Toshiba Semiconductor and Storage TB67S581FNG,EL

Overview

TB67S581FNG from Toshiba Electronic Devices & Storage Corporation is a BiCD monolithic two-phase bipolar stepping motor driver IC with PWM chopper control, rated for 50 V / 2.5 A absolute maximum output, integrated 3.3 V regulator, and selectable decay modes (Slow/Fast/Mixed). It supports microstepping down to 1/32-step resolution and delivers precise current control via external sense resistors RSA/RSB - used in compact CNC stages, precision lab automation actuators, and closed-loop stepper positioning systems.

For engineers reviewing the TB67S581FNG datasheet, TB67S581FNG pinout, TB67S581FNG application, or TB67S581FNG equivalent, key selection considerations include its HTSSOP-28 package thermal performance, dual-channel current-setting flexibility (VREFA/VREFB), nFAULT flag signaling, and clock-input step sequencing without requiring external phase logic.

Technical Context

The TB67S581FNG implements a constant-current PWM chopper architecture with independent current reference inputs (VREFA, VREFB) per H-bridge channel, enabling asymmetric current tuning. Its BiCD process integrates DMOSFET power transistors with on-chip logic, supporting full/half/quarter/1/8/1/16/1/32 step modes via DMODE0–DMODE2.

Thermal and fault protection includes auto-recovery thermal shutdown (TSD, 150–180 °C trip), latch-type overcurrent detection (ISD, 3.0 A threshold), and UVLO (VM POR at 7.8–8.2 V). The DECAY pin selects decay behavior: Slow (L), Fast (H), or Mixed (open), with mixed mode automatically transitioning from fast to slow decay within 75% of the PWM cycle.

Key Specifications

Pinout & Package

Package: P-HTSSOP28-0510-0.65-001 - thermally enhanced 28-pin thin shrink small outline package (0.65 mm pitch), 5.0 × 10.0 mm body, 0.105 g typical weight, designed for high-power density PCB layouts with dedicated PGND/AGND separation and VM power plane routing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bipolar stepper motor driver applications.

Compared with STSPIN820 and DRV8825, the TB67S581FNG offers unique analog per-phase current control (VREFA/VREFB), built-in 3.3 V regulator, and electrical angle monitor (MO) - making it optimal for applications demanding torque matching, self-contained power, and position-aware diagnostics.

Availability

TB67S581FNG is available at Aetrix Electronics and suitable for desktop 3D printer extruder drive, lab automation XYZ stage, medical infusion pump actuator, and industrial pick-and-place end effector applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for TB67S581FNG 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 analog and power ICs for industrial, automotive, and consumer applications, with deep expertise in BiCD process technology and motor control integration.

The TB67S581FNG belongs to Toshiba's TB67S series of bipolar stepper drivers, engineered specifically for compact, high-torque motion systems requiring microstepping precision, thermal robustness, and minimal external components.

FAQ

What is the maximum continuous current per phase the TB67S581FNG can deliver in normal operation?

The TB67S581FNG supports up to 2.0 A per phase under operating conditions (Ta = –40 to 85 °C), as specified in Table 14. While its absolute maximum rating is 2.5 A, sustained operation above 1.8 A per phase requires careful thermal design - including proper PCB copper area, airflow, and derating per the 32 mW/°C rule above 25 °C ambient. The TB67S581FNG's RON(D-S) of 0.4 Ω (typ.) directly impacts heat generation at higher currents.

How does the TB67S581FNG implement microstepping, and what step resolutions are supported?

The TB67S581FNG uses three digital inputs - DMODE0, DMODE1, and DMODE2 - to select step resolution: Full, Half, Quarter, 1/8, 1/16, or 1/32 step. Each mode defines a specific excitation pattern (e.g., W1-2-phase for Quarter step) and corresponding current waveform table (Table 7.9). The TB67S581FNG generates these waveforms internally using its PWM chopper and dual VREF inputs, eliminating need for external phase sequencers.

Can the TB67S581FNG operate from a single power supply, and what voltages are supported?

Yes, the TB67S581FNG operates from a single VM supply for both motor and internal logic. Its VM input accepts 8.2 V to 44 V (operating range), with power-on reset triggered at 7.8–8.2 V. The integrated 3.3 V regulator (VREG pin) supplies up to 1 mA, enabling direct powering of MCU peripherals or sensors - confirming the TB67S581FNG's true single-supply capability without auxiliary rails.

What protection features does the TB67S581FNG include, and how do they behave during fault events?

The TB67S581FNG integrates thermal shutdown (TSD, auto-recovery), overcurrent detection (ISD, latch-type), and under-voltage lockout (UVLO). On TSD activation, outputs disable until junction temperature falls 30 °C below trip point; ISD latches off both channels permanently until RESET_X is asserted. All faults assert the open-drain nFAULT pin low, providing immediate system-level alerting - a core safety feature of the TB67S581FNG.

How is current regulation set on the TB67S581FNG, and what is the formula for calculating output current?

Current regulation is set independently per phase using external sense resistors (RSA, RSB) and reference voltages (VREFA, VREFB). The TB67S581FNG uses the formula IOUT = VREF / (5 × RRS), where VREF is applied to VREFA or VREFB and RRS is the sense resistor value. For example, with VREFA = 2.0 V and RSA = 0.22 Ω, the TB67S581FNG delivers 1.82 A per phase - enabling precise, tunable torque control.