LTC2262-12
11
226212fc
For more information www.linear.com/LTC2262-12
LTC2262-12: IOVDD vs Sample
Rate, 5MHz Sine Wave Input,
–1dB, 5pF on Each Data Output
LTC2262-12: SNR vs SENSE,
fIN = 5MHz, –1dB
TYPICAL PERFORMANCE CHARACTERISTICS
SAMPLE RATE (Msps)
0
25
10
15
20
5
0
45
30
35
40
I OVDD
(mA)
25
50
75
100
150
125
226212 G14
1.75mA LVDS
1.8V CMOS
1.2V CMOS
3.5mA LVDS
SENSE PIN (V)
0.6
71
68
69
70
67
66
SNR
(dBFS)
0.7
0.8
0.9
1.1
1.2
1.3
1
226212 G15
SAMPLE RATE (Msps)
0
71
68
69
70
67
SNR
(dBFS)
25
50
75
100
150
125
226212 G18
CMOS
DDR CMOS
LVDS
LTC2262-12: SNR vs Sample Rate
and Digital Output Mode,
30MHz Sine Wave Input, –1dB
PIN FUNCTIONS
PINS THAT ARE THE SAME FOR ALL DIGITAL OUTPUT
MODES
AIN+ (Pin 1): Positive Differential Analog Input.
AIN– (Pin 2): Negative Differential Analog Input.
GND (Pin 3): ADC Power Ground.
REFH (Pins 4, 5): ADC High Reference. Bypass to Pins
6, 7 with a 2.2F ceramic capacitor and to ground with a
0.1F ceramic capacitor.
REFL (Pins 6, 7): ADC Low Reference. Bypass to Pins
4, 5 with a 2.2F ceramic capacitor and to ground with a
0.1F ceramic capacitor.
PAR/SER (Pin 8): Programming Mode Selection Pin. Con-
nect to ground to enable the serial programming mode.
CS, SCK, SDI, SDO become a serial interface that control
the A/D operating modes. Connect to VDD to enable the
parallel programming mode where CS, SCK, SDI become
parallel logic inputs that control a reduced set of the A/D
operating modes. PAR/SER should be connected directly
to ground or the VDD of the part and not be driven by a
logic signal.
VDD (Pins 9, 10, 40): 1.8V Analog Power Supply. Bypass
to ground with 0.1F ceramic capacitors. Pins 9 and 10
can share a bypass capacitor.
ENC+ (Pin 11): Encode Input. Conversion starts on the
rising edge.
ENC– (Pin 12): Encode Complement Input. Conversion
starts on the falling edge.
CS (Pin 13): In serial programming mode, (PAR/SER =
0V), CS is the serial interface chip select input. When
CS is low, SCK is enabled for shifting data on SDI into
the mode control registers. In the parallel programming
mode (PAR/SER = VDD), CS controls the clock duty cycle
stabilizer. When CS is low, the clock duty cycle stabilizer is
turned off. When CS is high, the clock duty cycle stabilizer
is turned on. CS can be driven with 1.8V to 3.3V logic.
SCK (Pin 14): In serial programming mode, (PAR/SER =
0V), SCK is the serial interface clock input. In the parallel
programming mode (PAR/SER = VDD), SCK controls the
digital output mode. When SCK is low, the full-rate CMOS
output mode is enabled. When SCK is high, the double
data rate LVDS output mode (with 3.5mA output current)
is enabled. SCK can be driven with 1.8V to 3.3V logic.
SDI (Pin 15): In serial programming mode, (PAR/SER =
0V), SDI is the serial interface data input. Data on SDI is
clocked into the mode control registers on the rising edge
of SCK. In the parallel programming mode (PAR/SER =
VDD), SDI can be used to power down the part. When SDI
is low, the part operates normally. When SDI is high, the