The ISL78235 is a highly efficient, monolithic, synchronous step-down DC/DC converter that can deliver 5A of continuous output current from a 2. 7V to 5. 5V input supply. The device uses peak current mode control architecture to achieve very low duty cycle operation at high frequency with fast transient response and excellent loop stability. The ISL78235 integrates a low ON-resistance P-channel (35mΩ, typical) high-side FET and N-channel (11mΩ, typical) low-side FET to maximize efficiency and minimize external component count. The 100% duty cycle operation allows less than 250mV dropout voltage at 5A output current. The operating frequency of the Pulse-Width Modulator (PWM) is adjustable from 500kHz to 4MHz. The default switching frequency of 2MHz is set by connecting the FS pin high. The ISL78235 can be configured for discontinuous (PFM) or forced continuous (PWM) operation at light load. Forced continuous operation reduces noise and RF interference; discontinuous mode provides higher efficiency by reducing switching losses at light loads. Fault protection is provided by internal hiccup mode current limiting during short-circuit and overcurrent conditions. The device also integrates output overvoltage and over-temperature protections. A power-good monitor indicates when the output is in regulation. The ISL78235 features a 1ms Power-Good (PG) timer at power-up. When in shutdown, the ISL78235 discharges the output capacitor through an internal 100Ω soft-stop switch. Other features include internal fixed or adjustable soft-start and internal/external compensation. The ISL78235 is available in a 3mm x 3mm 16 Ld Thin Quad Flat No-lead (TQFN) Pb-free package and in a 5mmx5mm 16 Ld Wettable Flank Quad Flat No-Lead (WFQFN) package with an exposed pad for improved thermal performance. The ISL78235 is rated to operate across the temperature range of -40°C to +105°C in the 3mmx3mm package and -40°C to +125°C in the 5mmx5mm package.

Features

  • 2.7V to 5.5V input voltage range
  • 2MHz default switching frequency
  • 100ns guaranteed phase minimum on time for wide output regulation
  • Adjustable switching frequency from 500kHz to 4MHz
  • External synchronization from 1MHz to 4MHz
  • Optional PFM mode for light-load efficiency improvement
  • Very low ON-resistance HS/LS switches: 35mΩ/11mΩ
  • Internal 1ms or adjustable external soft-start
  • Soft-stop output discharge during disable
  • OTP, OCP, output OVP, and input UVLO protections
  • 1% reference accuracy over-temperature
  • Up to 95% efficiency
  • AEC-Q100 qualified
  • ISL78233 pinout family allows migration from 3A without PCB change
  • ISL78234 pinout family allows migration from 4A without PCB change
  • ISL78235 pinout family allows migration from 5A without PCB change

Product Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active WFQFN Tube 60
Availability
Active WFQFN Reel 6000
Availability
Active WFQFN Reel 250
Availability
Active TQFN Tube 100
Availability
Active TQFN Reel 6000
Availability
Active TQFN Reel 250
Availability

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
ISL78235 Datasheet Datasheet PDF 2.28 MB
User Guides & Manuals
ISL7823xEVAL2Z User Guide Manual PDF 925 KB
ISL7823xEVAL1Z User Guide Manual PDF 925 KB
Application Notes & White Papers
Powering Automotive Cockpit Electronics White Paper PDF 360 KB
AN1681: Grounding Techniques Application Note PDF 509 KB
AN1684: Nonideality of Ground Application Note PDF 397 KB
Downloads
ISL78235EVAL1Z Design Files Design File ZIP 678 KB
ISL78235EVAL2Z Design Files Design File ZIP 723 KB
Other
ISL78235 iSim:PE Model Schematic SXSCH 232 KB

Software & Tool Pages

Title Type Description Company
iSim:PE Offline Simulation Tool Simulator iSim Personal Edition (iSim:PE) speeds the design cycle and reduces risk early in any project, identifying parts that can be used in current as well as next-generation designs. Renesas

Boards & Kits

Part Number Title Type Company
ISL78233EVAL1Z Automotive Synchronous Buck Regulator Evaluation Board Evaluation Renesas
ISL78233EVAL2Z Automotive Synchronous Buck Regulator Evaluation Board Evaluation Renesas
ISL78234EVAL1Z Automotive Synchronous Buck Regulator Evaluation Board Evaluation Renesas
ISL78234EVAL2Z Automotive Synchronous Buck Regulator Evaluation Board Evaluation Renesas
ISL78235EVAL1Z Automotive Synchronous Buck Regulator Evaluation Board Evaluation Renesas
ISL78235EVAL2Z Automotive Synchronous Buck Regulator Evaluation Board Evaluation Renesas