My Inquiry
My Account
Analog Devices Inc. ADM802LARNZ
- Part No.:
- ADM802LARNZ
- Manufacturer:
- Analog Devices Inc.
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ADM802LARNZ.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,614
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ADM802LARNZ from Analog Devices is a precision microprocessor supervisory circuit with active-low reset, 4.65 V reset threshold, 200 ms reset timeout, 1.6 s watchdog timer, and automatic battery switchover for CMOS RAM backup in embedded systems requiring reliable power monitoring.
For engineers reviewing the ADM802LARNZ datasheet, ADM802LARNZ pinout, ADM802LARNZ application, or ADM802LARNZ equivalent, this page delivers verified functional specifications, real-world timing behavior, battery switchover hysteresis, PFI comparator accuracy, and direct substitution guidance for industrial control and instrumentation designs.
Technical Context
The ADM802LARNZ integrates four core functions: a precision 4.65 V supply monitor with 40 mV hysteresis, a 1.6 s watchdog transition detector that resets on missing WDI toggles, a 1.25 V reference-based power fail comparator (PFI/PFO) with ±2% accuracy, and bidirectional PMOS battery switchover with 20 mV turn-on/off thresholds and 40 mV hysteresis.
It operates across VCC = 1.0 V to 5.5 V, asserts RESET down to 1 V VCC, draws only 100 µA quiescent current, and supports battery backup mode with 0.05 µA standby current - all implemented in an 8-lead SOIC package with pin-compatible footprint to legacy MAX802L.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65 V nominal; guaranteed 4.55–4.70 V at 25°C - ensures deterministic reset initiation during 5 V supply brownout. |
| Reset Timeout | 200 ms typical; 140–280 ms range - provides sufficient stabilization time for microprocessors after power recovery. |
| Watchdog Timeout | 1.6 s nominal; 1.0–2.25 s range - enables robust software execution monitoring without false triggers from transient delays. |
| PFI Threshold Accuracy | ±2% (1.225–1.275 V) - allows precise early-warning power-fail detection using external resistor dividers. |
| Battery Switchover Hysteresis | 40 mV - prevents oscillation during VCC/VBATT crossover near switchover point. |
| Quiescent Current | 100 µA max at VCC = 4.75–5.5 V - minimizes system power overhead in always-on monitoring applications. |
| VCC Operating Range | 1.0 V to 5.5 V - guarantees RESET assertion integrity even during deep brownout or partial power loss. |
Pinout & Package
ADM802LARNZ is housed in an 8-lead SOIC (SO-8) package with standard 1.27 mm pitch, 5.00 mm × 4.00 mm body, and gull-wing leads - compatible with automated PCB assembly and thermal performance up to 110°C/W θJA.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC | Main power supply input | +5 V nominal supply; powers internal circuits and sources VOUT when above reset threshold. |
| VBATT | Backup battery input | Connects to 3 V lithium or capacitor backup; automatically engages when VCC drops 20 mV below VBATT. |
| VOUT | Switched output rail | Delivers VCC or VBATT (whichever higher) to RAM or low-power logic; supports ≥100 mA load in normal mode. |
| GND | Ground reference | Common return for all analog and digital functions; required for accurate voltage monitoring and comparator operation. |
| PFI | Power fail comparator input | Accepts divided-down supply voltage; triggers PFO low when input falls below 1.25 V reference. |
| PFO | Power fail output | Active-low open-drain signal used to interrupt µP or initiate orderly shutdown before main supply collapse. |
| RESET | Reset output | Active-low push-pull output asserted during VCC brownout, watchdog timeout, or power-up; holds low ≥200 ms. |
| WDI | Watchdog input | Three-level input (high/low/floating); resets watchdog timer on each transition; disables timer if left floating. |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed reset assertion down to 1 V VCC | Ensures microprocessor remains held in reset during deep brownout, preventing undefined state or corruption. |
| ±2% PFI comparator accuracy | Enables reliable early power-fail warning with minimal external component tolerance dependency. |
| 40 mV battery switchover hysteresis | Eliminates chatter during VCC recovery near VBATT level, ensuring clean RAM power handover. |
| 100 µA max quiescent current | Reduces standby power draw in battery-backed systems, extending operational lifetime of backup sources. |
| Pin-compatible upgrade path from MAX802L | Allows drop-in replacement in existing designs without layout or firmware changes. |
Applications
| Industrial PLC Control | Medical Instrumentation |
|---|---|
Use Scenario: Power monitoring and RAM retention during mains interruption in programmable logic controllers with nonvolatile configuration storage. IC Role / Device Role / Timing Role: Supervisory IC providing brownout reset, watchdog supervision, and seamless VBATT-to-VOUT switchover for SRAM backup. Use Value: Prevents configuration loss and ensures deterministic restart after brief AC dropout via 200 ms reset hold and 1 V reset assertion. | Use Scenario: Maintaining real-time clock and patient data buffers during battery-swapped or low-power diagnostic modes in portable monitors. IC Role / Device Role / Timing Role: Voltage supervisor enabling safe memory retention and controlled shutdown via PFO-triggered NMI interrupt. Use Value: Delivers ±2% PFI accuracy for predictable power-fail warning and 0.05 µA battery standby current to extend backup runtime. |
| Telecom Base Station Management | Automotive Infotainment Head Unit |
Use Scenario: Monitoring 5 V management rail in remote radio units where intermittent power faults must not corrupt firmware state. IC Role / Device Role / Timing Role: Reset generator and watchdog enforcer ensuring firmware integrity during unstable DC-DC converter output. Use Value: 1.6 s watchdog timeout detects stalled boot sequences, while 4.65 V reset threshold aligns with telecom 5 V tolerance specs. | Use Scenario: Securing infotainment system RAM during ignition cycling or accessory-mode transitions where VCC dips below 4.65 V. IC Role / Device Role / Timing Role: Battery switchover controller preserving user settings and audio buffer state during engine cranking events. Use Value: 20 mV switchover threshold and 40 mV hysteresis prevent glitching during fast VCC transients common in automotive electrical environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX802LCSA+ | Same 4.65 V reset threshold, 200 ms timeout, and SO-8 package; but higher 120 µA quiescent current and no guaranteed 1 V reset assertion. | Lacks 1 V reset guarantee and ±2% PFI accuracy; suitable only where brownout depth is shallow and PFI precision is noncritical. | Select MAX802LCSA+ only if legacy MAXIM compatibility is mandatory and 1 V operation is not required. |
| TPS3808G16DBVR | Adjustable reset threshold (via external resistor), 200 ms timeout, 1.8–6.0 V VCC range; but no integrated battery switchover or PFI/PFO comparator. | Requires external MOSFET and divider for battery backup; lacks power-fail warning capability - adds BOM cost and board space. | Choose TPS3808G16DBVR only when adjustable reset voltage is needed and battery switchover is implemented separately. |
Compared with ADM802LARNZ, MAX802LCSA+ offers pin compatibility but sacrifices brownout robustness and PFI precision, while TPS3808G16DBVR trades integration for flexibility - making ADM802LARNZ optimal for compact, battery-backed 5 V systems needing guaranteed 1 V reset and ±2% power-fail detection.
Availability
ADM802LARNZ is available at Aetrix Electronics and suitable for industrial PLC control, medical instrumentation, telecom base station management, and automotive infotainment head units requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for ADM802LARNZ 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
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, communications, automotive, and healthcare markets since 1965.
The ADM802LARNZ belongs to Analog Devices' microprocessor supervisory circuit product line, designed specifically to provide integrated power monitoring, reset generation, watchdog supervision, and battery backup switching for mission-critical embedded systems.
FAQ
What is the guaranteed reset voltage threshold range for ADM802LARNZ?
The ADM802LARNZ has a guaranteed reset voltage threshold of 4.55 V to 4.70 V at 25°C, with 4.65 V as the nominal value. This specification ensures consistent brownout detection across temperature and process variations, and is distinct from the 4.40 V threshold used in the ADM802M variant. The 40 mV hysteresis prevents chatter during supply recovery.
Does ADM802LARNZ support operation below 2.0 V VCC?
Yes, ADM802LARNZ guarantees RESET assertion down to 1.0 V VCC, enabling reliable microprocessor hold during deep brownout conditions. Its internal circuitry remains functional and the RESET output stays low until VCC rises above the 4.65 V threshold and remains stable for 200 ms. This capability is confirmed in the Absolute Maximum Ratings and functional specifications sections of the official Analog Devices datasheet for ADM802LARNZ.
How does the battery switchover function work in ADM802LARNZ?
The ADM802LARNZ uses an internal PMOS switch to connect VCC to VOUT during normal operation. When VCC falls 20 mV below VBATT, it automatically switches VOUT to VBATT to maintain power to attached RAM. On power-up, VOUT reverts to VCC once VCC exceeds VBATT by 20 mV. The 40 mV hysteresis prevents oscillation, and standby current in battery mode is as low as 0.05 µA - all verified in the ADM802LARNZ datasheet's "Battery Switchover Section".
What is the accuracy of the PFI power fail comparator in ADM802LARNZ?
The PFI comparator in ADM802LARNZ has a guaranteed accuracy of ±2%, with a nominal 1.25 V internal reference and trip range of 1.225 V to 1.275 V. This enables precise early-warning power-fail detection using external resistive dividers, and is tighter than the ±2.5% spec of the ADM690A/ADM692A series. The value is explicitly stated in the "ADM802L/M" row of the "PFI Input Threshold" table in the ADM802LARNZ datasheet.
Can ADM802LARNZ replace MAX802L in existing designs?
Yes, ADM802LARNZ is a pin-compatible and functionally equivalent upgrade for MAX802L, offering identical SO-8 footprint, 4.65 V reset threshold, 200 ms timeout, and battery switchover functionality. It improves upon MAX802L with guaranteed 1 V reset assertion, ±2% PFI accuracy, and lower 100 µA max quiescent current. Analog Devices explicitly states this compatibility in the "GENERAL DESCRIPTION" section of the ADM802LARNZ datasheet.
ADM802LARNZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.65V
- Output:
- Push-Pull, Totem Pole
- 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
ADM802LARNZ FAQ
1.How can I place an order for ADM802LARNZ through Aetrix?
Please submit a Request for Quotation (RFQ) for ADM802LARNZ 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 ADM802LARNZ reliable?
The price and inventory of ADM802LARNZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ADM802LARNZ is usually 5 days.
3.What payment methods are accepted for ADM802LARNZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ADM802LARNZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ADM802LARNZ?
ADM802LARNZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ADM802LARNZ 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 ADM802LARNZ?
For technical support, including ADM802LARNZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ADM802LARNZ requirements.
6.How does Aetrix verify that ADM802LARNZ is sourced from the original manufacturer or authorized distributors?
All ADM802LARNZ 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 ADM802LARNZ meets industry standards.
7.What is the process for return or replacement of ADM802LARNZ?
All ADM802LARNZ units undergo pre-shipment inspection (PSI). If there is an issue with ADM802LARNZ, 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 ADM802LARNZ part is unused and in its original packaging.
Return procedure for ADM802LARNZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ADM802LARNZ Tags
-
MIC826SYMT-TR
Microchip Technology
-
APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
-
TPS3828-33DBVR
Texas Instruments
-
V6340RSP3B+
EM Microelectronic
-
EM6325CXSP5B-2.9+
EM Microelectronic
-
MCP120T-300I/TT
Microchip Technology
-
MCP130T-315I/TT
Microchip Technology
-
MCP120T-475I/TT
Microchip Technology
-
MCP111T-300E/TT
Microchip Technology
-
MCP120T-315I/TT
Microchip Technology
-
MCP809T-315I/TT
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
