LTC1857 LINEAR [Linear Integrated Systems], LTC1857 Datasheet - Page 7

• Manufacturer Part Number: LTC1857
• Description: 8-Channel, 12-/14-/16-Bit, 100ksps SoftSpan A/D Converters with Shutdown
• Manufacturer: LINEAR [Linear Integrated Systems]

TYPICAL PERFOR A CE CHARACTERISTICS
PI FU CTIO S
COM (Pin 1): Common Input. This is the reference point
for all single-ended inputs. It must be free of noise and is
usually connected to the analog ground plane.
CH0 (Pin 2): Analog MUX Input.
CH1 (Pin 3): Analog MUX Input.
CH2 (Pin 4): Analog MUX Input.
CH3 (Pin 5): Analog MUX Input.
CH4 (Pin 6): Analog MUX Input.
CH5 (Pin 7): Analog MUX Input.
CH6 (Pin 8): Analog MUX Input.
CH7 (Pin 9): Analog MUX Input.
MUXOUT
analog multiplexer. Connect to ADC
MUXOUT
analog multiplexer. Connect to ADC
ADC
Digital Converter.
ADC
Digital Converter.
–10
–20
–30
–40
–50
–60
–70
–80
U
100
+
–
LTC1859 Power Supply
Feedthrough vs Ripple Frequency
f
V
SAMPLE
(Pin 13): Negative Analog Input to the Analog-to-
(Pin 12): Positive Analog Input to the Analog-to-
RIPPLE
+
–
U
= 60mV
(Pin 11): Negative MUX Output. Output of the
= 100kHz
(Pin 10): Positive MUX Output. Output of the
1k
RIPPLE FREQUENCY (Hz)
10k
U
100k
W
1859 G10
U
1M
+
–
for normal operation.
for normal operation.
9.0
8.5
8.0
7.5
7.0
4.5
Supply Current vs Supply Voltage
f
SAMPLE
4.75
= 100kHz
SUPPLY VOLTAGE (V)
5
AGND1 (Pin 14): Analog Ground.
V
ground with a 1µF tantalum capacitor.
REFCOMP (Pin 16): Reference Buffer Output. Bypass to
analog ground with a 10µF tantalum and a 0.1µF ceramic
capacitor. Nominal output voltage is 4.096V.
AGND2 (Pin 17): Analog Ground.
AGND3 (Pin 18): Analog Ground. This is the substrate
connection.
AV
with a 0.1µF ceramic and a 10µF tantalum capacitor.
DV
with a 0.1µF ceramic and a 10µF tantalum capacitor.
OV
Buffers (3V to 5V). Bypass to digital ground with a 0.1µF
ceramic and a 10µF tantalum capacitor.
BUSY (Pin 22): Output shows converter status. It is low
when a conversion is in progress.
SDO (Pin 23): Serial Data Output.
REF
DD
DD
DD
(Pin 15): 2.5V Reference Output. Bypass to analog
(Pin 19): 5V Analog Supply. Bypass to analog ground
(Pin 20): 5V Digital Supply. Bypass to digital ground
5.25
LTC1857/LTC1858/LTC1859
(Pin 21): Positive Supply for the Digital Output
1859 G11
5.5
8.5
7.5
7.0
9.0
8.0
–50
Supply Current vs Temperature
f
SAMPLE
–25
= 100kHz
TEMPERATURE (°C)
0
25
50
75
1859 G12
185789f
7
100