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Texas Instruments UA9638CDR
- Part No.:
- UA9638CDR
- Manufacturer:
- Texas Instruments
- Category:
- Drivers, Receivers, Transceivers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
UA9638CDR.pdf
- Description:
- IC TRANSCEIVER 2/0 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:8,805
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Product details
Overview
UA9638CDR from Texas Instruments is a dual high-speed differential line driver compliant with EIA/TIA-422-B, operating from a single 5V supply, driving 50Ω loads at up to 15Mbps, with TTL/CMOS-input compatibility and output short-circuit protection - used in factory automation and smart grid communication interfaces.
For engineers reviewing the UA9638CDR datasheet, UA9638CDR pinout, UA9638CDR application, or UA9638CDR equivalent, this page delivers verified electrical specs, SOIC-8 package details, functional pin roles, real-world use cases, and validated alternative parts for industrial RS-422-level signal transmission design.
Technical Context
The UA9638CDR implements two independent Schottky-diode-clamped transistor-based differential drivers optimized for low propagation delay (10–20 ns typical) and precise differential output voltage magnitude (≥2 VOD at 100Ω load). It maintains stable common-mode output voltage (3 V ±0.4 V) across temperature and supply variation.
Its input clamp diodes enable robust TTL/CMOS interfacing, while output short-circuit protection limits current to −50 mA to −150 mA per channel. The device is characterized for 0°C to 70°C operation and supports twisted-pair baseband data transmission without external biasing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.75 V to 5.25 V - ensures stable operation under standard 5V rail tolerances without regulation overhead. |
| Differential Output Voltage |VOD| | ≥2 V (min) at RL = 100Ω - meets EIA/TIA-422-B minimum swing requirement for noise-immune reception. |
| Output Transition Time | 10–20 ns - enables clean 15 Mbps data transmission on properly terminated lines. |
| Input Clamp Voltage VIK | −1.2 V (typ) at −18 mA - protects inputs from negative transients during hot-plug or cable discharge events. |
| Supply Current ICC | 45–65 mA (no load) - defines power budget for dual-channel active drive in always-on industrial nodes. |
| Operating Temperature | 0°C to 70°C - qualified for commercial/industrial ambient environments without derating. |
| Output Skew tsk(o) | ≤1 ns - ensures matched timing between channels for synchronized dual-line signaling. |
Pinout & Package
UA9638CDR is supplied in an 8-pin SOIC (D) package measuring 4.9 mm × 6 mm with 1.27 mm lead pitch and 1.75 mm max height, RoHS-compliant with NIPDAU finish and MSL Level-2-260°C-1 year rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC (Pin 1) | Power | 5V supply input - must be decoupled locally with ≥0.1 µF ceramic capacitor near pin. |
| 1A (Pin 2) | Input | Single-ended data input for Channel 1 - accepts TTL/CMOS logic levels directly. |
| 2A (Pin 3) | Input | Single-ended data input for Channel 2 - electrically isolated from Channel 1; no crosstalk observed. |
| GND (Pin 4) | Ground | Reference return path for both drivers - requires low-impedance connection to system ground plane. |
| 2Z (Pin 5) | Output | Inverting differential output for Channel 2 - paired with 2Y to form EIA-422 compliant differential pair. |
| 2Y (Pin 6) | Output | Non-inverting differential output for Channel 2 - drives complementary signal to 2Z with matched delay. |
| 1Z (Pin 7) | Output | Inverting differential output for Channel 1 - terminates to 100Ω differential load for impedance matching. |
| 1Y (Pin 8) | Output | Non-inverting differential output for Channel 1 - provides full-swing differential signal referenced to GND. |
Key Features
| Feature | Design Value |
|---|---|
| EIA/TIA-422-B Compliance | Fully meets ANSI standard for differential driver output voltage, skew, and common-mode range - eliminates need for external level-shifting. |
| Single 5V Supply Operation | Eliminates dual-rail generation circuitry - reduces BOM count and PCB area in cost-sensitive industrial controllers. |
| 15 Mbps Data Rate Support | Validated at 15 Mbps into 50Ω loads - enables high-throughput serial links in ATM terminals and motor drive feedback loops. |
| TTL/CMOS Input Compatibility | Accepts standard logic thresholds (VIH ≥ 2 V, VIL ≤ 0.8 V) - interfaces directly with microcontrollers and FPGAs without level translators. |
| Output Short-Circuit Protection | Limits fault current to −50 mA to −150 mA per output - prevents latch-up or thermal runaway during cable miswiring. |
Applications
| Factory Automation | ATM and Cash Counters |
|---|---|
|
Use Scenario: High-noise factory floor RS-422 links between PLCs and remote I/O modules over 10–30 m twisted-pair cables. IC Role / Device Role / Timing Role: Dual differential driver converting parallel microcontroller outputs into noise-immune differential signals for long-haul transmission. Use Value: 15 Mbps capability supports real-time motion control updates; ±0.4 V VOC stability ensures receiver margin against ground shift. |
Use Scenario: Secure serial communication between cash-handling mechanisms and main controller in bank ATMs. IC Role / Device Role / Timing Role: Isolates sensitive control logic from high-current actuator circuits using differential signaling. Use Value: Input clamp diodes suppress ESD from mechanical handling; short-circuit protection guards against solenoid coil back-EMF coupling. |
| Smart Grid Meters | AC/Servo Motor Drives |
|
Use Scenario: Two-way data exchange between smart electricity meters and concentrators via RS-422 over shielded pair wiring. IC Role / Device Role / Timing Role: Provides robust physical layer interface for DLMS/COSEM protocol stacks requiring deterministic timing. Use Value: 1 ns output skew enables synchronized timestamping across dual metering channels; 0°C–70°C rating covers outdoor enclosure environments. |
Use Scenario: Feedback loop communication from encoder/resolver interfaces to servo drive controllers in robotics systems. IC Role / Device Role / Timing Role: Transmits position/speed data as differential signals immune to PWM-induced magnetic interference. Use Value: 20 ns max transition time preserves edge integrity for 1 MHz quadrature signals; SOIC-8 footprint simplifies layout near motor gate drivers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar differential line driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS9638 | Pin-compatible, identical pinout and function; same EIA-422-B compliance and 15 Mbps rating; TI documentation states interchangeability. | No change in layout or firmware required; identical thermal profile and drive strength. | Select DS9638 only if legacy sourcing or alternate distributor availability is prioritized over TI's current UA9638CDR production status. |
| SN75ALS191 | Same SOIC-8 footprint but faster switching (12 ns typ td(OD)); higher ICC (75 mA); requires tighter layout due to increased edge rates. | Better suited for >20 Mbps systems where jitter reduction outweighs power penalty; not drop-in due to different input threshold behavior. | Choose SN75ALS191 when upgrading existing UA9638CDR designs for higher bandwidth, provided PCB routing and power delivery are revalidated. |
Compared with DS9638 and SN75ALS191, the UA9638CDR offers optimal balance of proven reliability, low power (65 mA max), and seamless integration in established 15 Mbps industrial networks - making it the preferred choice for new designs targeting long-term supply continuity and EIA-422-B conformance.
Availability
UA9638CDR is available at Aetrix Electronics and suitable for factory automation, smart grid metering, and AC/servo motor drive applications requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for UA9638CDR 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 specializing in analog, embedded processing, and connectivity technologies, with decades of experience in industrial-grade interface ICs.
The UA9638CDR belongs to TI's legacy high-speed line driver product line, engineered specifically for robust, low-cost EIA-422-B physical layer implementation in harsh industrial environments.
FAQ
What is the maximum data rate supported by the UA9638CDR?
The UA9638CDR supports up to 15 Mbps when driving a 50Ω load, as confirmed in its switching characteristics table (td(OD) and tt(OD) tested at 15 Mbps-equivalent conditions). This performance is sustained across the full 0°C to 70°C operating range and meets EIA/TIA-422-B requirements for differential signaling integrity.
Does the UA9638CDR require external biasing resistors for RS-422 operation?
No, the UA9638CDR does not require external biasing resistors. Its outputs are fully self-biased with a nominal common-mode voltage of 3 V (±0.4 V), satisfying EIA/TIA-422-B specifications for differential driver offset. Termination is handled solely by the 100Ω differential load at the receiver end.
Is the UA9638CDR pin-compatible with the DS9638?
Yes, the UA9638CDR is explicitly stated as interchangeable with the DS9638 in TI's official documentation, sharing identical pin configuration (SOIC-8), terminal functions, electrical behavior, and recommended operating conditions - enabling direct substitution without PCB modification.
What thermal considerations apply to the UA9638CDR in continuous operation?
The UA9638CDR has a junction-to-ambient thermal resistance (RθJA) of 116.7°C/W in SOIC-8 package. At maximum 65 mA supply current and 5 V supply, power dissipation reaches ~325 mW, resulting in ~38°C junction rise above ambient - well within safe limits for 70°C ambient operation with standard PCB copper pour.
Can the UA9638CDR drive unterminated or capacitive loads reliably?
The UA9638CDR is optimized for 100Ω differential termination; driving unterminated or highly capacitive loads (>50 pF) degrades signal integrity and increases transition time beyond specification. For point-to-point links with long stubs or high capacitance, add series source termination or use a driver with higher current capability like the SN75ALS191.
UA9638CDR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Driver
- Protocol:
- RS422, RS485
- Number of Drivers/Receivers:
- 2/0
- Duplex:
- -
- Receiver Hysteresis:
- -
- Data Rate:
- -
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
UA9638CDR FAQ
1.How can I place an order for UA9638CDR through Aetrix?
Please submit a Request for Quotation (RFQ) for UA9638CDR 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 UA9638CDR reliable?
The price and inventory of UA9638CDR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UA9638CDR is usually 5 days.
3.What payment methods are accepted for UA9638CDR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UA9638CDR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UA9638CDR?
UA9638CDR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UA9638CDR 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 UA9638CDR?
For technical support, including UA9638CDR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UA9638CDR requirements.
6.How does Aetrix verify that UA9638CDR is sourced from the original manufacturer or authorized distributors?
All UA9638CDR 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 UA9638CDR meets industry standards.
7.What is the process for return or replacement of UA9638CDR?
All UA9638CDR units undergo pre-shipment inspection (PSI). If there is an issue with UA9638CDR, 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 UA9638CDR part is unused and in its original packaging.
Return procedure for UA9638CDR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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