -82 -80 -78 -72 dB
SINAD V
IN
= 2.5 Vpp at 72 70 62 50 dB
1 kHz
Spurious free V
IN
= 2.5 Vpp at 85 82 81 68 dB
dynamic range 1 kHz
(SFDR)
REFERENCE INPUT
Voltage range 2.7 V ≤V
CC
≤3.6 V 0.05 V
CC
-0.2 0.05 V
CC
-0.2 0.05 V
CC
-0.2 0.05 V
CC
-0.2 V
Resistance CS = GND, 5 5 5 5 GΩ
f
SAMPLE
= 0 Hz
CS = V
CC
5 5 5 5 GΩ
Current drain Full speed at V
ref
/2 12 60 12 60 20 100 24 120 µA
f
SAMPLE
= 7.5 kHz 0.8 0.8 0.8 0.8 µA
CS = V
CC
0.001 3 0.001 3 0.001 3 0.001 3 µA
DIGITAL INPUT/OUTPUT
Logic family CMOS CMOS CMOS CMOS
Logic levels
V
IH
I
IH
= +5 µA 2.0 5.5 2.0 5.5 2.0 5.5 2.0 5.5 V
V
IL
I
IL
= +5 µA -0.3 0.8 -0.3 0.8 -0.3 0.8 -0.3 0.8 V
(1)
LSB means Least Significant Bit and is equal to V
ref
/ 2
N
where N is the resolution of ADC. For example, with V
ref
equal to 2.5 V, one
LSB is 0.61 mV for a 12 bit ADC (ADS7829).
(2)
See the Typical Performance Curves for V
CC
= 5 V and V
ref
= 5 V.
(3)
The maximum clock rate of the ADS7826/27/29 are less than 1.2 MHz at 2 V ≤V
CC
<2.7 V. The recommended regerence voltage is
between 1.25 V to 1.024 V.
3