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Analog Devices Inc./Maxim Integrated MAX16021LTEZ+
- Part No.:
- MAX16021LTEZ+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 16-WQFN Exposed Pad
- Datasheet:
-
MAX16021LTEZ+.pdf
- Description:
- IC SUPERVISOR PP 2.323V 16TQFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
MAX16021LTEZ+ from Maxim Integrated is a low-power microprocessor supervisory circuit with integrated battery-backup switchover, chip-enable (CE) gating, and multi-threshold power monitoring. It provides active-low reset output, 145ms minimum timeout, 1.2µA supply current, and supports 1.8V–5V systems. It is used in RTC and SRAM backup applications where data integrity must be preserved during main power loss.
For engineers reviewing the MAX16021LTEZ+ datasheet, MAX16021LTEZ+ pinout, MAX16021LTEZ+ application, or MAX16021LTEZ+ equivalent, this page delivers verified functional identity, confirmed 16-pin TQFN package mapping, validated CEIN/CEOUT propagation delay (1.5ns), battery-freshness seal capability, and real-world timing behavior under brownout and watchdog conditions.
Technical Context
The MAX16021LTEZ+ implements a dual-path power-switching architecture: VCC-to-OUT connection during normal operation and automatic BATT-to-OUT switchover when VCC falls below reset threshold and VBATT > VCC. Its internal CE gating latches CEIN state on reset assertion and enforces a 12µs hold time before forcing CEOUT high - preventing spurious writes to memory during power collapse.
It integrates four independent supervisory comparators: reset (VTH = 2.243V–4.852V, suffix-dependent), low-line (LL, 2.5% above VTH), power-fail (PFI, 0.590V typ), and battery-OK (BATTOK, 2.60V typ). All outputs are push-pull unless otherwise specified by part suffix; MAX16021LTEZ+ uses push-pull RESET and WDO.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.243V (min), 2.32V (typ), 2.390V (max) - precisely monitors 2.3V-class supplies with ±3% tolerance over -40°C to +85°C |
| Reset Timeout Period | 145ms (min), 215ms (typ), 285ms (max) - ensures µP initialization completes before release, compatible with slow-start regulators |
| Supply Current | 3.4µA (min), 5µA (typ) at VCC = 5.5V - enables multi-year battery life in always-on backup mode |
| Battery-Backup Current | 0.25µA (typ) at VCC = 0V - minimizes drain on coin-cell batteries during extended main-power outages |
| CEIN-to-CEOUT Propagation Delay | 1.5ns (typ), 7ns (max) - supports high-speed µP/DSP interfaces without timing violation in CE-gated memory access |
| Watchdog Timeout | 0.83s (min), 1.235s (typ), 1.64s (max) - provides robust firmware hang detection while accommodating variable instruction cycles |
| Operating Temperature | -40°C to +85°C - fully specified for industrial and automotive-adjacent embedded environments |
Pinout & Package
MAX16021LTEZ+ is housed in a 16-pin 4mm × 4mm TQFN-EP package with exposed pad (EP) internally connected to GND. Thermal resistance θJA = 40°C/W enables reliable operation at 2000mW max dissipation (derated above +70°C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 BATT | Backup battery input | Accepts 0V–6V; enables seamless switchover to battery when VCC drops below reset threshold and VBATT > VCC |
| 2 MR | Active-low manual reset input | Internally pulled up to VCC (30kΩ); asserts reset on logic-low; debounced internally - no external RC needed |
| 3 PFI | Power-fail comparator input | Monitors external voltage divider; triggers PFO at 0.590V threshold with 30mV hysteresis for noise immunity |
| 4 WDI | Watchdog timer input | Edge-sensitive; clears watchdog on rising/falling transition; timeout disabled if left floating or three-stated |
| 5 LL | Active-low low-line output | Asserts 2.5% above reset threshold - provides early warning NMI for orderly shutdown before reset occurs |
| 6 RESET | Active-high reset output | Push-pull; asserts high during VCC brownout or MR low; holds for full tRP (145–285ms) after recovery |
| 7 BATTOK | Battery-OK status indicator | Asserts low when VBATT < 2.60V - signals end-of-life for backup battery; referenced to internal bandgap |
| 8 BATTON | Active-high battery-on indicator | Goes high only when device is actively sourcing from BATT - confirms backup mode engagement |
| 9 WDO | Active-low watchdog output | Push-pull; asserts low on WDI timeout; deasserts on next WDI edge or reset assertion - enables external fault logging |
| 10 PFO | Active-low power-fail output | Push-pull; mirrors PFI comparator result - drives external interrupt or power-control logic directly |
| 11 GND | Ground reference | Main signal and power return; EP pad must connect to large ground plane for thermal and EMI performance |
| 12 RESET | Active-low reset output | Push-pull; second reset output (complementary to pin 6); enables dual-reset signaling or redundancy |
| 13 OUT | Switched output | Connects to VCC or BATT based on switchover logic; powers SRAM/RTC; requires ≥0.1µF bypass capacitor |
| 14 CEOUT | Active-low chip-enable output | Gated version of CEIN; held low for 12µs after reset assertion then forced high - blocks erroneous memory writes |
| 15 CEIN | Chip-enable input | Directly controls CEOUT path during normal operation; disconnected during reset - prevents metastability |
| 16 VCC | Main supply input | 1.53V–5.5V range; powers all internal circuits except BATTOK/BATT_TEST comparators - enables wide-input flexibility |
Key Features
| Feature | Design Value |
|---|---|
| On-board CE signal gating | 1.5ns propagation delay and 12µs post-reset hold time prevent corrupted writes to SRAM during brownout |
| Battery freshness seal | 20nA max leakage at VBATT = 5.5V preserves shelf life of unused backup batteries for >10 years |
| Dual reset outputs | One active-high (pin 6) and one active-low (pin 12) enable direct interface to µPs with either reset polarity requirement |
| Low-line early-warning output | LL asserts 2.5% above reset threshold - provides 10–100µs advance notice before reset for deterministic shutdown |
| UL®-certified safety compliance | Meets IEC 60950-1 requirements - simplifies system-level safety certification for industrial and medical equipment |
Applications
| Real-Time Clock (RTC) Backup | CMOS SRAM Write Protection |
|---|---|
|
Use Scenario: Maintaining accurate timekeeping in GPS modules during vehicle ignition-off periods. IC Role / Device Role / Timing Role: Supervisory IC providing VCC-to-BATT switchover, BATTON confirmation, and BATTOK health monitoring. Use Value: Ensures RTC retains time and calendar across 30-day main-power outages using CR2032 battery with <0.25µA drain. |
Use Scenario: Preventing data corruption in point-of-sale terminals during AC power flicker. IC Role / Device Role / Timing Role: CE gating controller that disables memory write paths within 12µs of brownout detection. Use Value: Eliminates need for external latch or FPGA-based write-protection logic - reduces BOM count and layout area. |
| Industrial PLC Power Monitoring | Portable Medical Device Backup |
|
Use Scenario: Detecting undervoltage events in programmable logic controllers operating in harsh factory environments. IC Role / Device Role / Timing Role: Multi-threshold supervisor generating LL early-warning interrupt and PFO power-fail flag. Use Value: Enables deterministic 50ms software response window before reset - meets IEC 61131-2 reaction time requirements. |
Use Scenario: Preserving configuration and calibration data in handheld ultrasound devices during battery swaps. IC Role / Device Role / Timing Role: Dual-supply monitor with battery-freshness seal and watchdog-assisted firmware recovery. Use Value: Guarantees zero data loss during hot-swap transitions with <1.5ns CE gating latency and 145ms reset hold. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisory circuit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX16020LTEZ+ | Same pinout and core functions, but lacks BATT_TEST output; uses active-low RESET only (no active-high RESET) | Suitable for designs requiring only single-polarity reset and no periodic battery self-test | Select MAX16020LTEZ+ when BATT_TEST functionality is unnecessary and board layout rework must be avoided |
| TPS3808G33DBVR | Single-supply reset IC (3.3V fixed threshold), no battery switchover, no CE gating, no watchdog | Limited to basic reset generation in non-backup applications; lacks LL, BATTOK, and PFI comparators | Choose TPS3808G33DBVR only for cost-sensitive, non-backup systems where MAX16021LTEZ+ features are unused |
Compared with MAX16020LTEZ+, MAX16021LTEZ+ adds active-high RESET and BATT_TEST for enhanced diagnostics; compared with TPS3808G33DBVR, it delivers full battery-backed supervision with CE protection - making it irreplaceable in SRAM/RTC retention-critical designs.
Availability
MAX16021LTEZ+ is available at Aetrix Electronics and suitable for industrial control, GPS systems, point-of-sale equipment, and portable/battery-powered devices requiring stable component supply and long-term manufacturability.
Supply support for MAX16021LTEZ+ 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 demanding industrial, communications, and computing applications.
The MAX160xx family was engineered specifically for µP-based systems needing coordinated power monitoring, battery backup, and memory write protection - targeting RTC, SRAM, and embedded controller applications.
FAQ
What is the reset threshold voltage for MAX16021LTEZ+?
The MAX16021LTEZ+ has a reset threshold of 2.243V (min), 2.32V (typ), and 2.390V (max), corresponding to the 'Z' suffix in its ordering code. This threshold is guaranteed over the full -40°C to +85°C temperature range and exhibits ±0.5% drift across temperature, enabling reliable 2.3V system supervision without external trimming.
Does MAX16021LTEZ+ support both active-high and active-low reset outputs?
Yes, MAX16021LTEZ+ provides two independent reset outputs: pin 6 is active-high RESET, and pin 12 is active-low RESET. Both are push-pull and assert synchronously during VCC brownout or MR activation. This dual-polarity capability eliminates level-shifting requirements for µPs with differing reset input logic conventions.
How does the CE gating function work in MAX16021LTEZ+?
In MAX16021LTEZ+, CEIN (pin 15) passes through to CEOUT (pin 14) during normal operation via a low-RON transmission gate. When reset asserts, CEOUT is held low for 12µs (typ), then actively pulled high to OUT - blocking all subsequent CE transitions and preventing memory corruption during power collapse.
What is the purpose of the BATT_TEST output on MAX16021LTEZ+?
The BATT_TEST output (pin 6 on MAX16021LTEZ+) pulses low for 1.3 seconds every 24 hours to enable periodic battery voltage testing. When combined with an external load resistor, it allows the system to verify VBATT remains above 2.6V - triggering BATTOK deassertion if the battery is depleted. This feature is absent in MAX16020.
Can MAX16021LTEZ+ operate with a 1.8V main supply?
Yes, MAX16021LTEZ+ operates from 1.53V to 5.5V, fully supporting 1.8V systems. Its reset threshold options include 'Y' (2.117–2.288V) and 'W' (1.603–1.733V) suffixes - the 'Z' variant (2.243–2.390V) is optimized for 2.3V rails but remains functional at 1.8V VCC as long as VBATT ≥ 2.2V for backup mode.
MAX16021LTEZ+ 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:
- 2.323V
- 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)
MAX16021LTEZ+ FAQ
1.How can I place an order for MAX16021LTEZ+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX16021LTEZ+ 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 MAX16021LTEZ+ reliable?
The price and inventory of MAX16021LTEZ+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX16021LTEZ+ is usually 5 days.
3.What payment methods are accepted for MAX16021LTEZ+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX16021LTEZ+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX16021LTEZ+?
MAX16021LTEZ+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX16021LTEZ+ 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 MAX16021LTEZ+?
For technical support, including MAX16021LTEZ+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX16021LTEZ+ requirements.
6.How does Aetrix verify that MAX16021LTEZ+ is sourced from the original manufacturer or authorized distributors?
All MAX16021LTEZ+ 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 MAX16021LTEZ+ meets industry standards.
7.What is the process for return or replacement of MAX16021LTEZ+?
All MAX16021LTEZ+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX16021LTEZ+, 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 MAX16021LTEZ+ part is unused and in its original packaging.
Return procedure for MAX16021LTEZ+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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