Datasheet

ADS7846
3
SBAS125H
www.ti.com
ANALOG INPUT
Full-Scale Input Span Positive Input-Negative Input 0 V
REF
V
Absolute Input Range Positive Input –0.2 +V
CC
+ 0.2 V
Negative Input –0.2 +0.2 V
Capacitance 25 pF
Leakage Current 0.1 µA
SYSTEM PERFORMANCE
Resolution 12 Bits
No Missing Codes 11 Bits
Integral Linearity Error ±2 LSB
(1)
Offset Error ±6LSB
Gain Error External V
REF
±4LSB
Noise Including Internal V
REF
70 µVrms
Power-Supply Rejection 70 dB
SAMPLING DYNAMICS
Conversion Time 12 CLK Cycles
Acquisition Time 3 CLK Cycles
Throughput Rate 125 kHz
Multiplexer Settling Time 500 ns
Aperture Delay 30 ns
Aperture Jitter 100 ps
Channel-to-Channel Isolation V
IN
= 2.5Vp-p at 50kHz 100 dB
SWITCH DRIVERS
On-Resistance
Y+, X+ 5 Ω
Y–, X– 6 Ω
Drive Current
(2)
Duration 100ms 50 mA
REFERENCE OUTPUT
Internal Reference Voltage 2.45 2.50 2.55 V
Internal Reference Drift 15 ppm/°C
Quiescent Current 500 µA
REFERENCE INPUT
Range 1.0 +V
CC
V
Input Impedance SER/DFR = 0, PD1 = 0, 1 GΩ
Internal Reference Off
Internal Reference On 250 Ω
BATTERY MONITOR
Input Voltage Range 0.5 6.0 V
Input Impedance
Sampling Battery 10 kΩ
Battery Monitor Off 1GΩ
Accuracy External V
REF
= 2.5V –2+2%
Internal Reference –3+3%
TEMPERATURE MEASUREMENT
Temperature Range –40 +85 °C
Resolution Differential Method
(3)
1.6 °C
TEMP0
(4)
0.3 °C
Accuracy Differential Method
(3)
±2 °C
TEMP0
(4)
±3 °C
DIGITAL INPUT/OUTPUT
Logic Family CMOS
Logic Levels, Except
PENIRQ
V
IH
| I
IH
| ≤ +5µA+V
CC
• 0.7 +V
CC
+ 0.3
V
IL
| I
IL
| ≤ +5µA –0.3 +0.8 V
V
OH
I
OH
= –250µA+V
CC
• 0.8 V
V
OL
I
OL
= 250µA 0.4 V
PENIRQ
V
OL
T
A
= 0°C to +85°C, 50kΩ Pull-Up 0.8 V
Data Format Straight Binary
POWER-SUPPLY REQUIREMENTS
+V
CC
(5)
Specified Performance 2.7 3.6 V
Operating Range 2.2 5.25 V
Quiescent Current Internal Reference Off 280 650 µA
Internal Reference On 780 µA
f
SAMPLE
= 12.5kHz 220 µA
Power-Down Mode with 3 µA
CS = DCLK = DIN = +V
CC
Power Dissipation +V
CC
= +2.7V 1.8 mW
TEMPERATURE RANGE
Specified Performance –40 +85 °C
NOTES: (1) LSB means least significant bit. With V
REF
equal to +2.5V, one LSB is 610µV. (2) Ensured by design, but not tested. Exceeding 50mA source current
may result in device degradation. (3) Difference between TEMP0 and TEMP1 measurement. No calibration necessary. (4) Temperature drift is –2.1mV/°C.
(5) ADS7846 operates down to 2.2V.
ADS7846E
PARAMETER CONDITIONS MIN TYP MAX UNITS
ELECTRICAL CHARACTERISTICS
At T
A
= –40°C to +85°C, +V
CC
= +2.7V, V
REF
= 2.5V internal voltage, f
SAMPLE
= 125kHz, f
CLK
= 16 • f
SAMPLE
= 2MHz, 12-bit mode, and digital inputs = GND or +V
CC
,
unless otherwise noted.