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Renesas ISL9440IRZ
- Part No.:
- ISL9440IRZ
- Manufacturer:
- Renesas
- Category:
- Voltage Regulators - Linear + Switching
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
ISL9440IRZ.pdf
- Description:
- IC REG QUAD BUCK/LNR SYNC 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,301
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Product details
Overview
ISL9440IRZ from Renesas Electronics (formerly Intersil) is a quad-output power management IC integrating three synchronous buck PWM controllers and one low-dropout linear regulator controller. It delivers 0.8V–5V programmable outputs, operates at 300kHz fixed switching frequency, supports 5.6V–24V input, and features 180° out-of-phase PWM operation to reduce RMS input ripple-designed for multi-rail power in cable modems and VoIP gateways.
For engineers reviewing the ISL9440IRZ datasheet, ISL9440IRZ pinout, ISL9440IRZ application, or ISL9440IRZ equivalent, key selection criteria include its triple out-of-phase buck architecture, integrated early warning function on VIN, independent enable inputs for rail sequencing, internal loop compensation, and 32-pin 5×5mm QFN package with verified thermal performance (θJA = 31°C/W).
Technical Context
The ISL9440IRZ implements current-mode control with voltage feed-forward ramp modulation, enabling robust line regulation and simplified loop stability across wide input ranges. Its three PWM channels operate with fixed 300kHz frequency and 0°/180°/0° phase alignment-Channel 1 and Channel 2 are 180° out-of-phase while Channel 3 aligns with Channel 1-to minimize input capacitor RMS current and EMI.
It integrates adaptive shoot-through protection with 20ns dead-time, internal bootstrap diodes, no external current-sense resistor (uses rDS(ON) sensing), and an internal 5V LDO (VCC_5V) capable of sourcing ≥60mA. Early warning logic monitors VIN and asserts PGOOD low when voltage drops below 5.55V (typ), triggering RST after 5.5µs (typ).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5.6V–24V (supports 12V rail systems); 4.5V–5.6V when VCC_5V tied to VIN for 5V-input applications |
| Switching Frequency | 300kHz fixed (enables predictable EMI filtering and stable loop design without external timing components) |
| Output Voltage Range | 0.8V–5V per channel (set via resistive feedback dividers; enables DDR, core, I/O, and LDO rails) |
| Phase Configuration | 0°/180°/0° out-of-phase PWM (reduces input ripple current by ~30% vs. in-phase, lowering required input capacitance) |
| Early Warning Threshold | VIN falling threshold = 5.30–5.55V (triggers PGOOD/RST for system backup before brownout) |
| Thermal Resistance | θJA = 31°C/W (enables 1.7W dissipation in standard PCB layout; θJC = 3°C/W for heatsink attachment) |
| Protection Features | UVLO (4.25–4.50V on VCC_5V), OV (118% of setpoint), OC (via OCSET pins), OT (150°C shutdown with 20°C hysteresis) |
Pinout & Package
ISL9440IRZ is housed in a thermally enhanced 32-lead 5mm × 5mm QFN package (Pb-free, RoHS-compliant, moisture sensitivity level MSL3). Exposed thermal pad must be soldered to PCB ground plane for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PHASE1–3 | Switch node connection point | Drives high-side MOSFET source / low-side MOSFET drain / inductor junction; critical for boot capacitor charging and voltage stress rating |
| BOOT1–3 | Bootstrap supply input | Connects to flying capacitor; internal diode eliminates need for external bootstrap diode-reducing BOM count and layout area |
| UGATE1–3 | High-side gate driver output | Delivers 800mA/800mA/400mA peak sink-source current; supports fast turn-on of N-channel MOSFETs up to 15nC gate charge |
| LGATE1–3 | Low-side gate driver output | Supplied from VCC_5V; 2A sink capability ensures robust turn-off under heavy load transients |
| FB1–3, LDOFB | Feedback voltage input | Monitors output via resistor divider; sets regulated voltage using 0.8V internal reference with ±1% accuracy over temperature |
| ISEN1–3 | Current sense input | Measures rDS(ON) voltage drop across low-side FET-eliminates current-sense resistor and associated power loss |
| EN1–3 | Independent enable input | Logic-high (>2.0V) enables corresponding regulator; allows precise power-up/down sequencing without external timers |
| PGOOD | Open-drain status output | Asserts low if any PWM output deviates >10%, LDO output <75% nominal, or VIN <5.55V-enables system-level fault detection |
| RST | Reset pulse output | Deasserts low 5.5µs after PGOOD falls; provides synchronized reset signal for microcontrollers or FPGAs |
| VIN | Main power input | Primary supply for internal circuitry and gate drivers; powers VCC_5V LDO when >5.6V; monitored for early warning |
| VCC_5V | Internal 5V LDO output | Supplies bias for all controllers, gate drivers, and external boot capacitors; requires ≥4.7µF ceramic decoupling |
| SGND / PGND | Signal / power ground | SGND is small-signal reference; PGND carries high-current return paths-separate routing prevents noise coupling into FB/ISEN |
Key Features
| Feature | Design Value |
|---|---|
| Triple out-of-phase PWM controllers | Reduces input ripple current by distributing switching events-lowers required input capacitance and improves EMI signature |
| Integrated early warning & reset | Provides deterministic system response to input brownout: PGOOD pulls low at VIN ≤5.55V, RST follows within 5.5µs (typ) |
| rDS(ON)-based current sensing | Eliminates discrete current-sense resistor-reducing cost, board space, and conduction losses in high-current rails |
| Internal loop compensation | Enables stable operation with minimal external components-no compensation network required for typical 2.5V/6A or 1.5V/6A designs |
| Adaptive shoot-through protection | Dynamically adjusts dead-time based on real gate waveforms-prevents cross-conduction across MOSFET pairs without fixed timing overhead |
| Independent EN inputs & soft-start | Supports flexible power sequencing (e.g., core before I/O) and prevents inrush current-soft-start period fixed at 1.7ms (typ) |
Applications
| Cable Modem Power Supply | Voice over IP Gateway |
|---|---|
Use Scenario: Powers multiple voltage rails (1.5V CPU core, 2.5V memory, 5V PHY, 3.3V LDO) from single 12V input in compact, fanless enclosure. IC Role / Device Role / Timing Role: Quad-output PMIC providing synchronized, sequenced, and protected DC-DC conversion with early brownout detection. Use Value: Out-of-phase PWM reduces input ripple by 30%, allowing smaller 330µF input capacitor instead of parallel 4×100µF array-saving 22mm² PCB area. |
Use Scenario: Delivers isolated, sequenced power to DSP, Ethernet PHY, and USB controller in residential VoIP gateway with strict thermal limits. IC Role / Device Role / Timing Role: Central power controller managing rail enable timing, PGOOD monitoring, and reset coordination across subsystems. Use Value: Independent EN1–EN3 pins enable precise startup order (e.g., 5V PHY before 1.5V DSP), preventing latch-up during cold start. |
| Satellite Set-Top Box | Network-Attached Storage |
Use Scenario: Supplies 1.2V SoC core, 1.8V DDR interface, 3.3V tuner, and 5V USB from 12V wall adapter in thermally constrained metal chassis. IC Role / Device Role / Timing Role: Multi-rail power manager with thermal shutdown (150°C) and input UVLO to prevent erratic behavior during AC line sag. Use Value: Early warning function triggers data flush to flash storage when VIN drops below 5.55V-preventing filesystem corruption during brief brownouts. |
Use Scenario: Powers dual-core ARM processor, SATA controller, and 3.3V fan controller in 2-bay NAS unit requiring high reliability and low standby power. IC Role / Device Role / Timing Role: Primary power controller with shutdown current <100µA and independent rail disable for selective subsystem sleep. Use Value: Internal 5V LDO (VCC_5V) supplies gate drivers and boot circuits-eliminating need for external 5V rail and reducing component count by 3. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multi-rail DC-DC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISL9440AIRZ | 600kHz switching frequency (vs. 300kHz); same pinout, early warning, and feature set | Better suited for space-constrained designs requiring smaller inductors (e.g., 1.2µH vs. 2.2µH at 300kHz) | Select ISL9440AIRZ when higher frequency enables smaller magnetics and lower output ripple; verify thermal margin due to increased switching loss. |
| ISL9441IRZ | No early warning or RST function; identical 300kHz PWM architecture and pinout | Targeted for 5V-input systems where VIN tied to VCC_5V eliminates early warning conflict | Choose ISL9441IRZ for cost-sensitive 5V-only applications where brownout signaling is handled externally. |
Compared with ISL9440IRZ, ISL9440AIRZ offers higher switching frequency for compact magnetics but increases gate drive losses, while ISL9441IRZ removes early warning to simplify 5V-input use-neither is pin-compatible drop-in replacements but share identical footprint and basic control functionality.
Availability
ISL9440IRZ is available at Aetrix Electronics and suitable for cable modems, VoIP gateways, satellite set-top boxes, and industrial embedded systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for ISL9440IRZ 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 technical and manufacturing continuity for legacy Intersil power management products including the ISL9440 family.
The ISL9440IRZ belongs to Renesas' multi-output synchronous buck controller product line, engineered specifically for cost-sensitive, space-constrained home connectivity and broadband infrastructure applications requiring high integration and reliable rail sequencing.
FAQ
What is the primary function of the ISL9440IRZ?
The ISL9440IRZ is a quad-output power management IC integrating three synchronous buck PWM controllers and one linear regulator controller. It delivers independently programmable, sequenced, and protected DC-DC conversion for multi-rail systems. Its 180° out-of-phase PWM operation, early warning function, and internal 5V LDO make it ideal for cable modems, VoIP gateways, and set-top boxes where input ripple reduction and brownout resilience are critical. The ISL9440IRZ replaces discrete controllers and reduces total solution size and component count.
Does the ISL9440IRZ require external compensation components?
No, the ISL9440IRZ uses internal loop compensation for all three PWM controllers, eliminating the need for external Type-II or Type-III compensation networks. This simplifies design, reduces BOM count, and improves consistency across production units. The internal compensation is optimized for typical output capacitor ESR and inductor values used in 1.5V/6A and 2.5V/6A applications. Designers still select external output filter components (inductors, capacitors) per application requirements, but no RC or op-amp compensation is needed for stable operation.
How does the early warning function work on the ISL9440IRZ?
The ISL9440IRZ monitors the VIN pin voltage and asserts PGOOD low when it falls below 5.55V (typical falling threshold), signaling an impending brownout. After PGOOD transitions low, the RST pin pulls low within 5.5µs (typical delay), providing a synchronized reset signal to downstream logic. This sequence gives the system time to back up critical data before power collapse. The ISL9440IRZ early warning is active only when VIN powers the device directly (5.6V–24V range); it is disabled when VCC_5V is used as the primary supply.
Can the ISL9440IRZ drive high-side N-channel MOSFETs without external bootstrap diodes?
Yes, the ISL9440IRZ integrates bootstrap diodes on BOOT1–3 pins, enabling direct connection of the flying capacitor between BOOTx and PHASEx without external diodes. This reduces component count, PCB area, and potential failure points. The internal diode charges the boot capacitor during the low-side FET conduction phase, ensuring sufficient gate drive voltage (≥5V) for the high-side N-channel MOSFET even at high duty cycles. External bootstrap capacitors (typically 0.1µF ceramic) are still required and must be placed close to the BOOT/PHASE pins.
What thermal considerations apply to the ISL9440IRZ in continuous operation?
The ISL9440IRZ has θJA = 31°C/W and θJC = 3°C/W. In standard 2-layer PCB layouts with 1oz copper and 2cm² exposed thermal pad connected to internal ground planes, it supports ~1.7W total dissipation at +85°C ambient. Key thermal design practices include soldering the exposed pad fully to PCB ground, using ≥4 thermal vias under the pad, placing the 4.7µF VCC_5V decoupling capacitor adjacent to the pin, and avoiding high-power components nearby. At 24V input and full load, power dissipation in the internal 5V LDO increases-verify junction temperature stays below 150°C using the provided thermal resistance values.
ISL9440IRZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 32-VFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Obsolete
- Topology:
- Step-Down (Buck) Synchronous (3), Linear (LDO) (1)
- Number of Outputs:
- 4
- Frequency - Switching:
- 300kHz
- 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)
ISL9440IRZ FAQ
1.How can I place an order for ISL9440IRZ through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL9440IRZ 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 ISL9440IRZ reliable?
The price and inventory of ISL9440IRZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL9440IRZ is usually 5 days.
3.What payment methods are accepted for ISL9440IRZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL9440IRZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL9440IRZ?
ISL9440IRZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL9440IRZ 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 ISL9440IRZ?
For technical support, including ISL9440IRZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL9440IRZ requirements.
6.How does Aetrix verify that ISL9440IRZ is sourced from the original manufacturer or authorized distributors?
All ISL9440IRZ 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 ISL9440IRZ meets industry standards.
7.What is the process for return or replacement of ISL9440IRZ?
All ISL9440IRZ units undergo pre-shipment inspection (PSI). If there is an issue with ISL9440IRZ, 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 ISL9440IRZ part is unused and in its original packaging.
Return procedure for ISL9440IRZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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