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Renesas ISL9123BII9Z-T
- Part No.:
- ISL9123BII9Z-T
- Manufacturer:
- Renesas
- Package:
- 8-UFBGA, WLCSP
- Datasheet:
-
ISL9123BII9Z-T.pdf
- Description:
- IC REG BUCK PROG 600MA 8WLCSP
- Quantity:
- Payment:
- Shipping:
Inventory:1,660
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Product details
Overview
ISL9123BII9Z-T from Renesas Electronics is an ultra-low quiescent current (7.5–125nA shutdown) buck switching regulator in 1.8mm×1.0mm 8-bump WLCSP, delivering up to 600mA output current with 0.4V–1.180V I²C-programmable output voltage and hysteretic PWM control. It targets power-constrained wearable and IoT devices requiring stable sub-1V core supply under light-load conditions.
For engineers reviewing the ISL9123BII9Z-T datasheet, ISL9123BII9Z-T pinout, ISL9123BII9Z-T application, or ISL9123BII9Z-T equivalent, this page delivers verified specifications, validated pin functions, confirmed use cases in hearing aids and smart sensors, and two technically documented alternative regulators for low-voltage, ultra-low-IQ DC/DC conversion.
Technical Context
The ISL9123BII9Z-T implements a fixed-frequency hysteretic PWM controller with adaptive switching frequency, no external compensation required, and integrated P/N-channel MOSFETs (rDS(ON) = 95/100 mΩ typ). It operates exclusively in buck mode-unlike ISL9123/A variants-and lacks auto/forced bypass functionality.
Startup includes OTP-read initialization and programmable soft-start ramp rate (0.156–1.25 mV/µs), while protection features include hiccup-mode overcurrent response (100ms fault wait), thermal shutdown at 140°C (25°C hysteresis), and soft discharge via I²C-controlled 1.15MΩ internal resistor between VOUT and GND.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 1.8V to 5.5V - supports single-cell Li-ion, Li-poly, or coin-cell input without pre-regulation. |
| Output Voltage Range | 0.4V to 1.180V - covers sub-1V logic cores (e.g., ARM Cortex-M0+, RISC-V microcontrollers) and analog sensor biasing. |
| Shutdown Current | 7.5–125nA - enables multi-year battery life in always-on IoT endpoints and hearing aids. |
| Max Output Current | 600mA at VIN > 2.5V - sufficient for active BLE/Wi-Fi SoCs during transmit bursts. |
| Switching Frequency | 1.75MHz (typ, forced PWM, VOUT = 0.8V) - allows use of tiny 1µH 0603 inductors and minimizes output ripple. |
| I²C Interface | Fast-mode (up to 400kHz) - enables dynamic voltage scaling and real-time telemetry without dedicated PMIC bus. |
| Package | 1.8mm × 1.0mm 8-bump WLCSP - footprint smaller than 0402 passives, ideal for space-constrained wearables. |
Pinout & Package
ISL9123BII9Z-T uses an 8-bump Wafer-Level Chip-Scale Package (WLCSP) with 0.4mm pitch, optimized for minimal PCB area and high-density routing in compact wearables.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (A1) | Ground reference | Primary return path for power and control circuits; must be connected to low-impedance ground plane. |
| VSW (A2) | Switch node | Internally shorted to VOUT on ISL9123B; not usable as auxiliary output-connect externally only to VOUT if needed for layout symmetry. |
| LX (B1) | Inductor switch node | Drives external 1µH inductor; requires tight loop layout with CIN/COUT to minimize EMI and switching losses. |
| VOUT (B2) | Regulated output | Main power rail; connects directly to load and output capacitor (min 6µF); routed away from noise-sensitive signals. |
| VIN (C1) | Input supply | Accepts 1.8–5.5V; requires ≥5µF ceramic input capacitor placed near package for stability and transient response. |
| EN (C2) | Enable control | Active-high logic input; must be pulled HIGH to enable regulation; minimum 50µs LOW pulse required for disable. |
| SCL (D1) | I²C clock | Fast-mode I²C interface clock line; requires external pull-up to VDD_I2C (≤3.6V); do not leave floating. |
| SDA (D2) | I²C data | Bi-directional I²C data line; requires external pull-up; used for VOUT programming, status readback, and fault flag monitoring. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low shutdown IQ | 7.5nA typical - extends shelf life and standby time in sealed medical and metering devices. |
| Programmable soft-start ramp | 0.156–1.25 mV/µs via I²C - prevents inrush current into large capacitive loads (e.g., RF front-end modules). |
| Integrated soft-discharge | 1.15MΩ internal VOUT-to-GND resistor - safely discharges output capacitance when disabled via I²C, avoiding voltage hold-up. |
| Hysteretic PWM architecture | No external compensation required - reduces BOM count and design iteration time for compact layouts. |
| Thermal & overcurrent protection | Hiccup-mode OCP (100ms retry) + 140°C thermal shutdown - ensures robust operation in thermally constrained enclosures. |
Applications
| Hearing Aid Power Management | Smart Sensor Node Core Supply |
|---|---|
|
Use Scenario: Ultra-low-power Class-D receiver ICs and MEMS microphones require stable 0.8–1.1V rails with <100nA quiescent draw during sleep. IC Role / Device Role / Timing Role: Primary buck regulator supplying DSP core and audio codec; dynamically scaled via I²C during voice activity detection. Use Value: Enables >5-year battery life on Zn-air cells by maintaining 7.5nA shutdown current and 950nA regulation IQ. |
Use Scenario: Environmental sensor clusters (temperature/humidity/pressure) in wireless gas meters operate intermittently with 10s–hour wake intervals. IC Role / Device Role / Timing Role: Single-rail DC/DC converter powering MCU and analog front-end; configured at boot to 0.9V for lowest active power. Use Value: Reduces system-level standby power by 40% vs. LDO alternatives, extending 10-year field deployment without maintenance. |
| Wearable Health Monitor SoC Supply | Low-Voltage IoT Edge Processor Rail |
|
Use Scenario: Optical heart-rate monitors (PPG) integrate photodiode arrays and ADCs requiring precise 0.88V ±17.6mV output per ISL9123BII9Z-T spec. IC Role / Device Role / Timing Role: Dedicated buck regulator for analog signal chain; output set to 0.88V at POR and held stable during LED pulsing transients. Use Value: Delivers 80% efficiency at 10µA load (VIN=3.6V), minimizing self-heating and optical measurement drift. |
Use Scenario: Sub-1V RISC-V microcontrollers (e.g., SiFive FE310) in battery-powered asset trackers demand fast voltage scaling across performance states. IC Role / Device Role / Timing Role: Programmable core supply enabling DVS from 0.4V (deep sleep) to 1.18V (peak compute); updated via I²C in <100µs. Use Value: Achieves 1.75MHz switching with 1µH inductor, reducing solution size by 35% vs. legacy 500kHz converters. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ultra-low-IQ buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TI TPS62840YKAR | 0.7V–3.3V output range; 300nA shutdown IQ; 1.8V–5.5V input; same 1.8×1.0mm DSBGA package. | Supports higher VOUT (up to 3.3V) but lacks soft-discharge and has lower max output current (400mA). | Choose for systems needing >1.18V output or tighter VOUT accuracy (±1%), but verify soft-discharge requirement. |
| Analog Devices ADP5302ACBZ-1-R7 | 0.4V–1.2V output; 25nA shutdown IQ; 1.8V–5.5V input; 1.22×0.83mm 6-bump WLCSP. | Smaller footprint and lower shutdown IQ, but no I²C interface-output fixed at factory or set via external resistors. | Choose for cost-sensitive, static-VOUT designs where programmability is unnecessary and board space is critical. |
Compared with TPS62840YKAR and ADP5302ACBZ-1-R7, the ISL9123BII9Z-T uniquely combines sub-1V programmability, integrated soft-discharge, and 600mA capability in a standardized WLCSP-making it optimal for dynamically scaled, safety-critical wearable power rails.
Availability
ISL9123BII9Z-T is available at Aetrix Electronics and suitable for hearing aid manufacturing, smart meter production, and wearable health monitor development requiring stable component supply and long-term lifecycle support.
Supply support for ISL9123BII9Z-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 management, and embedded solutions for automotive, industrial, and IoT markets.
The ISL9123BII9Z-T belongs to Renesas' ultra-low-IQ buck regulator product line, engineered specifically for battery-powered edge devices demanding sub-100nA shutdown and precise sub-1V core voltage control.
FAQ
What is the default output voltage of the ISL9123BII9Z-T at power-on reset?
The ISL9123BII9Z-T defaults to 0.88V at power-on reset, as specified in its one-time programmable (OTP) memory. This value is factory-set and matches the device's designated VOUT trim point per datasheet Table 3.4 (ISL9123BII9Z entry). The output can be reprogrammed via I²C after startup to any value between 0.4V and 1.180V.
Does the ISL9123BII9Z-T support bypass mode like the ISL9123A?
No, the ISL9123BII9Z-T does not support auto or forced bypass mode. Unlike ISL9123/A variants, the ISL9123B operates exclusively in buck conversion mode across its entire input-output voltage range. This is explicitly stated in the datasheet Section 5.6 and Figure 4 (ISL9123B Block Diagram), which omits bypass control logic and auxiliary switch circuitry.
How is soft discharge implemented on the ISL9123BII9Z-T?
The ISL9123BII9Z-T implements soft discharge via an internal 1.15MΩ resistor between VOUT and GND, activated only when disabled through the I²C interface (by setting DISCH=1 and EN_AND=0 in CONV_CFG register). This differs from EN-driven shutdown, which leaves VOUT floating. The feature prevents unsafe voltage hold-up on sensitive downstream circuitry during firmware-controlled power-down sequences.
What is the maximum supported I²C clock frequency for the ISL9123BII9Z-T?
The ISL9123BII9Z-T supports Fast-mode I²C operation up to 400kHz, as confirmed in Section 3.5 of the datasheet. Timing parameters-including tLOW (1300ns min), tHIGH (600ns min), and tSU:STA (600ns min)-are fully compliant with standard Fast-mode specifications, enabling reliable communication with common microcontroller I²C peripherals without custom timing adjustments.
Can the ISL9123BII9Z-T drive a 600mA load across its full input voltage range?
The ISL9123BII9Z-T delivers up to 600mA output current only when VIN exceeds 2.5V, per Section 3.3 Recommended Operating Conditions. At lower inputs (1.8V–2.5V), peak current limit scales linearly with VIN (e.g., ~560mA at VIN=2.3V). Designers must verify load capability against actual operating VIN and thermal conditions, especially in compact enclosures where θJA = 110°C/W may limit sustained current.
ISL9123BII9Z-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):
- 1.18V
- Current - Output:
- 600mA
- Frequency - Switching:
- 1.75MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-WLCSP (1.8x1)
ISL9123BII9Z-T FAQ
1.How can I place an order for ISL9123BII9Z-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL9123BII9Z-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 ISL9123BII9Z-T reliable?
The price and inventory of ISL9123BII9Z-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL9123BII9Z-T is usually 5 days.
3.What payment methods are accepted for ISL9123BII9Z-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL9123BII9Z-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL9123BII9Z-T?
ISL9123BII9Z-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL9123BII9Z-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 ISL9123BII9Z-T?
For technical support, including ISL9123BII9Z-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL9123BII9Z-T requirements.
6.How does Aetrix verify that ISL9123BII9Z-T is sourced from the original manufacturer or authorized distributors?
All ISL9123BII9Z-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 ISL9123BII9Z-T meets industry standards.
7.What is the process for return or replacement of ISL9123BII9Z-T?
All ISL9123BII9Z-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL9123BII9Z-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 ISL9123BII9Z-T part is unused and in its original packaging.
Return procedure for ISL9123BII9Z-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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