Datasheet

AD7142
Rev. A | Page 4 of 72
SPECIFICATIONS
AV
CC
, DV
CC
= 2.6 V to 3.6 V, T
A
= −40
o
C to +85°C, unless otherwise noted.
Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
CAPACITANCE-TO-DIGITAL CONVERTER
Update Rate 35.45 36.86 38.4 ms 12 conversion stages in sequencer, decimation rate = 256
Resolution 16 Bit
CIN Input Range
1
±2 pF
No Missing Codes 16 Bit Guaranteed by design, but not production tested
CIN Input Leakage 25 nA
Total Unadjusted Error ±20 %
Output Noise (Peak-to-Peak) 7 Codes Decimation rate = 128
3 Codes Decimation rate = 256
Output Noise (RMS) 0.8 Codes Decimation rate = 128
0.5 Codes Decimation rate = 256
Parasitic Capacitance 40 pF
Parasitic capacitance to ground, per CIN input
guaranteed by characterization
C
BULK
Offset Range
1
±20 pF
C
BULK
Offset Resolution 156.25 fF
Low Power Mode Delay Accuracy 4 % % of 200 ms, 400 ms, 600 ms, or 800 ms
EXCITATION SOURCE
Frequency 240 250 260 kHz
Output Voltage AV
CC
V
Short-Circuit Source Current 20 mA
Short-Circuit Sink Current 50 mA
Maximum Output Load 250 pF Capacitance load on source to ground
C
SHIELD
Output Drive 10 μA
C
SHIELD
Bias Level AV
CC
/2 V
LOGIC INPUTS (SDI, SCLK,
CS
, SDA, GPI TEST)
V
IH
Input High Voltage 0.7 × V
DRIVE
V
V
IL
Input Low Voltage 0.4 V
I
IH
Input High Voltage −1 μA V
IN
= V
DRIVE
I
IL
Input Low Voltage 1 μA V
IN
= DGND
Hysteresis 150 mV
OPEN-DRAIN OUTPUTS (SCLK, SDA, INT)
V
OL
Output Low Voltage 0.4 V I
SINK
= −1 mA
I
OH
Output High Leakage Current 0.1 ±1 μA V
OUT
= V
DRIVE
LOGIC OUTPUTS (SDO, GPO)
V
OL
Output Low Voltage 0.4 V I
SINK
= 1 mA, V
DRIVE
= 1.65 V to 3.6 V
V
OH
Output High Voltage V
DRIVE
− 0.6 V I
SOURCE
= 1 mA, V
DRIVE
= 1.65 V to 3.6 V
SDO Floating State Leakage Current ±1 μA Pin three-state, leakage measured to GND and DV
CC
GPO Floating State Leakage Current −5 2 μA Pin three-state, leakage measured to GND and DV
CC
POWER
AV
CC
, DV
CC
2.6 3.3 3.6 V
V
DRIVE
1.65 3.6 V Serial interface operating voltage
I
CC
0.9 1 mA In full power mode
20 μA Low power mode, converter idle, T
A
= 25°C
16 33 μA Low power mode, converter idle
4.5 μA Full shutdown, T
A
= 25°C
2.25 18 μA Full shutdown
1
C
IN
and C
BULK
are defined in Figure 2.