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Renesas ISL85418FRZ
- Part No.:
- ISL85418FRZ
- Manufacturer:
- Renesas
- Package:
- 12-VFDFN Exposed Pad
- Datasheet:
-
ISL85418FRZ.pdf
- Description:
- IC REG BUCK ADJ 800MA 12DFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,490
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Product details
Overview
ISL85418FRZ from Renesas Electronics is a wide-input synchronous buck regulator delivering up to 800mA output current with 3V–40V input range, 500kHz default switching frequency, integrated high-side/low-side NMOS FETs, and PFM/PWM light-load mode selection-designed for industrial power rails and battery-powered instrumentation.
For engineers reviewing the ISL85418FRZ datasheet, ISL85418FRZ pinout, ISL85418FRZ application, or ISL85418FRZ equivalent, key selection criteria include its internal compensation option, 12-lead DFN package with exposed thermal pad, -40°C to +125°C operating range, and programmable frequency via FS pin resistor.
Technical Context
The ISL85418FRZ implements peak current-mode PWM control with 450mV/T slope compensation and 500mV/A current sense gain, enabling fast transient response and inherent pulse-by-pulse overcurrent protection. Its error amplifier supports both internal (50µA/V) and external (230µA/V) transconductance configurations.
Light-load operation is managed via SYNC pin logic: tied low enables automatic PFM/PWM transition, while tied high forces continuous PWM mode. The device integrates a 5V bias LDO (VCC), power-good monitoring with ±6% FB window, and thermal shutdown at 150°C with 20°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3V to 40V - supports direct connection to 12V/24V industrial buses and 3S–10S Li-ion battery packs. |
| Output Current | 800mA continuous - sufficient for powering microcontrollers, sensors, and communication ICs in compact systems. |
| Switching Frequency | Default 500kHz; adjustable 300kHz–2MHz via FS pin resistor - enables optimization of size vs. efficiency trade-offs. |
| Integrated FETs | High-side RDS(on) = 350mΩ, low-side RDS(on) = 130mΩ - eliminates need for external MOSFETs and gate drivers. |
| Compensation | Internal (COMP tied to VCC) or external RC network - reduces BOM count or allows fine-tuned loop stability. |
| Operating Temp | -40°C to +125°C junction - qualified for under-hood automotive auxiliary rails and industrial control cabinets. |
| Protection | Overcurrent (1.2A peak limit), overtemperature (150°C shutdown), negative current limit (-0.6A), boot UVLO - ensures robust fault recovery without external circuitry. |
Pinout & Package
The ISL85418FRZ is housed in a RoHS-compliant, thermally enhanced 4mm × 3mm 12-lead DFN package (L12.4x3) with an exposed EPAD for efficient heat dissipation. The package supports reflow per JEDEC J-STD-020 and has θJA = 42°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SS | Soft-start timing control | Capacitor-to-ground sets ramp time; tie to VCC for fixed 2ms internal soft-start. |
| SYNC | Mode selection & synchronization input | Logic level selects PFM/PWM; accepts external clock up to 2MHz for multi-rail synchronization. |
| BOOT | Bootstrap supply for high-side gate driver | Requires 100nF ceramic capacitor to PHASE; enables NMOS high-side switch operation. |
| VIN | Main power input | Supplies power stage and internal LDO; requires ≥4.7µF local ceramic decoupling. |
| PHASE | Switch node | Connects to external inductor; carries high di/dt switching current and must be routed with minimal loop area. |
| PGND | Power ground return | Low-impedance path for inductor current; must connect directly to system GND plane. |
| EN | Enable control | Active-high; >1V enables regulator; tie to VIN for automatic startup. |
| PG | Open-drain power-good indicator | Pulled low during soft-start or FB out-of-window; includes 5MΩ internal pull-up. |
| VCC | Bias LDO output | 5V ±0.6V regulated supply; decouple with 1µF ceramic to PGND. |
| FB | Feedback voltage sensing | Inverting input of error amplifier; monitors output via resistor divider (0.6V reference). |
| COMP | Error amplifier output | Tie to VCC for internal compensation; add RC network to GND for external loop tuning. |
| FS | Frequency selection | Tie to VCC for 500kHz; resistor-to-GND sets frequency from 300kHz to 2MHz. |
Key Features
| Feature | Design Value |
|---|---|
| Wide 3V–40V input range | Enables single-buck solution across diverse power sources including automotive batteries, PoE-derived rails, and industrial 24V/48V supplies. |
| Integrated NMOS FETs | Eliminates four external components (two MOSFETs, two gate drivers), reducing PCB area and layout complexity. |
| Selectable PFM/PWM mode | Extends battery runtime in portable devices by maintaining >85% efficiency at 10mA load (VIN=12V, VOUT=3.3V). |
| Internal or external compensation | Accelerates design cycle: internal option achieves stable regulation with zero external compensation parts. |
| Power-good and enable functions | Supports sequenced power-up in multi-rail systems and enables host-controlled brown-out detection. |
Applications
| Industrial Control | Medical Devices |
|---|---|
Use Scenario: Powering PLC I/O modules and sensor signal conditioning circuits in factory automation cabinets. IC Role / Device Role / Timing Role: Primary DC-DC converter generating isolated 3.3V/5V rails from unregulated 24V field bus. Use Value: Withstands 40V transients and operates reliably at +85°C ambient, eliminating need for derating or heatsinks. | Use Scenario: Supplying analog front-end and low-power MCU in portable ultrasound probes and patient monitors. IC Role / Device Role / Timing Role: Efficient step-down regulator converting 3S Li-ion (9–12.6V) to 3.3V for noise-sensitive analog circuitry. Use Value: PFM mode delivers >88% efficiency at 20mA load, extending probe battery life beyond 8 hours. |
| Portable Instrumentation | Distributed Power Supplies |
Use Scenario: Providing regulated 5V and 3.3V outputs in handheld multimeters and thermal imagers. IC Role / Device Role / Timing Role: Compact, high-efficiency buck converter replacing discrete solutions in space-constrained enclosures. Use Value: 4mm×3mm DFN package fits within 12mm² footprint, enabling integration into sub-50g handheld units. | Use Scenario: Local point-of-load conversion in rack-mounted servers and telecom line cards. IC Role / Device Role / Timing Role: Secondary regulator deriving 1.8V/3.3V from intermediate 5V or 12V backplane rails. Use Value: Synchronization capability (via SYNC pin) enables phase-aligned switching across multiple ISL85418FRZ units, reducing input ripple current. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR36520RNXR | 2A output current, 3V–65V input, 1.2MHz fixed frequency, no PFM mode, different pinout. | Higher current and wider VIN suit harsher environments but require redesign for thermal and layout. | Select when >800mA load or >40V transients are expected; not drop-in compatible. |
| TPS54202HDDCR | 2A output, 4.5V–28V input, 500kHz/2.1MHz selectable, integrated compensation, smaller 3mm×2mm package. | Limited to ≤28V input; lacks PFM mode and sync capability; optimized for cost-sensitive consumer apps. | Choose for lower-cost, lower-voltage designs where light-load efficiency is secondary. |
Compared with LMR36520RNXR and TPS54202HDDCR, the ISL85418FRZ uniquely balances 40V max input, true PFM efficiency down to 10mA, and 12-pin DFN thermal performance-making it optimal for industrial and medical applications requiring reliability across wide temperature and input ranges.
Availability
ISL85418FRZ is available at Aetrix Electronics and suitable for industrial control, medical devices, and portable instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for ISL85418FRZ 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 delivering microcontrollers, analog power, and SoC solutions for automotive, industrial, and enterprise markets.
The ISL85418FRZ belongs to Renesas' ISL85xx family of wide-VIN synchronous buck regulators, engineered specifically for high-reliability industrial and medical power conversion where input voltage variation, thermal stress, and long product lifecycles are critical.
FAQ
What is the maximum input voltage rating for the ISL85418FRZ?
The ISL85418FRZ has an absolute maximum input voltage rating of +43V, with recommended operating range from 3V to 40V. Operation above 40V risks exceeding safe operating area limits and may trigger overvoltage protection on internal circuitry. For sustained 40V operation, ensure adequate thermal management using the exposed EPAD and maintain ambient temperature below +85°C.
Does the ISL85418FRZ support external frequency synchronization?
Yes, the ISL85418FRZ supports external synchronization via the SYNC pin. When driven with a clean TTL/CMOS clock signal between 300kHz and 2MHz, the device locks its switching frequency to the external source on the rising edge. The external clock must exceed the programmed internal frequency; for example, a 1MHz SYNC signal will override a 500kHz FS setting. This feature enables EMI reduction through frequency dithering or multi-phase interleaving.
How does the ISL85418FRZ handle light-load efficiency optimization?
The ISL85418FRZ uses Pulse-Frequency Modulation (PFM) mode to maintain high efficiency at light loads. When the SYNC pin is pulled low or left floating (with internal 5MΩ pull-down), the controller automatically transitions from PWM to PFM below ~100mA load. In PFM, switching frequency drops dynamically while maintaining regulation, achieving >85% efficiency at 10mA (VIN=12V, VOUT=3.3V). Forced PWM mode disables this behavior for constant-frequency noise control.
Can the ISL85418FRZ operate with internal compensation only?
Yes, the ISL85418FRZ supports fully internal compensation by connecting the COMP pin directly to VCC. This configuration uses a fixed 50µA/V transconductance and built-in compensation network, eliminating all external compensation components. It delivers stable regulation across the full load and input range for standard output voltages (1.8V–12V) with typical inductors (12–22µH) and output capacitors (22–47µF).
What thermal performance can be expected from the ISL85418FRZ in its DFN package?
The ISL85418FRZ in its 4mm×3mm DFN package achieves θJA = 42°C/W and θJC = 4.5°C/W when mounted on a 4-layer PCB with ≥5 thermal vias under the EPAD. At 800mA output and 24V input, junction temperature rise is approximately 35°C above ambient-well within the +125°C max rating. For continuous 800mA operation at +85°C ambient, derating to 700mA is recommended to maintain <+125°C junction temperature.
ISL85418FRZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 12-VFDFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 34V
- Current - Output:
- 800mA
- Frequency - Switching:
- 500kHz, 300kHz ~ 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 12-DFN (4x3)
ISL85418FRZ FAQ
1.How can I place an order for ISL85418FRZ through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL85418FRZ 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 ISL85418FRZ reliable?
The price and inventory of ISL85418FRZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL85418FRZ is usually 5 days.
3.What payment methods are accepted for ISL85418FRZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL85418FRZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL85418FRZ?
ISL85418FRZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL85418FRZ 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 ISL85418FRZ?
For technical support, including ISL85418FRZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL85418FRZ requirements.
6.How does Aetrix verify that ISL85418FRZ is sourced from the original manufacturer or authorized distributors?
All ISL85418FRZ 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 ISL85418FRZ meets industry standards.
7.What is the process for return or replacement of ISL85418FRZ?
All ISL85418FRZ units undergo pre-shipment inspection (PSI). If there is an issue with ISL85418FRZ, 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 ISL85418FRZ part is unused and in its original packaging.
Return procedure for ISL85418FRZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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