Datasheet

LTC2225
7
2225fa
TYPICAL PERFOR A CE CHARACTERISTICS
UW
I
OVDD
vs Sample Rate, 5MHz Sine
Wave Input, –1dB, O
VDD
= 1.8V
I
VDD
vs Sample Rate,
5MHz Sine Wave Input, –1dB
UU
U
PI FU CTIO S
A
IN
+ (Pin 1): Positive Differential Analog Input.
A
IN
- (Pin 2): Negative Differential Analog Input.
REFH (Pins 3, 4): ADC High Reference. Short together and
bypass to pins 5, 6 with a 0.1µF ceramic chip capacitor as
close to the pin as possible. Also bypass to pins 5, 6 with
an additional 2.2µF ceramic chip capacitor and to ground
with a 1µF ceramic chip capacitor.
REFL (Pins 5, 6): ADC Low Reference. Short together and
bypass to pins 3, 4 with a 0.1µF ceramic chip capacitor as
close to the pin as possible. Also bypass to pins 3, 4 with
an additional 2.2µF ceramic chip capacitor and to ground
with a 1µF ceramic chip capacitor.
V
DD
(Pins 7, 32): 3V Supply. Bypass to GND with 0.1µF
ceramic chip capacitors.
GND (Pin 8): ADC Power Ground.
CLK (Pin 9): Clock Input. The input sample starts on the
positive edge.
SHDN (Pin 10): Shutdown Mode Selection Pin. Connect-
ing SHDN to GND and OE to GND results in normal
operation with the outputs enabled. Connecting SHDN to
GND and OE to V
DD
results in normal operation with the
outputs at high impedance. Connecting SHDN to V
DD
and
OE to GND results in nap mode with the outputs at high
impedance. Connecting SHDN to V
DD
and OE to V
DD
results in sleep mode with the outputs at high impedance.
OE (Pin 11): Output Enable Pin. Refer to SHDN pin
function.
NC (Pins 12, 13): Do Not Connect These Pins.
D0 – D11 (Pins 14, 15, 16, 17, 18, 19, 22, 23, 24, 25, 26,
27): Digital Outputs. D11 is the MSB.
OGND (Pin 20): Output Driver Ground.
OV
DD
(Pin 21): Positive Supply for the Output Drivers.
Bypass to ground with 0.1µF ceramic chip capacitor.
OF (Pin 28): Over/Under Flow Output. High when an over
or under flow has occurred.
MODE (Pin 29): Output Format and Clock Duty Cycle
Stabilizer Selection Pin. Connecting MODE to GND selects
offset binary output format and turns the clock duty cycle
stabilizer off. 1/3 V
DD
selects offset binary output format
and turns the clock duty cycle stabilizer on. 2/3 V
DD
selects
2’s complement output format and turns the clock duty
cycle stabilizer on. V
DD
selects 2’s complement output
format and turns the clock duty cycle stabilizer off.
SAMPLE RATE (Msps)
10
I
VDD
(mA)
15
20
25
02468
2225 G12
10 12 14
2V RANGE
1V RANGE
SAMPLE RATE (Msps)
0
0
I
OVDD
(mA)
0.1
0.3
0.4
0.5
1.0
0.7
4
8
10
2225 G13
0.2
0.8
0.9
0.6
2
6
12
14