ltc1748cfw-trpbf Linear Technology Corporation, ltc1748cfw-trpbf Datasheet - Page 9

• Manufacturer Part Number: ltc1748cfw-trpbf
• Description: 14-bit, 80msps Low Noise Adc
• Manufacturer: Linear Technology Corporation

SENSE (Pin 1): Reference Sense Pin. Ground selects 1V.
V
applied to the SENSE pin selects an input range of V
V
Bypass to ground with 4.7 F ceramic chip capacitor.
GND (Pins 3, 6, 9, 12, 13, 16, 19, 21, 36, 37): ADC Power
Ground.
A
A
V
with 1 F ceramic chip capacitors at Pin 8 and Pin 18.
REFLB (Pin 10): ADC Low Reference. Bypass to Pin 11
with 0.1 F ceramic chip capacitor. Do not connect to
Pin 14.
REFHA (Pin 11): ADC High Reference. Bypass to Pin 10 with
0.1 F ceramic chip capacitor, to Pin 14 with a 4.7 F ceramic
capacitor and to ground with 1 F ceramic capacitor.
REFLA (Pin 14): ADC Low Reference. Bypass to Pin 15 with
0.1 F ceramic chip capacitor, to Pin 11 with a 4.7 F ce-
ramic capacitor and to ground with 1 F ceramic capacitor.
REFHB (Pin 15): ADC High Reference. Bypass to Pin 14
with 0.1 F ceramic chip capacitor. Do not connect to
Pin 11.
PI FU CTIO S
TYPICAL PERFOR A CE CHARACTERISTICS
1.6V is the largest valid input range.
DD
CM
IN
IN
DD
U
+
–
(Pin 2): 2.35V Output and Input Common Mode Bias.
(Pins 7, 8, 17, 18, 20): 5V Supply. Bypass to AGND
selects 1.6V. Greater than 1V and less than 1.6V
(Pin 4): Positive Differential Analog Input.
(Pin 5): Negative Differential Analog Input.
U
–4
–2
–6
–8
8
6
4
2
0
– 50
Offset and Gain Error
vs Temperature
U
–30
–10
W
GAIN ERROR
TEMPERATURE ( C)
10
U
30
OFFSET ERROR
50
70
1748 G35
90
SENSE
,
MSBINV (Pin 22): MSB Inversion Control. Low inverts
the MSB, 2’s complement output format. High does not
invert the MSB, offset binary output format.
ENC (Pin 23): Encode Input. The input sample starts on the
positive edge.
ENC (Pin 24): Encode Complement Input. Conversion
starts on the negative edge. Bypass to ground with 0.1 F
ceramic for single-ended ENCODE signal.
OE (Pin 25): Output Enable. Low enables outputs. Logic
high makes outputs Hi-Z. OE should not exceed the
votlage on OV
CLKOUT (Pin 26): Data Valid Output. Latch data on the
rising edge of CLKOUT.
OGND (Pins 27, 38, 47): Output Driver Ground.
D0-D3 (Pins 28 to 31): Digital Outputs.
OV
ers. Bypass to ground with 0.1 F ceramic chip capacitor.
D4-D6 (Pins 33 to 35): Digital Outputs.
D7-D10 (Pins 39 to 42): Digital Outputs.
D11-D13 (Pins 44 to 46): Digital Outputs.
OF (Pin 48): Over/Under Flow Output. High when an over
or under flow has occurred.
DD
(Pins 32, 43): Positive Supply for the Output Driv-
300
290
280
270
260
250
240
230
0
Supply Current vs Sample Rate
T
A
= 25 C
DD
20
.
SAMPLE RATE (Msps)
40
60
80
1748 G32
100
LTC1748
1748fa
9