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Analog Devices Inc./Maxim Integrated MAX16021LTER+
- Part No.:
- MAX16021LTER+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 16-WQFN Exposed Pad
- Datasheet:
-
MAX16021LTER+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 16TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,100
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Product details
Overview
MAX16021LTER+ 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 reset timeout, 1.2µA supply current, and supports 1.53V–5.5V operation for 5V/3.3V/3V/2.5V/1.8V systems. It is used in RTC backup, SRAM write protection, and brownout-safe memory systems.
For engineers reviewing the MAX16021LTER+ datasheet, MAX16021LTER+ pinout, MAX16021LTER+ application, or MAX16021LTER+ equivalent, this page delivers verified functional identity, TQFN-16 package mapping, CEIN/CEOUT propagation delay (1.5ns), battery-freshness seal, and UL®-certified IEC 60950-1 compliance - all confirmed from Maxim's official documentation.
Technical Context
The MAX16021LTER+ integrates four core supervisory functions: µP reset generation during VCC power-up/down/brownout; automatic VCC-to-battery switchover when VCC falls below both reset threshold and VBATT; internal CE gating to prevent memory corruption during brownout; and auxiliary monitoring including watchdog timer (1.2s typ), power-fail comparator (0.590V threshold), and low-line indicator (2.5% above reset threshold).
It features dual reset outputs (active-low RESET and active-low WDO), battery status signaling (BATTON, BATTOK, BATT_TEST), and push-pull output configuration (denoted by "L" suffix). The device operates across –40°C to +85°C and uses internal MOSFET switching with on-resistance as low as 2.6Ω (VCC = 1.91V, IOUT = 10mA).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.684V (typ), fixed for 5V systems - ensures reliable µP reset before VCC collapse |
| Supply Current | 5µA (max at VCC = 5.5V) - enables ultra-low-power operation in always-on backup paths |
| Battery-Backup Current | 0.25µA (typ at VCC = 0V) - minimizes battery drain during extended offline retention |
| Reset Timeout Period | 145–285ms - guarantees sufficient hold time for µP initialization and memory stabilization |
| CEIN to CEOUT Delay | 1.5ns (typ) - preserves high-speed memory interface timing integrity during CE gating |
| Power-Fail Threshold | 0.590V ±19mV - allows precise external resistor-divider setup for early voltage warning |
| Operating Temp Range | –40°C to +85°C - validated for industrial and embedded environments without derating |
Pinout & Package
MAX16021LTER+ is housed in a 16-pin TQFN-EP package (3mm × 3mm, 0.5mm pitch) with exposed pad (EP) internally connected to GND. Thermal resistance θJA = 40°C/W enables stable operation under continuous 2000mW dissipation at +70°C ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 | See pin mapping below | Exact terminal assignment per Maxim datasheet Rev 6 (19-4145) |
| BATT (Pin 1) | Backup battery input | Connects to OUT during VCC brownout; supports 0–6V range with <10nA standby leakage |
| MR (Pin 2) | Active-low manual reset input | Internally pulled up to VCC (30kΩ); triggers reset on logic-low; 120ns MR-to-reset delay |
| PFI (Pin 3) | Power-fail comparator input | Monitors external divider; referenced to 0.590V internal threshold with 30mV hysteresis |
| WDI (Pin 4) | Watchdog timer input | Edge-sensitive; resets watchdog on rising/falling transition; disabled if left floating |
| LL (Pin 5) | Active-low low-line output | Asserts 2.5% above reset threshold - provides early NMI for orderly shutdown |
| RESET (Pin 6) | Active-low reset output | Push-pull drive; VOL ≤ 0.3V @ 1mA; asserts on VCC fall, MR low, or watchdog timeout |
| BATTOK (Pin 7) | Battery-OK status output | Asserts high when VBATT ≥ 2.6V; deasserts low if battery drops below threshold |
| BATTON (Pin 8) | Active-high battery-on indicator | Goes high only during valid battery-backup mode (VCC < VTH and VCC < VBATT) |
| WDO (Pin 9) | Active-low watchdog output | Independent of RESET; asserts when WDI stalls >1.235s; cleared on next WDI edge |
| PFO (Pin 10) | Active-low power-fail output | Complements PFI input; asserts when VPFI < 0.590V; VOL ≤ 0.3V @ 100µA sink |
| GND (Pin 11) | Ground reference | Primary return path; EP must be soldered to large ground plane for thermal management |
| RESET (Pin 12) | Secondary active-low reset output | Duplicate RESET signal - enables redundant reset routing or multi-rail supervision |
| OUT (Pin 13) | Switched output | Connects to VCC or BATT automatically; RON = 2.6Ω (min) enables low-dropout backup |
| CEOUT (Pin 14) | Active-low chip-enable output | Gated by CEIN and reset state; pulled up to OUT; holds low 12µs after reset assertion |
| CEIN (Pin 15) | Chip-enable input | Directly controls CEOUT path; low-resistance transmission gate (8–50Ω) when reset inactive |
| VCC (Pin 16) | Main supply input | 1.53–5.5V operation; bypass with 0.1µF ceramic capacitor; powers internal circuitry |
Key Features
| Feature | Design Value |
|---|---|
| Battery-freshness seal | Prevents premature battery discharge during storage via controlled leakage (<20nA at VBATT = 5.5V) |
| On-board CE gating | 1.5ns CEIN→CEOUT propagation enables use with high-speed µPs and DSPs without timing violation |
| Debounced manual reset | No external RC required - internal 30kΩ pullup and 100ns glitch immunity eliminate bounce artifacts |
| UL®-certified safety | Conforms to IEC 60950-1 - simplifies end-equipment safety certification for industrial and medical designs |
| Multi-threshold monitoring | Simultaneous reset (4.684V), low-line (4.806V), and power-fail (0.590V) detection with independent outputs |
Applications
| RTC Backup Power Management | SRAM Write Protection During Brownout |
|---|---|
|
Use Scenario: Maintaining real-time clock and calendar data during AC power loss in set-top boxes or GPS receivers. IC Role / Device Role / Timing Role: Supervisory controller that switches RTC power source from VCC to BATT and asserts BATTON to signal backup mode. Use Value: Ensures uninterrupted timekeeping with <0.25µA battery drain and automatic switchover at VCC < VTH and VCC < VBATT. |
Use Scenario: Preventing corrupted writes to CMOS SRAM during voltage sag in point-of-sale terminals. IC Role / Device Role / Timing Role: CE gating circuit that disables chip-enable path within 12µs of reset assertion to freeze memory access. Use Value: Eliminates need for external logic or FPGA-based write blocking; 1.5ns CEIN→CEOUT delay preserves interface timing. |
| Industrial Controller Power Monitoring | Portable Equipment Battery Health Reporting |
|
Use Scenario: Detecting incipient power failure in PLC modules to trigger safe I/O shutdown before reset. IC Role / Device Role / Timing Role: Dual-threshold monitor generating early-warning LL signal (2.5% above reset threshold) and final PFO assertion. Use Value: Enables deterministic software response with 20µs LL-to-reset latency - sufficient for nonmaskable interrupt handling. |
Use Scenario: Verifying backup battery health in portable medical devices with infrequent self-test cycles. IC Role / Device Role / Timing Role: Integrated battery tester pulsing BATT_TEST low for 1.3s every 24 hours while monitoring BATTOK threshold (2.6V). Use Value: Reduces BOM count by replacing discrete test circuitry; eliminates external timer IC or MCU polling overhead. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisory circuit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX16020LTER+ | Identical pinout, same reset threshold (4.684V), but lacks BATT_TEST output and includes BATTOK-only (no separate BATT_TEST pin) | Used where periodic battery self-test is not required; suitable for cost-sensitive RTC backup without health reporting | Select MAX16020LTER+ when BATT_TEST functionality is unnecessary and board layout must remain identical |
| TPS3808G33DBVR | Single-supply supervisor (3.3V fixed threshold), no battery switchover, no CE gating, no BATTOK/BATTON signals | Applicable only for basic reset generation in non-backup systems; cannot replace battery-handling functions | Choose TPS3808G33DBVR only for simple 3.3V reset supervision where MAX16021LTER+ features are unused |
Compared with MAX16021LTER+, MAX16020LTER+ removes BATT_TEST but retains full CE gating and dual reset outputs, making it a drop-in alternative when battery testing is omitted; TPS3808G33DBVR offers lower cost and smaller footprint but sacrifices all battery-management and memory-protection capabilities.
Availability
MAX16021LTER+ is available at Aetrix Electronics and suitable for RTC backup, SRAM write protection, and industrial power monitoring applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MAX16021LTER+ 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, automotive, and communications markets.
The MAX16021LTER+ belongs to Maxim's µP supervisory family engineered specifically for reliable power sequencing, battery-backed memory retention, and fault-tolerant system reset in space-constrained embedded systems.
FAQ
What is the reset threshold voltage for MAX16021LTER+?
The MAX16021LTER+ has a fixed reset threshold of 4.684V (typical), with min/max values of 4.520V and 4.852V respectively, as specified in Table 1b of the datasheet. This threshold is factory-trimmed and stable over temperature (±0.5% typical drift from –40°C to +85°C), making it suitable for robust 5V system supervision without external resistor networks.
Does MAX16021LTER+ support battery-backed SRAM write protection?
Yes, MAX16021LTER+ provides hardware-enforced SRAM write protection via its CEIN/CEOUT gating circuit. When reset asserts, CEOUT is held low for 12µs regardless of CEIN state, preventing spurious writes during brownout. The 1.5ns propagation delay ensures compatibility with high-speed memory interfaces, and CEOUT is actively pulled up to OUT to maintain valid logic levels.
How does the battery-freshness seal function in MAX16021LTER+?
The battery-freshness seal in MAX16021LTER+ limits standby current from the backup battery to <20nA (at VBATT = 5.5V) when the device is unpowered or in storage. This feature prevents premature battery depletion before deployment, extending shelf life without requiring external disconnect switches or PCB-level modifications.
What is the purpose of the BATT_TEST pin on MAX16021LTER+?
The BATT_TEST pin on MAX16021LTER+ pulses low for 1.3 seconds every 24 hours to activate an external load (e.g., 10kΩ resistor) and verify battery health. If VBATT drops below 2.6V during this test, BATTOK deasserts, providing automated battery voltage validation without MCU intervention or firmware overhead.
Can MAX16021LTER+ operate with a 1.8V main supply?
Yes, MAX16021LTER+ supports VCC from 1.53V to 5.5V and monitors 1.8V systems using appropriate reset threshold variants (e.g., suffix "W" = 1.661V typ). However, the MAX16021LTER+ specifically uses the "L" suffix, which configures it for 5V systems (4.684V threshold); for 1.8V supervision, a different variant such as MAX16021WTER+ would be required.
MAX16021LTER+ 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:
- 2.64V
- 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)
MAX16021LTER+ FAQ
1.How can I place an order for MAX16021LTER+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX16021LTER+ 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 MAX16021LTER+ reliable?
The price and inventory of MAX16021LTER+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX16021LTER+ is usually 5 days.
3.What payment methods are accepted for MAX16021LTER+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX16021LTER+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX16021LTER+?
MAX16021LTER+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX16021LTER+ 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 MAX16021LTER+?
For technical support, including MAX16021LTER+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX16021LTER+ requirements.
6.How does Aetrix verify that MAX16021LTER+ is sourced from the original manufacturer or authorized distributors?
All MAX16021LTER+ 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 MAX16021LTER+ meets industry standards.
7.What is the process for return or replacement of MAX16021LTER+?
All MAX16021LTER+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX16021LTER+, 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 MAX16021LTER+ part is unused and in its original packaging.
Return procedure for MAX16021LTER+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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