Texas Instruments UC3637NG4

Overview

UC3637NG4 from Texas Instruments is a monolithic PWM motor controller IC designed for DC motor drive applications requiring bi-directional or uni-directional control. It integrates a sawtooth oscillator, dual ±100mA PWM comparators with source/sink drivers, error amplifier, under-voltage lockout, pulse-by-pulse current limiting, and a temperature-compensated 2.5V shutdown threshold. It operates across 0°C to +70°C and supports ±2.5V to ±20V dual supply rails.

For engineers reviewing the UC3637NG4 datasheet, UC3637NG4 pinout, UC3637NG4 application, or UC3637NG4 equivalent, key selection considerations include its dual-output PWM modulation architecture, ±100mA output drive capability, oscillator frequency stability (±10% over temperature), and compatibility with power-FET or bipolar transistor gate driving in servo and motion control systems.

Technical Context

The UC3637NG4 implements a fixed-frequency sawtooth oscillator whose frequency is set externally via RT and CT components, with initial accuracy of ±5% at 25°C and ±10% over full operating temperature. Its uncommitted PWM comparators accept analog error signals referenced to ±VS and generate complementary pulse trains with programmable deadtime via differential inputs on Pins 9/11 and 10/8.

Internal protection includes under-voltage lockout triggering at 4.15–5.0V (measured between +VS and –VS), latched pulse-by-pulse current limiting with 180–220mV offset, and shutdown activation when Pin 15 is pulled >2.3V below +VS. The error amplifier delivers 15V/µs slew rate, 2MHz unity-gain bandwidth, and ±20mA output drive into low-impedance loads.

Key Specifications

Pinout & Package

UC3637NG4 is housed in an 18-pin PDIP (Plastic Dual In-line Package) with 0.3-inch body width and through-hole mounting. Lead finish is lead-free (CU NIPDAU), RoHS-compliant, and rated for soldering up to 300°C for 10 seconds.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PWM motor controller applications.

Compared with UC2637NG4 and UC3637DW, the UC3637NG4 provides identical PWM control functionality in a cost-effective, through-hole PDIP package optimized for 0°C to +70°C commercial applications-making it ideal for lab equipment, consumer robotics, and low-volume industrial controls where ease of hand-soldering and socket-based testing are priorities.

Availability

UC3637NG4 is available at Aetrix Electronics and suitable for industrial servo positioning, DC brush motor speed control, bi-directional linear actuator drive, and lab equipment motion control requiring stable component supply and long-term sourcing continuity.

Supply support for UC3637NG4 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 over 50 years of innovation in industrial control ICs.

The UC3637NG4 belongs to TI's legacy PWM motor controller family, engineered specifically for analog-based DC motor drive systems requiring precision error amplification, robust protection, and flexible modulation schemes in commercial-grade applications.

FAQ

What is the recommended oscillator timing component configuration for UC3637NG4?

The UC3637NG4 oscillator uses external RT and CT components referenced to ground. With RT = 16.7kΩ and CT = 1500pF, the device achieves ~10kHz nominal frequency. The +VTH pin (Pin 1) biases the internal charging current, ensuring frequency stability across supply variations. Always verify layout parasitics and capacitor tolerance (±5% NP0/C0G preferred) to maintain ±10% accuracy over temperature.

Does UC3637NG4 support single-supply operation?

Yes, UC3637NG4 supports single-supply operation by grounding the –VS pin (Pin 5) and applying VCC to +VS (Pin 7). Input common-mode range extends to –VS+2V, allowing analog inputs (e.g., Pins 9, 11, 12) to operate down to +2V above ground. However, output swing is reduced: high-level output drops to ~VCC – 2V, and low-level rises to ~0.2V, requiring verification against downstream FET thresholds.

How does the current limit function work on UC3637NG4?

The UC3637NG4 features a latched current limit amplifier with a 180–220mV internal offset. Differential inputs (+C/L Pin 13, –C/L Pin 14) accept a sense voltage across a shunt resistor in the motor phase leg. When the differential exceeds the offset, the output drivers shut down until reset via the SHUTDOWN pin (Pin 15). This protects against short-circuit or stall conditions on a pulse-by-pulse basis without requiring external latch circuitry.

Can UC3637NG4 generate complementary PWM outputs with adjustable deadtime?

Yes, UC3637NG4 enables three deadtime configurations via Pins 9 (+BIN), 11 (–AIN), and 12 (+AIN). Zero deadtime occurs when +BIN and –AIN voltages match, maximizing torque stiffness. Small deadtime is achieved by setting +BIN > –AIN, introducing intentional delay to prevent shoot-through. Increased deadband mode widens the comparator acceptance window, reducing power dissipation near null position-fully configurable without external logic.

What is the thermal derating guidance for UC3637NG4 in PDIP package?

UC3637NG4 in PDIP package has 1000mW power dissipation limit at TA = 25°C and 2000mW at TC = 25°C. For reliable operation above 25°C ambient, linear derating applies: reduce power by 11.1mW/°C above 25°C (based on θJA ≈ 90°C/W). Ensure minimum 0.5-inch² copper pour under the package and avoid enclosing the IC in sealed enclosures without airflow to maintain junction temperature below 150°C.