My Inquiry
My Account
Renesas ISL91108IINZ-T
- Part No.:
- ISL91108IINZ-T
- Manufacturer:
- Renesas
- Package:
- 20-UFBGA, WLCSP
- Datasheet:
-
ISL91108IINZ-T.pdf
- Description:
- IC REG BCK BST 3.3V 3.7A 20WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:3,025
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ISL91108IINZ-T from Renesas (formerly Intersil) is a fully synchronous 4-switch buck-boost DC/DC regulator delivering up to 1.6A DC output current at 3.3V with 2.6MHz switching frequency, 27.5µA quiescent current, and automatic seamless buck/boost mode transition - designed for space-constrained mobile power rails in smartphones and tablets.
For engineers reviewing the ISL91108IINZ-T datasheet, ISL91108IINZ-T pinout, ISL91108IINZ-T application, or ISL91108IINZ-T equivalent, key selection criteria include its fixed 3.3V output, 20-bump WLCSP package, input range of 1.8V–5.5V, burst current capability of 2.7A, and support for forced PWM or external clock synchronization in noise-sensitive RF power amplifier supplies.
Technical Context
The ISL91108IINZ-T implements a true 4-switch buck-boost topology with independent P-channel and N-channel MOSFETs (RDSON_P = 90mΩ, RDSON_N = 75mΩ), enabling continuous conduction across input voltages both above and below the regulated 3.3V output. Its internal error amplifier and PWM controller dynamically select operating mode based on real-time VIN–VOUT differential.
It features dual ground paths (GND for analog reference, PGND for high-current switching), dedicated PVIN and VIN inputs for optimized reference stability, and integrated protection including thermal shutdown (150°C), short-circuit detection via FB monitoring, and undervoltage lockout (1.775V rising threshold). Soft-start time is 2ms in buck mode and 3ms in boost mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V - eliminates external feedback resistors and simplifies layout for single-rail applications. |
| Input Voltage Range | 1.8V to 5.5V - supports direct battery input from single-cell Li-ion (2.8V–4.4V) or USB-powered systems without pre-regulation. |
| DC Output Current | 1.6A at PVIN = 2.8V, VOUT = 3.3V - sufficient for baseband processors and modem power domains in portable devices. |
| Burst Current | 2.7A for tON <600µs (4.6ms period) - handles transient loads from 2G/3G/4G power amplifiers without voltage droop. |
| Switching Frequency | 2.6MHz (typ) - enables use of compact 1µH inductors and minimizes EMI in frequency bands above AM radio. |
| Quiescent Current | 27.5µA in PFM mode - extends battery life during standby or low-activity states in always-on subsystems. |
| Package | 20-bump WLCSP (2.34mm × 1.72mm, 0.4mm pitch) - ultra-small footprint compatible with fine-pitch mobile PCB assembly. |
Pinout & Package
ISL91108IINZ-T uses a 20-bump Wafer-Level Chip-Scale Package (WLCSP) with 0.4mm pitch, measuring 2.34mm × 1.72mm. The package exposes solder bumps on the die side for direct board mounting, requiring compliant land pattern per drawing W4x5.20F.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A5, B5, C5 | VOUT | Main regulated output node; connects to 2×22µF ceramic output capacitors at PGND for low-impedance filtering. |
| A4, B4, C4 | LX2 | Boost-side switch node; connects to one end of the single external inductor (L1). |
| A3, B3, C3 | PGND | Power ground return for high di/dt switching currents; must be tied directly to input/output capacitor grounds. |
| A2, B2, C2 | LX1 | Buck-side switch node; connects to the other end of L1, forming the buck-boost inductor interface. |
| A1, B1, C1 | PVIN | Main power input (1.8V–5.5V); supplies switching circuitry and requires 2×10µF ceramic decoupling to PGND. |
| D1 | VIN | Analog supply input for internal reference and control logic; separate from PVIN to improve regulation accuracy. |
| D2 | EN | Active-high enable; drives HIGH to start soft-start sequence; pulls LOW to activate 110Ω internal VOUT discharge path. |
| D3 | MODE/SYNC | Selects PFM (HIGH) or forced PWM (LOW); also accepts 2.75–3.25MHz external clock for EMI reduction. |
| D4 | GND | Analog ground reference for error amplifier and feedback circuitry; isolated from PGND to prevent noise coupling. |
| D5 | FB | Feedback input - internally shorted to VOUT in ISL91108IINZ-T (fixed 3.3V version), eliminating external divider. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic buck/boost mode transition | Zero-output-disturbance crossover when VIN crosses VOUT - maintains stable 3.3V rail during battery discharge or USB voltage variation. |
| 2.6MHz constant-frequency operation | Reduces required inductor size to 1µH and enables use of small 0402/0603 MLCCs, cutting total solution area by >40% vs. 1MHz designs. |
| 27.5µA quiescent current | Extends system standby time in always-on mobile peripherals (e.g., NFC, sensors) without compromising dynamic response. |
| Integrated 4-switch power stage | Eliminates need for external MOSFETs or gate drivers - reduces BOM count, layout complexity, and thermal hotspots. |
| Full protection suite | Includes thermal shutdown (150°C), short-circuit detection via FB monitoring, and UVLO (1.775V) - ensures robustness in unregulated battery environments. |
Applications
| Smartphone Baseband Power | Tablet Application Processor Core Rail |
|---|---|
Use Scenario: Powering LTE/WCDMA baseband ICs requiring stable 3.3V from a single-cell Li-ion battery (2.8V–4.4V). IC Role / Device Role / Timing Role: Primary buck-boost regulator maintaining regulated 3.3V output while automatically transitioning between buck and boost as battery voltage drops below 3.3V. Use Value: Enables uninterrupted operation across full battery discharge curve without intermediate LDOs or discrete regulators. |
Use Scenario: Supplying I/O or auxiliary core voltage for ARM-based application processors in tablets with variable input from USB-C PD or battery. IC Role / Device Role / Timing Role: Standalone fixed-output DC/DC converter delivering 1.6A at 3.3V with <2ms soft-start and minimal output ripple. Use Value: Reduces solution size and component count versus multi-stage conversion, supporting thin-profile industrial tablet designs. |
| 2G/3G/4G Power Amplifier Bias | Wireless Modem RF Front-End |
Use Scenario: Providing pulsed 3.3V bias to cellular PA stages during transmission bursts in feature phones and IoT modules. IC Role / Device Role / Timing Role: High-burst-current regulator supplying up to 2.7A peak for <600µs to meet GSM/UMTS PA envelope requirements. Use Value: Prevents VOUT sag during transmit events, improving EVM and reducing adjacent channel leakage. |
Use Scenario: Powering RF transceivers and front-end switches in Bluetooth/Wi-Fi modules where EMI sensitivity demands clean, synchronized switching. IC Role / Device Role / Timing Role: Synchronizable buck-boost regulator operating at 2.6MHz or locked to external clock to avoid interference with 2.4GHz ISM band. Use Value: Enables coexistence with RF radios by eliminating switching noise in critical receive bands through precise frequency control. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck-boost regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS63020DSJR | Fixed 3.3V output, 2.5MHz switching, 96% peak efficiency, but higher 40µA quiescent current and larger 2.5mm × 2.5mm QFN package. | Less suitable for ultra-thin mobile PCBs due to 0.5mm height and 6.25mm² footprint vs. ISL91108IINZ-T's 4.0mm² WLCSP. | Choose when higher thermal margin is needed and board space allows larger package. |
| MAX77827AEWE+T | Adjustable output (0.6V–5.2V), 2.2MHz, 1.2A DC rating, integrated input current limit, but no external sync capability and 35µA IQ. | Requires external resistor divider and lacks burst-current headroom (2.7A) needed for PA bias applications. | Prefer for programmable multi-rail systems where flexibility outweighs peak current and sync requirements. |
Compared with TPS63020DSJR and MAX77827AEWE+T, the ISL91108IINZ-T offers the smallest footprint, lowest quiescent current, and unique combination of fixed 3.3V output, 2.7A burst capability, and external clock synchronization - making it optimal for space- and noise-constrained mobile RF power stages.
Availability
ISL91108IINZ-T is available at Aetrix Electronics and suitable for smartphone baseband power, tablet application processor rails, and wireless communication device RF front-ends requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.
Supply support for ISL91108IINZ-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 (acquired Intersil in 2017) is a global leader in microcontrollers, analog, and power management ICs, serving automotive, industrial, and consumer markets with high-reliability semiconductor solutions.
The ISL91108 product line was developed specifically for high-efficiency, ultra-compact buck-boost power conversion in battery-powered mobile devices - emphasizing seamless mode transition, minimal external components, and robust protection for unregulated input sources.
FAQ
What is the maximum continuous output current supported by the ISL91108IINZ-T?
The ISL91108IINZ-T delivers up to 1.6A DC output current under specified conditions (PVIN = 2.8V, VOUT = 3.3V, TA = +25°C). This rating is validated across the full –40°C to +85°C operating temperature range and accounts for thermal derating in the 2.34mm × 1.72mm WLCSP package. The ISL91108IINZ-T also supports 2.7A burst current for short durations (<600µs), enabling it to handle transient loads in RF power amplifier applications without output collapse.
Does the ISL91108IINZ-T require external feedback resistors to set the output voltage?
No - the ISL91108IINZ-T is the fixed 3.3V output variant. Its FB pin is internally connected to VOUT, eliminating the need for external resistors or compensation components. This simplifies design, reduces BOM cost, and improves layout reliability compared to adjustable versions like ISL91108IIAZ-T. The datasheet confirms this configuration in Figure 5 and the Ordering Information table.
Can the ISL91108IINZ-T be synchronized to an external clock, and what is the acceptable frequency range?
Yes, the ISL91108IINZ-T supports external clock synchronization via the MODE/SYNC pin (D3). When driven with a clean CMOS-level signal, it locks to input frequencies between 2.75MHz and 3.25MHz (±2% tolerance). This feature allows designers to shift switching noise away from sensitive RF bands such as 2.4GHz Wi-Fi or Bluetooth, improving system-level EMC performance without modifying the regulator's internal oscillator.
What protection features are integrated into the ISL91108IINZ-T?
The ISL91108IINZ-T integrates short-circuit protection (via FB voltage monitoring), over-temperature shutdown (150°C trip, 115°C hysteresis), and input undervoltage lockout (UVLO with 1.775V rising threshold). It also includes reverse-current blocking and soft-discharge functionality (110Ω internal pull-down activated on EN deassertion). These protections operate autonomously without external components, ensuring safe operation in unpredictable battery or adapter input conditions.
What is the recommended inductor value and saturation current rating for the ISL91108IINZ-T?
The datasheet specifies a 1µH inductor with ≥4.0A saturation current rating for the ISL91108IINZ-T. Ferrite-core inductors such as Toko 1277AS-H-1R0M or Coilcraft XFL4020-102ME are explicitly recommended. Using an inductor rated below 4A risks saturation during 2.7A burst events, causing excessive ripple, efficiency loss, and potential thermal stress on the ISL91108IINZ-T's internal MOSFETs.
ISL91108IINZ-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 20-UFBGA, WLCSP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck-Boost
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.8V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 3.7A (Switch)
- Frequency - Switching:
- 2.6MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-WLCSP
ISL91108IINZ-T FAQ
1.How can I place an order for ISL91108IINZ-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL91108IINZ-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 ISL91108IINZ-T reliable?
The price and inventory of ISL91108IINZ-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL91108IINZ-T is usually 5 days.
3.What payment methods are accepted for ISL91108IINZ-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL91108IINZ-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL91108IINZ-T?
ISL91108IINZ-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL91108IINZ-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 ISL91108IINZ-T?
For technical support, including ISL91108IINZ-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL91108IINZ-T requirements.
6.How does Aetrix verify that ISL91108IINZ-T is sourced from the original manufacturer or authorized distributors?
All ISL91108IINZ-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 ISL91108IINZ-T meets industry standards.
7.What is the process for return or replacement of ISL91108IINZ-T?
All ISL91108IINZ-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL91108IINZ-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 ISL91108IINZ-T part is unused and in its original packaging.
Return procedure for ISL91108IINZ-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ISL91108IINZ-T Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
