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Texas Instruments SN75477DG4
- Part No.:
- SN75477DG4
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN75477DG4.pdf
- Description:
- IC PERIPHERAL DRIVER 5.5V 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,777
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Product details
Overview
SN75477DG4 from Texas Instruments is a dual NAND peripheral driver IC designed for high-voltage, high-current switching in electromechanical interface circuits. It delivers 300 mA continuous output current per channel, supports 100 V typical output breakdown voltage, features integrated output clamp diodes (70 V, 300 mA), and operates across 0°C to 70°C - enabling robust hammer-driver and relay-control applications.
For engineers reviewing the SN75477DG4 datasheet, SN75477DG4 pinout, SN75477DG4 application, or SN75477DG4 equivalent, this page provides verified functional identity, SOIC-8 package mapping, confirmed NAND logic behavior, absolute maximum ratings, and validated alternative options for industrial peripheral interfacing.
Technical Context
The SN75477DG4 implements two independent open-collector NAND drivers with PNP transistor inputs that reduce input current demand and enable TTL- or MOS-compatible operation. Each channel integrates diode-clamped inputs and high-voltage output clamp diodes for inductive transient suppression during switching of solenoids or relays.
It operates from a single 4.5 V to 5.5 V supply, exhibits propagation delays of 200–350 ns (CL = 15 pF, RL = 100 Ω), and maintains latch-up immunity at 55 V after conducting 300 mA - confirming suitability for noisy industrial load-driving environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Function | Dual NAND gate - each output Y = A·S (positive logic), enabling active-low enable control of external loads. |
| Output Current | 300 mA continuous per channel - sufficient to directly drive relays, solenoids, and small DC motors without external buffers. |
| Output Breakdown Voltage | 100 V typical - allows safe switching of inductive loads with flyback voltages up to 70 V under clamp conditions. |
| Input Compatibility | TTL- and MOS-compatible with diode-clamped inputs - accepts standard 0.8 V/2.0 V logic thresholds and tolerates overvoltage transients. |
| Propagation Delay | 200–350 ns - ensures deterministic timing in real-time peripheral control loops with minimal skew between channels. |
| Operating Temperature | 0°C to 70°C - validated for commercial-grade embedded systems including point-of-sale terminals and industrial controllers. |
| Supply Voltage | 4.5 V to 5.5 V - aligns with standard 5 V logic rails and avoids need for auxiliary voltage regulation. |
Pinout & Package
SN75477DG4 is housed in an 8-pin SOIC (D) package with 1.27 mm lead pitch and 1.75 mm max height, optimized for surface-mount assembly and thermal reliability in compact PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (1A) | Input A for Channel 1 | Active-high NAND input; referenced to GND; diode-clamped for transient protection. |
| 2 (1S) | Enable Input S for Channel 1 | Active-high NAND enable; when low, forces 1Y high-impedance (open-collector inactive). |
| 3 (GND) | Ground Reference | Common return path for inputs, outputs, and internal clamp diodes; must be low-impedance. |
| 4 (1Y) | Output Y for Channel 1 | Open-collector output; sinks current only; requires external pull-up to VCC or higher voltage rail. |
| 5 (2Y) | Output Y for Channel 2 | Open-collector output; electrically isolated from 1Y; shares same GND and VCC connections. |
| 6 (2S) | Enable Input S for Channel 2 | Independent enable for second channel; identical function and electrical specs as Pin 2. |
| 7 (2A) | Input A for Channel 2 | Independent NAND input; no crosstalk with Channel 1; matches Pin 1 functionality. |
| 8 (VCC) | Positive Supply | Single 4.5–5.5 V supply powering internal logic and output clamp circuitry; bypass capacitor recommended. |
Key Features
| Feature | Design Value |
|---|---|
| No latch-up at 55 V | Guarantees fault resilience when driving inductive loads that generate high-voltage flyback spikes. |
| Integrated output clamp diodes | Eliminates need for external flyback diodes in relay/solenoid circuits - reduces BOM count and board area. |
| PNP transistor inputs | Reduces input current to ≤ –220 µA (low-level), minimizing loading on upstream logic or microcontroller GPIOs. |
| Diode-clamped inputs | Protects against ESD and overvoltage transients up to ±1.5 V beyond supply rails without external components. |
| Plastic SOIC package | Enables automated reflow assembly, meets RoHS compliance, and provides thermal performance suitable for 464 mW max power dissipation at 70°C. |
Applications
| Relay Control Interface | Dot-Matrix Printer Hammer Driver |
|---|---|
|
Use Scenario: Driving 12 V/24 V electromagnetic relays in PLC I/O modules where fast turn-off and flyback suppression are critical. IC Role / Device Role / Timing Role: Dual NAND driver providing isolated, current-sinking switch control with built-in clamp diodes to absorb inductive kickback. Use Value: Enables direct microcontroller GPIO interfacing without discrete transistors or external diodes, reducing component count by ≥3 per channel. |
Use Scenario: Controlling print head solenoids in legacy dot-matrix printers requiring precise 300 mA pulse current and sub-400 ns response. IC Role / Device Role / Timing Role: High-speed NAND-gated driver delivering synchronized, high-current pulses to mechanical hammers with controlled rise/fall times. Use Value: Meets strict timing requirements (tPLH/tPHL ≤ 350 ns) while sustaining 300 mA per pulse - eliminating need for external gate drivers. |
| Industrial Stepper Motor Phase Driver | Legacy Instrumentation Load Switching |
|
Use Scenario: Switching phase windings in unipolar stepper motor drivers used in CNC equipment and lab automation systems. IC Role / Device Role / Timing Role: Dual-channel current sink managing coil energization/de-energization sequences with simultaneous clamp-diode protection. Use Value: Supports bidirectional logic control via NAND enables (S inputs), allowing flexible step/direction sequencing without additional logic gates. |
Use Scenario: Replacing aging discrete transistor arrays in test equipment front panels for lamp, buzzer, and indicator load control. IC Role / Device Role / Timing Role: Drop-in replacement for obsolete peripheral driver ICs with identical pinout and logic behavior (SN75477 family). Use Value: Maintains legacy system functionality while improving reliability through integrated clamping and latch-up immunity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual NAND peripheral driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN75477D | Same silicon die and electrical specs; differs only in RoHS-compliant NiPdAu lead finish vs. SN75477DG4's NiPdAu with green mold compound. | Identical use cases; SN75477D is standard RoHS variant with same SOIC-8 footprint and thermal profile. | Select SN75477D for new designs requiring full TI-standard RoHS compliance without green compound restrictions. |
| ULN2003A | Seven-channel Darlington array with higher VCE(sat) (1.1 V), lower speed (500 ns typ), no NAND logic - requires external gate logic for enable control. | Better suited for high-voltage (50 V), low-speed relay banks; lacks integrated NAND function and fast switching capability. | Choose ULN2003A only when multi-channel count outweighs need for logic integration and speed; not a functional substitute for SN75477DG4's NAND gating. |
Compared with SN75477D, SN75477DG4 offers identical performance but with TI's green compound packaging for enhanced environmental compliance; versus ULN2003A, it provides faster switching, built-in NAND logic, and lower saturation voltage - making it superior for time-critical dual-load control where logic integration reduces external component count.
Availability
SN75477DG4 is available at Aetrix Electronics and suitable for relay control interfaces, printer hammer drivers, stepper motor phase switching, and legacy instrumentation load management requiring stable component supply across extended production lifecycles.
Supply support for SN75477DG4 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 global semiconductor leader founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The SN75477DG4 belongs to TI's legacy peripheral driver product line, engineered specifically for robust high-voltage, high-current interfacing between digital logic and electromechanical loads in commercial-grade systems.
FAQ
What logic function does the SN75477DG4 implement?
The SN75477DG4 implements two independent NAND gates with active-high inputs (A and S) and open-collector outputs (Y). Its truth table shows Y = HIGH when either A or S is LOW, and Y = LOW only when both A and S are HIGH - enabling enable-controlled sinking of current to external loads. This behavior is confirmed in the official SLRS025A datasheet function tables and logic diagrams.
Can SN75477DG4 drive a 24 V relay directly?
Yes, SN75477DG4 can drive a 24 V relay directly when used with an external pull-up resistor to 24 V on the open-collector output pin. Its 100 V typical output breakdown voltage and integrated 70 V clamp diodes protect against flyback transients, and its 300 mA continuous output rating covers typical relay coil currents. Ensure the relay coil resistance limits peak current within the 300 mA limit.
What is the maximum operating temperature for SN75477DG4?
The SN75477DG4 is characterized for operation from 0°C to 70°C ambient temperature, as specified in the "recommended operating conditions" section of the SLRS025A datasheet. Its power dissipation is derated above 25°C (5.8 mW/°C for SOIC package), limiting usable output current at elevated temperatures - e.g., 464 mW max at 70°C.
Does SN75477DG4 require external flyback diodes?
No, SN75477DG4 does not require external flyback diodes. It integrates internal clamp diodes rated for 300 mA and 70 V reverse voltage on each output, explicitly designed to suppress inductive transients from relays, solenoids, and other inductive loads - a key feature highlighted in the device description and absolute maximum ratings.
How does SN75477DG4 differ from SN75476 and SN75478?
SN75477DG4 implements dual NAND logic (Y = A·S), whereas SN75476 is dual AND (Y = A·S) and SN75478 is dual OR (Y = A+S). All three share identical pinouts, package options, electrical specs (current, voltage, timing), and thermal characteristics - differing only in internal logic configuration. The SN75477DG4 is functionally distinct and not interchangeable without logic redesign.
SN75477DG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Logic Type:
- Peripheral Driver
- Number of Elements:
- 2
- Number of Bits per Element:
- 1
- Input Type:
- -
- Output Type:
- -
- Current - Output High, Low:
- -, 300mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
SN75477DG4 FAQ
1.How can I place an order for SN75477DG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN75477DG4 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 SN75477DG4 reliable?
The price and inventory of SN75477DG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN75477DG4 is usually 5 days.
3.What payment methods are accepted for SN75477DG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN75477DG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN75477DG4?
SN75477DG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN75477DG4 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 SN75477DG4?
For technical support, including SN75477DG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN75477DG4 requirements.
6.How does Aetrix verify that SN75477DG4 is sourced from the original manufacturer or authorized distributors?
All SN75477DG4 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 SN75477DG4 meets industry standards.
7.What is the process for return or replacement of SN75477DG4?
All SN75477DG4 units undergo pre-shipment inspection (PSI). If there is an issue with SN75477DG4, 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 SN75477DG4 part is unused and in its original packaging.
Return procedure for SN75477DG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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