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Analog Devices Inc. ADM691AARWZ-REEL
- Part No.:
- ADM691AARWZ-REEL
- Manufacturer:
- Analog Devices Inc.
- Category:
- Supervisors
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
ADM691AARWZ-REEL.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,000
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Product details
Overview
ADM691AARWZ-REEL from Analog Devices is a microprocessor supervisory circuit integrating power-on reset, battery backup switchover, watchdog timer, chip enable gating, and power-fail detection. It features a 4.65 V ±3% reset threshold, 200 ms fixed or adjustable reset timeout, 1.6 s/100 ms selectable watchdog timeout, and supports VCC down to 1 V operation. It is used in industrial controllers and automotive ECUs requiring reliable brownout protection and nonvolatile memory retention.
For engineers reviewing the ADM691AARWZ-REEL datasheet, ADM691AARWZ-REEL pinout, ADM691AARWZ-REEL application, or ADM691AARWZ-REEL equivalent, key selection criteria include its dual-supply switchover capability (VCC/VBATT), open-drain RESET and complementary active-high RESET outputs, integrated CEIN/CEOUT write-protection logic, and 1.25 V PFI comparator for early power-fail warning.
Technical Context
The ADM691AARWZ-REEL implements a precision voltage detector with 15 mV hysteresis and internal oscillator-based timing for both reset generation and watchdog timeout. Its battery switchover uses PMOS (VCC→VOUT, RON = 0.75 Ω typ) and NMOS (VBATT→VOUT, RON = 7 Ω typ) switches, enabling seamless transition between main supply and backup source while maintaining VOUT regulation down to VBATT = 2.0 V.
It integrates three independent functional blocks: (1) a reset generator with 80 µs VCC-to-RESET delay and 200 ms timeout; (2) a transition-sensitive watchdog with WDI input capable of disabling via floating; and (3) a CMOS RAM write-protection gate where CEOUT follows CEIN only when VCC > 4.65 V, otherwise forcing CEOUT high to prevent corruption.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65 V ±3% - ensures compatibility with +5 V ±5% supplies and prevents false resets during nominal ripple. |
| Reset Timeout | 200 ms typ - holds µP in reset long enough for power supply and clock stabilization after power-up. |
| Watchdog Timeout | 1.6 s (long) or 100 ms (short) - configurable via OSC SEL/OSC IN to match software execution cycles. |
| VCC-to-VOUT RON | 0.75 Ω typ - enables 250 mA continuous output with <188 mV dropout at full load, minimizing heat dissipation. |
| Battery Standby Current | 0.04 µA typ - extends backup battery life for multi-year CMOS RAM retention without periodic recharge. |
| PFI Comparator Threshold | 1.25 V - allows precise early-warning detection of 5 V rail collapse using external resistor divider. |
| Operating Voltage Range | VCC = 4.75–5.5 V; VBATT = 2.0–5.5 V - supports wide-input backup sources including Li-ion, supercaps, and NiMH cells. |
Pinout & Package
ADM691AARWZ-REEL is housed in a 16-pin wide-body SOIC (R-16W) package with 1.27 mm pitch, RoHS-compliant, and rated for –40°C to +85°C operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VBATT | Backup battery input | Connects to external battery/capacitor; enables automatic switchover when VCC drops below reset threshold. |
| 2 VOUT | Switched output | Delivers either VCC or VBATT depending on switchover logic; powers CMOS RAM or low-power logic. |
| 3 VCC | Main supply input | +5 V system rail; powers internal circuitry and enables CEOUT pass-through mode. |
| 4 GND | Ground reference | Common return for all analog/digital functions; must be low-impedance for noise immunity. |
| 5 BATT ON | Battery status indicator | Open-drain logic output signaling VBATT is active; can drive external PNP base for higher-current backup. |
| 6 LOW LINE | Power-fail flag | Active-low signal indicating VCC has fallen below reset threshold; used for immediate system response. |
| 7 OSC IN | Oscillator control input | Selects reset/watchdog timing via external capacitor or clock; floating = 1.6 s, grounded = 100 ms. |
| 8 OSC SEL | Oscillator mode select | High/floating = internal oscillator; low = external clock/capacitor mode; includes 10 µA internal pullup. |
| 9 PFI | Power fail input | Noninverting input to 1.25 V comparator; monitors auxiliary rail or divided VCC for early warning. |
| 10 PFO | Power fail output | Active-low interrupt output tied to µP NMI; triggers data save before main supply collapse. |
| 11 WDI | Watchdog input | Three-level input (low/mid/high); toggling resets watchdog timer; floating disables watchdog function. |
| 12 CEOUT | Chip enable output | Buffered CEIN replica when VCC valid; forced high during reset to block RAM writes. |
| 13 CEIN | Chip enable input | Accepts µP CE/CS signal; gated internally to prevent invalid memory access during brownout. |
| 14 WDO | Watchdog output | Active-low status flag indicating watchdog timeout; remains low until next WDI transition. |
| 15 RESET | Active-low reset | Open-drain output asserting µP reset line; guaranteed functional down to VCC = 1 V. |
| 16 RESET | Active-high reset | Complementary push-pull output for processors requiring active-high reset assertion. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic battery backup switchover | Seamless transition between VCC and VBATT with <60 mV hysteresis, supporting 2.0–5.5 V backup sources. |
| Integrated RAM write protection | CEOUT forces high during reset/brownout, blocking µP write cycles to preserve data integrity in CMOS RAM. |
| Configurable watchdog timing | 100 ms or 1.6 s timeout selectable via pins-no external components required for basic operation. |
| Low-power battery monitoring | 0.04 µA standby current in backup mode enables >10-year coin-cell operation for critical memory retention. |
| Dual reset outputs | Open-drain RESET and push-pull RESET provide flexibility for legacy and modern µP interface requirements. |
| Early power-fail warning | 1.25 V PFI comparator with 25 µs response enables >10 ms advance notice before VCC collapse. |
Applications
| Industrial PLC Controller | Automotive Body Control Module |
|---|---|
Use Scenario: Continuous operation in factory-floor environments with fluctuating 24 VDC supplies converted to 5 V. IC Role / Device Role / Timing Role: Supervises 5 V rail, triggers controlled shutdown on undervoltage, and maintains SRAM state during brief outages. Use Value: Prevents firmware corruption during 10–100 ms brownouts by holding RESET low until VCC stabilizes above 4.65 V. |
Use Scenario: Power management in vehicle door modules exposed to cold-cranking (4.5 V) and load-dump transients. IC Role / Device Role / Timing Role: Monitors regulated 5 V bus, asserts PFO to initiate EEPROM save before ignition-off power decay. Use Value: Enables deterministic data persistence using 1.25 V PFI threshold set to detect 5 V rail collapse ≥5 ms before RESET activation. |
| Medical Infusion Pump | Point-of-Sale Terminal |
Use Scenario: Battery-backed operation during AC mains failure, requiring uninterrupted RAM retention and safe motor stop. IC Role / Device Role / Timing Role: Switches VOUT to VBATT at 4.65 V threshold, asserts LOW LINE to halt motor drivers, and gates CEOUT to freeze configuration registers. Use Value: Guarantees <0.04 µA battery drain in backup mode, extending lithium primary cell life to >5 years in standby. |
Use Scenario: Transaction rollback during unexpected power loss in retail kiosks powered by unregulated wall adapters. IC Role / Device Role / Timing Role: Uses WDI toggled by real-time OS heartbeat to detect software lockup and force hard reset via RESET pulse. Use Value: Eliminates need for external watchdog IC-1.6 s timeout matches typical Linux userspace watchdog daemon intervals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX691ACPE+ | Same pinout, 4.65 V reset threshold, but 120 µA standby current vs. ADM691AARWZ-REEL's 100 µA; no integrated CE gating. | Lacks CEIN/CEOUT write-protection logic-requires external gating for RAM safety. | Choose MAX691ACPE+ only if CE gating is unnecessary and legacy MAX compatibility is mandatory. |
| TPS3823-46DBVR | 4.63 V reset threshold, 200 ms timeout, but no battery switchover, watchdog, or PFI comparator-only reset supervisor. | Cannot replace ADM691AARWZ-REEL in battery-backed systems or watchdog-critical designs. | Select TPS3823-46DBVR only for cost-sensitive, single-function reset-only applications without backup or watchdog needs. |
Compared with MAX691ACPE+, ADM691AARWZ-REEL adds integrated CE gating and lower battery standby current; compared with TPS3823-46DBVR, it delivers full supervisory functionality-including switchover, watchdog, and PFI-enabling single-chip system-level power management.
Availability
ADM691AARWZ-REEL is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, and medical infusion pumps requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for ADM691AARWZ-REEL 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, automotive, communications, and healthcare markets since 1965.
The ADM691AARWZ-REEL belongs to Analog Devices' microprocessor supervisory circuit family, designed specifically to consolidate power monitoring, battery backup, watchdog, and memory protection into a single IC for space-constrained embedded systems.
FAQ
What is the reset threshold voltage for ADM691AARWZ-REEL?
The ADM691AARWZ-REEL has a guaranteed reset threshold of 4.65 V ±3%, with min/max values of 4.5 V and 4.75 V respectively. This ensures reliable reset assertion for +5 V systems operating within –5%/+10% tolerance, and the 15 mV hysteresis prevents chatter near the trip point. The threshold remains stable over –40°C to +85°C.
Does ADM691AARWZ-REEL support battery backup switching?
Yes, ADM691AARWZ-REEL provides automatic battery backup switching between VCC and VBATT inputs. When VCC drops below the reset threshold and VBATT > VCC, it connects VBATT to VOUT via a 7 Ω switch, sustaining CMOS RAM with <0.04 µA standby current. Switchover hysteresis is 60 mV to prevent oscillation.
How is the watchdog timeout configured on ADM691AARWZ-REEL?
The ADM691AARWZ-REEL watchdog timeout is selected using OSC SEL and OSC IN pins: with both floating, timeout is 1.6 s; with OSC IN grounded, it becomes 100 ms (except first timeout post-reset, which remains 1.6 s). External capacitors or clocks allow further adjustment per Table II in the datasheet.
Can ADM691AARWZ-REEL protect CMOS RAM during power failure?
Yes, ADM691AARWZ-REEL protects CMOS RAM using dual mechanisms: (1) CEOUT forces high when VCC falls below 4.65 V, blocking write operations; and (2) VOUT automatically switches to VBATT to maintain RAM supply. This ensures data integrity during brownouts, power-down, and momentary interruptions.
What package type is used for ADM691AARWZ-REEL?
ADM691AARWZ-REEL is supplied in a 16-pin wide-body SOIC (R-16W) package with 1.27 mm lead pitch, RoHS-compliant, and rated for –40°C to +85°C operation. It is distinct from the narrow SOIC (R-16N) and DIP (N-16) variants listed in the ordering guide.
ADM691AARWZ-REEL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.65V
- 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:
- 16-SOIC
ADM691AARWZ-REEL FAQ
1.How can I place an order for ADM691AARWZ-REEL through Aetrix?
Please submit a Request for Quotation (RFQ) for ADM691AARWZ-REEL 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 ADM691AARWZ-REEL reliable?
The price and inventory of ADM691AARWZ-REEL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ADM691AARWZ-REEL is usually 5 days.
3.What payment methods are accepted for ADM691AARWZ-REEL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ADM691AARWZ-REEL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ADM691AARWZ-REEL?
ADM691AARWZ-REEL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ADM691AARWZ-REEL 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 ADM691AARWZ-REEL?
For technical support, including ADM691AARWZ-REEL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ADM691AARWZ-REEL requirements.
6.How does Aetrix verify that ADM691AARWZ-REEL is sourced from the original manufacturer or authorized distributors?
All ADM691AARWZ-REEL 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 ADM691AARWZ-REEL meets industry standards.
7.What is the process for return or replacement of ADM691AARWZ-REEL?
All ADM691AARWZ-REEL units undergo pre-shipment inspection (PSI). If there is an issue with ADM691AARWZ-REEL, 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 ADM691AARWZ-REEL part is unused and in its original packaging.
Return procedure for ADM691AARWZ-REEL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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