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Renesas ISL91127IIAZ-T
- Part No.:
- ISL91127IIAZ-T
- Manufacturer:
- Renesas
- Package:
- 20-UFBGA, WLCSP
- Datasheet:
-
ISL91127IIAZ-T.pdf
- Description:
- IC REG BUCK BOOST 2.1A 20WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:3,195
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Product details
Overview
ISL91127IIAZ-T from Renesas Electronics is a high-efficiency, fully synchronous 4-switch buck-boost DC/DC regulator designed for single-cell Li-ion battery systems. It delivers up to 2A continuous output current at 3.3V across 2.5V–4.35V input, features 2.5MHz switching frequency, 30µA quiescent current, and supports adjustable output voltages from 1.0V to 5.2V via external resistor divider. It enables brownout-free system voltage in portable medical and handheld devices.
For engineers reviewing the ISL91127IIAZ-T datasheet, ISL91127IIAZ-T pinout, ISL91127IIAZ-T application, or ISL91127IIAZ-T equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters (including PFM/PWM transition thresholds, soft-start timing, and thermal shutdown behavior), and real-world application constraints for battery-powered systems with dynamic input-to-output voltage relationships.
Technical Context
The ISL91127IIAZ-T implements a proprietary 4-switch buck-boost topology with automatic mode transitions between buck and boost based on real-time PVIN–VOUT differential. Its control architecture uses a PWM controller with integrated gate drivers, anti-shoot-through logic, and adaptive soft-start ramping that slows slew rate during buck-to-boost transitions to limit output overshoot.
It separates power and analog grounds (PGND/SGND), employs dual supply inputs (PVIN for power path, VIN for internal reference), and integrates protection including short-circuit detection via FB voltage monitoring, thermal shutdown at 155°C with 30°C hysteresis, and undervoltage lockout (1.725V rising threshold).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 1.8V to 5.5V - supports full discharge of Li-ion cells down to 2.5V while maintaining regulated output. |
| Output Voltage Range | 1.0V to 5.2V - programmable via external resistor divider; fixed versions not applicable to ISL91127IIAZ-T. |
| Max Continuous Output Current | 2A at VOUT = 3.3V, PVIN = 2.5V - validated under worst-case battery sag condition. |
| Switching Frequency | 2.5MHz (typ) - reduces required inductor size (1µH typical) and output capacitance (2×22µF). |
| Quiescent Current | 30µA - maintains >85% efficiency at 10mA load, critical for standby battery life. |
| PFM/PWM Load Thresholds | 75mA (PWM→PFM), 200mA (PFM→PWM) - dynamically optimizes efficiency across light-to-moderate loads. |
| Thermal Shutdown | 155°C junction temperature with 30°C hysteresis - ensures safe recovery without manual reset. |
Pinout & Package
ISL91127IIAZ-T is housed in a 20-lead, 4mm × 4mm, 0.5mm pitch QFN package (RoHS-compliant, L20.4x4C drawing) with exposed thermal pad (EPAD) requiring connection to PGND for thermal performance and EMI control.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 | LX2 | Inductor connection (output side); carries high-frequency AC current during boost operation and reverse current during buck. |
| 3 | PGND | Power ground return for high di/dt switching currents; must be low-inductance plane tied to EPAD. |
| 4, 5 | LX1 | Inductor connection (input side); active during buck mode; shares same inductor node as LX2 in boost mode. |
| 6–9 | PVIN | Main power input (1.8V–5.5V); supplies DC/DC converter switches; requires 2×10µF ceramic decoupling to PGND. |
| 10 | VIN | Analog supply input (1.8V–5.5V); powers internal reference and control circuitry; separate from PVIN to isolate noise. |
| 11 | EN | Enable logic input (VIH ≥1.4V); asserts internal startup sequence and activates soft-start ramp. |
| 12 | MODE | Mode select/sync input; HIGH enables auto PFM; LOW forces PWM; also accepts 2.75–3.25MHz external clock. |
| 13, 14 | SGND | Analog ground reference for FB, MODE, EN; must be star-connected to minimize offset errors. |
| 15 | FB | Feedback input for adjustable output; monitors VOUT via resistor divider; 0.8V reference with 20nA bias current. |
| 16 | NC | No-connect pin; must remain unconnected per datasheet. |
| 17–20 | VOUT | Regulated output terminal; delivers up to 2A; requires 2×22µF low-ESR ceramic capacitors to PGND. |
| EPAD | Thermal Pad | Exposed metal pad on underside; must be soldered to solid PGND plane for thermal dissipation (θJC = 5°C/W). |
Key Features
| Feature | Design Value |
|---|---|
| Automatic Buck-Boost Mode Transition | Seamless switching between topologies when PVIN ≈ VOUT; eliminates output ripple spikes and improves regulation stability. |
| Low Quiescent Current | 30µA in PFM mode - extends battery runtime in always-on sensor or BLE subsystems without compromising wake-up response. |
| Integrated Soft-Discharge | 120Ω internal pull-down on VOUT when EN = LOW - safely discharges output caps without external circuitry. |
| High-Efficiency Synchronous Switches | 32mΩ (P-ch) and 37mΩ (N-ch) RDS(ON) at 3.6V - minimizes conduction loss across full load range, enabling >94% peak efficiency. |
| Robust Protection Suite | Short-circuit foldback, thermal shutdown with hysteresis, and UVLO - prevents damage during abnormal conditions without external supervision. |
Applications
| Smartphone System Rail | Portable Medical Monitor |
|---|---|
Use Scenario: Maintaining stable 3.3V system rail as Li-ion battery discharges from 4.2V to 2.8V. IC Role / Device Role / Timing Role: Primary buck-boost regulator supplying SoC I/O, memory, and display interface rails. Use Value: Eliminates brownouts during deep discharge, enabling uninterrupted operation without voltage supervisor intervention. |
Use Scenario: Powering ECG front-end, microcontroller, and Bluetooth LE radio from a single-cell Li-ion battery. IC Role / Device Role / Timing Role: Central power management IC delivering regulated 1.8V (MCU core), 3.3V (analog sensors), and 5.0V (USB charging port). Use Value: Supports multi-rail generation with one IC, reducing BOM count and PCB area while sustaining >88% efficiency at 100mA load. |
| Wireless Headset Audio Codec | Handheld Barcode Scanner |
Use Scenario: Supplying low-noise 1.2V bias to MEMS microphone and 3.3V to DSP in ultra-low-power wearable audio device. IC Role / Device Role / Timing Role: High PSRR buck-boost regulator operating in PFM mode during idle, transitioning to PWM during voice capture bursts. Use Value: Achieves <10µVrms output ripple in PFM mode, preserving SNR in analog signal chain without additional LDO post-regulation. |
Use Scenario: Powering laser diode driver, CMOS image sensor, and ARM Cortex-M4 MCU in battery-operated industrial scanner. IC Role / Device Role / Timing Role: Main power stage handling pulsed 1.5A laser current demands while sustaining 3.3V logic rail during decode cycles. Use Value: Delivers 2A peak current capability with <2ms soft-start into boost mode, preventing reset glitches during cold start from 2.7V battery. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck-boost regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2918GQ-Z | 4-switch architecture, 2.2MHz switching, 3.5A switch rating; lacks integrated soft-discharge and has higher 55µA IQ. | Requires external discharge FET for controlled VOUT decay; better suited for higher-current (>1.8A) constant-load apps. | Select MP2918GQ-Z only if peak current >2A is required and soft-discharge is implemented externally. |
| TPS63020DSJR | 4-switch buck-boost, 2.5MHz, 3A switches; includes I²C interface and DVS support; 25µA IQ but no MODE pin sync capability. | Enables dynamic voltage scaling in PMIC-like systems; unsuitable where pin-count or firmware overhead must be minimized. | Choose TPS63020DSJR when programmable output and telemetry are needed; avoid if standalone operation is mandatory. |
Compared with MP2918GQ-Z and TPS63020DSJR, the ISL91127IIAZ-T offers superior light-load efficiency (30µA vs ≥25µA), integrated soft-discharge, and direct MODE pin synchronization-making it optimal for cost-sensitive, firmware-light portable designs requiring robust brownout immunity.
Availability
ISL91127IIAZ-T is available at Aetrix Electronics and suitable for handheld consumer electronics, portable medical instrumentation, wireless communication modules, and industrial barcode scanners requiring stable component supply across extended temperature ranges (–40°C to +85°C).
Supply support for ISL91127IIAZ-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 is a global semiconductor leader specializing in microcontrollers, analog power, and connectivity solutions for automotive, industrial, and IoT markets.
The ISL91127 product line was engineered specifically for high-efficiency, single-cell Li-ion battery systems demanding seamless buck-boost operation, minimal quiescent power, and robust protection-targeting next-generation portable and medical devices.
FAQ
What output voltage range does the ISL91127IIAZ-T support?
The ISL91127IIAZ-T supports an adjustable output voltage range of 1.0V to 5.2V, set by an external resistor divider connected to the FB pin. Its internal 0.8V reference and 20nA FB bias current enable precise programming using high-value resistors (e.g., 1MΩ/324kΩ for 3.3V), minimizing divider current loss. Fixed-output variants (e.g., ISL91127IRNZ-T) are separate part numbers and not interchangeable with ISL91127IIAZ-T.
How does the ISL91127IIAZ-T handle input voltage near the output voltage?
The ISL91127IIAZ-T automatically and seamlessly transitions between buck and boost modes when PVIN approaches VOUT, using Renesas' proprietary algorithm to maintain regulation with very low output ripple. During these transitions, the controller modulates duty cycle and adjusts soft-start ramp rate to prevent overshoot, ensuring stable operation without external intervention-even during dynamic load steps like those in smartphone CPU burst modes.
What is the purpose of the separate VIN and PVIN pins on the ISL91127IIAZ-T?
VIN supplies power to the internal reference, error amplifier, and control logic, while PVIN feeds the high-current power switches. This separation isolates sensitive analog circuitry from switching noise, improving regulation accuracy and stability. VIN must be connected within 1.8V–5.5V and can share the same source as PVIN-but routing them separately with individual 10µF decoupling to PGND is recommended for noise-sensitive applications like medical sensor rails.
Does the ISL91127IIAZ-T include short-circuit protection?
Yes, the ISL91127IIAZ-T provides short-circuit protection by continuously monitoring the FB pin voltage. When feedback drops below a threshold indicating output overload or short, the controller reduces switching frequency and maintains P-channel MOSFET peak current limiting (4.5A typ) to prevent thermal runaway. Recovery is automatic once the fault clears and FB rises above the threshold, with no latch-off or external reset required.
Can the ISL91127IIAZ-T be synchronized to an external clock?
Yes, the MODE pin of the ISL91127IIAZ-T accepts an external clock signal in the 2.75MHz to 3.25MHz range, allowing synchronization with system clocks to reduce EMI peaks. When driven with a clean square wave, the internal oscillator locks to the external frequency-enabling deterministic switching alignment across multiple converters in dense PCB layouts, such as those found in multi-rail portable devices.
ISL91127IIAZ-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:
- -
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.8V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- -
- Voltage - Output (Max):
- -
- Current - Output:
- 2.1A
- Frequency - Switching:
- 2.5MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-WLCSP (2.15x1.74)
ISL91127IIAZ-T FAQ
1.How can I place an order for ISL91127IIAZ-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL91127IIAZ-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 ISL91127IIAZ-T reliable?
The price and inventory of ISL91127IIAZ-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL91127IIAZ-T is usually 5 days.
3.What payment methods are accepted for ISL91127IIAZ-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL91127IIAZ-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL91127IIAZ-T?
ISL91127IIAZ-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL91127IIAZ-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 ISL91127IIAZ-T?
For technical support, including ISL91127IIAZ-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL91127IIAZ-T requirements.
6.How does Aetrix verify that ISL91127IIAZ-T is sourced from the original manufacturer or authorized distributors?
All ISL91127IIAZ-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 ISL91127IIAZ-T meets industry standards.
7.What is the process for return or replacement of ISL91127IIAZ-T?
All ISL91127IIAZ-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL91127IIAZ-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 ISL91127IIAZ-T part is unused and in its original packaging.
Return procedure for ISL91127IIAZ-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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