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Texas Instruments UC3770BN
- Part No.:
- UC3770BN
- Manufacturer:
- Texas Instruments
- Category:
- Full Half-Bridge (H Bridge) Drivers
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
UC3770BN.pdf
- Description:
- IC HALF BRIDGE DRIVER 2A 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:131
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Product details
Overview
UC3770BN 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 output current, supports 10–50V motor supply voltage, and enables full-step, half-step, and micro-step operation in industrial motion control systems.
For engineers reviewing the UC3770BN datasheet, UC3770BN pinout, UC3770BN application, or UC3770BN equivalent, this device is selected for precision open-loop stepper drive where configurable current thresholds (tailored for 50%/71%/100% half-step levels), low saturation voltage, and thermal protection are critical design requirements.
Technical Context
The UC3770BN implements a monolithic H-bridge power stage with separate source/sink drivers, external high-side clamp diodes, and a comparator-based current regulation loop using VR reference and Pin 10 analog input. Its logic interface accepts standard TTL-level signals on Pins 7–9 for phase, I0, and I1 control.
Current sensing is achieved via internal sense resistors and a programmable off-time monostable (RT/CT controlled), enabling step-mode selection and continuous current adjustment from 5mA to 2A. Thermal shutdown activates at +170°C junction temperature with soft intervention behavior.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | ±2A max - supports NEMA 17–23 stepper motors without external current amplification |
| Motor Supply Voltage | 10–50V - compatible with common industrial DC bus rails including 24V and 48V systems |
| Logic Supply Voltage | 4.75–5.3V - tightly regulated 5V TTL interface requiring no level translation |
| Sink Saturation Voltage | 0.8V @ 1.0A - reduces conduction loss and heat generation in low-side switching path |
| Source Saturation Voltage | 1.3V @ 1.0A - defines minimum headroom needed between VM and motor winding voltage |
| Comparator Thresholds | 70–430mV range (mode-dependent) - enables precise half-step current ratios: 50%, 71%, 100% |
| Off Time | 25–35ms (RT=56kΩ, CT=820pF) - sets minimum pulse width for current decay and chopper frequency |
Pinout & Package
UC3770BN is housed in a 16-pin plastic dual in-line package (PDIP-N), with 0–70°C ambient operating range and RoHS-compliant NiPdAu lead finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–3, 9, 13–17, 28 | Gnd | Dedicated ground pins for logic, power, and current sense return paths to minimize noise coupling |
| 4, 12 | VM | Main motor supply input - connects to 10–50V rail feeding H-bridge high-side and low-side switches |
| 6 | AOUT | Bridge output A - drives one terminal of bipolar stepper motor winding |
| 8 | Emitters | Internal emitter connection point - requires external high-side clamp diodes per datasheet requirement |
| 10 | BOUT | Bridge output B - drives opposite terminal of same stepper motor winding |
| 11 | Timing | RC timing node for off-time monostable - sets chopper frequency and current decay interval |
| 18 | VCC | 5V logic supply - powers internal logic, comparators, and gate drivers |
| 19, 21, 23 | I1, I0, Current | Mode select and current control inputs - configure step mode and set current threshold via VR reference |
| 20 | Phase | Direction control input - toggles H-bridge polarity to reverse motor rotation |
| 24 | VR | Reference voltage input - sets full-scale current limit; accepts 0–15V, typically 5V |
Key Features
| Feature | Design Value |
|---|---|
| Half-step optimized thresholds | Three discrete current levels (50%, 71%, 100%) enable smooth torque delivery without microstepping complexity |
| Thermal protection with soft intervention | Gradual current reduction before shutdown avoids abrupt motor stall and preserves system stability |
| LS-TTL compatible inputs | Pins 7–9 accept standard 5V logic without pull-ups or level shifters - simplifies MCU interface |
| Wide current control range | 5mA–2A via VR and I0/I1 configuration - supports small holding currents and full-torque motion |
| Low saturation voltage | 0.8V sink / 1.3V source @ 1A - minimizes power dissipation and improves efficiency at rated load |
Applications
| Industrial CNC Positioning | Automated Test Equipment (ATE) |
|---|---|
|
Use Scenario: Open-loop positioning of X-Y stages in benchtop CNC mills using NEMA 23 stepper motors. IC Role / Device Role / Timing Role: Full-bridge driver controlling bidirectional winding current and step sequencing via microcontroller GPIO. Use Value: UC3770BN's 2A drive capability and half-step thresholds deliver consistent torque across speed range without encoder feedback. |
Use Scenario: Precision actuator control in semiconductor wafer probers requiring repeatable sub-millimeter motion. IC Role / Device Role / Timing Role: Stepper motor driver executing calibrated move sequences under test controller command. Use Value: UC3770BN's low saturation voltage and thermal shutdown ensure stable operation during extended duty cycles in enclosed ATE enclosures. |
| Medical Infusion Pumps | Lab Automation Platforms |
|
Use Scenario: Peristaltic pump actuation in IV infusion systems requiring silent, reliable fluid dosing. IC Role / Device Role / Timing Role: Bipolar stepper driver translating pulse/direction commands into precise motor rotation. Use Value: UC3770BN's 5mA–2A current adjustability allows fine-tuning of holding torque versus dynamic torque to reduce audible vibration. |
Use Scenario: Multi-axis sample handling in DNA sequencers and ELISA washers with synchronized motion profiles. IC Role / Device Role / Timing Role: Motor interface IC managing independent stepper axes under real-time scheduler control. Use Value: UC3770BN's wide 10–50V VM range supports shared 24V system rail across multiple axes without dedicated regulators. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar stepper motor driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UC3770AN | Identical pinout and architecture; current sense thresholds match UC3717 (not UC3770B), supporting legacy drop-in replacement where half-step optimization is not required. | Preferred in designs reusing UC3717 layouts without external high-side diode redesign. | Select UC3770AN when maintaining compatibility with older UC3717-based PCBs and half-step current ratios are unnecessary. |
| TB6560AHQ | Higher integration: includes built-in oscillator, indexer, and overcurrent protection; 3.3V/5V logic compatible; 3.5A peak output. | Reduces external component count but requires different control protocol (step/direction vs. I0/I1/Phase). | Choose TB6560AHQ for new designs prioritizing integration and higher current, accepting revised firmware interface. |
Compared with UC3770AN and TB6560AHQ, the UC3770BN uniquely balances legacy compatibility, half-step precision, and discrete H-bridge flexibility-making it optimal for industrial upgrades where thermal robustness and configurable current decay are essential.
Availability
UC3770BN is available at Aetrix Electronics and suitable for industrial CNC positioning, automated test equipment, medical infusion pumps, and lab automation platforms requiring stable component supply and long-term production continuity.
Supply support for UC3770BN 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 power management technologies, with decades of experience in motor control ICs.
The UC3770BN belongs to TI's legacy high-performance stepper driver family, designed specifically for industrial open-loop motion systems demanding robust current regulation, thermal resilience, and flexible step-mode control.
FAQ
What is the maximum motor supply voltage supported by the UC3770BN?
The UC3770BN supports a motor supply voltage (VM) range of 10V to 50V, with absolute maximum rating at 50V. This allows direct use with standard 24V and 48V industrial power rails. Operation above 45V may reduce reliability and is not characterized per datasheet specifications; sustained use at 50V requires careful thermal design due to increased power dissipation in the H-bridge stage of the UC3770BN.
Does the UC3770BN require external high-side clamp diodes?
Yes, the UC3770BN requires external high-side clamp diodes - unlike the UC3717, its architecture does not integrate these components. This is explicitly stated in the datasheet and applies to all UC3770A/B variants. The diodes must be fast-recovery types rated for ≥2A and placed between VM and each bridge output (AOUT and BOUT) to safely dissipate inductive kickback energy from stepper windings during switching transitions in the UC3770BN.
How does the UC3770BN differ from the UC3770AN in current control behavior?
The UC3770BN uses current sense thresholds optimized for half-stepping (50%, 71%, 100% levels), while the UC3770AN matches UC3717 thresholds for full/half-step compatibility without half-step tuning. This difference affects the analog comparator response at Pin 10 under identical VR and I0/I1 conditions. As a result, the UC3770BN delivers smoother torque transitions in half-step mode, whereas the UC3770AN is suited for drop-in replacement in legacy UC3717 designs where those specific ratios are not required.
What is the operating temperature range for the UC3770BN?
The UC3770BN is specified for ambient operating temperatures from 0°C to +70°C. Its thermal shutdown activates at +170°C junction temperature, providing protection during overload or poor heatsinking. For continuous 2A operation, PCB copper area, airflow, and optional heatsinking must be designed to maintain junction temperature below +150°C - the absolute maximum rated TJ - ensuring long-term reliability of the UC3770BN in enclosed industrial environments.
Can the UC3770BN be used for micro-stepping applications?
The UC3770BN supports full-step, half-step, and micro-step operation per its block diagram and functional description, but it does not include an internal indexer or PWM generator for true microstepping. Micro-stepping requires external circuitry - such as a DAC-controlled current reference or digital current shaping - to modulate the VR input dynamically. The UC3770BN provides the necessary H-bridge and current-sense infrastructure, but micro-step resolution depends entirely on the external control design interfacing with the UC3770BN.
UC3770BN 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
UC3770BN FAQ
1.How can I place an order for UC3770BN through Aetrix?
Please submit a Request for Quotation (RFQ) for UC3770BN 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 UC3770BN reliable?
The price and inventory of UC3770BN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC3770BN is usually 5 days.
3.What payment methods are accepted for UC3770BN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC3770BN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for UC3770BN?
UC3770BN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your UC3770BN 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 UC3770BN?
For technical support, including UC3770BN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC3770BN requirements.
6.How does Aetrix verify that UC3770BN is sourced from the original manufacturer or authorized distributors?
All UC3770BN 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 UC3770BN meets industry standards.
7.What is the process for return or replacement of UC3770BN?
All UC3770BN units undergo pre-shipment inspection (PSI). If there is an issue with UC3770BN, 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 UC3770BN part is unused and in its original packaging.
Return procedure for UC3770BN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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