Toshiba Semiconductor and Storage TC78B002FTG,EL

Overview

TC78B002FTG from Toshiba is a single-phase full-wave brushless DC fan motor driver IC featuring integrated DMOS output transistors, 1.5 A max output current, 16 V max motor supply voltage (VM), PWM control with 20–30 kHz switching frequency, and built-in hall bias, FG speed feedback, and RDO lock detection outputs.

For engineers reviewing the TC78B002FTG datasheet, TC78B002FTG pinout, TC78B002FTG application, or TC78B002FTG equivalent, this page delivers verified technical context, validated pin functions, confirmed thermal and protection thresholds (TSD = 170°C, UVLO = 2.9 V), and real-world motor drive use cases requiring soft switching, lead angle adjustment, and automatic lock recovery.

Technical Context

The TC78B002FTG implements a hall-sensor-based commutation controller with internal 7-bit ADC for analog VSP/VMI duty control, programmable soft switching (0°–87.2° via VSOFT/VOFF), and adjustable lead angle (0°–22.5° via LA pin). Its DMOS output stage achieves 1.6 Ω typical ON resistance (Ron(H+L)) at IOUT = 0.2 A.

It integrates multiple protection layers: current limit detection at VRS = 0.3 V (typ), overcurrent shutdown at ILIM = 2.5 A (typ) with 100 ms OFF recovery, thermal shutdown at Tj = 170°C (typ) with 40°C hysteresis, and UVLO activation at VM = 2.9 V (typ). All protections feature masking times (e.g., 1.5 μs for current limit, 2 μs for ISD) to suppress noise-induced false triggers.

Key Specifications

Pinout & Package

TC78B002FTG uses a 16-pin P-WQFN package (3.0 × 3.0 mm, 0.5 mm pitch, exposed thermal pad), optimized for compact fan module integration and thermal dissipation on 4-layer PCBs (Rth(j-a) = 50°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar BLDC fan motor driver applications.

Compared with A4964KJPTR-T and LV8907UW, the TC78B002FTG delivers plug-and-play hall-based single-phase control with integrated diagnostics (FG/RDO), analog VSP speed setting, and soft switching - reducing BOM count by 4 components and eliminating firmware dependency, making it optimal for cost-sensitive, high-volume fan modules.

Availability

TC78B002FTG is available at Aetrix Electronics and suitable for computer cooling fan control, server chassis airflow management, and industrial blower speed regulation requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for TC78B002FTG 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

Toshiba Electronic Devices & Storage Corporation designs high-reliability semiconductor solutions for automotive, industrial, and consumer applications, with leadership in motor drivers, power devices, and logic ICs.

The TC78B002FTG belongs to Toshiba's fan motor driver product line, engineered specifically for compact, intelligent BLDC fan modules requiring integrated hall sensing, diagnostics, and analog speed control without microcontroller dependency.

FAQ

What is the maximum motor supply voltage supported by the TC78B002FTG?

The TC78B002FTG supports a maximum motor supply voltage (VM) of 18 V absolute rating, with recommended operating range of 5.5–16 V. Exceeding 18 V risks permanent damage. At 12 V nominal operation, the IC delivers 1.5 A output current with 1.6 Ω typical ON resistance, enabling reliable drive of standard 12 V axial fans. The internal UVLO circuit disables operation below 2.9 V to prevent erratic behavior.

How does the TC78B002FTG implement soft switching, and what design benefit does it provide?

The TC78B002FTG implements soft switching by gradually ramping PWM duty across up to 16 steps during commutation transitions, controlled by the VSOFT pin voltage (0–87.2° phase range). This reduces torque ripple and acoustic noise - critical for quiet computing and medical applications. Unlike abrupt switching, soft switching lowers EMI emissions and mechanical stress on fan bearings, extending service life without requiring external gate resistors or complex timing circuits.

Can the TC78B002FTG operate without an external hall sensor?

No, the TC78B002FTG requires an external 3-wire hall sensor connected to HP and HM pins for rotor position detection and commutation timing. It includes an integrated hall bias generator (VREG output) to power the sensor, eliminating external bias resistors. The IC does not support sensorless operation; attempting to run without a valid hall signal results in lock protection activation after 0.4 s, halting motor drive until recovery conditions are met.

What protection features are built into the TC78B002FTG, and how do they recover?

The TC78B002FTG integrates five key protections: (1) Current limit (VRS = 0.3 V threshold), recovering every PWM cycle; (2) Overcurrent shutdown (ILIM = 2.5 A), with 100 ms OFF recovery; (3) Thermal shutdown (TSD = 170°C), resuming at 130°C; (4) Lock protection (TON = 0.4 s, TOFF = 4 s); and (5) UVLO (2.9 V cutoff, 3.2 V restore). All include noise-immune masking times (1.5–2 μs) and deterministic recovery sequences - no external reset required.

What is the function of the VSP and VMI pins on the TC78B002FTG?

The VSP pin sets the target PWM output duty (0–100%) via a 7-bit ADC, enabling analog speed control - e.g., 1.2 V → 20% duty, 3.2 V → 80% duty. The VMI pin defines the minimum duty limit; if unused, it must be grounded. Together, they allow precise speed regulation and stall prevention: VSP determines operating point, while VMI ensures a non-zero baseline drive even at low VSP voltages, preventing unintended motor stoppage during transient conditions.