My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX6391KA16+T
- Part No.:
- MAX6391KA16+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-8
- Datasheet:
-
MAX6391KA16+T.pdf
- Description:
- IC SUPERVISOR MPU DL SOT23-8
- Quantity:
- Payment:
- Shipping:
Inventory:4,804
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX6391KA16+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with sequenced active-low open-drain reset outputs, factory-set 1.58V VCC reset threshold, 625mV adjustable secondary reset input (RESET IN2), and guaranteed reset validity down to VCC = 1.0V. It monitors master and slave supplies in multi-rail systems and ensures controlled power-up sequencing for critical µP-based industrial controllers and servers.
For engineers reviewing the MAX6391KA16+T datasheet, MAX6391KA16+T pinout, MAX6391KA16+T application, or MAX6391KA16+T equivalent, key selection criteria include its fixed 140ms (min) RESET1 timeout, user-adjustable or fixed RESET2 delay via CSRT pin, internal 47kΩ pullup resistors on both RESET outputs, and operation across –40°C to +85°C in SOT23-8.
Technical Context
The MAX6391KA16+T implements two independent voltage monitoring paths: one dedicated to VCC (with preset 1.58V threshold) driving RESET1, and a second path monitoring both VCC and RESET IN2 (625mV reference) to control RESET2. RESET2 deasserts only after RESET1 has deasserted, enforcing strict power-up order.
Its timing architecture uses an internal 600nA current source charging an external capacitor on CSRT for adjustable RESET2 timeout (e.g., 3.1ms with 1500pF), or connects CSRT to VCC for fixed 140ms (min) delay. Reset assertion is guaranteed valid at VCC ≥ 1.0V, supporting low-voltage system operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Reset Threshold | 1.54V (min) to 1.61V (max); factory-trimmed 1.58V nominal - sets precise brownout detection point for primary supply |
| RESET IN2 Threshold | 610mV to 640mV; fixed 625mV internal reference - enables monitoring of secondary supplies as low as 625mV via external resistor divider |
| RESET1 Timeout Period | 140ms (min) to 280ms (max); internally fixed - ensures minimum reset hold time after VCC recovery |
| RESET2 Timeout Period | 140ms (min) to 280ms (max) when CSRT tied to VCC; user-adjustable with capacitor - provides flexible sequencing window between RESET1 and RESET2 deassertion |
| Supply Current | 15µA typical at +25°C; ≤25µA over full temperature range - enables ultra-low-power supervision in battery-backed or energy-sensitive systems |
| Reset Valid Down To | VCC = 1.0V (guaranteed) - supports reliable reset generation even during deep brownout conditions |
| Output Type | Open-drain RESET1 and RESET2 with internal 47kΩ pullup resistors (R1/R2) - allows independent VOH level setting without external components |
Pinout & Package
MAX6391KA16+T is housed in an 8-pin SOT23 package (JEDEC MO-178 compliant), measuring 3.00mm × 1.75mm × 1.30mm, with gull-wing leads and lead-free finish (+T suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET IN2 | Secondary supply monitor input | High-impedance comparator input referenced to 625mV; accepts external resistor divider to set custom reset threshold for slave rail |
| 2 - VCC | Main supply and master reset monitor | Power supply input and primary voltage sense node; all resets assert when VCC falls below 1.58V threshold |
| 3 - CSRT | RESET2 timeout configuration terminal | Connect to VCC for fixed 140ms (min) RESET2 delay; connect to capacitor-to-ground for user-adjustable timeout (e.g., 3.1ms with 1500pF) |
| 4 - GND | Ground reference | Analog and digital ground return; must be low-impedance for accurate voltage monitoring |
| 5 - RESET2 | Secondary sequenced reset output | Active-low open-drain output; asserts before RESET1 on power-down and deasserts after RESET1 on power-up |
| 6 - R2 | Internal pullup connection for RESET2 | 47kΩ internal resistor connected to RESET2; tie to desired VOH voltage (e.g., 3.3V or 5V) for level-shifted reset signaling |
| 7 - RESET1 | Primary master reset output | Active-low open-drain output; first to assert on power-down and last to deassert on power-up - defines system reset anchor point |
| 8 - R1 | Internal pullup connection for RESET1 | 47kΩ internal resistor connected to RESET1; enables independent high-level voltage setting without external resistors |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring paths | Enables simultaneous supervision of master (VCC) and slave (RESET IN2) rails with distinct thresholds and timing |
| Guaranteed reset operation down to VCC = 1.0V | Ensures functional reset generation during severe brownout, improving system robustness in unstable power environments |
| Internal 47kΩ pullup resistors on both RESET outputs | Eliminates need for external pullups and allows flexible VOH assignment per rail (e.g., RESET1 to 5V, RESET2 to 3.3V) |
| Sequenced reset assertion/deassertion logic | Hardware-enforced ordering: RESET2 always asserts before RESET1 on power-down and deasserts after RESET1 on power-up |
| Immunity to short negative VCC transients | Rejects glitches ≤100ns wide at 100mV overdrive - prevents spurious resets from noise or coupling |
Applications
| Industrial PLC Controller Power Sequencing | Multi-Rail Server Board Supervision |
|---|---|
Use Scenario: A programmable logic controller uses separate 5V, 3.3V, and 1.8V rails to power CPU, I/O, and FPGA subsystems. IC Role / Device Role / Timing Role: MAX6391KA16+T acts as the central sequencer: RESET1 controls 5V domain power-on reset, while RESET2 (configured via RESET IN2 divider) triggers 3.3V/1.8V domain reset only after 5V is stable. Use Value: Prevents FPGA configuration failure and I/O lockup by enforcing strict voltage ramp order and eliminating race conditions during cold start. | Use Scenario: A 1U server motherboard requires coordinated reset of CPU, memory controller, and baseboard management controller (BMC) across three voltage domains. IC Role / Device Role / Timing Role: MAX6391KA16+T serves as dual-supply supervisor: VCC monitors 12V-to-5V converter output; RESET IN2 monitors 5V-to-3.3V regulator via resistor divider; RESET1 resets CPU, RESET2 resets BMC after CPU is ready. Use Value: Ensures BMC firmware initializes only after CPU reset completes - enabling reliable out-of-band management and remote diagnostics. |
| Embedded Medical Diagnostic Equipment | Automated Test Equipment (ATE) Power Management |
Use Scenario: Portable ultrasound device with analog front-end (2.5V), digital signal processor (1.2V), and display controller (3.3V) demands fail-safe startup. IC Role / Device Role / Timing Role: MAX6391KA16+T supervises main 3.3V rail (VCC) and auxiliary 2.5V rail (via RESET IN2 divider); RESET1 holds DSP in reset until 3.3V stabilizes; RESET2 releases analog front-end only after DSP is operational. Use Value: Avoids analog signal corruption and data acquisition errors caused by premature analog subsystem activation. | Use Scenario: Rack-mounted ATE system powers multiple instrument modules requiring staggered enable timing to limit inrush current. IC Role / Device Role / Timing Role: MAX6391KA16+T monitors main 24V DC-DC output (VCC) and isolated 5V module bus (via RESET IN2); RESET1 enables first module group; RESET2 (CSRT = 1500pF) delays second group by ~3.1ms. Use Value: Reduces peak inrush current by >40% versus simultaneous module enable - preventing tripped breakers and voltage droop on shared supply. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6392KA16+T | Includes active-low manual reset (MR) input and push-pull RESET1; lacks R1 pullup resistor | Required where hardware-initiated system reset (e.g., front-panel button) is needed; not drop-in compatible due to MR pin and different RESET1 drive type | Select MAX6392KA16+T only if manual reset functionality is mandatory and PCB layout accommodates MR trace and push-pull load requirements |
| TPS3808G15DBVR | Single-supply supervisor with adjustable threshold (0.4V–5.0V); no secondary input or sequenced dual outputs | Suitable for single-rail systems only; cannot replicate RESET1/RESET2 sequencing or dual-monitoring capability of MAX6391KA16+T | Use TPS3808G15DBVR only for cost-sensitive, single-voltage applications where sequencing is handled externally or unnecessary |
Compared with MAX6392KA16+T, the MAX6391KA16+T offers simpler open-drain RESET1 with internal pullup but no manual reset; compared with TPS3808G15DBVR, it delivers unique dual-input, sequenced-reset functionality essential for multi-rail coordination - neither alternative replicates its exact timing and monitoring architecture.
Availability
MAX6391KA16+T is available at Aetrix Electronics and suitable for industrial PLC controllers, multi-rail server boards, embedded medical diagnostic equipment, automated test equipment, and critical µP power monitoring applications requiring stable component supply and long-term design continuity.
Supply support for MAX6391KA16+T 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, communications, and automotive markets.
The MAX6391/MAX6392 product line delivers dual-voltage microprocessor supervisory circuits with hardware-enforced reset sequencing - engineered specifically for reliability-critical multi-rail systems where uncontrolled power-up order risks data corruption or hardware damage.
FAQ
What is the factory-set VCC reset threshold voltage for MAX6391KA16+T?
The MAX6391KA16+T has a factory-trimmed VCC reset threshold of 1.58V nominal, with a guaranteed range of 1.54V (min) to 1.61V (max) over the full –40°C to +85°C temperature range. This precise threshold enables reliable brownout detection for 1.8V or higher logic rails while maintaining margin against noise-induced false triggering. The value is laser-trimmed during production and documented in the device's selector guide and electrical characteristics table.
How does the CSRT pin configure RESET2 timeout behavior in MAX6391KA16+T?
In MAX6391KA16+T, the CSRT pin determines RESET2 timeout mode: connecting CSRT to VCC selects a fixed 140ms (min) delay, while connecting CSRT to an external capacitor (e.g., 1500pF to ground) enables user-adjustable timing based on tRP2 = 2.08 × 10⁶ × CCSRT seconds. The internal 600nA current source charges the capacitor to a 1.25V reference, and the resulting ramp time sets the delay. This dual-mode flexibility allows designers to choose between simplicity (fixed delay) or precision tuning (capacitor-adjusted) without changing the IC.
Does MAX6391KA16+T support independent VOH levels for RESET1 and RESET2 outputs?
Yes, MAX6391KA16+T supports independent high-level output voltages for RESET1 and RESET2 via its internal 47kΩ pullup resistors (R1 on pin 8, R2 on pin 6). Each resistor can be connected to a different external voltage rail - for example, R1 to 5V for RESET1 VOH and R2 to 3.3V for RESET2 VOH - enabling level-shifted reset signaling across mixed-voltage domains without external components. This eliminates the need for discrete pullup resistors and simplifies BOM and layout.
What is the minimum VCC voltage at which MAX6391KA16+T guarantees valid reset operation?
MAX6391KA16+T guarantees valid reset assertion and deassertion functionality down to VCC = 1.0V, as explicitly specified in its absolute maximum and electrical characteristics tables. This ensures reliable supervision during deep brownout conditions where other supervisors may fail to generate or maintain reset signals. The guarantee covers full temperature range (–40°C to +85°C) and applies to both RESET1 and RESET2 outputs, making it suitable for ultra-low-voltage or battery-depleted scenarios.
Is MAX6391KA16+T pin-compatible with MAX6392KA16+T?
No, MAX6391KA16+T is not pin-compatible with MAX6392KA16+T. While both share the same SOT23-8 package and pin 1–7 functions, pin 8 differs: MAX6391KA16+T uses pin 8 as R1 (internal pullup for RESET1), whereas MAX6392KA16+T repurposes pin 8 as MR (active-low manual reset input). Additionally, MAX6392KA16+T features push-pull RESET1 instead of open-drain. Therefore, direct substitution requires PCB modification and firmware validation.
MAX6391KA16+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-8
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 1.58V, Adj
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 140ms/Adjustable Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-8
MAX6391KA16+T FAQ
1.How can I place an order for MAX6391KA16+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6391KA16+T 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 MAX6391KA16+T reliable?
The price and inventory of MAX6391KA16+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6391KA16+T is usually 5 days.
3.What payment methods are accepted for MAX6391KA16+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6391KA16+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6391KA16+T?
MAX6391KA16+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6391KA16+T 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 MAX6391KA16+T?
For technical support, including MAX6391KA16+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6391KA16+T requirements.
6.How does Aetrix verify that MAX6391KA16+T is sourced from the original manufacturer or authorized distributors?
All MAX6391KA16+T 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 MAX6391KA16+T meets industry standards.
7.What is the process for return or replacement of MAX6391KA16+T?
All MAX6391KA16+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6391KA16+T, 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 MAX6391KA16+T part is unused and in its original packaging.
Return procedure for MAX6391KA16+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6391KA16+T 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…
