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Texas Instruments UC3770AN
- Part No.:
- UC3770AN
- Manufacturer:
- Texas Instruments
- Category:
- Full Half-Bridge (H Bridge) Drivers
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
UC3770AN.pdf
- Description:
- IC HALF BRIDGE DRIVER 2A 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:206
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Product details
Overview
UC3770AN from Texas Instruments is a high-performance bipolar stepper motor full-bridge driver IC with LS-TTL-compatible logic inputs, integrated current sense and thermal shutdown. It delivers up to 2A bipolar output current, supports motor supply voltages from 10V to 45V, and operates across 0°C to 70°C ambient. Designed for microprocessor-controlled stepper systems, it enables full-step, half-step, and micro-step excitation in industrial motion control.
For engineers reviewing the UC3770AN datasheet, UC3770AN pinout, UC3770AN application, or UC3770AN equivalent, key selection criteria include its 2A current capability, 45V motor supply rating, DIP-16 package, current-sense threshold compatibility with UC3717, and requirement for external high-side clamp diodes.
Technical Context
The UC3770AN implements a monolithic H-bridge power stage with separate source and sink drivers, each rated for ±2A continuous output. Its current regulation uses an internal comparator (Pin 10) with three selectable thresholds-430mV, 265mV, and 90mV-corresponding to full, half, and quarter current levels under defined I0/I1 logic states.
Thermal protection triggers at +170°C junction temperature with soft intervention, and timing is externally set via RT/CT network (e.g., 56kΩ/820pF yields 25–35ms off-time). Unlike UC3717, UC3770AN requires external high-side clamp diodes due to absence of internal clamping.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | ±2A bipolar - supports NEMA 17–23 stepper motors with full torque at low speeds |
| Motor Supply Voltage | 10–45V - compatible with standard 12V/24V/48V industrial motor rails |
| Logic Supply Voltage | 4.75–5.3V - ensures robust TTL-level interface with microcontrollers and FPGAs |
| Current Sense Thresholds | 430mV / 265mV / 90mV - enables precise 100%/50%/25% current scaling per step mode |
| Sink Saturation Voltage | 0.8V @ 1.0A - reduces conduction loss and heat generation in low-side switching |
| Source Saturation Voltage | 1.3V @ 1.0A - defines upper-bound voltage drop across high-side driver during on-state |
| Thermal Shutdown | +170°C - provides fail-safe protection without latch-up, enabling recovery after cooldown |
Pinout & Package
UC3770AN is housed in a 16-pin plastic dual in-line package (PDIP-N), with 0.3-inch body width and through-hole mounting. Pin 1 is located at the left end of the top row when viewed from top with notch or dot orientation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–3, 9, 13–17, 28 | GND | Multiple ground connections reduce impedance and improve current return path stability |
| 4, 12 | VM | Motor supply input - connects directly to high-current DC bus (10–45V) |
| 6 | VCC | Logic supply input - powers internal logic and level-shifting circuitry (4.75–5.3V) |
| 7, 8, 9 | Logic Inputs (I0, Phase, I1) | Control sequencing: I0/I1 select current level; Phase sets direction; all TTL-compatible |
| 10 | Current Sense Input | Analog input for external sense resistor feedback - thresholds set by I0/I1 state |
| 11 | Timing (RT/CT) | Connects external RC network to define off-time duration for current decay control |
| 18 | VCC | Secondary logic supply connection - improves noise immunity and decoupling |
| 19–21, 23–24 | I1, Phase, I0, Current, VR | Configuration and reference inputs - VR sets current reference voltage (up to 15V) |
| 25–27 | N/C | No-connect pins - must remain unconnected per datasheet guidance |
Key Features
| Feature | Design Value |
|---|---|
| Full/Half/Micro-step support | Enables smooth motion and high-resolution positioning without external sequencer hardware |
| Three-level current control | Hardware-selectable 100%/50%/25% motor current via I0/I1 logic - no software overhead |
| Integrated thermal shutdown | Self-resetting +170°C protection prevents permanent damage during overload or stall |
| Low saturation voltage | 0.8V sink / 1.3V source @ 1A - minimizes power dissipation and heatsink requirements |
| LS-TTL compatible inputs | Direct interface with 5V microcontrollers, CPLDs, and discrete logic without level shifters |
Applications
| Industrial CNC Positioning | Medical Infusion Pumps |
|---|---|
|
Use Scenario: Precision open-loop positioning of X/Y/Z axes in benchtop CNC mills using NEMA 17 stepper motors. IC Role / Device Role / Timing Role: Full-bridge driver executing micro-stepped commutation sequences generated by MCU GPIO. Use Value: UC3770AN's 2A drive capability and 45V VM rating enable high-torque operation at 24V rail; selectable current levels reduce motor heating during idle. |
Use Scenario: Controlled peristaltic fluid delivery in portable infusion pumps requiring silent, repeatable dosing. IC Role / Device Role / Timing Role: Bipolar stepper driver managing 7.5° step angle motor with half-step excitation for fine flow resolution. Use Value: UC3770AN's 50% current threshold (265mV) allows halving motor current between steps - lowering audible noise and power consumption. |
| Automated Test Equipment (ATE) | Lab Automation Stage Control |
|
Use Scenario: High-speed actuator movement in semiconductor probe stations where repeatability and thermal stability are critical. IC Role / Device Role / Timing Role: Stepper driver operating in full-step mode with external current sensing for closed-loop current monitoring. Use Value: UC3770AN's 0.8V sink saturation voltage limits conduction loss at 1.3A, reducing board-level thermal rise in densely packed ATE modules. |
Use Scenario: Multi-axis optical alignment stages in spectroscopy instruments requiring sub-micron positioning accuracy. IC Role / Device Role / Timing Role: Micro-step driver controlled via SPI-to-GPIO bridge, using UC3770AN's RT/CT timing for consistent decay control. Use Value: UC3770AN's 25–35ms off-time programmability ensures predictable current decay across temperature, maintaining step accuracy over 0–70°C range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar stepper motor driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UC3717N | Lower max current (1.5A), no external high-side diode requirement, identical current sense thresholds to UC3770AN | Preferred where board space prohibits external diodes and 1.5A suffices for motor torque | Select UC3717N only if motor current ≤1.5A and layout cannot accommodate external clamp diodes |
| UC3770BN | Same package and pinout; different current sense thresholds (430mV/315mV/225mV) optimized for 100%/71%/50% stepping | Better suited for half-step dominant motion profiles requiring precise 71% intermediate current | Choose UC3770BN when half-step operation with 71% current level is required; UC3770AN remains optimal for full/half/micro with 100%/50%/25% scaling |
Compared with UC3717N, UC3770AN offers higher 2A current and wider 45V VM range but requires external diodes; compared with UC3770BN, UC3770AN provides lower 90mV third threshold enabling finer micro-step resolution at reduced current.
Availability
UC3770AN is available at Aetrix Electronics and suitable for industrial motion control, medical device actuation, and automated test equipment requiring stable component supply and long-term production continuity.
Supply support for UC3770AN 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.
The UC3770A/B series was developed by Unitrode (acquired by TI in 1999) specifically for cost-effective, high-current stepper motor drive in microprocessor-based motion systems - emphasizing integration, thermal resilience, and flexible current control.
FAQ
What is the maximum motor supply voltage supported by UC3770AN?
The UC3770AN supports a motor supply voltage (VM) up to 45V, as specified in its absolute maximum ratings and electrical characteristics table. This allows direct use with common 24V and 48V industrial motor rails. Operation beyond 45V risks permanent damage; the 50V rating cited elsewhere applies only to transient conditions and must not be used for steady-state design.
Does UC3770AN require external high-side clamp diodes?
Yes, UC3770AN requires external high-side clamp diodes - unlike UC3717 - because it lacks internal clamping circuitry. These diodes protect the high-side source drivers during inductive kickback from stepper windings. The datasheet explicitly states this requirement and identifies it as a key distinction from earlier devices.
What are the current sense threshold voltages for UC3770AN?
The UC3770AN has three current sense threshold voltages: 430mV (full current), 265mV (half current), and 90mV (quarter current), selected by the logic states of I0 and I1 inputs. These values are confirmed in the Electrical Characteristics table under "Comparator Threshold (Pin 10)" with VM = 36V, VCC = 5V, and VR = 5V.
Can UC3770AN be used in micro-stepping configurations?
Yes, UC3770AN supports micro-stepping through external current control circuitry and its programmable off-time (via RT/CT), enabling precise current decay shaping. While it does not integrate a micro-step indexer, its three-level current scaling and stable thermal behavior make it suitable for external micro-step controllers driving two UC3770ANs per motor.
What is the operating temperature range for UC3770AN?
The UC3770AN is specified for operation from 0°C to +70°C ambient temperature. This commercial-grade range is documented in both the device description and Absolute Maximum Ratings section. Junction temperature must not exceed +150°C, and thermal shutdown activates at +170°C to prevent damage.
UC3770AN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Output Configuration:
- Half Bridge (2)
- Applications:
- General Purpose, Stepper Motors
- Interface:
- Logic
- Load Type:
- Inductive
- Technology:
- Bipolar
- Rds On (Typ):
- -
- Current - Output / Channel:
- 2A
- Current - Peak Output:
- -
- Voltage - Supply:
- 4.75V ~ 5.3V
- Voltage - Load:
- 10V ~ 45V
- Operating Temperature:
- 0°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Features:
- -
- Fault Protection:
- Over Temperature
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-PDIP
UC3770AN FAQ
1.How can I place an order for UC3770AN through Aetrix?
Please submit a Request for Quotation (RFQ) for UC3770AN 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 UC3770AN reliable?
The price and inventory of UC3770AN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC3770AN is usually 5 days.
3.What payment methods are accepted for UC3770AN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC3770AN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC3770AN?
UC3770AN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC3770AN 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 UC3770AN?
For technical support, including UC3770AN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC3770AN requirements.
6.How does Aetrix verify that UC3770AN is sourced from the original manufacturer or authorized distributors?
All UC3770AN 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 UC3770AN meets industry standards.
7.What is the process for return or replacement of UC3770AN?
All UC3770AN units undergo pre-shipment inspection (PSI). If there is an issue with UC3770AN, 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 UC3770AN part is unused and in its original packaging.
Return procedure for UC3770AN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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