AD9952/PCB Analog Devices Inc, AD9952/PCB Datasheet - Page 17

• Manufacturer Part Number: AD9952/PCB
• Description: BOARD EVAL FOR AD9952
• Manufacturer: Analog Devices Inc
• Series: AgileRF™r
• Type: DDS (Direct Digital Synthesis)r

Specifications of AD9952/PCB

• Rohs Status: RoHS non-compliant
• Contents: Evaluation Board
• For Use With/related Products: AD9952

CFR1 [6]: Comparator Power-Down Bit
CFR1 [6] = 0 (default). The comparator is enabled for operation.
CFR1 [6] = 1. The comparator is disabled and is in its lowest
power dissipation state.
CFR1 [5]: DAC Power-Down Bit
CFR1 [5] = 0 (default). The DAC is enabled for operation.
CFR1 [5] = 1. The DAC is disabled and is in its lowest power
dissipation state.
CFR1 [4]: Clock Input Power-Down Bit
CFR1 [4] = 0 (default). The clock input circuitry is enabled for
operation.
CFR1 [4] = 1. The clock input circuitry is disabled and the
device is in its lowest power dissipation state.
CFR1 [3]: External Power-Down Mode
CFR1 [3] = 0 (default). Selects the external rapid recovery
power-down mode. In this mode, when the PWRDWNCTL
input pin is high, the digital logic and the DAC digital logic are
powered down. The DAC bias circuitry, PLL, oscillator, and
clock input circuitry are not powered down.
CFR1 [3] = 1. Selects the external full power-down mode. In
this mode, when the PWRDWNCTL input pin is high, all
functions are powered down. This includes the DAC and PLL,
which take a significant amount of time to power up.
CFR1 [2]: Not Used
CFR1 [1]: SYNC_CLK Disable Bit
CFR1 [1] = 0 (default). The SYNC_CLK pin is active.
CFR1 [1] = 1. The SYNC_CLK pin assumes a static Logic 0
state to keep noise generated by the digital circuitry at a
minimum. However, the synchronization circuitry remains
active (internally) to maintain normal device timing.
CFR1 [0]: Not Used, Leave at 0
Control Function Register 2 (CFR2)
The CFR2 bits control the functions, features, and modes of the
AD9952, primarily related to the analog sections of the chip.
CFR2 [23:12]: Not Used
CFR2 [11]: High Speed Sync Enable Bit
CFR2 [11] = 0 (default). The high speed sync enhancement is off.
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CFR2 [11] = 1. The high speed sync enhancement is on. This bit
should be set when using the autosynchronization feature for
SYNC_CLK inputs beyond 50 MHz, (200 MSPS SYSCLK). See
the Synchronizing Multiple AD9952S section.
CFR2 [10]: Hardware Manual Sync Enable Bit
CFR2 [10] = 0 (default). The hardware manual sync function is off.
CFR2 [10] = 1. The hardware manual sync function is enabled.
While this bit is set, a rising edge on the SYNC_IN pin causes
the device to advance the SYNC_CLK rising edge by one
REFCLK cycle. Unlike the software manual sync enable bit, this
bit does not self-clear. Once the hardware manual sync mode is
enabled, it stays enabled until this bit is cleared (see the
Synchronizing Multiple AD9952 section).
CFR2 [9]: CRYSTAL OUT Enable Bit
CFR2 [9] = 0 (default). The CRYSTAL OUT pin is inactive.
CFR2 [9] = 1. The CRYSTAL OUT pin is active. When active,
the crystal oscillator circuitry output drives the CRYSTAL OUT
pin, which can be connected to other devices to produce a
reference frequency. The oscillator responds to crystals in the
range of 20 MHz to 30 MHz.
CFR2 [8]: Not Used
CFR2 [7:3]: Reference Clock Multiplier Control Bits
This 5-bit word controls the multiplier value out of the clock-
multiplier (PLL) block. Valid values are 4 decimal to 20 decimal
(0x04 to 0x14). Values entered outside this range bypass the
clock multiplier. See the Phase-Locked Loop (PLL) section).
CFR2 [2]: VCO Range Control Bit
This bit is used to control the range setting on the VCO.
CFR2 [2] = 0 (default). The VCO operates in a range of 100
MHz to 250 MHz.
CFR2 [2] = 1. The VCO operates in a range of 250 MHz to
CFR2 [1:0]: Charge Pump Current Control Bits
These bits are used to control the current setting on the charge
pump. The default setting, CFR2 [1:0], sets the charge pump
current to the default value of 75 µA. For each bit added (Bit 01,
Bit 10, and Bit 11), 25 µA of current is added to the charge
pump current: 100 µA, 125 µA, and 150 µA.
MHz.
AD9952