AD9517-4/PCBZ Analog Devices Inc, AD9517-4/PCBZ Datasheet - Page 48

• Manufacturer Part Number: AD9517-4/PCBZ
• Description: BOARD EVALUATION AD9517-4
• Manufacturer: Analog Devices Inc

Specifications of AD9517-4/PCBZ

• Design Resources: High Performance, Dual Channel IF Sampling Receiver (CN0140)
• Main Purpose: Timing, Clock Generator
• Utilized Ic / Part: AD9517-4
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD9517-4
LVPECL Outputs—OUT0 to OUT3
The LVPECL differential voltage (V
to ~960 mV (see Register 0x0F0[3:2] to Register 0x0F5[3:2]).
The LVPECL outputs have dedicated pins for power supply
(VS_LVPECL), allowing a separate power supply to be used.
V
The LVPECL output polarity can be set as noninverting or
inverting, which allows for the adjustment of the relative
polarity of outputs within an application without requiring a
board layout change. Each LVPECL output can be powered
down or powered up as needed. Because of the architecture of
the LVPECL output stages, there is the possibility of electrical
overstress and breakdown under certain power-down conditions.
For this reason, the LVPECL outputs have several power-down
modes. This includes a safe power-down mode that continues
to protect the output devices while powered down, although it
consumes somewhat more power than a total power-down. If
the LVPECL output pins are terminated, it is best to select the
safe power-down mode. If the pins are not connected (unused),
it is acceptable to use the total power-down mode.
LVDS/CMOS Outputs—OUT4 to OUT7
OUT4 to OUT7 can be configured as either an LVDS
differential output or as a pair of CMOS single-ended outputs.
The LVDS outputs allow for selectable output current from
~1.75 mA to ~7 mA.
The LVDS output polarity can be set as noninverting or
inverting, which allows for the adjustment of the relative
polarity of outputs within an application without requiring a
board layout change. Each LVDS output can be powered down
if not needed to save power.
OUT4 to OUT7 can also be CMOS outputs. Each LVDS output
can be configured to be two CMOS outputs. This provides for
up to eight CMOS outputs: OUT4A, OUT4B, OUT5A, OUT5B,
OUT6A, OUT6B, OUT7A, and OUT7B. When an output is
configured as CMOS, CMOS Output A is automatically turned on.
CMOS Output B can be turned on or off independently. The
relative polarity of the CMOS outputs can also be selected for
any combination of inverting and noninverting (see Table 57,
Register 0x140[7:5], Register 0x141[7:5], Register 0x142[7:5],
and Register 0x143[7:5]).
S_LVPECL
can be from 2.5 V to 3.3 V.
Figure 58. LVPECL Output Simplified Equivalent Circuit
GND
3.3V
OD
) is selectable from ~400 mV
OUT
OUT
Rev. B | Page 48 of 80
Each LVDS/CMOS output can be powered-down as needed to
save power. The CMOS output power-down is controlled by the
same bit that controls the LVDS power-down for that output.
This power-down control affects both the CMOS A and CMOS B
outputs. However, when the CMOS A output is powered up, the
CMOS B output can be powered on or off separately.
RESET MODES
The AD9517 has several ways to force the chip into a reset
condition that restores all registers to their default values and
makes these settings active.
Power-On Reset—Start-Up Conditions When V
A power-on reset (POR) is issued when the V
turned on. This initializes the chip to the power-on conditions
that are determined by the default register settings. These are
indicated in the Default Value (Hex) column of Table 52. At
power-on, the AD9517 also executes a SYNC operation, which
brings the outputs into phase alignment according to the default
settings.
Asynchronous Reset via the RESET Pin
An asynchronous hard reset is executed by momentarily pulling
RESET low. A reset restores the chip registers to the default settings.
Soft Reset via Register 0x00[2]
A soft reset is executed by writing Register 0x000[2] and
Register 0x000[5] = 1b. This bit is not self-clearing; it must be
cleared by writing Register 0x000[2] and Register 0x000[5] = 0b to
reset it and complete the soft reset operation. A soft reset restores
the default values to the internal registers. The soft reset bit does
not require an update registers command (Register 0x232) to be
issued.
Figure 59. LVDS Output Simplified Equivalent Circuit with
Figure 60. CMOS Equivalent Output Circuit
3.5 mA Typical Current Source
3.5mA
3.5mA
V
S
OUT
OUT
OUT
S
power supply is
S
Is Applied