![](http://datasheet.mmic.net.cn/330000/LTC2231CUP_datasheet_16429992/LTC2231CUP_13.png)
LTC2230/LTC2231
13
22301p
SENSE (Pin 59):
Reference Programming Pin. Connecting
SENSE to V
CM
selects the internal reference and a
±
0.5V
input range. V
DD
selects the internal reference and a
±
1V
input range. An external reference greater than 0.5V and
less than 1V applied to SENSE selects an input range of
±
V
SENSE
.
±
1V is the largest valid input range.
V
CM
(Pin 60):
1.6V Output and Input Common Mode Bias.
Bypass to ground with 2.2
μ
F ceramic chip capacitor.
GND (Exposed Pad):
ADC Power Ground. The exposed
pad on the bottom of the package needs to be soldered to
ground.
(LVDS Mode)
AIN
+
(Pins 1, 2):
Positive Differential Analog Input.
AIN
–
(Pins 3, 4):
Negative Differential Analog Input.
REFHA (Pins 5, 6):
ADC High Reference. Bypass to
Pins 7, 8 with 0.1
μ
F ceramic chip capacitor, to Pins 11, 12
with a 2.2
μ
F ceramic capacitor and to ground with 1
μ
F
ceramic capacitor.
REFLB (Pins 7, 8):
ADC Low Reference. Bypass to Pins 5,
6 with 0.1
μ
F ceramic chip capacitor. Do not connect to
Pins 11, 12.
REFHB (Pins 9, 10):
ADC High Reference. Bypass to
Pins 11, 12 with 0.1
μ
F ceramic chip capacitor. Do not
connect to Pins 5, 6.
REFLA (Pins 11, 12):
ADC Low Reference. Bypass to
Pins 9, 10 with 0.1
μ
F ceramic chip capacitor, to Pins 5, 6
with a 2.2
μ
F ceramic capacitor and to ground with 1
μ
F
ceramic capacitor.
V
DD
(Pins 13, 14, 15, 62, 63):
3.3V Supply. Bypass to
GND with 0.1
μ
F ceramic chip capacitors.
GND (Pins 16, 61, 64):
ADC Power Ground.
ENC
+
(Pin 17):
Encode Input. The input sample starts on
the positive edge.
ENC
–
(Pin 18):
Encode Complement Input. Conversion
starts on the negative edge. Bypass to ground with 0.1
μ
F
ceramic for single-ended ENCODE signal.
SHDN (Pin 19):
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 20):
Output Enable Pin. Refer to SHDN pin
function.
DNC (Pins 21, 22, 23, 24):
Do not connect these pins.
OGND (Pins 25, 33, 41, 50):
Output Driver Ground.
OVDD (Pins 26, 34, 42, 49):
Positive Supply for the
Output Drivers. Bypass to ground with 0.1
μ
F ceramic chip
capacitor.
D0
–
/D0
+
to D9
–
/D9
+
(Pins 27 to 32, 37 to 40, 43 to 48, 51
to 54):
LVDS Digital Outputs. All LVDS outputs require
differential 100
termination resistors at the LVDS re-
ceiver.
D9
–
/D9
+
is the MBS.
CLKOUT
–
/CLKOUT
+
(Pins 35 to 36):
LVDS Data Valid
Output. Latch data on rising edge of CLKOUT
–
, falling edge
of CLKOUT
+
.
OF
–
/OF
+
(Pins 55 to 56):
LVDS Over/Under Flow Output.
High when an over or under flow has occurred.
LVDS (Pin 57):
Output Mode Selection Pin. Connecting
LVDS to 0V selects full rate CMOS mode. Connecting
LVDS to 1/3V
DD
selects demux CMOS mode with simulta-
neous update. Connecting LVDS to 2/3V
DD
selects demux
CMOS mode with interleaved update. Connecting LVDS to
V
DD
selects LVDS mode.
MODE (Pin 58):
Output Format and Clock Duty Cycle
Stabilizer Selection Pin. Connecting MODE to 0V selects
straight binary output format and turns the clock duty
cycle stabilizer off. Connecting MODE to 1/3V
DD
selects
straight binary output format and turns the clock duty
cycle stabilizer on. Connecting MODE to 2/3V
DD
selects
2’s complement output format and turns the clock duty
cycle stabilizer on. Connecting MODE to V
DD
selects 2’s
complement output format and turns the clock duty cycle
stabilizer off.
PU