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Renesas ISL1557AIRZ-T7S2705
- Part No.:
- ISL1557AIRZ-T7S2705
- Manufacturer:
- Renesas
- Category:
- Telecom
- Package:
- 16-VQFN Exposed Pad
- Datasheet:
-
ISL1557AIRZ-T7S2705.pdf
- Description:
- IC TELECOM INTERFACE 16QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,525
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Product details
Overview
ISL1557AIRZ-T7S2705 from Renesas Electronics is a dual current-feedback operational amplifier engineered for xDSL line driving in ADSL2+, VDSL2, and G.SHDSL systems. It delivers 21dBm output power, drives up to 750mA into a 12V supply, achieves –80dBc distortion at 150kHz into 25Ω, and operates across –40°C to +85°C. Its primary circuit role is differential signal amplification in DSL CPE modems with enhanced lightning transient protection.
For engineers reviewing the ISL1557AIRZ-T7S2705 datasheet, ISL1557AIRZ-T7S2705 pinout, ISL1557AIRZ-T7S2705 application, or ISL1557AIRZ-T7S2705 equivalent, key selection considerations include differential output drive capability (20VP-P into 21Ω), programmable bias control via C0/C1 pins, thermal shutdown, 300MHz bandwidth, and QFN-16 package compatibility with single- or dual-supply operation.
Technical Context
The ISL1557AIRZ-T7S2705 implements a proprietary current-feedback architecture enabling bandwidth adjustment via external feedback resistor (RF = 750Ω typical), with gain set independently by RG. Its dual-amplifier topology forms a single DSL port where Amplifier A and B operate in complementary differential mode.
It integrates two digital control pins (C0, C1) that configure four bias states-full (15mA/amplifier), medium (11mA), low (6mA), and power-down (0.6–1.0mA)-enabling dynamic power/performance trade-offs without changing external components. Thermal shutdown and robust output clamps are embedded for field reliability in telecom line interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Power | 21dBm - enables compliance with VDSL2 Class B line driver requirements into 100Ω load |
| Differential Output Drive | 20VP-P into 21Ω - supports transformer-coupled DSL line interface with 1:2 ratio and back termination |
| THD @ 150kHz | –80dBc typical - ensures low harmonic contamination in DMT tone bands critical for high-bitrate ADSL/VDSL |
| Supply Current (Low Bias) | 6.0mA per amplifier - reduces total system power in idle or low-data-rate modes while maintaining functionality |
| Bandwidth (–3dB) | 300MHz (RF = 499Ω, AV = +5) - provides ample margin for wideband VDSL2 signals up to 17MHz and beyond |
| Operating Temp Range | –40°C to +85°C - qualified for industrial-grade deployment in outdoor DSLAM cabinets and CPE equipment |
| Protection Features | Integrated output clamps + thermal shutdown - mitigates damage from lightning-induced transients and sustained overloads |
Pinout & Package
The ISL1557AIRZ-T7S2705 is housed in a thermally-enhanced 16-lead 4×4mm QFN package (L16.4x4H) with exposed thermal pad connected to VS–. This package supports both single-supply (4.5V–12V) and dual-supply (±2.25V–±6V) operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 5, 6, 12, 15 | NC | No-connect terminals - electrically isolated; must remain unconnected per datasheet |
| 2 | INA– | Inverting input of Amplifier A - forms differential pair with INA+; sensitive to stray capacitance |
| 3 | INA+ | Non-inverting input of Amplifier A - common-mode input range extends to VS– and within 1.3V of VS+ |
| 4 | GND / Thermal Pad | Ground reference and thermal conduction path - must be soldered to PCB ground plane for thermal integrity |
| 7 | VS– | Negative supply rail - thermal pad must be connected directly to this node for safe operation |
| 8 | C0 | Bias control input - sets amplifier quiescent current level (0V = low bias, 5V = full bias) |
| 9 | C1 | Bias control input - used with C0 to select one of four discrete bias states (see Table on p.4) |
| 10 | INB+ | Non-inverting input of Amplifier B - paired with INB– to form second half of differential DSL port |
| 11 | INB– | Inverting input of Amplifier B - complements INB+; requires matched layout for common-mode rejection |
| 13 | OUTB | Differential output of Amplifier B - driven 180° out-of-phase with OUTA to generate balanced line signal |
| 14 | VS+ | Positive supply rail - accepts 4.5V–12V single supply or ±2.25V–±6V dual supply |
| 16 | OUTA | Differential output of Amplifier A - forms active half of differential pair; outputs complement OUTB |
Key Features
| Feature | Design Value |
|---|---|
| Programmable Bias Control | C0/C1 pins enable four discrete supply current states (0.6–15mA/amplifier), allowing real-time adaptation to data rate and power budget |
| Enhanced Lightning Protection | Stronger internal output clamps reduce reliance on external TVS diodes, lowering BOM count and board area in DSL line cards |
| Current-Feedback Architecture | Bandwidth remains stable across gain settings and temperature; 300MHz flat response supports multi-band VDSL2 up to 17MHz |
| Differential Output Swing | 20VP-P into 21Ω meets stringent VDSL2 Class B line driver specs without external transformers or baluns |
| Thermal Shutdown | Automatic disable above +150°C junction temperature prevents latch-up and permanent damage during overload or poor heatsinking |
Applications
| VDSL2 Line Driver | ADSL2+ CPE Modem |
|---|---|
|
Use Scenario: High-speed broadband access node delivering up to 100Mbps downstream over twisted-pair copper lines using VDSL2 Annex A/B. IC Role / Device Role / Timing Role: Differential line driver generating compliant 21dBm output signal with <–80dBc THD across 17MHz bandwidth. Use Value: Enables full VDSL2 profile support including vectoring and bonding without external power boosters or complex compensation networks. |
Use Scenario: Residential customer premises equipment (CPE) modem connecting end-user devices to DSL infrastructure at 14.5dBm average line power. IC Role / Device Role / Timing Role: Dual-opamp DSL port driver providing transformer-coupled differential output with programmable bias for power-sensitive deployments. Use Value: Reduces standby power by 60% (vs full bias) using C0/C1 control, extending energy efficiency in always-on home gateways. |
| G.SHDSL Line Driver | HDSL2 Transceiver Interface |
|
Use Scenario: Symmetric DSL equipment operating at 2.32Mbps over distances up to 3.6km using G.SHDSL (ITU-T G.991.2) standard. IC Role / Device Role / Timing Role: Precision differential driver delivering stable 20VP-P swing into 21Ω with low offset voltage (<±7.5mV DM). Use Value: Maintains signal integrity across long loops with minimal distortion-induced bit errors, reducing retransmission overhead. |
Use Scenario: Legacy HDSL2 repeater or network termination unit requiring robust line driving at 784kbps with ±15V tolerance. IC Role / Device Role / Timing Role: Dual-channel line driver supporting dual-port HDSL2 framing with independent bias control per channel. Use Value: Eliminates need for discrete bias resistors and external current-setting circuits, simplifying analog front-end design. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar xDSL line driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISL1557AIUEZ | 10-lead HMSOP package; lower thermal resistance (θJA = 62°C/W vs 52°C/W); discontinued per datasheet | Designed exclusively for single-supply operation; lacks QFN thermal pad routing flexibility | Select only for legacy HMSOP-based designs with verified thermal margin; not recommended for new designs |
| MAX2245ETA+ | Single-channel VDSL2 driver; 17dBm max output; no C0/C1 bias control; 8-lead TDFN package | Requires two units for differential drive; higher THD (–72dBc @ 10MHz) limits multi-tone performance | Consider only for space-constrained single-port applications where programmable bias is unnecessary |
Compared with ISL1557AIUEZ and MAX2245ETA+, the ISL1557AIRZ-T7S2705 uniquely combines dual-channel integration, 21dBm output, four-level bias control, and QFN thermal performance-making it optimal for next-generation VDSL2 CPE and multi-port DSLAM line cards requiring scalability and power agility.
Availability
ISL1557AIRZ-T7S2705 is available at Aetrix Electronics and suitable for VDSL2 line drivers, ADSL2+ CPE modems, G.SHDSL equipment, and HDSL2 transceiver interfaces requiring stable component supply, RoHS-compliant packaging, and industrial temperature operation.
Supply support for ISL1557AIRZ-T7S2705 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 is a global semiconductor leader specializing in microcontrollers, analog, power, and connectivity solutions for industrial, automotive, and communications markets.
The ISL1557AIRZ-T7S2705 belongs to Renesas' high-performance xDSL line driver product line, designed specifically to meet ITU-T G.993.x and G.991.x standards for broadband access equipment with emphasis on low distortion, programmable power, and field-hardened protection.
FAQ
What is the maximum differential output voltage swing of the ISL1557AIRZ-T7S2705?
The ISL1557AIRZ-T7S2705 delivers a typical 20VP-P differential output swing into a 21Ω load when operating from a ±6V supply. This specification enables direct compliance with VDSL2 Class B line driver requirements without external gain stages or transformer ratio optimization beyond standard 1:2 configurations.
How does the C0 and C1 pin configuration affect power consumption in the ISL1557AIRZ-T7S2705?
The C0 and C1 pins on the ISL1557AIRZ-T7S2705 select four discrete bias states: full (15mA/amplifier), medium (11mA), low (6mA), and power-down (0.6–1.0mA). These digital inputs allow dynamic reduction of quiescent current without altering external components-critical for energy-efficient DSL CPE operation during low-traffic periods.
Can the ISL1557AIRZ-T7S2705 operate from a single 12V supply?
Yes, the ISL1557AIRZ-T7S2705 supports single-supply operation from +4.5V to +12V. When using +12V, inputs must be DC-biased within the common-mode range (VS– to VS+ –1.3V), and outputs deliver ±4.85V single-ended swing into 50Ω differential load-enabling simplified power architecture in compact CPE designs.
What package type and thermal characteristics does the ISL1557AIRZ-T7S2705 use?
The ISL1557AIRZ-T7S2705 uses a 16-lead 4×4mm QFN package (L16.4x4H) with exposed thermal pad connected to VS–. Its thermal resistance is θJA = 52°C/W on JEDEC-standard high-conductivity test board, enabling reliable operation at full bias under +85°C ambient conditions with proper PCB copper pour.
Does the ISL1557AIRZ-T7S2705 include built-in protection against lightning transients?
Yes, the ISL1557AIRZ-T7S2705 features enhanced internal output clamps specifically designed to improve immunity against lightning-induced transients-reducing dependency on external TVS diodes and improving system-level surge survivability in outdoor DSL line interfaces without sacrificing signal fidelity.
ISL1557AIRZ-T7S2705 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 16-VQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Line Interface Unit (LIU)
- Interface:
- -
- Number of Circuits:
- 1
- Voltage - Supply:
- 4.5V ~ 13.2V
- Current - Supply:
- 6mA
- Power (Watts):
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QFN (4x4)
ISL1557AIRZ-T7S2705 FAQ
1.How can I place an order for ISL1557AIRZ-T7S2705 through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL1557AIRZ-T7S2705 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 ISL1557AIRZ-T7S2705 reliable?
The price and inventory of ISL1557AIRZ-T7S2705 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL1557AIRZ-T7S2705 is usually 5 days.
3.What payment methods are accepted for ISL1557AIRZ-T7S2705?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL1557AIRZ-T7S2705 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL1557AIRZ-T7S2705?
ISL1557AIRZ-T7S2705 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL1557AIRZ-T7S2705 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 ISL1557AIRZ-T7S2705?
For technical support, including ISL1557AIRZ-T7S2705 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL1557AIRZ-T7S2705 requirements.
6.How does Aetrix verify that ISL1557AIRZ-T7S2705 is sourced from the original manufacturer or authorized distributors?
All ISL1557AIRZ-T7S2705 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 ISL1557AIRZ-T7S2705 meets industry standards.
7.What is the process for return or replacement of ISL1557AIRZ-T7S2705?
All ISL1557AIRZ-T7S2705 units undergo pre-shipment inspection (PSI). If there is an issue with ISL1557AIRZ-T7S2705, 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 ISL1557AIRZ-T7S2705 part is unused and in its original packaging.
Return procedure for ISL1557AIRZ-T7S2705:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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