Datasheet

LTC2298/LTC2297/LTC2296
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MUX (Pin 21): Digital Output Multiplexer Control. If MUX
is High, Channel A comes out on DA0-DA13, OFA; Channel B
comes out on DB0-DB13, OFB. If MUX is Low, the output
busses are swapped and Channel A comes out on DB0-
DB13, OFB; Channel B comes out on DA0-DA13, OFA. To
multiplex both channels onto a single output bus, connect
MUX, CLKA and CLKB together.
SHDNB (Pin 22): Channel B Shutdown Mode Selection
Pin. Connecting SHDNB to GND and OEB to GND results
in normal operation with the outputs enabled. Connecting
SHDNB to GND and OEB to V
DD
results in normal opera-
tion with the outputs at high impedance. Connecting
SHDNB to V
DD
and OEB to GND results in nap mode with
the outputs at high impedance. Connecting SHDNB to V
DD
and OEB to V
DD
results in sleep mode with the outputs at
high impedance.
OEB (Pin 23): Channel B Output Enable Pin. Refer to
SHDNB pin function.
DB0 – DB13 (Pins 24 to 30, 33 to 39): Channel B Digital
Outputs. DB13 is the MSB.
OGND (Pins 31, 50): Output Driver Ground.
OV
DD
(Pins 32, 49): Positive Supply for the Output Driv-
ers. Bypass to ground with 0.1µF ceramic chip capacitor.
OFB (Pin 40): Channel B Overflow/Underflow Output.
High when an overflow or underflow has occurred.
DA0 – DA13 (Pins 41 to 48, 51 to 56): Channel A Digital
Outputs. DA13 is the MSB.
OFA (Pin 57): Channel A Overflow/Underflow Output.
High when an overflow or underflow has occurred.
OEA (Pin 58): Channel A Output Enable Pin. Refer to
SHDNA pin function.
SHDNA (Pin 59): Channel A Shutdown Mode Selection
Pin. Connecting SHDNA to GND and OEA to GND results
in normal operation with the outputs enabled. Connecting
SHDNA to GND and OEA to V
DD
results in normal opera-
tion with the outputs at high impedance. Connecting
SHDNA to V
DD
and OEA to GND results in nap mode with
the outputs at high impedance. Connecting SHDNA to V
DD
and OEA to V
DD
results in sleep mode with the outputs at
high impedance.
MODE (Pin 60): Output Format and Clock Duty Cycle
Stabilizer Selection Pin. Note that MODE controls both
channels. 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 comple-
ment output format and turns the clock duty cycle stabi-
lizer on. V
DD
selects 2’s complement output format and
turns the clock duty cycle stabilizer off.
V
CMA
(Pin 61): Channel A 1.5V Output and Input Common
Mode Bias. Bypass to ground with 2.2µF ceramic chip
capacitor. Do not connect to V
CMB
.
SENSEA (Pin 62): Channel A Reference Programming Pin.
Connecting SENSEA to V
CMA
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 SENSEA selects an input
range of ±V
SENSEA
. ±1V is the largest valid input range.
GND (Exposed Pad) (Pin 65): ADC Power Ground. The
Exposed Pad on the bottom of the package needs to be
soldered to ground.
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