AD9954/PCB Analog Devices Inc, AD9954/PCB Datasheet - Page 8

• Manufacturer Part Number: AD9954/PCB
• Description: BOARD EVAL FOR AD9954
• Manufacturer: Analog Devices Inc

Specifications of AD9954/PCB

• Rohs Status: RoHS non-compliant

AD9954
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Note that the exposed paddle on the bottom of the package forms an electrical connection for the DAC and must be attached to
analog ground. Note that Pin 43, DVDD_I/O, can be powered to 1.8 V or 3.3 V. The DVDD pins (Pin 2 and Pin 34) must be
powered to 1.8 V.
Table 3. Pin Function Descriptions
Pin No.
1
2, 34
3, 33, 42
4, 6, 13, 16,
18, 19, 25,
27, 29
5, 7, 14, 15,
17, 22, 26,
32
8
9
10
11
12
20
21
23
24
28
30
Mnemonic
I/O UPDATE
DVDD
DGND
AVDD
AGND
OSC/REFCLK
OSC/REFCLK
CRYSTAL OUT
CLKMODESELECT
LOOP_FILTER
IOUT
IOUT
DACBP
DAC_R
COMP_OUT
COMP_IN
SET
I/O
I
I
I
I
I
I
I
O
I
I
O
O
I
I
O
I
CLKMODESELECT
CRYSTAL OUT
LOOP_FILTER
OSC/REFCLK
OSC/REFCLK
Description
The rising edge transfers the contents of the internal buffer memory to the I/O registers.
See Synchronization—Register Updates (I/O UPDATE) section for details.
Digital Power Supply Pins (1.8 V).
Digital Power Ground Pins.
Analog Power Supply Pins (1.8 V).
Analog Power Ground Pins.
Oscillator Input/Complementary Reference Clock. When the REFCLK port is operated in
single-ended mode, REFCLK should be decoupled to AVDD with a 0.1 μF capacitor.
Oscillator Input/Reference Clock. See Table 5 for details on the OSC/REFCLK operation.
Output of the Oscillator Section.
Control Pin for the Oscillator Section (1.8 V logic only). See REFCLK Input section for detailed
instructions.
This pin provides the connection for the external zero compensation network of the REFCLK
multiplier’s PLL loop filter. The network varies based on the multiplication value in the PLL loop.
See Table 4 for details.
Complementary DAC Output. Should be biased through a resistor to AVDD, not AGND.
DAC Output. Should be biased through a resistor to AVDD, not AGND.
DAC Band Gap Decoupling Pin. A 0.1 μF capacitor to AGND is recommended.
A resistor (3.92 kΩ nominal) connected from AGND to DAC_R
current for the DAC. See equation in DAC Output section.
Comparator Output.
Comparator Input.
I/O UPDATE
DGND
AGND
AGND
DVDD
AVDD
AVDD
10
11
12
1
2
3
4
5
6
7
8
9
48 47 46 45 44 43 42 41 40 39 38 37
13 14 15 16 17 18 19 20 21 22 23 24
Figure 4. Pin Configuration
PIN 1
Rev. B | Page 8 of 40
(Not to Scale)
AD9954
TOP VIEW
36
35
34
33
32
31
30
29
28
27
26
25
RESET
PWRDWNCTL
DVDD
DGND
AGND
COMP_IN
COMP_IN
AVDD
COMP_OUT
AVDD
AGND
AVDD
SET
establishes the reference