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Renesas ISL9123IITZ-T
- Part No.:
- ISL9123IITZ-T
- Manufacturer:
- Renesas
- Package:
- 8-UFBGA, WLCSP
- Datasheet:
-
ISL9123IITZ-T.pdf
- Description:
- IC REG BUCK PROG 600MA 8WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:1,326
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Product details
Overview
ISL9123IITZ-T from Renesas Electronics is an ultra-low quiescent current (950nA) buck switching regulator in an 8-bump WLCSP package, delivering up to 600mA output current with adaptive frequency hysteretic control. It supports 1.8V–5.5V input and a programmable 0.4V–1.9V output (per OTP setting), enabling precise voltage scaling in battery-powered wearables and IoT sensors.
For engineers reviewing the ISL9123IITZ-T datasheet, ISL9123IITZ-T pinout, ISL9123IITZ-T application, or ISL9123IITZ-T equivalent, this page delivers verified technical context on I²C-adjustable VOUT, forced bypass mode, soft-start ramp rate (3.125 mV/µs), auxiliary switched output (VSW), and thermal shutdown at 140°C - all critical for low-power system design and BOM optimization.
Technical Context
The ISL9123IITZ-T implements a hysteretic PWM controller with integrated P- and N-channel MOSFETs (rDSON = 95 mΩ typ each), supporting seamless PFM/PWM transition and auto-bypass operation when VIN approaches VOUT. Its digital core enables I²C register access to CONV_CFG, VSET, and INTFLG_MASK for dynamic voltage scaling and fault masking.
It features a dedicated auxiliary switched output (VSW) pin, internally connected to LX via an additional MOSFET (rDSON_VAUX = 62.5 mΩ typ), allowing independent power gating of peripheral rails. Soft discharge is not supported - unlike ISL9123B - and thermal protection triggers shutdown at 140°C with 25°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Quiescent Current | 950 nA in regulation mode - enables multi-year battery life in always-on sensor nodes. |
| Output Voltage Range | 0.4 V to 1.9 V (OTP-configured default) - matches core voltages of ultra-low-power MCUs like ARM Cortex-M0+. |
| Max Output Current | 600 mA (VIN > 2.5 V) - sufficient to power RF SoCs (e.g., Nordic nRF52840) during TX bursts. |
| I²C Interface | Fast-mode (400 kHz) compatible - allows real-time VOUT adjustment without external DAC or resistor networks. |
| Package | 1.8 mm × 1.0 mm, 8-bump WLCSP - fits within tight PCB area budgets of smart earbuds and hearing aids. |
| Efficiency | 97% peak (VIN = 3.6 V, VOUT = 3.3 V) - minimizes thermal rise in sealed enclosures. |
| Soft-Start Ramp Rate | 3.125 mV/µs (default) - prevents inrush current into large output capacitance (≥6 µF). |
Pinout & Package
ISL9123IITZ-T uses an 8-bump Wafer-Level Chip-Scale Package (WLCSP) with 0.4 mm pitch, optimized for minimal footprint and thermal resistance (θJA = 110 °C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (A1) | Ground reference | Primary return path for power and logic; must be connected to low-impedance ground plane. |
| VSW (A2) | Auxiliary switched output | Provides independent 1.9 V rail (same as VOUT) gated by internal MOSFET; usable for powering sensors or biasing analog front-ends. |
| LX (B1) | Switch node | Connects to 1 µH inductor; carries high di/dt switching current - requires short, low-inductance routing. |
| VOUT (B2) | Regulated output | Delivers configured 1.9 V output; requires ≥6 µF effective ceramic capacitance for stability. |
| VIN (C1) | Input supply | Accepts 1.8–5.5 V; requires ≥5 µF input capacitance placed near package for EMI suppression. |
| EN (C2) | Enable control | Active-high logic input; must be pulled HIGH to enable regulation; minimum 50 µs LOW pulse required for disable. |
| SCL (D1) | I²C clock | Fast-mode (400 kHz) interface clock; requires external pull-up to VDD_IO (≤3.6 V). |
| SDA (D2) | I²C data | Open-drain bidirectional data line; shares same pull-up as SCL; supports read/write of VSET and CONV_CFG registers. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low IQ regulation | 950 nA enables >10-year shelf life in coin-cell-powered utility meters. |
| Auto & forced bypass modes | Reduces dropout loss when VIN ≤ VOUT + 30 mV - extends runtime in deep-discharge battery states. |
| I²C-programmable VOUT | Adjusts output from 0.4 V to 5.375 V in 12.5 mV steps - supports dynamic voltage/frequency scaling (DVFS). |
| Hysteretic adaptive-frequency control | Eliminates external compensation; maintains stability across 0–600 mA load with no phase-margin tuning. |
| Auxiliary switched output (VSW) | Enables independent power sequencing of analog peripherals without adding discrete load switches. |
| Thermal shutdown with hysteresis | Shuts down at 140°C and resumes after 25°C cooldown - protects against sustained overloads in compact enclosures. |
Applications
| Smart Wearables | Wireless Audio |
|---|---|
|
Use Scenario: Power management in compact smartwatches with dual-core MCU and optical HR sensor. IC Role / Device Role / Timing Role: Primary buck regulator supplying 1.9 V to MCU core and 1.9 V auxiliary rail to photodiode amplifier via VSW pin. Use Value: 950 nA IQ and 3.125 mV/µs soft-start prevent brownout during wake-from-sleep transitions and extend CR2032 battery life to 24+ months. |
Use Scenario: Voltage regulation for Bluetooth LE earbud charging case and earbud PCB. IC Role / Device Role / Timing Role: Single-chip solution delivering 1.9 V to SoC and using VSW to gate power to MEMS microphone bias circuitry. Use Value: 8-bump WLCSP footprint (1.8 × 1.0 mm) fits within 3.5 mm × 3.5 mm earbud module; forced bypass mode sustains operation down to 1.95 V battery voltage. |
| IoT Edge Sensors | Portable Medical Devices |
|
Use Scenario: Low-power gas sensor node with LoRaWAN transceiver and electrochemical sensor array. IC Role / Device Role / Timing Role: Regulator for 1.9 V sensor analog front-end and 1.9 V transceiver VDDIO, leveraging I²C to scale VOUT during sleep vs. active transmit. Use Value: I²C-adjustable VOUT enables DVFS - reducing sensor bias current by 35% during idle, cutting average system IQ by 210 nA. |
Use Scenario: Hearing aid with programmable gain amplifier and DSP running on sub-1 V core. IC Role / Device Role / Timing Role: Buck regulator generating precise 1.9 V for RF section and using VSW to power analog audio codec only during call mode. Use Value: Auto-bypass threshold (20–30 mV) ensures seamless transition below 2.0 V battery, maintaining audio fidelity until end-of-life at 1.85 V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62840DRVR | Lower IQ (300 nA), but fixed 1.8 V output; no I²C or VSW pin; 6-pin WSON package (2.0 × 2.0 mm). | Lacks dynamic voltage scaling and auxiliary rail control - unsuitable for systems requiring multiple regulated outputs or DVFS. | Choose when absolute lowest IQ is prioritized over programmability and auxiliary switching. |
| MAX77650EWK+ | Multi-rail PMIC (buck + LDO + charger); IQ = 700 nA; I²C interface; 20-bump WLP (2.13 × 1.43 mm). | Integrates battery charging and LDOs - overkill for single-rail applications; higher cost and layout complexity. | Choose only if system requires integrated charging or multiple independent rails beyond VOUT/VSW. |
Compared with TPS62840DRVR and MAX77650EWK+, the ISL9123IITZ-T uniquely combines ultra-low IQ, I²C-adjustable VOUT, and a dedicated auxiliary switched output in the smallest footprint - making it optimal for space-constrained, multi-rail wearable designs where firmware-controlled power sequencing is essential.
Availability
ISL9123IITZ-T is available at Aetrix Electronics and suitable for smart wearables, wireless audio devices, and IoT edge sensors requiring stable component supply with guaranteed long-term availability and full traceability.
Supply support for ISL9123IITZ-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 ISL9123 family targets ultra-low-power portable electronics, delivering high-efficiency buck regulation with intelligent power-saving modes and I²C configurability for next-generation wearables and medical devices.
FAQ
What is the default output voltage of the ISL9123IITZ-T?
The ISL9123IITZ-T is factory-programmed with a default output voltage of 1.9 V, confirmed in the datasheet's Analog Specifications table (page 7, ISL9123IITZ row). This value is stored in One-Time Programmable (OTP) memory and can be adjusted via I²C register writes to VSET after power-on reset. The 1.9 V setting aligns with common core voltages for BLE SoCs and low-power MCUs.
Does the ISL9123IITZ-T support forced bypass mode?
Yes, the ISL9123IITZ-T supports forced bypass mode, consuming only 140 nA typical supply current. This mode is activated by writing FMODE = 0x3 to bits [3:2] of the CONV_CFG register via I²C. In forced bypass, the internal switches connect VIN directly to VOUT, eliminating switching losses when regulation is unnecessary - ideal for standby or deep-sleep states.
What is the function of the VSW pin on the ISL9123IITZ-T?
The VSW pin on the ISL9123IITZ-T is an auxiliary switched output tied to the same regulated voltage as VOUT (1.9 V). It is driven by a dedicated internal MOSFET (rDSON_VAUX = 62.5 mΩ typ) and can independently power peripherals like sensors or audio codecs. Unlike VOUT, VSW can be enabled/disabled via I²C without affecting main regulation - enabling precise power domain control.
What is the recommended output capacitance for the ISL9123IITZ-T?
The datasheet specifies a minimum effective output capacitance of 6 µF for the ISL9123IITZ-T (page 6, Recommended Operating Conditions). This value accounts for DC bias derating of ceramic capacitors; a typical design uses a 10 µF/0603 X5R capacitor (e.g., TDK C1005X5R1E106M050BC) placed adjacent to the VOUT pin to ensure loop stability and transient response under 600 mA load steps.
How does thermal protection operate on the ISL9123IITZ-T?
The ISL9123IITZ-T activates thermal shutdown at 140°C junction temperature (TSD), halting switching until the die cools by 25°C hysteresis (TSD_HYS). Upon cooldown, it executes full soft-start before resuming regulation. This behavior is confirmed in Section 5.5 and Table 3.4 (page 9), protecting against sustained overload in thermally constrained packages like the 1.8 mm × 1.0 mm WLCSP.
ISL9123IITZ-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-UFBGA, WLCSP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Programmable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.8V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.4V
- Voltage - Output (Max):
- 5.375V
- Current - Output:
- 600mA
- Frequency - Switching:
- 2.5MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-WLCSP (1.8x1)
ISL9123IITZ-T FAQ
1.How can I place an order for ISL9123IITZ-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL9123IITZ-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 ISL9123IITZ-T reliable?
The price and inventory of ISL9123IITZ-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL9123IITZ-T is usually 5 days.
3.What payment methods are accepted for ISL9123IITZ-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL9123IITZ-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL9123IITZ-T?
ISL9123IITZ-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL9123IITZ-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 ISL9123IITZ-T?
For technical support, including ISL9123IITZ-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL9123IITZ-T requirements.
6.How does Aetrix verify that ISL9123IITZ-T is sourced from the original manufacturer or authorized distributors?
All ISL9123IITZ-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 ISL9123IITZ-T meets industry standards.
7.What is the process for return or replacement of ISL9123IITZ-T?
All ISL9123IITZ-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL9123IITZ-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 ISL9123IITZ-T part is unused and in its original packaging.
Return procedure for ISL9123IITZ-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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