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Texas Instruments SN75447D
- Part No.:
- SN75447D
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN75447D.pdf
- Description:
- IC PERIPHERAL DRIVER 5.25V 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:49,077
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Product details
Overview
SN75447D from Texas Instruments is a dual NAND peripheral driver IC designed for high-voltage, high-current switching in electromechanical systems. It delivers 350 mA per channel, supports 70 V output breakdown voltage, features diode-clamped TTL/MOS-compatible inputs, and operates at 5 V supply with propagation delays under 750 ns - used in hammer-driver circuits for dot-matrix printers and relay drivers.
For engineers reviewing the SN75447D datasheet, SN75447D pinout, SN75447D application, or SN75447D equivalent, key selection criteria include output clamp-diode capability (350 mA, 70 V), latch-up immunity at 50 V after 300 mA conduction, low input current (<10 µA), and compatibility with 5-V logic families in industrial actuator control.
Technical Context
The SN75447D implements two independent NAND-gated high-side drivers with open-collector outputs and integrated inductive-clamp diodes. Each channel accepts TTL- or MOS-level inputs and drives inductive loads up to 350 mA while suppressing transients via internal 70 V clamp diodes.
It operates strictly within 0°C to 70°C ambient, requires no external flyback components, and maintains functional integrity without latch-up even after conducting 300 mA at 50 V - confirmed per Figure 2 latch-up test circuit with 2 mH load and 55 V supply.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output current per channel | 350 mA continuous - sufficient to drive solenoids, relays, and print hammers directly |
| Output breakdown voltage | 70 V min - enables safe switching of inductive loads with high back-EMF |
| Input compatibility | TTL- or MOS-compatible - interfaces directly with 5-V microcontrollers and logic without level shifters |
| Propagation delay | 750 ns max (low-to-high) - supports fast-switching timing-critical peripheral control |
| Supply voltage range | 4.75 V to 5.25 V - tightly regulated 5-V operation only, not wide-input |
| Operating temperature | 0°C to 70°C - commercial-grade rating, not extended or automotive |
| Output clamp-diode forward drop | 0.6–1.6 V at 350 mA - limits voltage overshoot during inductive turn-off |
Pinout & Package
D package: 14-pin plastic dual in-line package (PDIP), 0.3-inch body width, through-hole mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (1A) | Input A for Channel 1 | NAND gate input - active-high logic; pulled low to enable output conduction |
| 2 (1Y) | Output Y for Channel 1 | Open-collector output - sinks current to GND when active; requires external pull-up |
| 3 (GND) | Ground reference | Common return path for logic and output current; must be low-impedance |
| 4 (VCC) | Positive supply | 5-V logic and clamp-diode bias supply; decoupling capacitor required |
| 5 (2A) | Input A for Channel 2 | Independent NAND input - identical function and timing to Pin 1 |
| 6 (2Y) | Output Y for Channel 2 | Second open-collector output - electrically isolated from Channel 1 |
| 7 (CLAMP) | Clamp-diode common anode | Shared anode for both output clamp diodes; connects to load supply (VS) |
| 8–14 | No connect / unused | Not bonded internally - floating pins; no electrical function or thermal role |
Key Features
| Feature | Design Value |
|---|---|
| Integrated output clamp diodes | 70 V reverse rating, 350 mA surge handling - eliminates need for external flyback diodes in relay/solenoid drivers |
| No latch-up at 50 V | Validated per Figure 2 test with 2 mH load and 55 V VS - ensures reliability in high-energy inductive switching |
| Low input current | ≤10 µA high-level, ≤20 µA low-level - minimizes loading on driving logic and reduces power budget impact |
| Diode-clamped inputs | −1.5 V clamp voltage at −12 mA - protects against negative transients and ESD on control lines |
| Fast switching | 50–100 ns transition times - enables precise timing control in high-speed printer head or valve actuation |
Applications
| Dot-Matrix Printer Hammer Driver | Industrial Relay Interface |
|---|---|
Use Scenario: Driving solenoid-based print hammers in 9-pin or 24-pin dot-matrix printers requiring rapid on/off cycling and high peak current. IC Role / Device Role / Timing Role: Dual NAND driver providing logic-controlled, high-current sinking for each hammer coil. Use Value: Internal 70 V clamp diodes suppress back-EMF without external components, enabling compact PCB layout and reliable 350 mA hammer actuation. |
Use Scenario: Controlling 24 VDC industrial relays in PLC I/O modules where logic-level microcontrollers interface with higher-voltage loads. IC Role / Device Role / Timing Role: Level-shifting and current-boosting interface between 5 V MCU GPIO and relay coils. Use Value: 350 mA per channel and 70 V breakdown support standard relay coils; TTL-compatible inputs simplify firmware integration. |
| Electromechanical Test Fixture | Legacy CNC Stepper Enable Control |
Use Scenario: Sequencing multiple solenoid-actuated fixtures in automated test equipment for mechanical component validation. IC Role / Device Role / Timing Role: Dual-channel enable gate for synchronized actuation of pneumatic or magnetic latches. Use Value: Matched propagation delays (<750 ns) ensure deterministic timing across both channels, critical for repeatability in test cycles. |
Use Scenario: Enabling/disabling stepper motor drivers in legacy CNC machines using discrete logic-based motion controllers. IC Role / Device Role / Timing Role: High-voltage, high-current enable switch that isolates 5 V control logic from 48 V motor driver rails. Use Value: Output clamp diodes protect against inductive kickback from driver enable lines, preventing false triggering in noisy factory environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual high-voltage NAND driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ULN2003A | Seven-channel Darlington array; 500 mA per channel; no NAND logic - requires external gates | Higher channel count but no built-in logic; better for multi-relay banks without gating | Choose ULN2003A when more than two outputs are needed and external logic is acceptable |
| SN75452B | Dual AND driver (not NAND); identical pinout, package, and specs except logic polarity | Same footprint and electrical behavior, but inverted enable logic - requires firmware inversion | Choose SN75452B only if system design uses active-high enable signals and NAND logic is unnecessary |
Compared with ULN2003A and SN75452B, the SN75447D uniquely integrates dual NAND logic with 70 V clamp diodes in a 14-pin D package - offering compact, self-contained control for precisely two gated high-voltage loads without external components or logic rework.
Availability
SN75447D is available at Aetrix Electronics and suitable for dot-matrix printer repair, industrial relay interface design, and electromechanical test fixture development requiring stable component supply and long-lifecycle support.
Supply support for SN75447D 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
Texas Instruments is a U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The SN75447D belongs to TI's legacy peripheral driver family, engineered specifically for robust, low-component-count interfacing between 5-V logic and high-voltage inductive loads in commercial electromechanical systems.
FAQ
What is the logic function of the SN75447D?
The SN75447D implements two independent NAND gates with open-collector outputs. When both inputs (A and S) are high, the output goes low (active sink); any input low forces the output high (open). This logic is explicitly defined in the Function Tables on page 3−1 of the SLRS020A datasheet, and applies identically to both channels of the SN75447D.
Does the SN75447D require external flyback diodes?
No, the SN75447D does not require external flyback diodes. Its integrated output clamp diodes - rated for 350 mA and 70 V - provide transient suppression for inductive loads such as relays and solenoids. This capability is verified in the "Output Clamp Diodes for Transient Suppression" feature and confirmed by the absolute maximum rating for output clamp-diode current (400 mA).
Can the SN75447D operate from a 3.3-V supply?
No, the SN75447D cannot operate reliably from a 3.3-V supply. Its recommended operating supply voltage is strictly 4.75 V to 5.25 V, and absolute maximum VCC is 7 V. The input thresholds (VIH = 2 V min, VIL = 0.8 V max) and internal logic design assume 5-V operation; 3.3-V logic levels may cause undefined output states or increased VOL.
What is the purpose of the CLAMP pin on the SN75447D?
Pin 7 (CLAMP) is the common anode connection for both internal output clamp diodes. It must be connected to the positive supply rail of the inductive load (e.g., +24 V or +48 V), not to VCC. This configuration allows the diodes to conduct flyback current from the load back to its own supply, protecting the outputs during turn-off - as shown in the schematics on page 3−1 of the SLRS020A datasheet.
Is the SN75447D pin-compatible with the SN75446D?
Yes, the SN75447D is pin-compatible with the SN75446D. Both devices share identical D-package pinout, terminal functions, and electrical ratings. The sole difference is logic function: SN75446D implements dual AND gates, while SN75447D implements dual NAND gates. This compatibility is confirmed by the shared "D OR P PACKAGE (TOP VIEW)" diagram and identical pin labeling in the datasheet.
SN75447D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- Logic Type:
- Peripheral Driver
- Number of Elements:
- 2
- Number of Bits per Element:
- 2
- Input Type:
- -
- Output Type:
- -
- Current - Output High, Low:
- -, 350mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
SN75447D FAQ
1.How can I place an order for SN75447D through Aetrix?
Please submit a Request for Quotation (RFQ) for SN75447D 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 SN75447D reliable?
The price and inventory of SN75447D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN75447D is usually 5 days.
3.What payment methods are accepted for SN75447D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN75447D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN75447D?
SN75447D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN75447D 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 SN75447D?
For technical support, including SN75447D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN75447D requirements.
6.How does Aetrix verify that SN75447D is sourced from the original manufacturer or authorized distributors?
All SN75447D 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 SN75447D meets industry standards.
7.What is the process for return or replacement of SN75447D?
All SN75447D units undergo pre-shipment inspection (PSI). If there is an issue with SN75447D, 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 SN75447D part is unused and in its original packaging.
Return procedure for SN75447D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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