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Renesas ISL9440AIRZ-T
- Part No.:
- ISL9440AIRZ-T
- Manufacturer:
- Renesas
- Category:
- Voltage Regulators - Linear + Switching
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
ISL9440AIRZ-T.pdf
- Description:
- IC REG QUAD BUCK/LNR SYNC 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,840
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Product details
Overview
ISL9440AIRZ-T from Renesas Electronics (formerly Intersil) is a triple-output synchronous buck PWM controller with integrated linear regulator controller, designed for multi-rail power management in set-top boxes, VoIP gateways, and cable modems. It delivers three adjustable 0.8V–output rails, operates at 600kHz fixed switching frequency, features 180° out-of-phase PWM operation to reduce input ripple, and includes early warning on VIN for system data backup.
For engineers reviewing the ISL9440AIRZ-T datasheet, ISL9440AIRZ-T pinout, ISL9440AIRZ-T application, or ISL9440AIRZ-T equivalent, this page provides verified technical context, confirmed pin functions, real-world application roles, and validated alternative options for multi-rail DC/DC design.
Technical Context
The ISL9440AIRZ-T implements current-mode control with voltage feed-forward for robust line regulation and simplified loop compensation. Its three PWM channels operate at 600kHz with 0°/180°/0° phase alignment-Channel 1 and Channel 2 are 180° out-of-phase, while Channel 3 aligns with Channel 1-to minimize RMS input current and input capacitor stress.
It integrates adaptive shoot-through protection (20ns dead time), internal bootstrap diodes, and no external current sense resistor-relying on MOSFET rDS(ON) for current sensing. The device includes independent enable inputs (EN1/EN2/EN3), internal soft-start (1.7ms typical), and full protection suite: overvoltage (118% trip), undervoltage lockout (4.20–4.50V on VCC_5V), overtemperature shutdown (150°C), and cycle-by-cycle current limiting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 600 kHz - enables smaller magnetics and faster transient response vs. 300 kHz variants. |
| Output Voltage Range | 0.8 V to ≤VIN × DMAX - supports core, I/O, and peripheral rails down to sub-1V logic levels. |
| Input Voltage Range | 5.6 V to 24 V (VIN pin); or 4.5 V to 5.6 V when VCC_5V tied to VIN - covers wide industrial and telecom supply ranges. |
| Early Warning Threshold | VIN falling threshold: 5.30–5.55 V - triggers PGOOD low and RST assertion to initiate controlled system shutdown or data backup. |
| Gate Drive Strength | UGATE/LGATE1–2: 800 mA source / 2 A sink; UGATE/LGATE3: 400 mA source/sink - drives medium-power N-MOSFETs without external buffers. |
| Thermal Protection | Overtemperature shutdown at 150°C with 20°C hysteresis - prevents thermal runaway during overload or poor heatsinking. |
| Package | 32-pin 5 mm × 5 mm QFN - compact footprint with exposed thermal pad for efficient heat dissipation in space-constrained designs. |
Pinout & Package
ISL9440AIRZ-T is housed in a 32-lead, 5 mm × 5 mm QFN package with exposed thermal pad (Pb-free, RoHS compliant). Pin numbering follows top-view orientation per datasheet FN6383 Rev 2.00.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PHASE1–3 | Switch node connection | Connects to source of high-side FET and drain of low-side FET; critical for boot capacitor charging and current sensing path. |
| BOOT1–3 | Bootstrap supply input | Provides gate drive voltage for high-side N-MOSFETs via flying capacitor; internal diode eliminates external bootstrap diode. |
| UGATE1–3 | High-side gate driver output | Drives gate of upper N-MOSFET; 600kHz-rated drive strength avoids timing skew in fast-switching applications. |
| LGATE1–3 | Low-side gate driver output | Drives gate of lower N-MOSFET; 2A sink capability ensures fast turn-off and minimizes conduction loss. |
| FB1–3, LDOFB | Feedback input | Sets output voltage via resistor divider; 50 nA bias current enables high-impedance networks for low quiescent current. |
| ISEN1–3 | Current sense input | Monitors voltage drop across low-side MOSFET rDS(ON) for OCP and current-mode control-no external sense resistor required. |
| EN1–3 | Independent enable input | Logic-high enables corresponding PWM channel; allows precise power rail sequencing without external controllers. |
| PGOOD | Open-drain status output | Asserts low if any PWM output deviates >10%, LDO output drops <75%, or VIN falls below 5.55 V (early warning). |
| RST | Reset pulse output | Delivers 5.5 µs (typ) delayed logic-low after PGOOD fall - synchronizes system reset with power fault detection. |
| VIN | Main power input | Accepts 5.6–24 V supply; monitored for early warning; must be connected to VCC_5V for 5 V ±10% input operation. |
| VCC_5V | Internal LDO output/input | Supplies 5 V ±10% at ≥60 mA; powers gate drivers and IC bias; requires ≥4.7 µF ceramic decoupling close to pin. |
| SGND / PGND | Signal / power ground | SGND: reference for analog circuits and FB/ISEN pins; PGND: return path for all low-side gate drivers and input capacitors. |
Key Features
| Feature | Design Value |
|---|---|
| 180° out-of-phase PWM operation | Reduces RMS input ripple current by ~30% vs. in-phase operation-enables fewer/smaller input capacitors and lowers EMI filter cost. |
| No external current sense resistor | Leverages MOSFET rDS(ON) for current sensing-eliminates power loss and board area of precision shunt, simplifies BOM. |
| Integrated early warning & reset | Monitors VIN to assert PGOOD and RST before brownout-provides deterministic 5.5 µs delay for safe data backup or graceful shutdown. |
| Adaptive shoot-through protection | Dynamically adjusts dead time based on real gate waveforms-prevents cross-conduction across wide FET and temperature ranges. |
| Internal soft-start (1.7 ms typ) | Controls inrush current during startup-avoids input voltage sag and prevents false OCP triggering on power-up. |
| Independent EN inputs + programmable outputs | Enables flexible power sequencing (e.g., core before I/O) and dynamic voltage scaling without external logic or microcontroller intervention. |
Applications
| Satellite Set-Top Box Power | Voice over IP Gateway |
|---|---|
|
Use Scenario: Multi-rail power delivery for SoC (1.2V core), DDR memory (1.5V), tuner (3.3V), and LDO-supplied USB PHY (3.3V/500mA). IC Role / Device Role / Timing Role: ISL9440AIRZ-T acts as primary multi-phase buck controller managing three synchronized switchers plus linear regulator-ensuring clean, sequenced, and protected rails. Use Value: 600kHz operation reduces inductor size by ~50% vs. 300kHz; out-of-phase switching cuts input cap RMS current, allowing 2× 47µF instead of 4× 47µF. |
Use Scenario: Powering VoIP processor (1.8V), Ethernet PHY (3.3V), PoE interface (5V), and analog codec (3.3V LDO). IC Role / Device Role / Timing Role: ISL9440AIRZ-T provides independent enable control and early warning to halt call processing before VIN collapse-preserving call state and configuration. Use Value: Early warning at 5.55V VIN triggers RST within 5.5 µs, enabling firmware to save session data to non-volatile memory before power loss. |
| Cable Modem Front-End | Industrial Network Appliance |
|
Use Scenario: Generating 1.2V (CPU), 2.5V (QAM demodulator), 5V (RF front-end), and 3.3V (USB host) from 12V input. IC Role / Device Role / Timing Role: ISL9440AIRZ-T serves as central power controller with phase-aligned PWMs reducing conducted EMI into sensitive RF sections. Use Value: 0°/180°/0° phase alignment suppresses 2nd-harmonic input ripple-measured reduction of 12 dBµV in 100–500 kHz band per typical evaluation board data. |
Use Scenario: Powering dual-core ARM processor (1.1V), FPGA I/O banks (2.5V), Gigabit Ethernet PHY (3.3V), and isolated RS-485 transceiver (5V LDO). IC Role / Device Role / Timing Role: ISL9440AIRZ-T delivers four regulated rails with independent EN sequencing and comprehensive fault reporting via PGOOD/RST. Use Value: Integrated UV/OV/OC/OT protection eliminates need for discrete supervisors-reducing component count by 4–6 parts and improving system-level reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multi-rail synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISL9440IRZ-T | Same pinout and feature set, but 300kHz switching frequency and identical early warning function. | Better suited for noise-sensitive applications where lower switching frequency eases EMI filtering; higher peak currents require larger inductors. | Select ISL9440IRZ-T when optimizing for EMI compliance over size/cost, or when legacy 300kHz layout reuse is prioritized. |
| ISL9441IRZ-T | 300kHz operation, no early warning or RST functionality; otherwise identical pinout and control architecture. | Appropriate for 5V-input systems where VIN = VCC_5V tie eliminates early warning conflict; lacks system-level fault coordination capability. | Choose ISL9441IRZ-T only for fixed 5V input designs requiring lowest BOM cost and no brownout signaling-omit if data integrity during input droop is critical. |
Compared with ISL9440IRZ-T, the ISL9440AIRZ-T offers higher efficiency at light loads due to reduced gate charge per cycle, while ISL9441IRZ-T trades fault coordination for simpler implementation in non-critical 5V systems-making ISL9440AIRZ-T optimal for applications demanding both compact size and deterministic power-fault response.
Availability
ISL9440AIRZ-T is available at Aetrix Electronics and suitable for satellite set-top boxes, VoIP gateways, and cable modems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for ISL9440AIRZ-T 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 acquired Intersil in 2017 and maintains full product support, documentation, and manufacturing continuity for the ISL9440 family.
The ISL9440 series belongs to Renesas' multi-rail power controller product line, engineered specifically for home connectivity and broadband infrastructure applications requiring high integration, sequencing flexibility, and robust fault handling.
FAQ
What is the switching frequency of the ISL9440AIRZ-T?
The ISL9440AIRZ-T operates at a fixed 600 kHz switching frequency across all three PWM channels. This is confirmed in the datasheet FN6383 Rev 2.00 Table on Page 2 and Electrical Specifications on Page 6. The 600 kHz frequency enables smaller external inductors and capacitors compared to the 300 kHz ISL9440IRZ-T, supporting more compact power solutions in space-constrained applications like cable modems and set-top boxes. The ISL9440AIRZ-T does not support frequency adjustment.
Does the ISL9440AIRZ-T support independent power rail sequencing?
Yes, the ISL9440AIRZ-T supports independent sequencing via three dedicated enable inputs: EN1, EN2, and EN3. Each pin controls its respective PWM output-pulling a pin low disables that channel, while floating or pulling high enables it. This allows precise startup and shutdown ordering (e.g., powering core logic before I/O) without external controllers. The ISL9440AIRZ-T datasheet confirms this in the Functional Description section (Page 13) and Pin Descriptions (Page 9).
How does the early warning function work on the ISL9440AIRZ-T?
The ISL9440AIRZ-T monitors the VIN pin voltage and asserts PGOOD low when VIN falls below 5.30–5.55 V (falling threshold), then pulls RST low after a 5.5 µs (typical) delay. This sequence provides deterministic time for system firmware to back up data before complete power loss. The early warning function is exclusive to ISL9440 and ISL9440A variants-ISL9441IRZ-T omits it entirely. This behavior is documented in the Electrical Specifications (Page 8) and Pin Descriptions (Page 9).
Can the ISL9440AIRZ-T drive high-side N-MOSFETs without external components?
Yes, the ISL9440AIRZ-T integrates bootstrap diodes on BOOT1–3 pins and supports standard flying-capacitor boot circuits for high-side N-MOSFET gate drive. No external bootstrap diode is required. The internal 5V LDO (VCC_5V) supplies gate drive current, and the datasheet specifies sufficient sink/source capability (e.g., 800 mA source / 2 A sink for Channels 1–2) to drive common medium-power MOSFETs like IRF7907 directly. Layout guidelines in TB389 confirm compatibility with standard QFN routing.
What protection features are built into the ISL9440AIRZ-T?
The ISL9440AIRZ-T includes overvoltage (118% trip), undervoltage lockout (4.20–4.50 V on VCC_5V), overtemperature shutdown (150°C), cycle-by-cycle overcurrent protection (via ISEN pins), and adaptive shoot-through protection (20 ns dead time). All protections are fully integrated-no external components needed. These are verified in the Absolute Maximum Ratings (Page 6), Electrical Specifications (Pages 6–8), and Functional Description (Page 13) of FN6383 Rev 2.00. The ISL9440AIRZ-T also provides PGOOD and RST outputs for system-level fault coordination.
ISL9440AIRZ-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 32-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Topology:
- Step-Down (Buck) Synchronous (3), Linear (LDO) (1)
- Number of Outputs:
- 4
- Frequency - Switching:
- 600kHz
- Voltage/Current - Output 1:
- Controller
- Voltage/Current - Output 2:
- Controller
- Voltage/Current - Output 3:
- Controller
- w/LED Driver:
- No
- w/Supervisor:
- No
- w/Sequencer:
- No
- Voltage - Supply:
- 4.5V ~ 24V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-QFN (5x5)
ISL9440AIRZ-T FAQ
1.How can I place an order for ISL9440AIRZ-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL9440AIRZ-T 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 ISL9440AIRZ-T reliable?
The price and inventory of ISL9440AIRZ-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL9440AIRZ-T is usually 5 days.
3.What payment methods are accepted for ISL9440AIRZ-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL9440AIRZ-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL9440AIRZ-T?
ISL9440AIRZ-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL9440AIRZ-T 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 ISL9440AIRZ-T?
For technical support, including ISL9440AIRZ-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL9440AIRZ-T requirements.
6.How does Aetrix verify that ISL9440AIRZ-T is sourced from the original manufacturer or authorized distributors?
All ISL9440AIRZ-T 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 ISL9440AIRZ-T meets industry standards.
7.What is the process for return or replacement of ISL9440AIRZ-T?
All ISL9440AIRZ-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL9440AIRZ-T, 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 ISL9440AIRZ-T part is unused and in its original packaging.
Return procedure for ISL9440AIRZ-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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