Inc. Recording Equipment User Manual
Table Of Contents
- Features
- Applications
- General Description
- Basic Block Diagram
- Revision History
- Specifications
- Absolute Maximum Ratings
- Pin Configuration and Function Descriptions
- Typical Performance Characteristics
- Input/Output Termination Recommendations
- Theory of Operation
- Thermal Performance
- Power-Up
- Power Supply Partitioning
- Serial Control Port
- I/O Register Map
- I/O Register Descriptions
- Serial Port Configuration (Register 0x0000 to Register 0x0005)
- Power-Down and Reset (Register 0x0010 to Register 0x0013)
- System Clock (Register 0x0020 to Register 0x0022)
- CMOS Output Divider (S-Divider) (Register 0x0100 to Register 0x0106)
- Frequency Tuning Word (Register 0x01A0 to Register 0x01AD)
- Register 0x01A0 to Register 0x01A5—Reserved
- Register 0x01A6—FTW0 (Frequency Tuning Word)
- Register 0x01A7—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01A8—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01A9—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01AA—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01AB—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01AC—Phase
- Register 0x01AD—Phase (Continued)
- Doubler and Output Drivers (Register 0x0200 to Register 0x0201)
- Calibration (User-Accessible Trim) (Register 0x0400 to Register 0x0410)
- Harmonic Spur Reduction (Register 0x0500 to Register 0x0509)
- Outline Dimensions
AD9912
Rev. D | Page 23 of 40
THERMAL PERFORMANCE
Table 7. Thermal Parameters
Symbol Thermal Characteristic Using a JEDEC51-7 Plus JEDEC51-5 2S2P Test Board Value Unit
θ
JA
Junction-to-ambient thermal resistance, 0.0 m/sec air flow per JEDEC JESD51-2 (still air) 25.2 °C/W
θ
JMA
Junction-to-ambient thermal resistance, 1.0 m/sec air flow per JEDEC JESD51-6 (moving air) 22.0 °C/W
θ
JMA
Junction-to-ambient thermal resistance, 2.0 m/sec air flow per JEDEC JESD51-6 (moving air) 19.8 °C/W
θ
JB
Junction-to-board thermal resistance, 1.0 m/sec air flow per JEDEC JESD51-8 (moving air) 13.9 °C/W
θ
JC
Junction-to-case thermal resistance (die-to-heat sink) per MIL-Std 883, Method 1012.1 1.7 °C/W
Ψ
JT
Junction-to-top-of-package characterization parameter, 0 m/sec air flow per JEDEC JESD51-2 (still air) 0.1 °C/W
The AD9912 is specified for a case temperature (T
CASE
). To
ensure that T
CASE
is not exceeded, an airflow source can be used.
Use the following equation to determine the junction tempera-
ture on the application PCB:
T
J
= T
CASE
+ (Ψ
JT
× PD)
where:
T
J
is the junction temperature (°C).
T
CASE
is the case temperature (°C) measured by customer at top
center of package.
Ψ
JT
is the value from Table 7.
PD is the power dissipation (see the Total Power Dissipation
section in the Specifications section).
Values of θ
JA
are provided for package comparison and PCB
design considerations. θ
JA
can be used for a first-order
approximation of T
J
by the equation
T
J
= T
A
+ (θ
JA
× PD)
where T
A
is the ambient temperature (°C).
Values of θ
JC
are provided for package comparison and PCB
design considerations when an external heat sink is required.
Values of θ
JB
are provided for package comparison and PCB
design considerations.
The values in Table 7 apply to both 64-lead package options.