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Renesas ISL88708IB844Z
- Part No.:
- ISL88708IB844Z
- Manufacturer:
- Renesas
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ISL88708IB844Z.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,541
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Product details
Overview
ISL88708IB844Z from Renesas (formerly Intersil) is a microprocessor supervisor IC with fixed 4.38V VDD reset threshold, auxiliary 1.25V power-fail monitor (PFI/PFO), 1.6s watchdog timer, dual active-high/active-low reset outputs (RST/RST), and adjustable power-on reset delay via CPOR pin. It operates from 2.0V to 5.5V supply and draws ≤10µA at 3V, targeting battery-powered and industrial embedded systems requiring reliable voltage supervision.
For engineers reviewing the ISL88708IB844Z datasheet, ISL88708IB844Z pinout, ISL88708IB844Z application, or ISL88708IB844Z equivalent, this page delivers verified technical context, exact pin functions, real-world use cases, and validated alternative parts - all grounded in the FN8092 Rev 6.00 datasheet and official ordering information.
Technical Context
The ISL88708IB844Z integrates four core supervision functions: precise VDD monitoring with ±1.8% threshold accuracy and hysteresis, independent PFI input with 1.25V reference for low-battery or power-fail detection, a 1.6s nominal watchdog timer cleared by WDI edge transitions, and dual RST outputs supporting both active-high push-pull and active-low open-drain configurations.
Unlike ISL88705/ISL88706 variants, the ISL88708IB844Z includes the CPOR pin enabling external capacitor-based extension of the power-on reset timeout beyond the base 200ms - a feature absent in non-CPOR supervisors. Its SOIC-8 package supports surface-mount assembly with RoHS-compliant matte tin terminations rated for reflow soldering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDD Threshold | 4.38V ±1.8% - factory-trimmed trip point ensures accurate +5V rail supervision without external components. |
| Supply Current | ≤10µA at 3V - ultra-low quiescent current extends battery life in portable equipment. |
| Watchdog Timeout | 1.6s typical - monitors microprocessor activity; asserts WDO low if WDI fails to toggle within window. |
| PFI Threshold | 1.25V ±5% - enables flexible auxiliary voltage monitoring (e.g., battery voltage) using external resistor divider. |
| Reset Pulse Width | ≥140ms minimum - guarantees sufficient hold time for processor initialization during power-up/brownout. |
| Operating Temp | -40°C to +85°C - qualified for industrial environments with full parameter performance across range. |
| Package | 8-lead SOIC (M8.15) - standard surface-mount footprint compatible with automated PCB assembly. |
Pinout & Package
ISL88708IB844Z uses an 8-lead narrow-body SOIC package (JEDEC MS-012-AA compliant, M8.15 outline). Dimensions: 4.90mm × 3.90mm × 1.75mm height, 1.27mm lead pitch.
| 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 (2.0–5.5V); monitored against 4.38V threshold to assert reset during undervoltage or brownout. |
| 3 GND | Ground Reference | System ground return path for all internal circuits and output drivers. |
| 4 PFI | Power-Fail Input | Auxiliary voltage monitor input; compares external voltage to 1.25V reference to drive PFO state. |
| 5 PFO | Power-Fail Output | Active-high open-drain output; goes high when PFI > 1.25V, low otherwise - used for early warning or presence detection. |
| 6 CPOR | Adjustable POR Delay Input | Connect external capacitor to GND to extend tPOR beyond 200ms (e.g., 50pF → ~1.4s); unique to ISL88707/ISL88708 family. |
| 7 RST | Active-Low Reset Output | Open-drain output pulled low during reset; requires external pull-up; remains asserted ≥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 resistor. |
Key Features
| Feature | Design Value |
|---|---|
| Dual reset outputs (RST/RST) | Simultaneous active-high push-pull and active-low open-drain signals simplify interface to diverse logic families without level-shifting. |
| Adjustable power-on reset delay | CPOR pin enables precise tuning of tPOR from 200ms to seconds using a single external capacitor - critical for FPGA configuration timing. |
| 1.25V PFI threshold with hysteresis | 20mV hysteresis prevents chatter on marginal PFI inputs; supports resistor-divider scaling for monitoring voltages >1.25V (e.g., 12V rails). |
| Watchdog timer with WDI/WDO | 1.6s timeout detects software lockup; WDO provides dedicated watchdog status independent of reset assertion timing. |
| Immunity to supply transients | Internal hysteresis and filtering prevent false resets caused by brief voltage droops or switching noise on VDD. |
| RoHS-compliant SOIC packaging | M8.15 SOIC-8 footprint supports lead-free reflow soldering per JEDEC J-STD-020, with matte tin (e3) terminations. |
Applications
| Portable Medical Monitor | Notebook Power Management |
|---|---|
|
Use Scenario: Battery-powered ECG device with dual-supply rails (+3.3V MCU, +5V analog front-end) and low-battery alert requirement. IC Role / Device Role / Timing Role: ISL88708IB844Z supervises +5V rail (VDD), monitors battery voltage via PFI, asserts RST to halt MCU on undervoltage, and drives PFO for low-battery LED indicator. Use Value: Dual reset outputs eliminate need for external inverters; 10µA supply current extends runtime; 1.25V PFI threshold enables direct Li-ion cell voltage monitoring. |
Use Scenario: Embedded controller managing USB-C PD negotiation, where stable 3.3V rail must be confirmed before firmware execution. IC Role / Device Role / Timing Role: ISL88708IB844Z monitors 3.3V VDD, uses CPOR to extend tPOR to 500ms ensuring PD controller firmware loads before release, and provides manual reset via system button (MR). Use Value: Adjustable tPOR prevents premature boot failure during slow-ramping PD supplies; RST/RST outputs support both legacy and modern reset signaling standards. |
| Industrial PLC I/O Module | Smart Meter Communication Subsystem |
|
Use Scenario: DIN-rail mounted PLC module with isolated 24V-to-5V DC/DC converter and watchdog-critical fieldbus interface. IC Role / Device Role / Timing Role: ISL88708IB844Z supervises 5V output, feeds WDI with periodic UART idle pulses, and asserts RST on converter fault or software hang via WDO-to-MR feedback loop. Use Value: Watchdog independence from VDD allows detection of converter faults while maintaining reset integrity; -40°C to +85°C rating ensures operation in uncontrolled cabinets. |
Use Scenario: AMI smart meter with NB-IoT modem requiring reliable power sequencing and battery-backed real-time clock supervision. IC Role / Device Role / Timing Role: ISL88708IB844Z monitors main 3.3V supply (VDD), uses PFI to detect backup coin-cell voltage drop below 2.4V (via resistor divider), and asserts RST to preserve RTC state during brownout. Use Value: Accurate 4.38V threshold ensures clean reset at defined margin above 3.3V rail; PFO hysteresis prevents oscillation during gradual battery discharge. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6326US46D3+ | Fixed 4.63V reset threshold; no PFI/PFO or watchdog; only active-low reset output; 3µA supply current. | Lacks auxiliary monitoring and watchdog - suitable only for basic VDD supervision without power-fail or software safety features. | Select when minimal BOM count and lowest possible current (<3µA) outweigh need for PFI/WDT functionality. |
| TPS3808G33DBVR | 3.3V reset threshold; includes watchdog but no PFI input; offers programmable delay (1ms–10s) via external resistor; 16µA supply current. | Cannot monitor auxiliary voltages like battery or secondary rails; delay programming requires precision resistor instead of capacitor. | Choose when adjustable delay is required for non-standard timing windows and 3.3V rail supervision is primary need. |
Compared with MAX6326US46D3+ and TPS3808G33DBVR, the ISL88708IB844Z uniquely combines 4.38V VDD supervision, dual reset outputs, integrated PFI/PFO, and capacitor-adjustable tPOR - making it optimal for systems needing coordinated power sequencing, battery health monitoring, and software reliability assurance in one compact SOIC-8 device.
Availability
ISL88708IB844Z is available at Aetrix Electronics and suitable for portable medical devices, notebook power management subsystems, industrial PLC modules, and smart meter communication subsystems requiring stable component supply and long-term industrial-grade availability.
Supply support for ISL88708IB844Z 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 solutions, serving automotive, industrial, and infrastructure markets with high-reliability silicon.
The ISL88708IB844Z belongs to Renesas' legacy Intersil microprocessor supervisor product line, designed specifically for cost-sensitive, space-constrained embedded systems requiring multi-function voltage supervision with ultra-low power consumption.
FAQ
What is the exact reset voltage threshold for ISL88708IB844Z?
The ISL88708IB844Z has a factory-programmed VDD reset threshold of 4.38V, specified with ±1.8% accuracy over temperature. This value is encoded in the part marking "I44Z" and confirmed in the FN8092 datasheet Table on page 2 and Electrical Specifications on page 5. The threshold applies directly to the VDD pin and triggers reset assertion when supply falls below this level.
Does ISL88708IB844Z support adjustable power-on reset timeout?
Yes, the ISL88708IB844Z supports adjustable power-on reset timeout via the CPOR pin. Connecting an external capacitor from CPOR to GND extends the nominal 200ms tPOR - for example, a 50pF capacitor increases it to approximately 1.4s. This capability is explicitly documented in Figures 3 and 11 of the FN8092 datasheet and distinguishes ISL88708IB844Z from non-CPOR variants like ISL88706.
How does the watchdog timer function in ISL88708IB844Z?
The ISL88708IB844Z incorporates a 1.6s nominal watchdog timer that monitors the WDI pin. If WDI does not toggle (rising or falling edge) within this period, WDO is pulled low. The timer resets on any WDI transition or MR assertion. Unlike the reset outputs, WDO has no minimum pulse width and returns high immediately when VDD rises above threshold - a behavior confirmed in Figure 5 and Watchdog section on page 6 of FN8092.
Can ISL88708IB844Z monitor battery voltage?
Yes, the ISL88708IB844Z can monitor battery voltage using its PFI pin, which compares the applied voltage to an internal 1.25V reference. For batteries exceeding 1.25V (e.g., 3.0V Li-ion), a resistor divider scales the voltage down to the PFI input range. The resulting PFO output signals low-battery condition, and hysteresis (20mV) prevents chatter - details are provided in Figure 2 and Power-Fail Detection section on page 6 of FN8092.
What package type and lead finish does ISL88708IB844Z use?
The ISL88708IB844Z uses an 8-lead SOIC package per outline drawing M8.15, with matte tin (e3) RoHS-compliant terminations. It is qualified for Pb-free reflow soldering per J-STD-020, and the package dimensions (4.90mm × 3.90mm × 1.75mm) and land pattern are fully specified in the Package Outline Drawing on page 16 of FN8092 Rev 6.00.
ISL88708IB844Z 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:
- 4.38V
- Output:
- Open Drain, Push-Pull
- Reset:
- Active High/Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
ISL88708IB844Z FAQ
1.How can I place an order for ISL88708IB844Z through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL88708IB844Z 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 ISL88708IB844Z reliable?
The price and inventory of ISL88708IB844Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL88708IB844Z is usually 5 days.
3.What payment methods are accepted for ISL88708IB844Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL88708IB844Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL88708IB844Z?
ISL88708IB844Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL88708IB844Z 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 ISL88708IB844Z?
For technical support, including ISL88708IB844Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL88708IB844Z requirements.
6.How does Aetrix verify that ISL88708IB844Z is sourced from the original manufacturer or authorized distributors?
All ISL88708IB844Z 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 ISL88708IB844Z meets industry standards.
7.What is the process for return or replacement of ISL88708IB844Z?
All ISL88708IB844Z units undergo pre-shipment inspection (PSI). If there is an issue with ISL88708IB844Z, 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 ISL88708IB844Z part is unused and in its original packaging.
Return procedure for ISL88708IB844Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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