AD809BR - 155.52MHz Clock Synthesizer | Analog Devices
MPN: AD809BR ✗ End of Life| Qty | Unit Price | Extended |
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| 500 | $0 | $0.00 |
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AD809BR Overview
A frequency synthesizer generates or reconstructs a stable high-frequency clock from a lower-frequency reference. Clock generators and frequency synthesizers form part of the broader clock and timing IC category, where phase relationship, jitter, output logic standards, and reference stability determine system-level timing performance. The AD809BR targets telecommunications transport systems operating at the 155.52 Mbps line rate.
Its key verified features include synthesis from 9.72 MHz or 19.44 MHz references, selectable input-reference routing through a multiplexer, 2.0 degrees RMS output jitter, and a 10 kHz ECL/PECL-compatible output. The input accepts ECL, PECL, TTL, or CMOS signals, allowing the device to integrate with several source-interface families. The verified data also identifies single-supply operation at approximately 5.2 V and a 16-pin SOIC package.
The AD809BR uses frequency multiplication rather than a simple buffered-clock architecture. Its reference mux permits one device to select between two reference inputs before generating the 155.52 MHz transmit clock. This makes it useful in systems that need redundant references, switching between timing sources, or distributing a common transport clock to multiple ports while preserving a defined relationship to the selected reference.
Typical uses include SONET/SDH telecommunications line cards, 155.52 Mbps transmit-clock generation, backplane timing distribution, and multiport network-interface equipment. In these systems, the AD809BR can convert a 9.72 MHz or 19.44 MHz source into the required 155.52 MHz ECL/PECL clock. Output jitter is particularly relevant because accumulated timing uncertainty can affect line-interface margin.
When designing a board around the AD809BR, preserve short, controlled-clock paths and validate ECL/PECL termination, supply decoupling, reference jitter, and return current continuity. Input muxing and output-enable behavior must also be checked against the system timing state machine. The verified snippets do not provide the complete pin table, absolute limits, or reference-input sensitivity, so those values must be taken directly from the manufacturer datasheet.
This page consolidates the verified 155.52 MHz synthesis, supported logic standards, jitter, packaging, and source links while separating documented data from unavailable details. It also distinguishes a genuine timing function from generic buffer replacements and highlights what must be verified before any substitution is approved.
Drop-in alternatives for AD809BR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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Request AlternativesAD809BR Maximum Ratings & Electrical Characteristics
| Product Type | Clock generator / frequency synthesizer IC |
| Maximum Synthesized Output Frequency | 155.52 MHz |
| Reference Input Frequency Option 1 | 19.44 MHz |
| Reference Input Frequency Option 2 | 9.72 MHz |
| Reference Input Logic Compatibility | TTL / CMOS / ECL / PECL |
| Output Logic Compatibility | 10 kHz ECL / PECL |
| Output Jitter | 2.0 degrees RMS |
| Supply Voltage | Approximately 5.2 V |
| Input Selection | Reference signal select multiplexer |
| Clock Relationship | 155.52 MHz synthesis from 19.44 MHz or 9.72 MHz reference |
| Target Line Rate | 155.52 Mbps |
| Package | SOIC-16 |
| Package Width | 0.150 inch / 3.90 mm |
| Mounting Type | Surface mount |
| Bus Interface | ECL |
AD809BR 0.150 inch / 3.90 mm Pin Configuration Guide
Pin configuration for AD809BR (0.150 inch / 3.90 mm package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for AD809BR.
Refer to the datasheet for full pin configuration.
Typical Applications
AD809BR is suitable for 6 applications: SONET and SDH Line-Card Clocking, 155.52 Mbps Transmit Clock Generation, Backplane Timing Distribution, Selectable Dual-Reference Timing, Telecommunications Backplane Ports, Synchronous Network Interface Equipment.
SONET and SDH Line-Card Clocking
The AD809BR fits telecom line cards that require a 155.52 MHz clock derived from a 9.72 MHz or 19.44 MHz reference. Its documented 155.52 MHz synthesis and 2.0 degrees RMS output jitter target the clocking needs of 155.52 Mbps interfaces, while the ECL/PECL-compatible output supports conventional high-speed logic environments. The design should validate the complete datasheet timing and jitter limits against the line interface, and the printed circuit board must maintain controlled clock routing and suitable logic termination.
Recommended
155.52 Mbps Transmit Clock Generation
The AD809BR is appropriate for generating a transmit bit clock at the 155.52 MHz line rate from a supported 19.44 MHz or 9.72 MHz source. According to the Analog Devices product page, this relationship allows one timing device to support multiple transmit ports in a distributed architecture. Use the internal reference selection only when the system can switch sources without violating downstream interface timing, and verify the selected reference amplitude and edge quality against the manufacturer specifications.
Recommended
Backplane Timing Distribution
The AD809BR can create a 155.52 MHz ECL/PECL-compatible clock from a backplane or PCB timing reference of 19.44 MHz or 9.72 MHz. This makes it useful where several communication ports need a common derived clock rather than independent free-running oscillators. The stated 2.0 degrees RMS output jitter provides a documented timing metric, but engineers must still budget reference jitter, buffer delay, interconnect loss, receiver noise, and skew across every branch of the distribution network.
Recommended
Selectable Dual-Reference Timing
The AD809BR includes a reference-signal select multiplexer, allowing a design to choose between 19.44 MHz and 9.72 MHz reference inputs before producing the 155.52 MHz output clock. This is valuable for systems that monitor two timing sources or need controlled reference failover. Because source transitions can disturb phase and downstream devices can react differently to discontinuities, the controlling logic must define whether switchover must be phase-synchronized, momentarily disabled, or performed during an allowed maintenance interval.
Recommended
Telecommunications Backplane Ports
The AD809BR supports distributed timing for multiple 155.52 Mbps ports by deriving their operating clock from one of two accepted reference rates. It is well aligned with legacy and established transport-clock architectures that use ECL/PECL-compatible signaling rather than lower-voltage CMOS clocking. Board implementation should include impedance-controlled clock traces, minimal stubs, suitable terminations, solid ground-plane continuity, and point-of-use decoupling. Validate loss, skew, and jitter across the backplane before treating a successful bench test as production-qualified.
Recommended
Synchronous Network Interface Equipment
The AD809BR can provide the derived 155.52 MHz timing signal required by network-interface hardware built around 155.52 Mbps links. Its input mux permits a 19.44 MHz source to be used for eight-times synthesis or a 9.72 MHz source for sixteen-times synthesis, giving system architects two reference plans. Selection should follow the jitter, logic-level, and reliability budget of the complete interface rather than frequency alone. The output buffer, terminations, and receiver thresholds must also match the actual ECL/PECL implementation used on the board.
Recommended
Recommended Products Summary
Engineering reference data for AD809BR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Package | SOIC-16 |
| Brand | Analog Devices |
| Synthesized Output Frequency | 155.52 MHz |
| Reference Input Frequencies | 19.44 MHz or 9.72 MHz |
| Input Logic Compatibility | TTL / CMOS / ECL / PECL |
| Output Logic Compatibility | 10 kHz ECL / PECL |
| Output Jitter | 2.0 degrees RMS |
| Supply Voltage | Approximately 5.2 V |
| Reference Selection | Select mux |
| Target Data Rate | 155.52 Mbps |
Design Notes
Treat the 155.52 MHz ECL/PECL output as a controlled-impedance clock signal. Keep the route short, minimize branches and test pads, maintain a continuous reference plane, and use the termination network specified by the manufacturer and receiving-device requirements. Validate rise time, overshoot, undershoot, and settling with a short-interval time-domain measurement because a nominal 155.52 MHz frequency alone does not guarantee acceptable clock quality.
Use the manufacturer data sheet for the exact supply range, decoupling, and input thresholds; the verified material provides only an approximately 5.2 V operating point. Place the recommended supply capacitor and any logic-family bypass components close to their associated pins, and verify that high-speed return current has an uninterrupted low-impedance path. Do not substitute a generic TTL termination for ECL/PECL without checking voltage and current thresholds.
Do not assume that AD809BR, AD809BRZ, or a reel ordering suffix represents a different electrical design. More importantly, do not substitute a generic 155.52 MHz oscillator solely because its frequency matches. Validate reference ratio, reference selection, input thresholds, output logic, supply, pinout, package, jitter, and control behavior. Source switching must also be checked for phase discontinuities that could disturb downstream equipment.
Compliance Information
The verified sources do not provide explicit AD809BR compliance statements. AEC-Q100 is marked not applicable because this is a clock and timing IC and no automotive qualification was verified.
