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Analog Devices Inc./Maxim Integrated MAX6931AUI+T
- Part No.:
- MAX6931AUI+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Display Drivers
- Package:
- 28-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
MAX6931AUI+T.pdf
- Description:
- IC DRVR VFD TUBE SRL 28TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,806
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Product details
Overview
MAX6931AUI+T from Maxim Integrated is a 20-output, 76V vacuum-fluorescent display (VFD) tube driver with bipolar output swing enabled by dedicated VSS pin, supporting filament biasing in static and multiplexed VFD applications. It features 5MHz 4-wire serial interface (CLOCK/DIN/LOAD/BLANK), push-pull CMOS outputs sourcing up to 40mA continuously, and operates across -40°C to +125°C.
For engineers reviewing the MAX6931AUI+T datasheet, MAX6931AUI+T pinout, MAX6931AUI+T application, or MAX6931AUI+T equivalent, this page delivers verified technical context, real-world drive capability, bipolar supply handling, PWM intensity control via BLANK, and validated alternatives for VFD system design.
Technical Context
The MAX6931AUI+T implements a 20-bit serial-to-parallel shift register with transparent latch, driven by industry-standard 4-wire interface. Its outputs swing rail-to-rail between VBB (8V–76V) and VSS (–11V to 0V), enabling direct filament biasing without external level-shifting circuitry.
Each of the 20 push-pull CMOS outputs supports continuous 40mA source current and 4mA sink current, with 75mA repetitive pulsed sourcing capability (≤1ms on-time, ≤25% duty). Output rise/fall times are slew-rate controlled (0.9µs/0.6µs typical at 60V) to minimize EMI while maintaining compatibility with 100µs digit multiplex periods.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Count | 20 independent high-voltage drivers for VFD anodes/grids |
| Output Voltage Range | VBB to VSS: supports –11V to +76V total swing for bipolar filament bias |
| Logic Supply | 3V to 5.5V - compatible with 3.3V and 5V microcontrollers |
| Continuous Source Current | 40mA per output - sufficient for static VFD grid/anode drive |
| Serial Interface Speed | 5MHz max clock - enables fast update of full 20-bit display state |
| Operating Temperature | –40°C to +125°C - qualified for industrial and automotive environments |
| Output Rise/Fall Time | 0.9µs / 0.6µs (VBB = 60V, CL = 50pF) - optimized for EMI control and multiplex timing |
Pinout & Package
MAX6931AUI+T is housed in a RoHS-compliant 28-pin TSSOP package (package code U28+1), with 0.65mm pitch and exposed pad for thermal performance. Pin layout is optimized for VFD interconnect, separating high-voltage (VBB, OUT0–OUT19), logic (VCC, CLK, DIN, LOAD, BLANK), and bias (VSS) domains.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1–5, 10–19, 24–28 | OUT0–OUT19 | 20 high-voltage push-pull drivers swinging from VBB to VSS - configurable as anode or grid drivers |
| 6 | DIN | Serial data input - latched on rising edge of CLK; enables daisy-chaining when used with MAX6921 |
| 7 | VCC | 3V–5.5V logic supply - requires 100nF bypass capacitor to GND |
| 8 | VBB | 8V–76V VFD tube supply - supplies high-side drive voltage for all outputs |
| 9 | VSS | –11V to 0V filament bias supply - enables bipolar output swing; bypass with 100nF capacitor |
| 20 | BLANK | Active-high blanking input - forces all outputs low for display off or PWM intensity control |
| 21 | GND | Analog/digital ground reference - must be low-impedance connection shared with bypass caps |
| 22 | CLK | Serial clock input - shifts data into internal shift register on rising edge |
| 23 | LOAD | Load strobe - transfers data from shift register to output latches on falling edge |
Key Features
| Feature | Design Value |
|---|---|
| Bipolar output swing (VBB to VSS) | Eliminates need for external negative charge pumps or level shifters in filament-biased VFD designs |
| 40mA continuous source per output | Directly drives VFD grids/anodes without external boost transistors in static or low-multiplex displays |
| Active BLANK input with PWM support | Enables precise, flicker-free display intensity control without modifying display data registers |
| Slew-rate controlled outputs | Reduces EMI emissions while preserving <100µs multiplex timing integrity |
| –40°C to +125°C operation | Validated for under-hood automotive, industrial weighing, and avionics VFD modules |
Applications
| White Goods Control Panels | Industrial Weighing Displays |
|---|---|
|
Use Scenario: Digital weight readout on precision bench scales with ambient temperature variation from –10°C to +60°C. IC Role / Device Role / Timing Role: MAX6931AUI+T drives 16-segment VFD digits and status indicators using static drive mode with filament bias via VSS. Use Value: Bipolar output swing ensures stable filament voltage across temperature, eliminating brightness drift and extending tube life. |
Use Scenario: Multi-digit VFD display in factory-floor floor scales exposed to vibration, dust, and wide operating temperatures. IC Role / Device Role / Timing Role: MAX6931AUI+T serves as primary anode/grid driver in multiplexed 4-digit VFD, synchronized to microcontroller via 4-wire interface. Use Value: 40mA per output sustains segment brightness at full multiplex ratio; 125°C rating prevents thermal shutdown during extended operation. |
| Gaming Machine Front Panels | Avionics Cabin Displays |
|
Use Scenario: High-reliability VFD front panel in slot machines requiring >100,000-hour operational lifetime and immunity to ESD events. IC Role / Device Role / Timing Role: MAX6931AUI+T provides grid/anode drive with active BLANK-based PWM dimming for dynamic contrast control. Use Value: Slew-controlled outputs reduce radiated emissions below CISPR-22 Class B limits; robust 76V tolerance handles transient surges on VBB rail. |
Use Scenario: Cabin pressure/altitude indicator in commercial aircraft with DO-160D lightning-induced transient compliance requirements. IC Role / Device Role / Timing Role: MAX6931AUI+T drives dual 7-segment VFDs in redundant display path, powered from isolated 28V DC bus with local VSS bias. Use Value: VBB–VSS ≤76V rating meets DO-160D Section 22 surge withstand; –40°C start-up ensures cold-soak reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar VFD driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6921AUI+ | No VSS pin; outputs swing VBB to GND only - requires external negative bias for filament drive | Suitable for simpler VFD designs where filament bias is handled externally or not required | Select MAX6921AUI+ only if bipolar output swing is unnecessary and PCB layout allows separate filament bias generation |
| MAX6932AUI+ | 32-output version in same 28-pin TSSOP; shares identical VSS, BLANK, and serial interface architecture | Replaces two MAX6931AUI+T devices in high-channel-count VFD systems (e.g., multi-line instrumentation panels) | Choose MAX6932AUI+ when >20 outputs are needed and board space is constrained - no change to bias or control logic |
Compared with MAX6921AUI+, MAX6931AUI+T adds integrated filament bias capability via VSS, reducing component count and improving thermal stability. Against MAX6932AUI+, it offers lower channel count with identical feature set - ideal for cost-sensitive 20-output VFD applications where full 32-channel density is unnecessary.
Availability
MAX6931AUI+T is available at Aetrix Electronics and suitable for white goods control panels, industrial weighing displays, and gaming machine front panels requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.
Supply support for MAX6931AUI+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.
The MAX6931AUI+T belongs to Maxim's VFD driver product line, engineered specifically for reliable, high-voltage, multiplexed and static vacuum-fluorescent display control in harsh-environment applications.
FAQ
What is the maximum continuous output current per channel of the MAX6931AUI+T?
The MAX6931AUI+T supports 40mA continuous source current per output (OUT0–OUT19) under specified thermal conditions. This rating applies across the full –40°C to +125°C operating range and enables direct driving of VFD grids and anodes without external amplification in most static and low-multiplex applications. The device also supports 75mA repetitive pulsed sourcing (≤1ms on-time, ≤25% duty cycle) for higher peak brightness in multiplexed configurations.
Does the MAX6931AUI+T require a negative supply voltage to operate?
The MAX6931AUI+T does not require a negative supply to function - VSS can be tied to GND if bipolar output swing is not needed. However, connecting VSS to a negative voltage (–11V to 0V) enables true bipolar output operation (VBB to VSS), which simplifies filament biasing in many VFD applications. When VSS = GND, the device behaves like the MAX6921AUI+ with VBB-to-GND swing only.
Can the MAX6931AUI+T be used in place of the MAX6921AUI+ without hardware changes?
No - the MAX6931AUI+T is not a drop-in replacement for the MAX6921AUI+ due to the presence of the VSS pin (pin 9) and absence of the DOUT pin (pin 9 on MAX6921AUI+). While both share identical pinout for pins 1–8, 10–28, the VSS pin occupies position 9 on MAX6931AUI+T whereas MAX6921AUI+ uses that location for DOUT. PCB layout and schematic must be modified to accommodate VSS routing and remove DOUT connections.
How does the BLANK input function in the MAX6931AUI+T?
The BLANK input on the MAX6931AUI+T is an active-high signal that forces all 20 outputs (OUT0–OUT19) low regardless of latch state, turning off the VFD display instantly. Crucially, it does not alter the contents of the output latches - data remains intact for immediate re-enablement. This behavior enables clean PWM-based intensity control without disrupting serial data flow or requiring repeated register writes.
What is the purpose of the slew-rate control in MAX6931AUI+T outputs?
The slew-rate control in MAX6931AUI+T outputs intentionally slows rise time (0.9µs typical) relative to fall time (0.6µs typical) to prevent shoot-through current during transitions and reduce high-frequency EMI emissions. This controlled transition preserves signal integrity in noisy industrial environments while remaining fast enough to meet standard 100µs digit multiplex periods - ensuring consistent brightness and avoiding ghosting or crosstalk in multiplexed VFDs.
MAX6931AUI+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 28-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Display Type:
- Vacuum Fluorescent (VF)
- Configuration:
- -
- Interface:
- 4-Wire Serial
- Digits or Characters:
- -
- Current - Supply:
- 1.65 mA
- Voltage - Supply:
- 8V ~ 76V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSSOP
MAX6931AUI+T FAQ
1.How can I place an order for MAX6931AUI+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6931AUI+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 MAX6931AUI+T reliable?
The price and inventory of MAX6931AUI+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6931AUI+T is usually 5 days.
3.What payment methods are accepted for MAX6931AUI+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6931AUI+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6931AUI+T?
MAX6931AUI+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6931AUI+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 MAX6931AUI+T?
For technical support, including MAX6931AUI+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6931AUI+T requirements.
6.How does Aetrix verify that MAX6931AUI+T is sourced from the original manufacturer or authorized distributors?
All MAX6931AUI+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 MAX6931AUI+T meets industry standards.
7.What is the process for return or replacement of MAX6931AUI+T?
All MAX6931AUI+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6931AUI+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 MAX6931AUI+T part is unused and in its original packaging.
Return procedure for MAX6931AUI+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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