Texas Instruments SM74104SDX/NOPB

Overview

SM74104SDX/NOPB from Texas Instruments is a high-voltage half-bridge gate driver IC designed to control N-channel MOSFETs in synchronous buck and half-bridge topologies. It features adaptive shoot-through prevention, programmable dead-time via RT pin (90–270 ns), 100 V HS node rating, and integrated bootstrap diode with 0.85 V forward drop at 100 mA. Used in high-voltage DC/DC converters requiring robust gate drive and fast switching.

For engineers reviewing the SM74104SDX/NOPB datasheet, SM74104SDX/NOPB pinout, SM74104SDX/NOPB application, or SM74104SDX/NOPB equivalent, key selection considerations include bootstrap voltage range (up to 118 V), dual-output timing coordination, UVLO thresholds on VDD (6.9 V) and HB (6.6 V), and thermal performance in the 4.0 mm × 4.0 mm WSON package.

Technical Context

The SM74104SDX/NOPB implements adaptive edge control: rising/falling transitions on the single IN pin trigger synchronized LO/HO outputs with built-in dead-time generation. Its level-shifting architecture enables reliable high-side operation up to 100 V HS potential, while the internal bootstrap diode supports self-biasing without external components in many designs.

UVLO protection operates independently on VDD (6.0–7.4 V threshold) and HB (5.7–7.1 V), disabling only HO during HB undervoltage. The RT pin sets additional delay (140–270 ns typical at 100 kΩ), and the exposed thermal pad in the WSON-10 package delivers R_θJB = 14.9 °C/W for high-power density layouts.

Key Specifications

Pinout & Package

SM74104SDX/NOPB uses the 10-pin WSON (DPR) package (4.0 mm × 4.0 mm, 0.5 mm pitch) with an exposed thermal pad electrically isolated but recommended for soldering to VSS plane for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage half-bridge gate driver applications.

Compared with IRS21844STRPBF and LM5109BSDX/NOPB, SM74104SDX/NOPB uniquely combines adaptive shoot-through prevention, integrated bootstrap diode, and programmable dead-time in a thermally optimized WSON package-making it optimal for high-efficiency, high-reliability 48–100 V DC/DC converters where layout sensitivity and transient immunity matter.

Availability

SM74104SDX/NOPB is available at Aetrix Electronics and suitable for high-voltage buck regulators, active clamp forward converters, current-fed push-pull topologies, and half-bridge resonant LLC designs requiring stable component supply and long-term production support.

Supply support for SM74104SDX/NOPB 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 ICs, with decades of expertise in high-reliability power conversion solutions.

The SM74104 product line targets renewable-energy-grade, high-voltage DC/DC conversion systems requiring robust gate drive, adaptive timing, and integrated bootstrap functionality in space-constrained industrial and telecom applications.

FAQ

What is the maximum allowable voltage on the HS pin of SM74104SDX/NOPB?

The SM74104SDX/NOPB specifies an absolute maximum HS-to-VSS voltage of –1 V to 100 V. This rating enables use in 48 V, 60 V, and 100 V input bus applications with margin for switching transients. Operation beyond 100 V risks permanent damage, and the device's UVLO on HB ensures safe shutdown before HS overvoltage propagates to the high-side driver. Always verify layout parasitics and snubber design to maintain this limit in real-world conditions.

Does SM74104SDX/NOPB require an external bootstrap diode?

SM74104SDX/NOPB includes an integrated high-voltage bootstrap diode (V_F = 0.85 V @ 100 mA), making an external diode optional. However, TI recommends adding an external fast-recovery diode in parallel for high-frequency (>300 kHz) or high-current applications to reduce average power dissipation and thermal stress on the IC. The external diode must be placed close to the HB/VDD pins to minimize inductance and ensure effective current sharing.

How is dead-time configured on SM74104SDX/NOPB?

Dead-time on SM74104SDX/NOPB is configured using the RT pin: a resistor from RT to VSS sets the additional delay (T_RT). At RT = 100 kΩ, T_RT = 140–270 ns typical; at RT = 10 kΩ, it drops to 58–130 ns. This programmable delay works in conjunction with the adaptive circuit that monitors LO/HO gate voltage thresholds (~VDD/2) to prevent shoot-through. The total effective dead-time is t_P + T_RT, where t_P is the base propagation delay (~25 ns).

What thermal performance can be expected from SM74104SDX/NOPB in its WSON package?

SM74104SDX/NOPB in the 10-pin WSON (DPR) package achieves R_θJB = 14.9 °C/W (junction-to-board) and R_θJC(bot) = 4.4 °C/W when the exposed thermal pad is soldered to a solid VSS copper plane. This enables continuous operation at full load up to 125°C junction temperature in well-designed PCBs. Layout best practices-short traces to bypass capacitors, minimized HS loop inductance, and proper thermal vias under the pad-are essential to realize these ratings.

Is SM74104SDX/NOPB compatible with 3.3 V or 5 V PWM controllers?

Yes, SM74104SDX/NOPB accepts standard TTL/CMOS logic levels on its IN pin: V_IL ≤ 1.8 V (max) and V_IH ≥ 1.8 V (min), with typical thresholds near 1.2 V and 2.0 V. This makes it fully compatible with 3.3 V and 5 V microcontrollers, DSPs, and dedicated PWM controllers. Input hysteresis and pulldown resistance (100–500 kΩ) provide noise immunity, and no level-shifting circuitry is required between controller and SM74104SDX/NOPB.