Infineon IR2104STRPBF Half-Bridge MOSFET Driver IC: Datasheet, Pinout, and Application Circuit Guide

The Infineon IR2104STRPBF is a high-voltage, high-speed power MOSFET and IGBT driver specifically designed for half-bridge and other bridge topologies. This driver IC is a cornerstone in power electronics, enabling efficient control of N-channel MOSFETs in applications ranging from motor drives and switch-mode power supplies (SMPS) to DC-AC converters and inverters. Its ability to handle high-side switching with a bootstrap capacitor mechanism eliminates the need for a separate isolated power supply, simplifying design and reducing cost.

This guide delves into the key specifications of the IR2104, its pin configuration, and a fundamental application circuit to get you started.

Datasheet Overview and Key Specifications

The IR2104S is the variant housed in a compact SOIC-8 package. Key absolute maximum ratings and electrical characteristics from its datasheet include:

High-Side Voltage (V_B): Floating absolute maximum of 500V, allowing it to drive MOSFETs in high-voltage rails.

Output Current: Typical peak source/sink current of 210mA / 360mA, providing strong, fast switching to minimize transition losses in the power MOSFETs.

Supply Voltage (V_CC): Operational range from 10V to 20V, with an absolute maximum of 25V.

Under-Voltage Lockout (UVLO): Built-in protection for both the high-side and low-side drivers (~8.7V V_CC UVLO and ~8.5V V_BS UVLO) ensures the MOSFETs are only switched when the gate drive voltage is sufficient, preventing dangerous linear mode operation.

Propagation Delays: Typical delay of 150ns with excellent matching between the high-side and low-side channels (max 50ns), crucial for maintaining precise control and preventing shoot-through.

Dead Time (Internal): ~540ns typical, a fixed internal delay inserted to prevent cross-conduction (shoot-through) where both high-side and low-side MOSFETs could be on simultaneously, which would short-circuit the power supply.

Pinout Configuration

The IR2104STRPBF is an 8-pin IC. Understanding each pin's function is critical for proper circuit design:

1. V_CC: Low-side fixed supply voltage pin. Connects to the logic supply (typically +12-15V).

2. HIN: High-side logic input. This input signal controls the high-side output (H_O). It is level-shifted to drive the floating high-side MOSFET.

3. LIN: Low-side logic input. This input signal directly controls the low-side output (L_O).

4. COM: Ground reference for the low-side circuitry and logic inputs.

5. L_O: Low-side gate driver output. Connects directly to the gate of the low-side N-channel MOSFET.

6. V_S: High-side floating ground return. This pin connects to the source of the high-side MOSFET and the switching node.

7. H_O: High-side gate driver output. Connects directly to the gate of the high-side N-channel MOSFET.

8. V_B: High-side floating supply. This pin is connected to the bootstrap capacitor, which provides the voltage source for the high-side driver circuitry.

Typical Application Circuit Guide

A standard half-bridge application circuit is the primary use case for the IR2104. The core of the design revolves around the bootstrap circuitry.

Components Required:

IC: IR2104STRPBF

MOSFETs: Two N-channel power MOSFETs (Q1 - High-Side, Q2 - Low-Side)

Capacitors: C_VCC (10-100µF decoupling cap), C_BOOT (100nF - 1µF bootstrap cap)

Diodes: D_BOOT (Ultra-fast or Schottky bootstrap diode, e.g., 1N4148, UF4007)

Gate Resistors: R_{G_H} and R_{G_L} (e.g., 10-100Ω)

Circuit Operation:

1. Initialization: When the low-side MOSFET (Q2) is turned on via the LIN input and L_O output, the switching node (V_S pin) is pulled to ground (COM).

2. Bootstrap Charging: With V_S near ground, the bootstrap capacitor (C_BOOT) charges through the bootstrap diode (D_BOOT) from the V_CC supply. The voltage across C_BOOT becomes approximately V_CC.

3. High-Side Switching: When the microcontroller signals HIN to turn on the high-side switch, the driver uses the charge stored in C_BOOT (connected between V_B and V_S) to apply a gate-to-source voltage (V_GS) to the high-side MOSFET (Q1). This voltage, V_B - V_S, is sufficient to fully enhance Q1.

4. Cycling: As the bridge switches, the bootstrap capacitor is recharged every time the low-side switch is turned on and the switching node is low.

Key Design Consideration: The bootstrap capacitor must be sized to hold enough charge to keep the high-side MOSFET on for the required duration without discharging below the MOSFET's threshold voltage. The duty cycle and switching frequency are critical factors here.

ICGOODFIND: The Infineon IR2104STRPBF stands out as a robust and highly reliable solution for driving half-bridge stages. Its integrated bootstrap functionality, built-in dead time, and UVLO protection make it an exceptionally efficient choice for designers, simplifying complex high-side drive challenges and ensuring system safety and longevity.

Keywords:

Half-Bridge Driver

Bootstrap Circuitry

High-Side Switching

MOSFET Driver IC

Dead Time