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Analog Devices Inc./Maxim Integrated MAX16021LTEW+
- Part No.:
- MAX16021LTEW+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 16-WQFN Exposed Pad
- Datasheet:
-
MAX16021LTEW+.pdf
- Description:
- IC SUPERVISOR PP 1.661V 16TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,322
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Product details
Overview
MAX16021LTEW+ from Maxim Integrated is a low-power microprocessor supervisory circuit with integrated battery-backup switchover, chip-enable (CE) gating, and power-fail monitoring. It monitors 1.8V systems (reset threshold 1.616V–1.710V), provides 145ms reset timeout, 1.2µA supply current, and 1.5ns CEIN-to-CEOUT propagation delay. It is used in real-time clock (RTC) backup and CMOS memory write protection during brownout.
For engineers reviewing the MAX16021LTEW+ datasheet, MAX16021LTEW+ pinout, MAX16021LTEW+ application, or MAX16021LTEW+ equivalent, key selection criteria include its 16-pin TQFN package, push-pull reset output, 1.8V system compatibility, battery-OK/battery-on indicators, and CE gating for SRAM write protection in portable and industrial systems.
Technical Context
The MAX16021LTEW+ implements a dual-supply supervisory architecture with VCC-to-BATT switchover controlled by internal comparators and MOSFET switching. Its reset logic combines power-up, brownout, and manual reset inputs with a 145ms minimum timeout, while the watchdog timer offers 1.2s typical timeout with edge-triggered clearing.
It integrates dedicated analog blocks: a 0.590V power-fail comparator (PFI/PFO) with 30mV hysteresis, a low-line (LL) comparator set 2.5% above reset threshold, and independent BATTOK (2.508–2.673V threshold) and BATTON outputs. CE gating operates only when reset is deasserted, with 12µs hold time if CEIN is low at reset assertion.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 1.616V (min) to 1.710V (max) - precisely targets 1.8V supply monitoring with ±3% tolerance |
| Supply Current | 5µA (typ) at VCC = 5.5V - enables ultra-low-power operation in always-on systems |
| Battery-Backup Current | 0.25µA (typ) at VCC = 0V - minimizes battery drain during extended backup mode |
| Reset Timeout Period | 145ms (min) - ensures reliable µP initialization after power recovery |
| CEIN-to-CEOUT Delay | 1.5ns (typ) - supports high-speed µP/DSP interfaces without timing violation |
| Operating Temperature | -40°C to +85°C - qualified for industrial and automotive-adjacent environments |
| Power-Fail Threshold | 0.590V ±19mV - allows precise external resistor-divider setup for sub-1V monitoring |
Pinout & Package
MAX16021LTEW+ is housed in a 16-pin 4mm × 4mm TQFN-EP package with exposed pad (EP) connected to GND for thermal management. Pin 1 is BATT; pin 16 is VCC; EP is internally grounded and must be soldered to a large PCB ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BATT (Pin 1) | Backup battery input | Connects to 2.2–5.5V backup source; enables automatic switchover when VCC falls below reset threshold and VBATT > VCC |
| MR (Pin 2) | Active-low manual reset input | Internally pulled up to VCC (30kΩ); asserts reset on logic-low transition; debounced internally |
| PFI (Pin 3) | Power-fail comparator input | Accepts resistive divider output; referenced to 0.590V internal threshold with 30mV hysteresis |
| WDI (Pin 4) | Watchdog timer input | Edge-sensitive; resets watchdog on rising/falling edge; disabled if left floating or three-stated |
| LL (Pin 5) | Active-low low-line indicator | Asserts 2.5% above reset threshold - provides early warning NMI before reset triggers |
| BATT_TEST (Pin 6) | Battery-test pulse output | Open-drain; pulses low for 1.3s every 24h to verify battery health; triggers BATTOK deassertion if VBATT < 2.6V |
| RESET (Pin 12) | Active-low reset output | Push-pull driver; asserts during VCC brownout, MR low, or watchdog timeout; holds for ≥145ms |
| CEIN (Pin 15) | Chip-enable input | Directly gates CE signal path; must be tied to GND or OUT if unused; controls CEOUT only when reset is deasserted |
| CEOUT (Pin 14) | Active-low chip-enable output | Drives SRAM CE pin; held low for 12µs if CEIN is low at reset assertion; otherwise passes CEIN transparently |
| VCC (Pin 16) | Main supply input | Operates from 1.53V to 5.5V; powers all internal circuits except battery-monitoring comparators |
Key Features
| Feature | Design Value |
|---|---|
| Battery-freshness seal | Prevents premature battery discharge via 20nA max leakage at VBATT = 5.5V - extends shelf life of sealed systems |
| On-board CE gating | 1.5ns propagation delay and 12µs hold time prevent SRAM write corruption during power failure without external logic |
| Dual reset output configuration | Separate active-low RESET (Pin 12) and active-high RESET (Pin 6) - supports mixed-signaling µP platforms |
| Integrated battery status indicators | BATTOK (2.508–2.673V threshold) and BATTON outputs enable autonomous battery health monitoring and backup-mode detection |
| UL® certification | Complies with IEC 60950-1 - satisfies safety requirements for industrial and commercial end equipment without additional certification effort |
Applications
| Real-Time Clock (RTC) Backup | CMOS SRAM Write Protection |
|---|---|
Use Scenario: Maintaining RTC timekeeping and calendar data during main power loss in GPS modules or set-top boxes. IC Role / Device Role / Timing Role: Supervisory IC providing seamless VCC-to-BATT switchover, BATTON assertion to signal backup mode, and BATTOK monitoring to detect battery depletion. Use Value: Ensures continuous RTC operation with <0.25µA battery drain and prevents time/date corruption during brownout events. | Use Scenario: Preventing accidental writes to static RAM during voltage sag in point-of-sale terminals or industrial controllers. IC Role / Device Role / Timing Role: CE gating controller that disables SRAM chip-enable during reset assertion using 1.5ns-delay path and 12µs hold time. Use Value: Eliminates need for external CE logic or µP firmware intervention, reducing BOM count and improving data integrity under transient faults. |
| Industrial Power Monitoring | Portable Equipment Brownout Response |
Use Scenario: Detecting incipient power failure in PLCs or motor drives using PFI input and LL output for predictive shutdown. IC Role / Device Role / Timing Role: Dual-threshold supervisor with 0.590V PFI comparator and 2.5% higher LL output - delivers staged alerting before reset. Use Value: Enables nonmaskable interrupt (NMI) generation for orderly firmware shutdown, avoiding data loss or unsafe state transitions. | Use Scenario: Extending runtime and preserving state in handheld medical devices or barcode scanners during battery voltage droop. IC Role / Device Role / Timing Role: Low-quiescent-current (1.2µA) supervisor with battery-freshness seal and 145ms reset timeout - balances responsiveness and energy efficiency. Use Value: Delivers >1-year shelf life with sealed battery and maintains system state across intermittent power interruptions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisory circuit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX16020LTEW+ | Same pinout and function but lacks BATT_TEST output; no periodic battery self-test capability | Suitable where continuous battery health verification is not required; lower test overhead | Select MAX16020LTEW+ when BATT_TEST functionality is unnecessary and cost optimization is prioritized |
| TPS3808G18DBVR | Single-supply 1.8V supervisor only; no battery switchover, CE gating, or BATTOK/BATTON outputs | Limited to basic reset generation in non-backup systems; requires external circuitry for battery support | Choose TPS3808G18DBVR only for simple 1.8V reset-only applications without backup or memory protection needs |
Compared with MAX16020LTEW+, MAX16021LTEW+ adds BATT_TEST for automated battery validation; compared with TPS3808G18DBVR, it integrates full battery management, CE control, and multi-output supervision - eliminating 3–4 discrete components in RTC/SRAM backup designs.
Availability
MAX16021LTEW+ is available at Aetrix Electronics and suitable for real-time clock backup, industrial power monitoring, and portable equipment requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for MAX16021LTEW+ 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
Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, computing, and communications markets.
The MAX160xx family delivers integrated power supervision, battery backup, and memory protection for µP-based systems - targeting applications where reliability, low power, and board space reduction are critical.
FAQ
What is the reset threshold voltage range for MAX16021LTEW+?
The MAX16021LTEW+ has a reset threshold range of 1.616V (minimum) to 1.710V (maximum), optimized for reliable monitoring of 1.8V power supplies. This range is specified across -40°C to +85°C and includes ±3% tolerance, ensuring robust brownout detection without false triggering during normal operation. The exact threshold is fixed per device suffix 'W' and cannot be adjusted externally.
Does MAX16021LTEW+ support both VCC and battery power sources simultaneously?
Yes, MAX16021LTEW+ supports seamless dual-source operation: it connects OUT to VCC during normal operation and automatically switches OUT to BATT when VCC falls below the reset threshold and VBATT exceeds VCC. The switchover is handled by internal MOSFETs with on-resistance as low as 2.6Ω (at VCC = 1.91V), enabling efficient backup power delivery to SRAM or RTC without external diodes or controllers.
How does the CE gating function work in MAX16021LTEW+?
In MAX16021LTEW+, CE gating passes CEIN to CEOUT transparently during normal operation (reset deasserted), with 1.5ns propagation delay. When reset asserts, CEOUT is held low for 12µs if CEIN was low at assertion time - allowing completion of ongoing memory access - then pulled high to OUT. This prevents spurious writes to SRAM during power failure without µP intervention or external logic.
What is the purpose of the BATT_TEST output on MAX16021LTEW+?
The BATT_TEST output on MAX16021LTEW+ is an open-drain pin that pulses low for 1.3 seconds every 24 hours to activate an external load for battery health verification. If VBATT drops below 2.6V during this test, BATTOK deasserts, signaling battery depletion. This autonomous self-test eliminates manual battery checks and enables predictive maintenance in unattended systems like remote sensors or GPS trackers.
Can MAX16021LTEW+ operate with a 1.53V supply voltage?
Yes, MAX16021LTEW+ operates down to 1.53V on VCC, supporting ultra-low-voltage systems such as energy-harvesting or coin-cell-powered devices. At 1.53V, it maintains full functionality including reset generation, watchdog timing, and CE gating, with supply current dropping to ~1.2µA. The reset threshold remains valid, and BATT switchover activates when VBATT > VCC - enabling operation even as main supply decays near cutoff.
MAX16021LTEW+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 16-WQFN Exposed Pad
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 1.661V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active High/Active Low
- Reset Timeout:
- 145ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TQFN (4x4)
MAX16021LTEW+ FAQ
1.How can I place an order for MAX16021LTEW+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX16021LTEW+ 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 MAX16021LTEW+ reliable?
The price and inventory of MAX16021LTEW+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX16021LTEW+ is usually 5 days.
3.What payment methods are accepted for MAX16021LTEW+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX16021LTEW+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX16021LTEW+?
MAX16021LTEW+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX16021LTEW+ 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 MAX16021LTEW+?
For technical support, including MAX16021LTEW+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX16021LTEW+ requirements.
6.How does Aetrix verify that MAX16021LTEW+ is sourced from the original manufacturer or authorized distributors?
All MAX16021LTEW+ 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 MAX16021LTEW+ meets industry standards.
7.What is the process for return or replacement of MAX16021LTEW+?
All MAX16021LTEW+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX16021LTEW+, 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 MAX16021LTEW+ part is unused and in its original packaging.
Return procedure for MAX16021LTEW+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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