My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX16021LTEL+
- Part No.:
- MAX16021LTEL+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 16-WQFN Exposed Pad
- Datasheet:
-
MAX16021LTEL+.pdf
- Description:
- IC SUPERVISOR PP 4.6894V 16TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:525
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX16021LTEL+ from Maxim Integrated is a low-power microprocessor supervisory circuit with integrated battery-backup switchover, chip-enable (CE) gating, and power-fail monitoring. It provides active-low reset output, 145ms minimum reset timeout, 1.2µA supply current, and operates from 1.53V to 5.5V to protect SRAM/RTC in brownout conditions. Used in GPS modules and point-of-sale terminals for reliable memory write protection during main power loss.
For engineers reviewing the MAX16021LTEL+ datasheet, MAX16021LTEL+ pinout, MAX16021LTEL+ application, or MAX16021LTEL+ equivalent, key selection criteria include its 16-pin TQFN package, push-pull reset output (suffix 'L'), 4.684V typical reset threshold, CEIN/CEOUT 1.5ns propagation delay, and battery-OK/battery-on indicators for backup power state visibility.
Technical Context
The MAX16021LTEL+ integrates four core supervisory functions: µP reset generation during VCC power-up/down/brownout; automatic VCC-to-battery switchover when VCC falls below reset threshold and VBATT > VCC; internal CE gating to prevent memory corruption during brownout; and power-fail detection via PFI comparator with 0.590V typical threshold and 30mV hysteresis.
It features a watchdog timer with 1.235s typical timeout, debounced manual reset input with 30kΩ internal pullup, low-line (LL) output asserting 2.5% above reset threshold for early brownout warning, and battery-test functionality pulsing BATT_TEST low every 24 hours for 1.3s.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.684V typical (L-suffix); ensures reliable reset assertion before 5V system brownout |
| Reset Timeout Period | 145ms minimum; guarantees sufficient hold time for µP initialization after power recovery |
| Supply Current | 5µA max at 5.5V; enables ultra-low-power operation in always-on industrial control nodes |
| Battery-Backup Mode Current | 0.5µA max; minimizes battery drain during extended main-power outages |
| CEIN to CEOUT Propagation Delay | 1.5ns typical; supports high-speed µP/DSP interfaces without timing violation |
| Power-Fail Input Threshold | 0.590V ±19mV; allows precise low-voltage monitoring down to 0.6V with hysteresis |
| Operating Temperature Range | -40°C to +85°C; qualified for industrial and automotive-adjacent embedded applications |
Pinout & Package
MAX16021LTEL+ 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 must be soldered to a large ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BATT (Pin 1) | Backup battery input | Connects to 2.2–5.5V battery; enables automatic switchover when VCC drops below reset threshold and VBATT > VCC |
| MR (Pin 2) | Active-low manual reset input | Asserts reset on logic-low pulse; includes 30kΩ internal pullup to VCC; no external debounce required |
| PFI (Pin 3) | Power-fail comparator input | Monitors divided-down VCC against 0.590V internal reference; triggers PFO when voltage falls below threshold |
| WDI (Pin 4) | Watchdog timer input | Clears internal 1.235s watchdog on rising/falling edge; open or high-Z disables watchdog |
| LL (Pin 5) | Active-low low-line output | Asserts ~2.5% above reset threshold to provide early brownout warning for NMI-driven shutdown |
| BATT_TEST (Pin 6) | Open-drain battery-test output | Pulses low for 1.3s every 24h; used with external load to verify battery health without continuous discharge |
| BATTOK (Pin 7) | Battery-OK status indicator | Goes low when VBATT < 2.508V; signals degraded backup power before switchover failure |
| BATTON (Pin 8) | Active-high battery-on indicator | Asserts high only during valid battery-backup mode; confirms switchover completion and battery readiness |
| WDO (Pin 9) | Active-low watchdog output | Asserts on WDI timeout; resets on next WDI transition or RESET assertion; independent of reset state |
| PFO (Pin 10) | Active-low power-fail output | Complements PFI input; asserts low when VPFI < 0.590V; deasserts with 30mV hysteresis |
| GND (Pin 11) | Ground reference | Primary return path; EP pad must be connected to same ground plane for thermal integrity |
| RESET (Pin 12) | Active-low reset output | Push-pull drive (L-suffix); sinks 3.2mA min at 0.3V; holds low for full 145ms timeout after VCC recovery |
| OUT (Pin 13) | Switched output | Connects to VCC or BATT based on switchover logic; powers SRAM/RTC; bypass with ≥0.1µF capacitor |
| CEOUT (Pin 14) | Active-low chip-enable output | Gates CE signal to memory; held low for 12µs after reset assertion if CEIN was low; pulled up to OUT |
| CEIN (Pin 15) | Chip-enable input | Directly controls CEOUT path; disconnects from CEOUT during reset to prevent spurious writes |
| VCC (Pin 16) | Main supply input | Accepts 1.53–5.5V; powers internal circuitry; requires 0.1µF bypass capacitor to GND |
Key Features
| Feature | Design Value |
|---|---|
| Battery-freshness seal | Prevents premature battery discharge during storage by isolating BATT until first VCC application |
| On-board CE gating with 1.5ns delay | Eliminates need for external logic to protect SRAM during brownout; meets timing for 200MHz+ µPs |
| Debounced MR input with 30kΩ pullup | Enables direct switch connection without RC network; reduces BOM count and PCB area |
| Low-line (LL) output with 2.5% hysteresis margin | Provides deterministic early-warning interrupt before reset, enabling graceful firmware shutdown |
| UL®-certified per IEC 60950-1 | Satisfies safety compliance requirements for industrial and commercial end equipment without additional certification effort |
Applications
| GPS Receiver Modules | Point-of-Sale Terminals |
|---|---|
|
Use Scenario: Maintains RTC and SRAM data during vehicle ignition cycling or battery disconnection. IC Role / Device Role / Timing Role: Supervisory IC providing VCC brownout detection, battery switchover, and CE gating to preserve navigation state. Use Value: Prevents loss of last-known position and transaction logs by ensuring uninterrupted backup power and blocking invalid memory writes during voltage transients. |
Use Scenario: Secures financial transaction data in retail kiosks during AC power interruptions or surges. IC Role / Device Role / Timing Role: System monitor generating reset, asserting LL for NMI-triggered save routines, and disabling CE during brownout. Use Value: Guarantees atomic commit of sales records by halting memory writes before VCC collapse, eliminating corrupted receipts or inventory mismatches. |
| Industrial PLC I/O Modules | Set-Top Box Firmware Storage |
|
Use Scenario: Preserves configuration registers and real-time process variables during factory floor power flickers. IC Role / Device Role / Timing Role: Battery-backed supervisor with watchdog timer and PFI monitoring for fail-safe I/O state retention. Use Value: Enables deterministic restart without reinitialization delays by maintaining volatile memory contents and validating battery health via BATT_TEST pulses. |
Use Scenario: Protects channel lineup and parental control settings stored in CMOS SRAM during cable signal loss or power dips. IC Role / Device Role / Timing Role: Reset generator and CE gate preventing EEPROM/SRAM corruption during unstable 3.3V rail conditions. Use Value: Eliminates customer service calls for "lost settings" by ensuring memory write protection activates within 145ms of VCC droop below 3.08V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supervisory circuit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX16020LTEL+ | Identical pinout and function except lacks BATT_TEST output; no periodic battery self-test capability | Suitable where battery health verification is handled externally or not required | Select MAX16020LTEL+ when BATT_TEST functionality is unnecessary and cost optimization is prioritized |
| TPS3808G33DBVR | Single-supply reset IC only; no battery switchover, CE gating, or BATTOK/BATTON outputs | Limited to basic reset generation; cannot replace MAX16021LTEL+ in battery-backed memory systems | Choose TPS3808G33DBVR only for simple 3.3V reset supervision without backup power management |
Compared with MAX16020LTEL+, MAX16021LTEL+ adds verified battery-test signaling for predictive maintenance; compared with TPS3808G33DBVR, it delivers full power-fail, watchdog, and memory-protection integration in one 16-pin device-reducing board space and validation effort for battery-critical designs.
Availability
MAX16021LTEL+ is available at Aetrix Electronics and suitable for GPS receivers, point-of-sale terminals, and industrial PLC modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX16021LTEL+ 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 and mixed-signal ICs for industrial, communications, and computing applications, with emphasis on power efficiency and reliability.
The MAX160xx family targets µP-based systems needing consolidated power monitoring, battery backup, and memory protection-designed specifically for space-constrained, low-power embedded devices with stringent uptime requirements.
FAQ
What is the reset threshold voltage for MAX16021LTEL+?
The MAX16021LTEL+ has a fixed reset threshold of 4.684V typical (range 4.520V to 4.852V), as defined by the 'L' suffix in its ordering code. This value is guaranteed over -40°C to +85°C and enables reliable reset assertion in 5V systems before brownout-induced µP malfunction occurs. The threshold exhibits ±0.3% variation over temperature, confirmed in the device's normalized threshold vs. temperature plot.
Does MAX16021LTEL+ support both VCC and battery power sources simultaneously?
Yes, MAX16021LTEL+ automatically switches the OUT pin between VCC and BATT based on real-time voltage comparison: OUT connects to VCC when VCC > VBATT and VCC > reset threshold; it switches to BATT only when VCC falls below the reset threshold AND VBATT > VCC. During switchover, BATTON asserts high and BATTOK remains high if VBATT ≥ 2.508V, confirming valid backup operation.
How does the CE gating function work in MAX16021LTEL+?
In MAX16021LTEL+, CE gating blocks memory writes during brownout by disconnecting CEIN from CEOUT when RESET asserts. If CEIN is low at reset assertion, CEOUT stays low for 12µs to complete ongoing memory access, then pulls high to OUT. If CEIN is high, CEOUT remains high throughout reset. This 1.5ns propagation delay and controlled latch behavior prevents spurious writes to SRAM without external logic.
What is the purpose of the BATT_TEST pin on MAX16021LTEL+?
The BATT_TEST pin on MAX16021LTEL+ pulses low for 1.3 seconds every 24 hours to activate an external test load, enabling periodic verification of battery voltage under load. If VBATT drops below 2.508V during this test, BATTOK deasserts, signaling battery degradation. This autonomous health check eliminates manual intervention while minimizing average current draw to sub-nanoamp levels.
Can MAX16021LTEL+ operate with a 1.8V main supply?
No, MAX16021LTEL+ is not rated for 1.8V VCC operation. Its specified operating range is 1.53V to 5.5V, but the 'L' suffix denotes a 4.684V reset threshold optimized for 5V systems. For 1.8V applications, select a variant with 'W' (1.661V) or 'V' (1.571V) suffix-e.g., MAX16021LWEK+-which matches the supply rail and ensures proper reset margin. Using MAX16021LTEL+ on 1.8V would prevent reset assertion entirely.
MAX16021LTEL+ 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:
- 4.684V
- 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)
MAX16021LTEL+ FAQ
1.How can I place an order for MAX16021LTEL+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX16021LTEL+ 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 MAX16021LTEL+ reliable?
The price and inventory of MAX16021LTEL+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX16021LTEL+ is usually 5 days.
3.What payment methods are accepted for MAX16021LTEL+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX16021LTEL+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX16021LTEL+?
MAX16021LTEL+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX16021LTEL+ 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 MAX16021LTEL+?
For technical support, including MAX16021LTEL+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX16021LTEL+ requirements.
6.How does Aetrix verify that MAX16021LTEL+ is sourced from the original manufacturer or authorized distributors?
All MAX16021LTEL+ 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 MAX16021LTEL+ meets industry standards.
7.What is the process for return or replacement of MAX16021LTEL+?
All MAX16021LTEL+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX16021LTEL+, 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 MAX16021LTEL+ part is unused and in its original packaging.
Return procedure for MAX16021LTEL+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX16021LTEL+ 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…
