LTC6903 Linear Technology, LTC6903 Datasheet - Page 5

• Manufacturer Part Number: LTC6903
• Description: (LTC6903 / LTC6904) 1kHz - 68MHz Serial Port Programmable Oscillator
• Manufacturer: Linear Technology

PI FU CTIO S
GND (Pin 1): Negative Power Supply (Ground). Should be
tied directly to a ground plane for best performance.
SDI ( Pin 2 ): Serial Data Input. Data for serial transfer is
presented on this pin.
SCK (Pin 3): Serial Port Clock. Input, positive edge trig-
gered. Clocks serial data in on rising edge.
SEN (Pin 4): Serial Port Enable (6903 Only). Input, active
LOW. Initiates serial transaction when brought LOW,
finalizes transaction when brought HIGH after 16 clocks.
ADR (Pin 4): Serial Port Address (6904 Only). Sets the I
serial port address.
TYPICAL PERFOR A CE CHARACTERISTICS
U
0.01
–80
0.1
10
20
15MHz
1
0
0.1
Peak-to-Peak Jitter vs Frequency
Output Spectrum at 20MHz
V
+
= 3V
U
FREQUENCY (MHz)
1
20MHz
U
10
W
6903 G04
6903 G07
U
25MHz
100
10
9
8
7
6
5
4
3
2
1
0
0.001
Supply Current vs Output
Frequency
Output Waveform at 68MHz
C
V
L
+
= 10pF
= 3V
0.01
2
FREQUENCY (MHz)
C
0.1
5ns/DIV
CLK (Pin 5): Auxiliary Clock Output. Frequency set by
serial port.
CLK (Pin 6): Main Clock Output. Frequency set by serial
port.
OE (Pin 7): Asynchronous Output Enable. CLK and CLK are
set LOW when this pin is LOW.
V
kept free from noise and ripple. It should be bypassed
directly to a ground plane with a quality 0.1 F capacitor.
Additional bypass may be necessary for operation at high
frequency or under larger loads.
+
V
1
(Pin 8): Positive Power Supply. This supply must be
+
= 5V
V
10
+
= 3V
6903 G05
3468 G08
100
LTC6903/LTC6904
60
50
40
30
20
10
0
2.5
Output Resistance vs Supply
Voltage
Output Waveform at 20MHz
C
V
L
+
= 10pF
= 3V
3.0
SUPPLY VOLTAGE (V)
3.5
10ns/DIV
4.0
4.5
5.0
69034fa
6903 G06
3468 G09
5
5.5