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Renesas ISL88705IB846Z
- Part No.:
- ISL88705IB846Z
- Manufacturer:
- Renesas
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ISL88705IB846Z.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,313
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Product details
Overview
ISL88705IB846Z from Intersil is a microprocessor supervisor IC designed for power-supply and battery voltage monitoring in embedded systems. It provides fixed 4.64V VDD threshold supervision, active-low/high reset outputs (RST/RST), 1.25V auxiliary PFI monitoring with PFO output, and a 1.6s watchdog timer. It operates across -40°C to +85°C and consumes only 10µA at 3V, making it suitable for portable equipment requiring reliable brownout and power-fail detection.
For engineers reviewing the ISL88705IB846Z datasheet, ISL88705IB846Z pinout, ISL88705IB846Z application, or ISL88705IB846Z equivalent, this page delivers verified specifications, SOIC-8 package details, functional pin roles, real-world use cases in battery-powered systems and industrial controllers, and two validated alternative parts with precise technical and application differences.
Technical Context
The ISL88705IB846Z integrates three core supervision functions: power-on reset (POR) with 200ms nominal timeout, supply voltage monitoring via a factory-trimmed ±1.8% accurate 4.64V threshold (VTH1), and auxiliary voltage monitoring on PFI with 1.25V reference and 20mV hysteresis. Reset assertion remains valid down to VDD = 1V, ensuring robust operation during deep brownouts.
It features dual reset outputs - open-drain RST (active-low) and push-pull RST (active-high) - both asserting for ≥140ms after VDD recovery. The watchdog timer monitors WDI toggling every 1.6s (typical); if unattended, it pulls WDO low without minimum pulse width, enabling flexible system-level fault response independent of POR timing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDD Threshold (VTH1) | 4.64V ±1.8% - precisely monitors +5V rails for undervoltage conditions with minimal drift over temperature. |
| POR Timeout (tPOR) | 200ms (nominal) - holds reset asserted long enough for FPGA configuration and oscillator stabilization. |
| Supply Current (IDD) | 10µA max at 3V - enables multi-year battery life in always-on portable instrumentation. |
| Watchdog Timeout (tWDT) | 1.6s typical - detects microprocessor lockup without requiring software intervention or external timing components. |
| PFI Threshold | 1.25V ±5% - supports adjustable external voltage monitoring (e.g., battery voltage or secondary supply) via resistor divider. |
| Reset Pulse Width | ≥140ms - guarantees sufficient duration for processor initialization and peripheral reset sequencing. |
| Operating Temp Range | -40°C to +85°C - certified for industrial-grade reliability in harsh environments. |
Pinout & Package
ISL88705IB846Z is housed in an 8-lead narrow-body SOIC package (JEDEC MS-012-AA compliant, pkg drawing M8.15), RoHS-compliant and optimized for surface-mount reflow assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 MR | Manual Reset Input | Active-low debounced input with 20kΩ internal pull-up; triggers reset when pulled below 0.8V for ≥550ns. |
| 2 VDD | Power Supply Input | Main supply rail monitored against 4.64V threshold; reset asserts if VDD drops below VTH1 or during power-up. |
| 3 GND | Ground Reference | Common return path for all internal comparators, watchdog, and output drivers. |
| 4 PFI | Power-Fail Input | Auxiliary voltage monitor input; compares external voltage to 1.25V reference to enable early brownout warning. |
| 5 PFO | Power-Fail Output | Active-high open-drain output that goes high when PFI > 1.25V; used for low-battery flag or presence detection. |
| 6 WDO | Watchdog Output | Open-drain output pulled low on watchdog timeout or VDD undervoltage; no minimum pulse width ensures fast fault signaling. |
| 7 RST | Active-Low Reset Output | Open-drain output pulled low during reset; requires external pull-up; asserts for ≥140ms after VDD recovery. |
| 8 RST | Active-High Reset Output | Push-pull output driven high to VDD during reset; eliminates need for external pull-up in active-high reset architectures. |
Key Features
| Feature | Design Value |
|---|---|
| Dual reset polarity outputs | RST (active-low) and RST (active-high) provide hardware flexibility for legacy or modern reset logic without level-shifting. |
| Ultra-low quiescent current | 10µA max at 3V enables integration into energy-constrained battery-backed systems without compromising runtime. |
| Immunity to supply transients | Hysteresis (46mV at 4.64V) and internal filtering prevent false resets caused by brief noise spikes on VDD or PFI. |
| Reset validity down to 1V VDD | Ensures deterministic behavior even during deep brownout events where other supervisors may fail silently. |
| Factory-trimmed voltage accuracy | ±1.8% VTH1 tolerance eliminates need for external calibration or trimming resistors in production designs. |
Applications
| Portable Medical Monitor | Notebook Power Management |
|---|---|
|
Use Scenario: Battery-powered ECG device with dual-supply rails (+3.3V MCU, +5V analog front-end) operating in field environments with variable battery discharge profiles. IC Role / Device Role / Timing Role: ISL88705IB846Z supervises +5V rail and monitors battery voltage via PFI to trigger graceful shutdown before critical undervoltage. Use Value: Prevents data corruption during brownout by holding MCU in reset until stable power returns, while PFO alerts firmware of low battery 30 seconds prior to cutoff. |
Use Scenario: Embedded controller managing power sequencing and thermal throttling in a fanless notebook design. IC Role / Device Role / Timing Role: ISL88705IB846Z provides POR for the main SoC and uses WDI/WDO to detect firmware hangs during BIOS initialization. Use Value: Guarantees clean boot state after cold start and auto-recovery from watchdog timeout without user intervention or external reset circuitry. |
| Industrial PLC I/O Module | Smart Energy Meter |
|
Use Scenario: DIN-rail mounted programmable logic controller module exposed to wide ambient temperature swings and noisy 24V DC field power. IC Role / Device Role / Timing Role: ISL88705IB846Z monitors 5V local regulation derived from 24V input and asserts RST/RST simultaneously to synchronize CPU and FPGA reset domains. Use Value: Eliminates metastability risk during power-up by enforcing identical reset timing across heterogeneous logic blocks, improving system MTBF. |
Use Scenario: Revenue-grade electricity meter with tamper detection, RTC backup, and secure bootloader requiring guaranteed power integrity. IC Role / Device Role / Timing Role: ISL88705IB846Z supervises main 3.3V supply and uses PFI to monitor supercapacitor voltage for RTC hold-up during AC loss. Use Value: Enables seamless switchover to backup power with zero clock glitches, preserving timekeeping accuracy and cryptographic key integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISL88706IB844Z | 4.38V VDD threshold (vs. 4.64V); same SOIC-8 package, pinout, and feature set. | Designed for +5V systems with tighter tolerance margins or lower nominal rail voltages (e.g., LDO-regulated 4.5V). | Select when monitoring a 4.5V nominal supply instead of 5V; no layout or firmware changes required. |
| MAX6326US46D3+ | 4.63V threshold, 140ms min reset pulse, 2.5µA supply current, SOT23-3 package (3-pin, no PFI/WDT). | Minimalist supervisor for space-constrained designs lacking auxiliary monitoring or watchdog needs. | Choose only if PFI, WDT, and dual reset outputs are unnecessary; requires PCB redesign due to 3-pin SOT23 footprint. |
Compared with ISL88705IB846Z, ISL88706IB844Z offers identical functionality at a lower voltage threshold for tighter 5V rail monitoring, while MAX6326US46D3+ sacrifices PFI, WDT, and dual reset capability for ultra-low current and smaller size-making it suitable only for simplified reset-only use cases.
Availability
ISL88705IB846Z is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC modules, and smart energy meters requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for ISL88705IB846Z 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
Intersil Corporation is a precision analog and power management specialist, now part of Renesas Electronics, delivering high-reliability solutions for industrial, computing, and infrastructure markets.
The ISL88705IB846Z belongs to Intersil's microprocessor supervisor family, engineered specifically for cost-sensitive, battery-aware embedded systems needing accurate voltage monitoring, robust reset generation, and integrated watchdog functionality.
FAQ
What is the exact VDD voltage threshold for ISL88705IB846Z?
The ISL88705IB846Z has a factory-programmed VDD threshold (VTH1) of 4.64V, with a guaranteed tolerance of ±1.8% (4.556V to 4.724V) across temperature and process variation. This value is laser-trimmed during production and specified in the ordering code "B846Z", where "46" denotes 4.64V. It is designed to supervise standard +5V power rails with margin for ripple and droop.
Does ISL88705IB846Z support adjustable power-on reset delay?
No, ISL88705IB846Z does not support adjustable POR delay. Its tPOR is fixed at 200ms (min 140ms, max 260ms). Adjustable delay via CPOR capacitor is exclusive to ISL88707 and ISL88708 variants. The ISL88705IB846Z pinout lacks CPOR; pin 6 is WDO, not CPOR, confirming fixed timing architecture.
Can ISL88705IB846Z monitor a 3.3V supply directly?
No, ISL88705IB846Z is not rated for direct 3.3V supply monitoring because its fixed VTH1 = 4.64V exceeds 3.3V. Attempting to use it on a 3.3V rail would result in permanent reset assertion. For 3.3V supervision, select ISL88706IB831Z (3.09V threshold) or ISL88708IB831Z, both in the same SOIC-8 package and pin-compatible family.
How does the watchdog timer in ISL88705IB846Z interact with the reset outputs?
The ISL88705IB846Z watchdog timer asserts WDO low on timeout but does not directly drive RST or RST. To trigger system reset from watchdog timeout, WDO must be externally connected to MR. Without that connection, WDO serves only as a fault indicator; reset outputs respond only to VDD undervoltage, POR, or manual MR assertion.
Is ISL88705IB846Z compatible with Pb-free reflow soldering processes?
Yes, ISL88705IB846Z is RoHS-compliant and qualified for Pb-free reflow soldering per JEDEC J-STD-020. Its SOIC-8 package (M8.15) uses 100% matte tin (e3) termination and is rated for peak reflow temperatures up to 260°C. Unlike discontinued PDIP versions, the SOIC variant is explicitly intended for reflow-not wave-solder-processing.
ISL88705IB846Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.64V
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
ISL88705IB846Z FAQ
1.How can I place an order for ISL88705IB846Z through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL88705IB846Z 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 ISL88705IB846Z reliable?
The price and inventory of ISL88705IB846Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL88705IB846Z is usually 5 days.
3.What payment methods are accepted for ISL88705IB846Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL88705IB846Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL88705IB846Z?
ISL88705IB846Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL88705IB846Z 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 ISL88705IB846Z?
For technical support, including ISL88705IB846Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL88705IB846Z requirements.
6.How does Aetrix verify that ISL88705IB846Z is sourced from the original manufacturer or authorized distributors?
All ISL88705IB846Z 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 ISL88705IB846Z meets industry standards.
7.What is the process for return or replacement of ISL88705IB846Z?
All ISL88705IB846Z units undergo pre-shipment inspection (PSI). If there is an issue with ISL88705IB846Z, 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 ISL88705IB846Z part is unused and in its original packaging.
Return procedure for ISL88705IB846Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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