LTC1274 Linear Technology, LTC1274 Datasheet - Page 7

• Manufacturer Part Number: LTC1274
• Description: 12-Bit/ 10mW/ 100ksps ADCs with 1uA Shutdown
• Manufacturer: Linear Technology

PI FU CTIO S
LTC1274
A
0V) or 2.048V, bipolar (V
V
(10 F tantalum in parallel with 0.1 F ceramic). V
overdriven positive with an external reference voltage.
AGND (Pin 3): Analog Ground.
D11 to D4 (Pins 4 to 11): Three-State Data Outputs. D11
is the Most Significant Bit.
DGND (Pin 12): Digital Ground.
TYPICAL PERFORMANCE CHARACTERISTICS
IN
REF
3.0
2.5
2.0
1.5
1.0
0.5
3.0
2.5
2.0
1.5
1.0
0.5
U
0
0
(Pin 1): Analog Input. 0V to 4.096V, unipolar (V
–55
Supply Current vs Temperature
0
Supply Current vs
Supply Voltage
(Pin 2): 2.42V Reference Output. Bypass to AGND
f
SAMPLE
f
SAMPLE
–25
1
U
= 100kHz
= 100kHz
SUPPLY VOLTAGE (V)
0
TEMPERATURE ( C)
2
25
3
U
50
4
75
SS
LTC1274/77 • TPC14
W
LT1274/77 • TPC11
100
= – 5V).
5
U
125
6
10000
1000
–100
100
–10
–20
–30
–40
–50
–60
–70
–80
–90
10
1
0
0.1
Power Supply Feedthrough vs
Ripple Frequency
1
Supply Current vs Sample Rate
With Sleep and Nap Modes
V
C
REF
f
REF
SS
SAMPLE
(V
= 4.7 F
1
can be
RIPPLE
WITHOUT SLEEP OR NAP
RIPPLE FREQUENCY (kHz)
SS
= 100kHz
DGND (V
NAP = 5V
(SLEEP MODE)
AV
NAP = REFRDY
(SLEEP MODE)
SAMPLE RATE (Hz)
10
10
= 10mV)
=
DD
(V
RIPPLE
100
RIPPLE
D3 to D0 (Pins 13 to 16): Three-State Data Outputs.
REFRDY (Pin 17): Reference Ready Signal. It goes high
when the reference has settled after SLEEP indicating that
the ADC is ready to sample.
SLEEP (Pin 18): SLEEP Mode Input. Tie this pin to low to
put the ADC in Sleep mode and save power (REFRDY will
go low). The device will draw 1 A in this mode.
CONVST (Pin 19): Conversion Start Signal. This active low
signal starts a conversion on its falling edge (to recognize
CONVST, CS has to be low.)
= 0.1V)
= 1mV)
NAP MODE
100
1k
LTC1274/77 • TPC15
LTC1274/77 • TPC12
10k
1000
100k
2.435
2.430
2.425
2.420
2.415
2.410
2.405
10
9
8
7
6
5
4
3
2
1
0
LTC1274/LTC1277
–6
Wake-Up Time vs
C
0
Reference Voltage vs
Load Current
REF
T
A
5
–5
= 25 C
(Sleep Mode)
10
–4
LOAD CURRENT (mA)
15
20
–3
C
REF
25
( F)
–2
30
–1
35
LTC1274/77 • TPC16
LT1274/77 • TPC13
40
0
45
7
50
1