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Renesas ISL9440IRZ-T
- Part No.:
- ISL9440IRZ-T
- Manufacturer:
- Renesas
- Category:
- Voltage Regulators - Linear + Switching
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
ISL9440IRZ-T.pdf
- Description:
- IC REG QUAD BUCK/LNR SYNC 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,752
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Product details
Overview
ISL9440IRZ-T from Renesas Electronics (formerly Intersil) is a quad-output power management IC integrating three 300kHz synchronous buck PWM controllers and one LDO linear controller, designed for multi-rail DC/DC conversion in set-top boxes, VoIP gateways, and cable modems. It delivers adjustable outputs down to 0.8V, employs 180° out-of-phase switching across two PWM channels to reduce input RMS current, and includes integrated UV/OV/OC/OT protection, internal soft-start, and early warning functionality on VIN.
For engineers reviewing the ISL9440IRZ-T datasheet, ISL9440IRZ-T pinout, ISL9440IRZ-T application, or ISL9440IRZ-T equivalent, key selection considerations include its fixed 300kHz switching frequency, 5mm×5mm 32-pin QFN package, independent enable inputs for rail sequencing, no external current sense resistor (uses rDS(ON) sensing), and early warning logic output triggered at VIN < 5.55V (typ).
Technical Context
The ISL9440IRZ-T implements current-mode control with voltage feed-forward for robust line regulation and simplified loop compensation. Its three PWM channels operate with 0°/180°/0° phase alignment-PWM1 and PWM2 are synchronized 180° out-of-phase to minimize input capacitor ripple, while PWM3 remains in-phase with PWM1.
It integrates adaptive shoot-through protection with 20ns dead-time, internal bootstrap diodes, and an internal 5V LDO (VCC_5V) capable of sourcing ≥60mA. The device uses ISEN pins for rDS(ON)-based current sensing and supports independent FB-based output voltage programming per channel.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 300 kHz (fixed); enables predictable EMI profile and simplifies filter design for 12V input systems. |
| Output Configuration | Three synchronous buck PWMs + one LDO linear controller; supports four independent regulated rails (e.g., 1.5V/2.5V/5V/3.3V). |
| Input Voltage Range | 5.6V to 24V on VIN pin; supports wide-range industrial and broadband power supplies. |
| Early Warning Threshold | VIN falling threshold = 5.30–5.55V (typ 5.55V); asserts PGOOD low to signal impending brownout before system failure. |
| Overcurrent Protection | Programmable via OCSET resistors; uses ISEN pins to monitor lower MOSFET rDS(ON), eliminating external sense resistor. |
| Package | 32-lead 5mm × 5mm QFN (L32.5x5B); exposes thermal pad for efficient heat dissipation in high-current applications. |
| Operating Temperature | –40°C to +85°C; qualified for industrial and consumer broadband equipment environments. |
Pinout & Package
ISL9440IRZ-T is housed in a 32-lead, 5mm × 5mm QFN package with exposed thermal pad (PKG DWG # L32.5x5B). Pin 1 is located at top-left corner per standard QFN orientation (see datasheet Fig. 1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PHASE1–PHASE3 (Pins 32, 25, 19) | Switch node connection | Connects to junction of high-side MOSFET source, inductor, and low-side MOSFET drain; critical for boot capacitor charging and gate drive timing. |
| BOOT1–BOOT3 (Pins 31, 26, 20) | High-side gate driver bias | Supplies floating 5V bias to UGATE drivers via external boot capacitors; integrated bootstrap diodes reduce BOM count. |
| UGATE1–UGATE3 (Pins 30, 27, 21) | High-side N-MOSFET gate drive | Delivers peak sink/source currents up to 2A/800mA (Ch1/Ch2) and 400mA (Ch3); supports fast turn-on/turn-off with 18ns rise/fall times. |
| LGATE1–LGATE3 (Pins 29, 28, 22) | Low-side N-MOSFET gate drive | Driven from internal 5V LDO; provides 2A sink / 800mA source (Ch1/Ch2), 400mA sink/source (Ch3); enables efficient synchronous rectification. |
| ISEN1–ISEN3 (Pins 1, 24, 18) | Current sense input | Monitors voltage drop across low-side MOSFET rDS(ON) for cycle-by-cycle overcurrent protection and current-mode control. |
| FB1–FB3, LDOFB (Pins 6, 13, 16, 10) | Feedback reference input | Sets output voltage via resistor divider; internal 0.8V reference enables precise regulation from 0.8V to >VIN × DMAX. |
| EN1–EN3 (Pins 5, 14, 17) | Independent enable control | Logic-high enables respective PWM channel; allows flexible power-up/down sequencing without external controllers. |
| PGOOD (Pin 2) | Open-drain status output | Asserts low if any PWM output deviates >±10%, LDO output drops <75% nominal, or VIN falls below 5.55V (early warning). |
| RST (Pin 8) | Reset pulse output | Drives low 5.5µs (typ) after PGOOD falls; provides hardware reset signal for microcontrollers or FPGAs during brownout. |
| VIN (Pin 4) | Main power input | Primary supply for internal circuitry and gate drivers; powers VCC_5V LDO when VIN ≥ 5.6V. |
| VCC_5V (Pin 3) | Internal 5V LDO output | Supplies bias to IC core, low-side drivers, and boot circuits; requires ≥4.7µF ceramic decoupling close to pin. |
| SGND (Pin 11) | Small-signal ground | Reference for all analog blocks (FB, ISEN, references); must be routed separately from PGND to avoid noise coupling. |
| PGND (Pin 23) | Power ground return | Return path for low-side gate drivers and high-current paths; connects to sources of low-side MOSFETs and input capacitor negatives. |
Key Features
| Feature | Design Value |
|---|---|
| 180° out-of-phase PWM switching | Reduces input ripple current by ~30% vs. in-phase operation, enabling smaller input bulk capacitors and lower EMI filtering cost. |
| rDS(ON)-based current sensing | Eliminates need for external current sense resistors, reducing power loss, board area, and BOM cost in high-current (>6A) rails. |
| Integrated early warning function | Generates preemptive PGOOD/RST assertion at VIN < 5.55V (typ), allowing host system to initiate controlled data backup before shutdown. |
| Independent enable inputs (EN1–EN3) | Enables precise power rail sequencing without external logic or microcontroller intervention-critical for FPGA and SoC supply ordering. |
| Adaptive shoot-through protection | Monitors real-time gate waveforms to dynamically adjust dead time, preventing cross-conduction across all load and temperature conditions. |
| Internal 5V LDO with 60mA capability | Powers internal circuitry and boot capacitors directly; eliminates need for external bias supply in most 12V-input designs. |
Applications
| Satellite Set-Top Box Power | Cable Modem Multi-Rail Supply |
|---|---|
Use Scenario: Powers SoC core (1.2V), memory interface (1.5V), tuner (3.3V), and USB PHY (5V) from single 12V input in compact enclosure. IC Role / Device Role / Timing Role: Quad-output PMIC providing sequenced, regulated rails with PGOOD monitoring and early brownout warning. Use Value: Reduces input capacitance by 40% via 180° out-of-phase switching, lowering total solution size and cost versus discrete controllers. | Use Scenario: Supplies CPU (1.1V), DDR3 (1.5V), Ethernet PHY (3.3V), and LDO-regulated 5V USB port in DOCSIS 3.1-compliant modem. IC Role / Device Role / Timing Role: Synchronous buck controller with independent EN pins enabling strict power-up sequence per IEEE 802.3 specification. Use Value: Internal rDS(ON) current sensing avoids 2W+ losses from external shunts, improving thermal margin in sealed plastic housing. |
| Voice over IP Gateway | Industrial NAS Controller Board |
Use Scenario: Delivers DSP core (1.8V), codec (3.3V), PoE interface (5V), and isolated LDO (3.3V) in fanless VoIP gateway with thermal constraints. IC Role / Device Role / Timing Role: Triple-buck + LDO controller with integrated thermal shutdown (150°C) and overvoltage protection (118% trip). Use Value: Early warning output triggers firmware-initiated graceful shutdown before VIN collapse, preserving call state and configuration. | Use Scenario: Powers ARM-based storage controller (1.0V), SATA PHY (1.2V), DDR4 (1.2V), and 3.3V I/O in enterprise-grade NAS with 24/7 operation. IC Role / Device Role / Timing Role: High-reliability quad-output regulator with cycle-by-cycle current limiting and 200ms PGOOD delay for stable boot sequence. Use Value: Independent EN1–EN3 pins allow staggered rail activation to limit inrush current, preventing tripping of upstream 12V supply. |
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 |
|---|---|---|---|
| ISL9440AIRZ-T | 600kHz switching frequency (vs. 300kHz); identical pinout, early warning, and feature set. | Better suited for space-constrained designs requiring smaller inductors/capacitors; higher switching loss at full load. | Select ISL9440AIRZ-T when board area is critical and thermal headroom permits higher-frequency operation. |
| ISL9441IRZ-T | No early warning function; same 300kHz frequency and pinout; lacks RST assertion tied to VIN monitoring. | Appropriate for 5V-input systems where VIN = VCC_5V; avoids false PGOOD drops during nominal 5V operation. | Choose ISL9441IRZ-T for 5V ±10% input applications to eliminate early warning interference with normal regulation. |
Compared with ISL9440IRZ-T, ISL9440AIRZ-T offers higher switching frequency for smaller magnetics but increased gate drive loss, while ISL9441IRZ-T removes VIN monitoring to simplify 5V-only designs-neither is pin-compatible drop-in replacements due to functional differences in early warning and RST behavior.
Availability
ISL9440IRZ-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 ISL9440IRZ-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 Corporation is a global semiconductor leader delivering trusted embedded design innovation, with origins in Intersil's high-performance analog and power management portfolio.
The ISL9440IRZ-T belongs to Renesas' multi-rail power controller product line, engineered specifically for broadband connectivity equipment requiring tightly sequenced, high-efficiency DC/DC conversion with system-level fault signaling.
FAQ
What is the switching frequency of the ISL9440IRZ-T?
The ISL9440IRZ-T operates at a fixed 300kHz switching frequency across all three PWM channels. This frequency is factory-trimmed and not user-adjustable. It balances efficiency, magnetic component size, and EMI performance for 12V-input broadband applications. The ISL9440IRZ-T datasheet specifies typical frequency tolerance of ±13% (260–340kHz) over temperature and line variations.
Does the ISL9440IRZ-T require external current sense resistors?
No, the ISL9440IRZ-T does not require external current sense resistors. It implements rDS(ON)-based current sensing using the voltage drop across the low-side MOSFET's on-resistance, monitored via ISEN1–ISEN3 pins. This eliminates power loss and board area associated with shunt resistors while maintaining accurate cycle-by-cycle overcurrent protection.
How does the early warning function work on the ISL9440IRZ-T?
The ISL9440IRZ-T monitors VIN voltage continuously. When VIN falls below 5.30–5.55V (typ 5.55V), the PGOOD pin is pulled low to signal impending brownout. After 5.5µs (typ), the RST pin also goes low-providing a hardware reset trigger. This allows host systems to save critical data before complete power loss. The ISL9440IRZ-T datasheet confirms this behavior is active only on ISL9440 and ISL9440A variants.
What is the purpose of the G4 pin on the ISL9440IRZ-T?
The G4 pin on the ISL9440IRZ-T is the open-drain output of the integrated linear regulator controller. It drives the base/gate of an external PNP transistor or PFET used to implement the fourth regulated output rail (e.g., 3.3V LDO). Unlike the PWM outputs, G4 provides ultra-low-dropout regulation with programmable voltage via feedback to LDOFB (Pin 10).
Can the ISL9440IRZ-T operate from a 5V input supply?
Yes, the ISL9440IRZ-T can operate from a 5V ±10% input, but only when VIN is externally connected to VCC_5V (Pin 4 → Pin 3). In this configuration, the internal 5V LDO is disabled, and the device is powered directly from the 5V rail. Note that ISL9440IRZ-T's early warning function will falsely assert PGOOD/RST under this condition-use ISL9441IRZ-T instead for true 5V-only applications.
ISL9440IRZ-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 32-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- 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-T FAQ
1.How can I place an order for ISL9440IRZ-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL9440IRZ-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 ISL9440IRZ-T reliable?
The price and inventory of ISL9440IRZ-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL9440IRZ-T is usually 5 days.
3.What payment methods are accepted for ISL9440IRZ-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL9440IRZ-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL9440IRZ-T?
ISL9440IRZ-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL9440IRZ-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 ISL9440IRZ-T?
For technical support, including ISL9440IRZ-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL9440IRZ-T requirements.
6.How does Aetrix verify that ISL9440IRZ-T is sourced from the original manufacturer or authorized distributors?
All ISL9440IRZ-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 ISL9440IRZ-T meets industry standards.
7.What is the process for return or replacement of ISL9440IRZ-T?
All ISL9440IRZ-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL9440IRZ-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 ISL9440IRZ-T part is unused and in its original packaging.
Return procedure for ISL9440IRZ-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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