IR2104 — High and Low Side Half-Bridge Gate Driver IC

Overview

The IR2104 (and modern lead-free IRS2104PBF / IRS2104STRPBF) is a high-voltage, high-speed half-bridge power MOSFET and IGBT gate driver IC manufactured by Infineon Technologies (originally International Rectifier). It is the single-input, shutdown-enabled companion to the IR2103, designed to drive a complementary high- and low-side N-channel MOSFET pair in half-bridge converters, motor drivers, DC-DC buck stages, and class-D audio amplifiers.

Unlike dual-input drivers, the IR2104 accepts a single logic input (IN) that automatically drives high-side (HO) and low-side (LO) outputs in complementary antiphase, with internal cross-conduction shoot-through protection and a fixed $520\text{ ns}$ internal deadtime. An active-LOW shutdown pin (~SD~) allows instantly turning off both outputs to put the half-bridge in a high-impedance coast state.

Quick reference


Driver Type	High and Low Side Half-Bridge Gate Driver IC
Package	8-lead PDIP (IR2104) / 8-lead SOIC (IR2104S)
High-Side Floating Offset ( $V_S$ )	Up to $+600\text{ V}$ DC max
Gate Driver Supply Range ( $V_{CC}$ )	$10.0\text{ V}$ to $20.0\text{ V}$ DC
Output Peak Current	$+130\text{ mA}$ Source / $-270\text{ mA}$ Sink typical ( $+210\text{ mA} / -360\text{ mA}$ test)
Internal Deadtime	$520\text{ ns}$ typical (built-in shoot-through protection)
Turn-On / Turn-Off Delay	$t_{on} = 680\text{ ns}$ / $t_{off} = 150\text{ ns}$ typical
Shutdown Delay	$t_{sd} = 160\text{ ns}$ typical
Logic Compatibility	$3.3\text{ V}$ , $5.0\text{ V}$ , and $15.0\text{ V}$ CMOS / LSTTL inputs
Control Style	Single PWM input (`IN`) + Active-LOW Enable/Shutdown (`~SD~`)

Pinout (DIP-8 / SOIC-8 Package)

text

        ┌──────────────┐
    VCC ─│ 1          8 │─ VB
     IN ─│ 2          7 │─ HO
   ~SD~ ─│ 3          6 │─ VS
    COM ─│ 4          5 │─ LO
        └──────────────┘

Pin	Name	Description
1	`VCC`	Low-side fixed supply voltage and logic supply input (+10V to +20V DC)
2	`IN`	Single logic input for complementary gate drive (Controls HO and LO)
3	`~SD~`	Active-LOW shutdown control input (LOW = Shutdown/Both OFF, HIGH = Enabled)
4	`COM`	Logic and low-side power ground return
5	`LO`	Low-side gate drive output
6	`VS`	High-side floating supply return (Half-bridge switching node / MOSFET source)
7	`HO`	High-side gate drive output
8	`VB`	High-side floating bootstrap supply voltage pin

Input / Output Logic Truth Table

`~SD~` (Shutdown)	`IN` (Input)	`HO` (High-Side Gate)	`LO` (Low-Side Gate)	Half-Bridge State
Low (`0`)	X (Don't Care)	Low (OFF)	Low (OFF)	Shutdown / High-Z (Both switches OFF)
High (`1`)	Low (`0`)	Low (OFF)	High (ON)	Low-Side ON (Midpoint pulled to GND)
High (`1`)	High (`1`)	High (ON)	Low (OFF)	High-Side ON (Midpoint pulled to VBUS)

Note

Transitions between IN = 0 and IN = 1 enforce an internal $520\text{ ns}$ deadtime during which both HO and LO are held LOW, preventing simultaneous conduction.

Standard Half-Bridge Application Circuit

text

                      +V_BUS High Voltage (Up to 600V DC)
                         │
                         ├───────────┐ [D_BOOT Ultra-Fast]
                         │           │
                         │          ┌┴┐
                         │          │▲│
                         │          └┬┘
                         │           │
                     [Pin 1: VCC]    │
                       IR2104        │
                     [Pin 8: VB] ────┴──────┐
                         │                  │
                     [Pin 7: HO] ─[R_G1]─┐ [C_BOOT 0.1µF-1.0µF]
                         │               │  │
                         │             ┌─┴──┴─┐  [Q1 High-Side N-MOSFET]
                     [Pin 6: VS] ──────┤  S   │
                         │             └──┬───┘
                         │                ├──────────── Output / Motor / Inductor
                         │                │
                     [Pin 5: LO] ─[R_G2]─┐│
                         │               ││
                         │             ┌─┴┴───┐  [Q2 Low-Side N-MOSFET]
                     [Pin 4: COM] ─────┤  S   │
                         │             └──┬───┘
                        GND               │
                                         GND

Bootstrap Diode ( $D_{BOOT}$ ): Ultra-fast recovery diode ( $t_{rr} < 50\text{ ns}$ , e.g. UF4007 or ES1J) rated for $\ge V_{BUS} \times 1.2$ .
Bootstrap Capacitor ( $C_{BOOT}$ ): Ceramic or low-ESR film capacitor ( $0.1\ \mu\text{F} \dots 1.0\ \mu\text{F}$ , $\ge 25\text{V}$ ) recharged every cycle when LO conducts and $V_S$ drops to ground.

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
High-Side Floating Supply Voltage	$V_B$	-0.3	—	625	V	Relative to COM
High-Side Floating Offset Voltage	$V_S$	$V_B - 25$	—	$V_B + 0.3$	V	Switching node
Low-Side Supply Voltage	$V_{CC}$	10.0	—	20.0	V	Operating range
Logic High Input Threshold	$V_{IH}$	2.7	—	—	V	$V_{CC} = 10\text{V} \dots 20\text{V}$
Logic Low Input Threshold	$V_{IL}$	—	—	0.8	V	$V_{CC} = 10\text{V} \dots 20\text{V}$
Output High Short-Circuit Current	$I_{O+}$	130	210	—	mA	$V_O = 0\text{V}, V_{IN} = \text{High}, PW \le 10\ \mu\text{s}$
Output Low Short-Circuit Current	$I_{O-}$	270	360	—	mA	$V_O = 15\text{V}, V_{IN} = \text{Low}, PW \le 10\ \mu\text{s}$
Turn-On Propagation Delay	$t_{on}$	—	680	820	ns	$V_S = 0\text{V}$
Turn-Off Propagation Delay	$t_{off}$	—	150	220	ns	$V_S = 600\text{V}$
Shutdown Propagation Delay	$t_{sd}$	—	160	220	ns	$V_S = 600\text{V}$
Deadtime	$DT$	400	520	650	ns	Internal matched delay

Common mistakes

Leaving SD floating: Pin 3 (~SD~) has an internal pull-down resistor. If left unconnected, the driver remains in permanent shutdown with both outputs disabled. Pull ~SD~ to logic HIGH ( $3.3\text{V}$ or $5\text{V}$ ) to enable the driver.
Attempting 100% High-Side Duty Cycle ( $IN = 1$ static): The bootstrap capacitor only charges when the low-side switch is ON ( $IN = 0$ ). Holding IN = 1 continuously will cause $V_B - V_S$ to decay below the undervoltage threshold ( $UVLO \approx 8.2\text{V}$ ), turning off HO.
Using slow silicon rectifier diodes for bootstrap: Standard diodes (1N4001–1N4007) take microseconds to turn off, feeding high-voltage bus energy backwards into $V_{CC}$ during $V_S$ rising edges. Always use ultra-fast or SiC Schottky diodes.

Notes

Comparison with IR2103: The IR2103 provides separate inputs for high-side (HIN) and low-side (~LIN~) channels, allowing independent asymmetric duty cycles, whereas the IR2104 simplifies microcontroller drive by using a single PWM line (IN) with a dedicated shutdown line (~SD~).

Interface	Logic Input (IN), Active-LOW Shutdown (~SD~), High-Side Gate Drive (HO), Low-Side Gate Drive (LO), Bootstrap Supply (VB, VS)
Package	DIP-8 / SOIC-8 (SO-8)