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Renesas 728980JG8
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- Part No.:
- 728980JG8
- Manufacturer:
- Renesas
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 44-LCC (J-Lead)
- Datasheet:
-
728980JG8.pdf
- Description:
- IC MULTIPLEXER 1 X 8:8 44PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:2,300
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Product details
Overview
IDT728980JG8 from Renesas Electronics (formerly IDT) is a 256 × 256 non-blocking time slot interchange (TSI) digital switch for ST-BUS®-compliant telecom systems. It supports eight 2.048 Mb/s serial input streams (RX0–RX7), eight 2.048 Mb/s serial output streams (TX0–TX7), microprocessor-controlled configuration via an 8-bit parallel bus, and operates on a single +5.0 V supply across –40°C to +85°C. It is used in digital cross-connect systems and channelized T1/E1 multiplexers.
For engineers reviewing the IDT728980JG8 datasheet, IDT728980JG8 pinout, IDT728980JG8 application, or IDT728980JG8 equivalent, key selection criteria include ST-BUS® frame alignment (F0i), 4.096 MHz serial clock (C4i), per-channel connection memory control, ODE-driven three-state TX outputs, and PLCC-44 packaging with industrial temperature support.
Technical Context
The IDT728980JG8 implements dual-mode switching-Connection Mode (data routed from Data Memory using Connection Memory LOW addresses) and Processor Mode (data written directly to Connection Memory LOW by host CPU). Internal serial-to-parallel and parallel-to-serial conversion enables full 256-channel time-slot mapping with minimum 2-channel delay depending on RX/TX stream pairing.
It features 256-position Data Memory, split 16-bit Connection Memory (HIGH/LOW), and a programmable Control Register with Split Memory (SM), Processor Enable (PE), and Stream Address (STA) bits. The CCO output delivers a synchronized 256-bit control stream at 2.048 Mb/s, one channel ahead of corresponding TX data.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Capacity | 256 × 256 non-blocking time-slot interchange matrix |
| Serial Interface | ST-BUS® compliant: 8 RX + 8 TX streams, each 2.048 Mb/s (32 × 64 Kbit/s channels) |
| Frame & Clock | F0i frame pulse at 8 kHz; C4i serial clock at 4.096 MHz |
| Microprocessor Bus | 8-bit parallel interface (D0–D7), A0–A5 addressing, CS/DS/R/W control |
| Supply & Temp | +4.75 V to +5.25 V; operating range –40°C to +85°C |
| Output Drive | Three-state TX0–TX7 outputs controlled by ODE pin and Connection Memory HIGH OE bits |
| Package | 44-pin Plastic Leaded Chip Carrier (PLCC, J44 footprint) |
Pinout & Package
Package: 44-pin PLCC (J44), 0.65 in × 0.65 in, 0.05 in pitch, lead-free (Green) variant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pin 1, 28) | Ground reference | Primary ground rail for analog/digital sections; decoupling required near VCC pins |
| VCC (Pin 44) | Power supply | +5.0 V supply; requires local 0.1 µF ceramic bypass capacitor |
| RX0–RX7 (Pins 37–30, 27–20) | Serial input streams | Eight 2.048 Mb/s ST-BUS® inputs; each carries 32 time slots/frame |
| TX0–TX7 (Pins 11–18, 4–1) | Serial output streams | Eight 2.048 Mb/s ST-BUS® outputs; three-state enabled by ODE and CMH OE bits |
| F0i (Pin 39) | Frame synchronization | 8 kHz input marking start of 125 µs ST-BUS® frame; critical for internal memory addressing |
| C4i (Pin 40) | Serial clock | 4.096 MHz input driving all serial I/O timing and internal memory access cycles |
| ODE (Pin 3) | Master output enable | Active-HIGH control: when LOW, forces all TX0–TX7 into high-impedance regardless of software state |
| DTA (Pin 38) | Data acknowledge | Open-drain active-LOW signal indicating completion of microprocessor bus transfer; requires external pull-up |
| A0–A5 (Pins 26, 25, 24, 23, 22, 21) | Address bus | 6-bit address for accessing Control Register (A5=0) or 32-byte memory pages (A5=1) |
| D0–D7 (Pins 19, 17, 16, 15, 14, 13, 12, 10) | Data bus | 8-bit bidirectional interface for reading/writing Control Register, Data Memory, and Connection Memory |
| CS / DS / R/W (Pins 36, 35, 34) | Bus control | Chip Select (active LOW), Data Strobe (active HIGH), Read/Write direction control |
| CCO (Pin 33) | Control channel output | 2.048 Mb/s serial output carrying 256 control bits (one per time slot), synchronized to TX streams but one slot early |
Key Features
| Feature | Design Value |
|---|---|
| ST-BUS® Compatibility | Fully compliant with ETSI ST-BUS® framing: 32 time slots/frame, 8 kHz frame rate, 2.048 Mb/s data rate per stream |
| Dual Switching Modes | Hardware-configurable Connection Mode (memory-mapped routing) and Processor Mode (CPU-driven data injection) |
| Per-Channel Output Control | Each TX channel independently enabled/disabled via Connection Memory HIGH bit 0 (OE), enabling flexible matrix construction |
| Programmable Delay Management | Minimum 2-channel delay achievable for specific RX→TX stream combinations (e.g., RX0→TX1–TX7), critical for low-latency voice paths |
| Robust Initialization Sequence | ODE pin held LOW at power-up prevents bus contention; allows safe initialization of Connection Memory HIGH before enabling outputs |
Applications
| Digital Cross-Connect System (DCS) | T1/E1 Channelized Multiplexer |
|---|---|
Use Scenario: Dynamic reconfiguration of DS0 channels between multiple T1 lines in central office switching fabric. IC Role / Device Role / Timing Role: Time-slot interchange core performing non-blocking 256×256 channel mapping under microprocessor supervision; synchronizes to network-derived F0i and C4i. Use Value: Enables real-time provisioning of voice/data circuits without hardware changes; supports hitless reconfiguration using Connection Memory updates during active traffic. | Use Scenario: Aggregating 24 DS0 channels from four T1 lines into a single E1 (32-channel) output stream with selective channel insertion/drop. IC Role / Device Role / Timing Role: ST-BUS®-aligned TSI device mapping individual DS0 time slots between heterogeneous T1/E1 framing structures; uses F0i for frame alignment and C4i for bit-level timing. Use Value: Eliminates need for external framing converters; allows direct interworking between North American and European PCM hierarchies using same physical interface. |
| ISDN Primary Rate Interface (PRI) Concentrator | VoIP Gateway Media Plane |
Use Scenario: Consolidating 30 B-channels from multiple ISDN PRI lines into a shared media processing resource. IC Role / Device Role / Timing Role: Time-slot router connecting PRI B-channel time slots (64 Kbit/s) to DSP resources; operates in Processor Mode for dynamic channel assignment. Use Value: Provides deterministic, low-jitter channel routing essential for circuit-switched ISDN signaling integrity and bearer channel transparency. | Use Scenario: Bridging legacy TDM voice traffic (E1/T1) to packet-based VoIP infrastructure using transcoding DSPs. IC Role / Device Role / Timing Role: TDM interface adapter providing precise time-slot extraction/insertion synchronized to network clock; CCO output feeds DSP frame sync logic. Use Value: Maintains end-to-end timing alignment across TDM-to-packet boundary, minimizing packetization jitter and improving MOS scores in voice calls. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar time slot interchange applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC145506FN | 128 × 128 capacity; single 2.048 Mb/s ST-BUS® interface (4 RX/4 TX); no CCO output; requires external clock generation | Limited to smaller-scale concentrators or legacy PBX expansion modules where full 256×256 scale is unnecessary | Select when cost sensitivity outweighs scalability needs and system clock architecture cannot support C4i/F0i sourcing |
| Si2404-GM | 256 × 256 capacity; supports both ST-BUS® and MVIP interfaces; integrated PLL; 3.3 V operation; QFP-100 package | Suitable for multi-standard gateways requiring ST-BUS® and MVIP coexistence; incompatible with 5 V-only legacy backplanes | Choose for new designs needing mixed-interface flexibility or lower power, but requires PCB redesign due to QFP-100 and voltage change |
Compared with MC145506FN and Si2404-GM, the IDT728980JG8 offers native 5 V operation, PLCC-44 compatibility with legacy telecom modules, and dedicated CCO output for external frame sync distribution-making it optimal for drop-in upgrades in existing ST-BUS®-based DCS equipment.
Availability
IDT728980JG8 is available at Aetrix Electronics and suitable for digital cross-connect systems, T1/E1 multiplexers, and ISDN PRI concentrators requiring stable component supply, long-lifecycle support, and industrial temperature operation.
Supply support for IDT728980JG8 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Renesas Electronics Corporation is a global semiconductor leader delivering trusted embedded solutions for automotive, industrial, infrastructure, and IoT applications.
The IDT728980JG8 belongs to Renesas' legacy telecom timing and switching portfolio, originally developed by Integrated Device Technology (IDT) to address carrier-grade ST-BUS®-based time-division multiplexing requirements in digital switching systems.
FAQ
What is the minimum propagation delay through the IDT728980JG8 for a time slot routed from RX0 to TX1?
The minimum delay for RX0 → TX1 is two channel periods (2 × 125 µs = 250 ns), as confirmed in Table 1 of the datasheet. This occurs because data entering RX0 must be stored in Data Memory during one frame, then read out for TX1 in the subsequent frame. The IDT728980JG8 enforces this minimum delay to ensure reliable memory access timing and avoid intra-frame contention.
How does the IDT728980JG8 handle simultaneous access to Data Memory and Connection Memory during switching operations?
The IDT728980JG8 uses separate internal address decoders and arbitration logic to isolate Data Memory (256 locations) and Connection Memory (split HIGH/LOW, 256 × 16 bits total). During Connection Mode, Connection Memory LOW supplies source addresses while Data Memory provides payload-accesses occur in staggered cycles to prevent conflict. The Control Register's Split Memory (SM) bit further ensures reads/writes target correct memory banks without overlap.
Can the IDT728980JG8 operate with a 3.3 V supply instead of 5 V?
No, the IDT728980JG8 is specified only for +4.75 V to +5.25 V operation per its Absolute Maximum Ratings and Recommended Operating Conditions. Its input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and output drive strength (IOH = 10 mA, IOL = 5 mA) are designed for 5 V TTL/CMOS compatibility. Using 3.3 V will result in unreliable logic levels and potential functional failure.
What is the function of the CCO pin on the IDT728980JG8, and how is it synchronized to the TX outputs?
CCO (Control Channel Output) is a 2.048 Mb/s serial output carrying one control bit per time slot (256 bits/frame), sourced from Connection Memory HIGH bit 1 (CCO). It is synchronized to the TX streams but transmitted one time slot earlier-e.g., CCO bit for TX0, CH0 appears during TX0, CH31-to accommodate external logic delays. This allows real-time per-slot control signaling alongside payload data.
Is the IDT728980JG8 pin-compatible with other members of the IDT728xx family, such as IDT728960 or IDT728970?
No, the IDT728980JG8 is not pin-compatible with IDT728960 (128 × 128) or IDT728970 (192 × 192). Although all use PLCC-44 packages, pin assignments differ significantly-for example, IDT728960 lacks CCO and has fewer RX/TX lines. The IDT728980JG8's full 256 × 256 implementation requires dedicated routing for all eight RX/TX pairs and associated control signals, making direct substitution impossible without PCB revision.
728980JG8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- 7200
- Package/Case:
- 44-LCC (J-Lead)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Multiplexer
- Circuit:
- 1 x 8:8
- Independent Circuits:
- 1
- Current - Output High, Low:
- -
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-PLCC (16.59x16.59)
728980JG8 FAQ
1.How can I place an order for 728980JG8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 728980JG8 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for 728980JG8 reliable?
The price and inventory of 728980JG8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 728980JG8 is usually 5 days.
3.What payment methods are accepted for 728980JG8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 728980JG8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 728980JG8?
728980JG8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 728980JG8 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for 728980JG8?
For technical support, including 728980JG8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 728980JG8 requirements.
6.How does Aetrix verify that 728980JG8 is sourced from the original manufacturer or authorized distributors?
All 728980JG8 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 728980JG8 meets industry standards.
7.What is the process for return or replacement of 728980JG8?
All 728980JG8 units undergo pre-shipment inspection (PSI). If there is an issue with 728980JG8, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The 728980JG8 part is unused and in its original packaging.
Return procedure for 728980JG8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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