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Renesas ISL6843IUZ
- Part No.:
- ISL6843IUZ
- Manufacturer:
- Renesas
- Category:
- Power Supply Controllers, Monitors
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
ISL6843IUZ.pdf
- Description:
- IC REG CTRLR BOOST/FLYBACK 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,960
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Product details
Overview
ISL6843IUZ from Renesas Electronics is a single-ended current-mode PWM controller optimized for isolated flyback, boost, and forward power converters. It features 8.4V UVLO start threshold, 100% maximum duty cycle, 1A peak gate drive, 25ns CS-to-OUT propagation delay, and operates across –40°C to +105°C for telecom and industrial DC/DC power supplies.
For engineers reviewing the ISL6843IUZ datasheet, ISL6843IUZ pinout, ISL6843IUZ application, or ISL6843IUZ equivalent, key selection criteria include its 8-pin MSOP package, adjustable 2MHz switching frequency, tight 5.00V ±1.0%/–1.5% reference tolerance over line/load/temperature, and compatibility with peak-current-mode control loop design for fast transient response in isolated regulators.
Technical Context
The ISL6843IUZ implements peak current mode control using an internal 2.5V error amplifier reference and 100mV CS input offset, enabling inherent overcurrent protection and stable operation up to 96% duty cycle. Its oscillator uses RTCT pin with external R/C network to set frequency up to 2MHz while trimming discharge current for accurate deadtime control.
It integrates a high-bandwidth error amplifier (60–90dB open-loop gain), 5V reference with long-term stability of 5mV at +125°C/1000h, and fast 20ns rise/fall times into 1nF load - all within a BiCMOS process that achieves 60µA startup current and 4.1mA typical operating supply current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| UVLO Start Threshold | 8.4V ±0.6V - ensures reliable startup above brownout in 9–16V input systems |
| Max Duty Cycle | 96% - supports high-voltage-ratio flyback designs without external clamp |
| Gate Drive Peak Current | 1.0A - directly drives medium-size MOSFETs without buffer stage |
| CS-to-OUT Delay | 25ns - enables precise cycle-by-cycle current limiting at high frequencies |
| VREF Accuracy | 5.000V ±1.0%/–1.5% over line/load/temp - reduces output voltage drift in precision regulation |
| Switching Frequency Range | Up to 2MHz - allows compact magnetics and faster transient response |
| Startup Current | 60µA - minimizes auxiliary supply losses in high-efficiency offline adapters |
Pinout & Package
ISL6843IUZ is housed in an 8-lead MSOP package (M8.118), 3.0mm × 4.9mm footprint, 0.65mm pitch, with exposed pad not electrically connected. Thermal resistance θJA = 165°C/W (JEDEC standard board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 COMP | Error amplifier output / PWM comparator input | Connects compensation network between COMP and FB; sets loop stability and bandwidth |
| 2 FB | Inverting input of error amplifier | Receives scaled output voltage feedback; referenced to internal 2.514V bandgap |
| 3 CS | Current sense input | Accepts 0–1.0V signal with 100mV offset; triggers PWM shutdown on overcurrent |
| 4 RTCT | Oscillator timing control | RC network here sets frequency and max duty cycle; discharge current trimmed for accuracy |
| 5 GND | Power and signal reference ground | Must be low-impedance plane; separate high-di/dt return path required for stability |
| 6 OUT | MOSFET gate driver output | 1A sink/source capability; 20ns rise/fall into 1nF; requires external series resistor for damping |
| 7 VDD | Supply input | Operates from 9–16V; bypass with 0.1–3.3µF ceramic capacitor near pins |
| 8 VREF | 5.00V reference output | ±1.0%/–1.5% tolerance; used for feedback divider bias, sensing, or auxiliary rail |
Key Features
| Feature | Design Value |
|---|---|
| Peak current mode control | Enables inherent cycle-by-cycle overcurrent protection and fast load transient response without slope compensation below 50% duty |
| Trimmed RTCT discharge current | Ensures accurate maximum duty cycle and deadtime control across temperature and unit variation |
| High-bandwidth error amplifier | 60–90dB open-loop gain supports wide bandwidth compensation for tight output regulation |
| Tight VREF tolerance | ±1.0%/–1.5% over line/load/temperature maintains <±1% output voltage accuracy in closed-loop systems |
| Low startup current | 60µA enables efficient auxiliary supply design in high-input-voltage flyback converters |
Applications
| Telecom Power Supply | Industrial Isolated DC/DC |
|---|---|
Use Scenario: 48V input dual-output flyback converter powering +1.8V and +3.3V rails in telecom shelf management units. IC Role / Device Role / Timing Role: Primary-side PWM controller implementing peak current mode control with external MOSFET drive. Use Value: 25ns CS-to-OUT delay and 96% duty cycle enable high-efficiency, tightly regulated outputs under dynamic load steps. | Use Scenario: 24–48V input isolated buck-derived regulator for PLC I/O module power. IC Role / Device Role / Timing Role: Fixed-frequency current-mode controller managing transformer reset and output regulation via optocoupler feedback. Use Value: 5.00V ±1.0%/–1.5% VREF and high PSRR (>60dB) ensure stable feedback despite noisy industrial bus conditions. |
| PC Server VRM | Boost PFC Front-End |
Use Scenario: Auxiliary 12V-to-3.3V isolated flyback supplying control logic and sensors in server motherboard power tree. IC Role / Device Role / Timing Role: Secondary-side synchronized rectifier controller interface via opto-coupled FB signal. Use Value: 1A gate drive and 20ns edge speeds reduce conduction loss and EMI in high-density server PCB layouts. | Use Scenario: Non-isolated boost converter for 100W active PFC stage in industrial AC/DC power supply. IC Role / Device Role / Timing Role: Current-mode PWM modulator regulating inductor current to shape sinusoidal input current. Use Value: Adjustable 2MHz frequency allows small boost inductor and low-profile layout while maintaining THD compliance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PWM controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC28C43DR | 7.6V UVLO start, 100% duty cycle, 1A drive, but 500kHz max frequency and no VREF output | Lacks integrated 5V reference; requires external reference for precision feedback | Preferred where cost sensitivity outweighs need for VREF or >500kHz operation |
| TL3845P | 8.5V UVLO start, 50% max duty cycle, 200mA drive, no VREF output, higher 1mA startup current | Not suitable for high-duty-cycle flyback or boost; limited gate drive strength | Only viable for low-power, non-isolated applications with strict legacy pin compatibility needs |
Compared with UCC28C43DR and TL3845P, ISL6843IUZ delivers superior high-frequency capability (up to 2MHz), integrated precision VREF, and lower startup current - making it optimal for space-constrained, high-efficiency isolated converters requiring tight output regulation and fast transient immunity.
Availability
ISL6843IUZ is available at Aetrix Electronics and suitable for telecom power supplies, industrial isolated DC/DC converters, PC server VRMs, and boost PFC front-ends requiring stable component supply and extended temperature operation.
Supply support for ISL6843IUZ 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, infrastructure, and IoT applications.
The ISL6843IUZ belongs to Renesas' ISL684x family of current-mode PWM controllers, designed specifically for high-performance, low-cost isolated and non-isolated switch-mode power supplies demanding fast transient response and robust overcurrent protection.
FAQ
What is the UVLO start and stop threshold for ISL6843IUZ?
The ISL6843IUZ has a UVLO start threshold of 8.4V (min 7.8V, max 9.0V) and stop threshold of 7.2V (min 6.7V, max 7.7V), providing 0.8V hysteresis. This ensures reliable turn-on after input stabilization and prevents oscillatory restart during brownout conditions in 9–16V input power systems. The thresholds are factory-trimmed and specified across –40°C to +105°C.
Does ISL6843IUZ provide an internal voltage reference, and what is its accuracy?
Yes, ISL6843IUZ provides a 5.000V internal reference (VREF pin) with ±1.0%/–1.5% tolerance over line, load, and temperature (–40°C to +105°C), and long-term stability of 5mV after 1000 hours at +125°C. This reference is used for feedback divider biasing and can supply up to 10mA, eliminating need for external references in most isolated flyback and boost designs.
What is the maximum switching frequency supported by ISL6843IUZ?
The ISL6843IUZ supports an adjustable switching frequency up to 2MHz via external RT and CT components on the RTCT pin. Frequency accuracy is ±3% initial at +25°C, with <5% variation over temperature. The oscillator's sawtooth waveform and trimmed discharge current enable precise duty cycle control even at high frequencies.
Can ISL6843IUZ drive a power MOSFET directly without a gate driver IC?
Yes, ISL6843IUZ integrates a 1A peak gate driver (20ns rise/fall into 1nF) capable of directly driving medium-size MOSFETs (e.g., ≤500pF gate charge) in flyback and boost topologies. An external series resistor is recommended to damp ringing and limit peak current; layout must minimize trace inductance between OUT and MOSFET gate.
What package type and thermal characteristics does ISL6843IUZ use?
ISL6843IUZ uses an 8-lead MSOP package (M8.118), 3.0mm × 4.9mm, 0.65mm pitch, with θJA = 165°C/W on JEDEC-standard board. It is rated for –40°C to +105°C operation. The exposed pad is non-functional; thermal performance relies on copper area under the package and proper GND plane connection per M8.118 land pattern guidelines.
ISL6843IUZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- -
- Applications:
- Industrial Power Systems
- Voltage - Input:
- -
- Voltage - Supply:
- 9V ~ 16V
- Current - Supply:
- 5.5 mA
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
ISL6843IUZ FAQ
1.How can I place an order for ISL6843IUZ through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL6843IUZ 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 ISL6843IUZ reliable?
The price and inventory of ISL6843IUZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL6843IUZ is usually 5 days.
3.What payment methods are accepted for ISL6843IUZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL6843IUZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL6843IUZ?
ISL6843IUZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL6843IUZ 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 ISL6843IUZ?
For technical support, including ISL6843IUZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL6843IUZ requirements.
6.How does Aetrix verify that ISL6843IUZ is sourced from the original manufacturer or authorized distributors?
All ISL6843IUZ 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 ISL6843IUZ meets industry standards.
7.What is the process for return or replacement of ISL6843IUZ?
All ISL6843IUZ units undergo pre-shipment inspection (PSI). If there is an issue with ISL6843IUZ, 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 ISL6843IUZ part is unused and in its original packaging.
Return procedure for ISL6843IUZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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